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20180807 Late CorrespondencePRESERVING LAND AND RESTORING HABITAT FOR THE EDUCATION AND ENJOYMENT OF ALL August 7, 2018 City of Rancho Palos Verdes 30940 Hawthorne Boulevard Rancho Palos Verdes, CA 90275 Subject: Update to the Feasibility Study to remediate the Portuguese Bend Landslide Dear Honorable Mayor Brooks and City of Rancho Palos Verdes Council Members, Thank you for the opportunity to provide comments and for your time in serving the community. We offer the following comments to Recommended Council Action (1 ), to receive and File the Feasibility Study Update Portuguese Bend Landslide Complex (Update). It is stated in the feasibility study document that the identified remedy options can be implemented in accordance with the City's Natural Communities Conservation Plan/Habitat Conservation Plan (NCCP/HCP). While this is not inconceivable, it is not a certainty as the Update suggests. It is recommended that the feasibility study acknowledge the requirement to comply with minimization measures would occur with a project proposal. This includes an understanding of indirect impacts and citing project locations to avoid sensitive resources. The Feasibility Study Update discusses a meeting that was held in October 2017 between the City, DBS&A, the PVPLC and the Wildlife Agencies. As referenced in the Update, it is wonderful that the City will be developing a policy to ensure that all appropriate measures will be considered to minimize potential impacts to biological resources within the Preserve. It is requested that this policy be structured to include time for any needed consultants to participate in meetings with regard to the feasibility or project scoping/planning so potential projects are designed in accordance with minimization measures of the NCCP/HCP. The initial meeting that occurred in October was preliminary, and should a project be proposed, we look forward to an opportunity to provide guidance for avoidance of sensitive resources. Lastly, the Update asserts that it is feasible to restore native vegetation above canyon liners. It is requested that this inaccuracy be corrected. The likely inability to restore for coastal sage scrub above canyon liners has been explained by native plant experts and was also confirmed by the Principal Hydrologist at the most recent public workshop on June 28, 2018. Thank you for your consideration of the comments provided. Sincerely, Andrea Vona Executive Director Cc: Deborah Cullen, Director of Finance 916 SILVER SPUR ROAD Ii 207. ROLLING HILLS ESTATES. CA 90274-3826 T 310.541.7613 WWW.PVPLC.ORG TO: FROM: DATE: SUBJECT: CITY OF RA.NCHO PALOS VERDES HONORABLE MAYOR & CITY COUNCIL MEMBERS CITY CLERK AUGUST 7, 2018 ADDITIONS/REVISIONS AND AMENDMENTS TO AGENDA Attached are revisions/additions and/or amendments to the agenda material presented for tonight's meeting. Item No. M 1 2 Description of Material Revisions for pages A-1 through A-3 of Staff Report Email from Sharon Loveys Staff exchange with Eva Cicoria; Emails from: Eva Cicoria; Elizabeth Sala; Phil Adler **PLEASE NOTE: Materials attached after the color page(s) were submitted through Monday, August 6, 2018**. Respectfully submitted, W:\01 City Clerk\LATE CORRESPONDENCE\2018 Cover Sheets\20180807 additions revisions to agenda.doc Teresa Takaoka From: Sent: To: Cc: Subject: Attachments: Hi Emily/Teri, Charles Eder Monday, August 06, 2018 6:25 PM CityClerk Elias Sassoon; Ron Dragoo RE: Late Correspondence CIMP _SMBBBTMDL_MOU_Amendment 2018 (Final).pdf Please disregard the attachment for the correspondence below. Attached is the most updated Attachment. Thank you. Hi Emily/Teri, We were alerted that the wrong attachment was included in the agenda for Item M in tomorrow's August 7, 2018 City Council Meeting. For Item M -"Consideration and possible action to approve an amendment to a Memorandum of Understanding between the agencies participating in the Peninsula Watershed Management Group, and award a professional services contract for the Santa Monica Bay Beach Bacteria (SM BBB) Total Maximum Daily Load (TMDL) Monitoring Program Services to Geosyntec Consultant, Inc.," Please see the attached Supporting Document. This replaces "Attachment A. First Amendment to MOU (page A-1)." This is the MOU that was approved by the City Attorney. Please call if you have any questions. Thank you. Charles Eder, PE Department of Public Works CitY....QLfi~tt:}fb.Q_ Palos Verdes 30940 Hawthorne Blvd. Rancho Palos Verdes, CA 90275 Tel: 310-544-5282 1 H_ FIRST AMENDMENT TO THE MEMORANDUM OF UNDERSTANDING BETWEEN THE LOS ANGELES COUNTY FLOOD CONTROL DISTRICT, THE COUNTY OF LOS ANGELES, AND THE CITIES OF RANCHO PALOS VERDES, PALOS VERDES ESTATES, ROLLING HILLS, AND ROLLING HILLS ESTATES REGARDING THE ADMINISTRATION AND COST SHARING FOR IMPLEMENTING THE COORDINATED INTEGRATED MONITORING PROGRAM (CIMP) FOR THE PENINSULA CIMP AGENCIES This First Amendment to the Memorandum of Understanding is made and entered into as of August 7, 2018 between THE CITY OF RANCHO PALOS VERDES, a body corporate and politic, THE CITY OF ROLLING HILLS ESTATES, a body corporate and politic, THE CITY OF ROLLING HILLS, a body corporate and politic, LOS ANGELES COUNTY FLOOD CONTROL DISTRICT (LACFCD), a body corporate and politic, and THE COUNTY OF LOS ANGELES (COUNTY), a political subdivision of the State of California. Collectively, these entities shall be known herein as "PARTIES" or individually as "PARTY". WITNESSETH WHEREAS, the PARTIES entered into a Memorandum of Understanding on May 03, 2016 for the administration and cost sharing for implementing the Coordinated Integrated Monitoring Program (CIMP) for the Peninsula CIMP agencies; and WHEREAS, the Sanitation Districts of Los Angeles County (Sanitation Districts) was already conducting weekly shoreline monitoring satisfying the requirements of the Santa Monica Bay Beaches Bacteria TMDL, a part of the CIMP, at no cost to the PARTIES; and WHEREAS, the Sanitation Districts notified the PARTIES that effective June 30, 2018, the Sanitation District would discontinue this monitoring; and WHEREAS, the PARTIES have solicited and received bids from qualified monitoring contractors to continue this monitoring; and WHEAREAS, the PARTIES collaboratively selected a CONTRACTOR to continue this monitoring; and WHEREAS, the PARTIES have agreed to cooperatively share and fully fund the actual costs of implementing shoreline monitoring satisfying the requirements of the Santa Monica Bay Beaches Bacteria TMDL, a part of the CIMP, as estimated in Table 2 NOW, THEREFORE, the Parties agree to amend the Memorandum of Understanding to include the cost of monitoring for the Santa Monica Bay Beaches Bacteria TMDL to the Total Cost Allocations for implementing the CIMP. Tables 2 and 3 are amended to read as follows: 65277.00001 \31318074.1 A-1 Tables 2 and 3 shall be modified as follows. Table 2. Total Cost Allocation Area Percent of Percent of Total without Party (sq. mi.) Agency Area 1 City Area 2 Contingency orAdmin City of Rancho Palos Verdes5 13.5 52.73% 54.22% $215,491.06 City of Palos Verdes Estates 4.8 18.75% 19.28% $76,620.29 City of Rolling Hills Estates 3.6 14.06% 14.46% $57,464.96 City of Rolling Hills6 3 11.72% 12.05% $44,7S9.30 County of Los Angeles7 0.7 2.73% N/A $6,3S4.00 Area Allocated Total LACFCD ---$21,089.00 Total 25.6 100% 100% $421,778.61 1 Percent of Agency Area is the percent of total CIMP area including the County of Los Angeles Unincorporated area. 2 Percent of City Area is the percent of CIMP area excluding the County of Los Angeles Unincorporated area. 3 Contingency costs include 10% the total estimated implementation costs before administrative costs. Contract Subsequent Contingency3 Administrations 2018-19 Cost4 Annual Cost (5%) (2019-2022) $21,549.11 $10,774.55 $247,814.72 $235,422.68 $7,662.03 $3,831.01 $88,113.33 $83,706.87 $5,746.50 $2,873.25 $66,084.71 $62,779.86 $4,47S.93 $2,237.97 $Sl,473.20 $48,719.16 $63S.40 $317.70 $7,307.10 $7,307.10 $460,793.0S $437,93S.67 $2,108.90 $1,0S4.45 $24,2S2.3S $23,049.4S $42,177.86 $21,088.93 $48S,045.40 $460,98S.12 4 Cost includes cost based on area plus administration costs for each agency. The Santa Monica Bay Beaches Bacteria TMDL monitoring contractor estimated higher Year 1 (2018-2019} costs; the monitoring cost for subsequent years will be lowered and expected to be consistent. 5 The City of Rancho Palos Verdes has agreed to pay for the non-stormwater screening services and RFP /MOU development prior to MOU execution. 6 The City of Rolling Hills is paying for a separate non-stormwater screening; therefore, the non-stormwater screening costs are only applied to the agencies participating in those efforts. 7 The County of Los Angeles cost includes all services except for Receiving Water Monitoring. Table 3. Agency Participation Summary Task RPV PVE RHE RH LAC LACFCD Receiving Water Monitoring p p p p N p Outfall Monitoring p p p p p p Outfall Screening c p p N p p RFP/MOU Development c p p p p p Santa Monica Bay Beaches Bacteria Shoreline Monitoring p p p p N p c Credited RHE City of Rolling Hills Estates p Participating RH City of Rolling Hills N Not Participating LAC County of Los Angeles RPV City of Rancho Palos Verdes LACFCD LA County Flood Control District PVE City of Palos Verdes Estates 65277.00001\31318074.1 A-2 Except as above modified, in all other respects the Memorandum of Understanding remains in full force and effect. A-3 65277 .00001\31318074.1 REPLY OF SHARON LO VEYS TO STAFF REPORT & PROPOSED RESOLUTION IN SUPPORT OF HER APPEAL RE: ALTA VISTA DEVELOPMENT PROJECT- PLG2018-0008 1. The conditions of approval of deficient because they fail to specifv the precise number of earth interments which the City Council is proposing to "permit" for the Alta-Visa (open space) Development. The designation of the specific number of earth interments to be allowed is necessary for the City to make the "Finding" required under Section l 7.28.030(H) that the proposed development of the Alta-Vista "open space" allowing the open space to be used for the earth interments reflected on the proposed is "no more intensive" than the uses allowed under the current Master Plan (which is incorporated into the current conditional use permit). 2. There is no "Finding" by the City that the proposed development of open space (the Alta Vista Development) contemplates a use consistent with the use authorized under the Master Plan (as incorporated into the current conditional use permit) and is "no more intensive" than the currently permitted use under the Master Plan (as incorporated into the current conditional use permit). This "Finding" is mandated by Section l 7.28.030(H). Consequently, the City's failure to render such a "Finding" violates a mandatory duty the City has under its zoning code. 3. There is no "Finding" as required under Section l 7.76.040(E) of the City's zoning code that (i) the grading sought to be approved does not exceed that which is necessary for the permitted primary use(§ 17.76.040(E)(l)); (ii) the proposed grading does not significantly adversely affect the visual relationships with, nor the view from the viewing area of neighboring properties ( (§ 17. 76.040(E)(2)); (iii) the nature of the grading minimizes disturbance to the natural contours and finished contours are reasonably natural (§l 7.76.040(E)(3)); (iv) that the fill and cut proposed in excess of five feet is reasonable and necessary (§17.76.040(E)(9(c))); and (v) will not be detrimental to the public safety or other property (§l 7.76.040(E)(l)). Consequently, the City's failure to render each of the foregoing mandated "Findings" violates a mandatory duty the City has under its zoning code. 4. The City has abused its discretion in refusing to require Green Hills to provide a baseline accounting of the number of earth interments, crypt interments, and cinerary interments authorized or contemplated by the Master Plan (incorporated into the conditional use permit) because without such a base-line, it is impossible to exercise the discretion required under § 17 .28.030(H) to determine whether the proposed number of earth interments in the undeveloped area designated as open space under the Master Plan is or is "no more intensive" than the density and intensity contemplated under the Master Plan (as incorporated into the conditional use permit). The City's refusal to exercise discretion is itself an abuse of discretion. 5. Green Hills does not possess a "by right" entitlement (a right stemming from its ownership of the cemetery) to develop the cemetery as it wishes. Under § 17.20.030, 1 I~ ... , .. Green Hills may only develop the cemetery pursuant to a conditional use permit, and then only for the uses specified in § 17 .28.030 (A)-(H). The Green Hills Master Plan is incorporated into the conditional use permit. Like a specific plan, development of the cemetery under the Green Hills Master Plan still requires the City adhere to its zoning code. That means the evaluation of each development within the cemetery with reference to both the Master Plan and to specifics of each proposed development. If and to the extent that both in terms of 6. The "Findings" proposed by the City Resolution approving the project are deficient because they lack any findings respecting CEQA, including, but not limited to, whether the development is proceeding under a CEQA exemption, CEQA exception, or pursuant to a negative mitigated declaration. The City has a mandatory duty to make "Findings" respecting CEQA compliance. Because the City has not done so, it has both violated its mandatory duties under the CEQA laws; and has abused its discretion. · 7. The City's Proposed Resolution is legally insufficient because it fails to specify how Resolution No. 2015-02 (November 17, 2015), Resolution No. 2017-03 (January 31, 2017), or Resolution No. 2018 (February 6, 2018 (currently being challenged in a separate writ proceeding challenged by Appellant) in any way relates to the Alta-Vista Development as proposed by Green Hills, or the points raised in Appellant's appeal; 8. The City's Council's "Finding" that the grading permit is to be authorized under Resolution No. 2018-07 (February 6, 2018) is not supported by the Record in this case, or by the record supporting the adoption of Resolution No. 2018-07 (currently being challenged by way of writ proceeding initiated in and pending before the Los Angeles County Superior Court styled "Sharon Loveys, Petitioner, vs. City of Rancho Palos Verdes, et al., Respondents. (Case No. BS 172886 9. The City Council's "Finding" that the Master Plan should be used as "a reference document only" is an abuse of discretion because it is a misstatement of the law; and further because the City has abused its discretion in refusing to establish density or intensity caps on the number of earth interments and vault interments to be permitted under the Master Plan (as incorporated into the conditional use permit). The establishment of specific density caps is required because Condition 2(a)6) cannot reasonably be interpreted as a waiver or substitution for the "Findings" mandated under §17.76.040, but rather as a supplement thereto; and further because the scope of the City Council's action when passing Resolution No. 2018-07 was limited to "Compliance Review" issues only; and the City Council lacked the jurisdiction to amend the conditional use permit or Master Plan generally under the guise of a limited compliance review, absent a specific application to amend the conditional use permit and Master Plan having been filed by Green Hills (and no such application was filed or pending before the Council. Further, the allowance of grading to effectuate or "accommodate" the underlying development and use under Condition 2(a)(6) assumes the propose use has been entitled or authorized. The right to use the open space contemplated by the Alta Vista Development has never been specifically authorized (in general) by the City Council in the Green Hills Master Plan or conditional use permit; nor has the City 2 Council authorized a specific number of earth interments to intensity of development to be allowed in Area 2. Until the City Council does so, and until a base-line is established in order to evaluate on a project-specific basis whether the development, as proposed, is "no more intense " than the density and intensity of use generally permitted under the Master Plan (as incorporated into the conditional use permit), it is an abuse of discretion to grant Green Hills a grading permit. If the City Council can specify the height of walls, the City Council can and is required to specify, on a site specific basis, the number of earth interments which are to be permitted. The proposed "Findings" are thus deficient to the extent that the City Council expressly refuses to establish a specific cap on the density and intensity of the proposed Alta Vista Development 10. The "Finding" that Council Resolution No. 2018-07 expressly approved the development of the open space contemplated by the proposed Alta Vista Development is erroneous as both a matter of fact and as a matter oflaw. Resolution No. 2018-07 was adopted after a compliance review. At the time it was passed, there was no discussion as to whether the open space area contemplated by the Alta Vista Development was to be developed. Permission to operate as a cemetery does not equate with permission to develop the specific open space area contemplated by the Alta Vista Development. Allowing this open space area which Green Hills contemplates be developed in this case, in the absence of the City Council's making the appropriate mandatory findings under the §17.28.030(H), in connection with an evaluation of the conditional use permit's scope as it relates to the density and intensity of use contemplated, both generally and specifically, and how the intensity of use is to be measured on new projects and developments going forward, will create an adverse precedent which Green Hills can then exploit to render the Master Plan at worst a de facto nullity and at best, illusory. This is because absent an objective, measurable baseline with regard to the density and intensity of use limitations, there is no way to adequately measure if, whether, and to what extent any future development of open space will or will not be "no more intensive" that the uses as currently authorized and permitted. (§ 17.28.030(H)). 11. The "Finding" that the City Council has previously approved the "associated improvements" contemplated or proposed for the Alta Vista Project in Resolution No. 2018-07 (or other unnamed Resolutions) is incorrect as a matter of fact. The Master Plan (incorporated into the conditional use permit) contemplates the area to be developed as the Alta Vista Gardens as open space. To date, the City Council has never approved the use of the open space to be developed under this grading permit for earth interments; nor has the City Council ever approved a site specific number of earth interments which are to be permitted in Area 2 under either the Master Plan (as incorporated into the conditional use permit) or any prior Council Resolutions. As noted above, this is why the Council cannot issue a grading permit until such site specific density and intensity use caps and qualifications have been passed. 12. The City Council's "Finding" that site specific grading findings are not necessary or required is an abuse of discretion because the Master Plan (as incorporated into the conditional use permit) allocates specific "cut" and "fill" limitations respecting each "Area" designated in the Master Plan (as incorporated into the conditional use permit). 3 I" The City Council is required to make a "Finding" that the proposed amount of grading ("cut" and "fill") falls within the limits and caps set out in the Master Plan. The City's failure to render such a "Finding" with respect to the grading 13. To the extent the "Findings" allow for the use of the open space for earth interments, the "Findings" are deficient because no application was made by Green Hills amending the Master Plan or conditional use permit to allow for the use of the open space (undeveloped) area for earth interments. The implication that earth interments (in an unspecified quantity) should not be allowed to represent or substitute for formal approval of a site-specific number of earth interments to be authorized under and pursuant to a conditional use application to be submitted by Green Hills. What Green Hills wishes to avoid is having to follow the City's zoning laws and development limitations. The City Council needs to follow the rules and respect the City's procedural protocol and substantive requirements. Area 2 is already becoming "over-developed". If the City Council fails to be specific as to the permitted density and intensity allowed for this Alta- Vista Development, then Green Hills is going to cite the City's failure as justification to allow Green Hills to ignore any density or development limitations and develop the cemetery as it pleases, without regard to any meaningful or substantive base-line in terms of the density and intensity of development; all of which would render the Master Plan illusory and meaningless. The Staff Report reads like it could have been written by Green Hills. Green Hills submitted no formal written statement. Perhaps its statement was submitted to staff who merely "cribbed" and parroted what Green Hills wanted said. This idea that the Master Plan is merely a guide to future growth and nothing more than a conceptual layout is both absurd and an embarrassment. It is a shame that the Planning Department has to subordinate its intellectual honesty and planning integrity in this manner. When it comes to Green Hills, the Planning Department subordinates what should be its adherence to common and basic planning principles to the special political interests of Green Hills, as protected by the City Council. The Master Plan is more than a "guide" or "conceptual layout". It is the functional equivalent of a specific plan. Just as a specific plan operates to control the development standards attendant to the uses and limitations of a development which is to occur within the specific plan's boundaries, the Green Hills Master plan serves to implement the conditional use requirements, limitations, and development standards set out in the City's cemetery code. Development which is inconsistent with the criteria set out in a specific plan is not allowed, absent the property owner's procuring of a variance. Green Hill's right to use the cemetery to inter human remains is not absolute (or "by right"). It is conditional; subject to clear development standards and, where appropriate, the exercise of discretion by the Planning Department, particularly as it relates to the scope of a specific development contemplated within the ambit of the boundaries of the Master Plan. There are development standards with relate to height and set-back limits, both with regard to structures and "blow grade" interments. Nothing is said with regard to "roof-top" interments 4 made in artificial grade planted on the roof-tops of mausoleums. (§ 17 .28.040). There are limitations on the specific uses to be allowed in the cemetery (i.e. only three types of interments are specifically allowed: (I) earth interments; (2) vault or crypt interments (inside a mausoleum), and (3) cinerary interments inside a columbarium or niche. There is a fourth category of interments contemplated within the general subset of "such other uses as the director deems to be similar and no more intensive". (§ 17.28.030(H)). Therefore, the on page 3, lines 2-3) of the Staff Report that "inherent" in the Master Plan is an "inherent" ('by right' entitlement') "that all undeveloped open space will be developed for burial activity unless otherwise noted in the Master Plan" is absurd on the face of it because it contradicts the City laws and planning protocol. Firstly, with regard to the proposed Alta Vista site, the area identified on the Master Plan is open space. So no development is contemplated. Secondly, if what Green Hills means is that the intent of the Master Plan is to develop all open space unless there is a specific prohibition noted on the Master Plan, that is perverse, ambiguous, misleading, and intellectually dishonest. In short, it is "gamey" .... reflective of the same techniques Green Hills continues to use to "con" its way around and through this City's zoning laws. It is as if the Master Plan, for all intents and purposes, is pretty much of a nullity. Since the Alta Vista project is located in Area 2 (Inspiration Slope), it is relevant to note how the development of Area 2 has progressed since 2007. Even though the Master Plan never contemplated Green Hills being able to inter human remains on the roof of the Inspiration Slope Mausoleum (a free-standing structure), Green Hills was given the right to place (for "storage" an undetermined number of cement crypts on the roof under an artificial grade which Green Hills created. The amount of "cut" and "fill" used to accomplish this task has never been documented and is not referenced specifically in record of this case. It is therefore not possible to measure the extent to which Green Hills has abided by the generalized grading limitations set out in the Master Plan. Are those just for reference only; to be disregarded without Green Hills ever applying for a variance? So references to grading standards and the extent of grading compliance with those standards are meaningless because the City does not insist on Green Hills producing the specific grading quantities used to day so the public, the Planning Commission, and the Council can evaluate the true facts of the situation. The City's Staff Report is completely silent on this issue. Planning knows better; but is circumscribed by political limitations borne out of the fact that the City Council simply "rolls over" for Green Hills. The Planners, who know what is right, have no choice but to bend to the political pressures put on them by one or more members of the City Council because they want and need to feed their families. The statement in the Staff Report that "The entire Green Hills site is permitted to operate as a cemetery and there is an expectation to provide interment plots for burial activity. [Therefore grading in quantities sufficient] to accommodate earth interments throughout the cemetery site has been approved". Again, this absurd on the face of it; particularly when the Staff Report (on page 4, last full paragraph) acknowledges that site-specific review is undertaken. In fact, the false straw-man 5 characterization of appellant's argument that the Master Plan is "the final" plan (whatever that is supposed to mean) is reinforces the "sleight of hand" in which Green Hills continues to engage. On the one hand, Green Hills (i.e. the Staff Report) says that the Master Plan gives it carte- blanche (the functional equivalent of a "by-right entitlement) to develop the cemetery. The Staff Report then refers to non-specific portions of various City Council Resolutions which circumscribe or limit the extent to which Green Hills may develop the cemetery (again in general). But on the critical issue of "density and intensity of use" (which, by definition and direction control the exercise of the City's discretion in imposing the development limitations proscribed by the City Council under§ 17/.28.030 (A)-(H), the staff report applauds the fact that the "City Council-adopted Conditions of Approval do not regulate or establish density or intensity caps ... and because of that fact (i.e. the failure of the City Council to do it job and mandate a base-line against which to measure the intensity of use), no evaluation of density or intensity is required. Appellant's position is that the Council's failure to act to establish density and intensity caps, in general, and then apply those caps to specific projects as proposed, denies the public CEQA protections as well as protections against abuse of discretion in the granting of land use entitlements. Green Hills seems to be saying that it has the right to develop this open space area because no one has said it cannot; that the Master Plan (despite the fact that by law, it is incorporated into the conditional use permit) provides no practical limitation because it is vague and non-specific; and because there is no way to objectively measure whether the degree or extent or numbers of earth interments constitute a burden under CEQA or otherwise because the City Council has chosen to shut its eyes and close its ears, that the Director is therefore pretty much bound to have to "Find" that any project Green Hills submits to Planning has already been approved, and that all that is left is the issuance of a grading permit. This would be like a developer whose property was within a specific plan area being able to get a building permit to develop an overly dense or "intense" project simply because the specific plan contemplated a development on that parcel. Is there any question that such an approach would be dishonored and rejected? The City, before issuing a building permit, would require clearances from the relevant City Departments that the project as proposed is in compliance with CEQA (or allowable under an exemption or exception); and is compliance with the City's zoning code, the development standards incorporated into the zoning code, the City's general plan, and all building standards or any variances therefrom, which the City Council has approved. Here, the grading permit serves the functional purpose of a building permit. There is no approved right to earth interments in the area sought to be developed. Green Hills has no "by right" or "inherent" right to develop this open space. Green Hills can acquire the right by making application to amend its conditional use permit. To the extent that, as here, the development contemplates the development of open space, an amendment to the Master Plan would be required. 6 Then, as part of that approval process, Green Hills would need to demonstrate that the requested earth interments sought would be consistent with the Master Plan (as incorporated into the conditional use permit), and that the use of the open space would not be "more intensive" as developed. To measure the degree of "intensiveness, one would have to know the degree of development or proposed development is contemplated in Area 2. That would include the 1, 128 interment plots slated for the roof-top of the Inspiration Slope Mausoleum which the City Council (again in contravention of the City's rules and laws) has "permitted" Green Hills to establish by way of a simple "letter agreement" because Green Hills, knowing that it could not store cement vaults anywhere on the property except in the storage area, went ahead and purchased them anyway figuring it could "bully" its way through and "store" them on the roof of the Inspiration Slope Mausoleum building under the artificial grade placed on the roof. Those 1,000 "plots" represent approximately $20 Million in future revenue for Green Hills. If one really believes that those cement crypts will never be used, then one should look to buy the Brooklyn Bridge when it goes "on sale". So what Green Hills is doing is very simply "gaming" the system ... yet again ... to be positioned to say to the City and citizens that what it is doing is technically proper. Appellant is an interested party to this appeal because if Green Hills is able to get away with gaming the system in this manner, then Green Hills will at some point down the line seek to develop the area just to the east of the Vista Verde Complex which the is the area Green Hills and the City falsely told the Vista Verde residents they were going to develop; when, in fact, Green Hills was able to "game" the system to develop the Pacific Terrace Mausoleum. Allowing Green Hills to "game" the system this way is therefore prejudicial to appellant because it can be expected that Green Hills will cite these approvals as legal justification for its efforts to further develop the cemetery; even though at no time, in any approval to date, has the City ever approved a specific number of allowed interments, be they earth interments, vault interments (inside a mausoleum), or cinerary interments. SUMMARY: The City needs to follow its laws. There needs to be a specific CEQA finding incorporated into the entitlement. That did not and cannot occur with a grading permit. No grading permit can be issued without the requisite Findings in support of the Grading Permit. In this case, no such Findings were made. In addition, in this case, it is premature to issue a grading permit until Green Hills has first procured the right (entitlement) to develop open space. Green Hills has not applied for such a right (which would involve an application to amend the conditional use permit); and in the absence of such an application, this Council has no jurisdiction to grant Green Hills a conditional use permit amendment. 7 ~ From: Deborah Cullen Sent: Tuesday, August 07, 2018 2:44 PM To: 'Eva Cicoria' <cicoriae@aol.com> Cc: Doug Willmore <DWillmore@rpvca.gov>; Elias Sassoon <esassoon@rpvca.gov>; Ara Mihranian <AraM@rpvca.gov>; Emily Colborn <ecolborn@rpvca.gov>; CC <CC@rpvca.gov>; Teresa Takaoka <TeriT@rpvca.gov>; CC <CC@rpvca.gov> Subject: FW: missing pages Eva- The tables and diagrams are considered part of the FS and below and attached you will find the list of all the changes. The few changes made were to support the edits in the Feasibility Study document. All the tables, figures and appendices are attached to the 2018 FINAL Portuguese Bend Feasibility Study that is posted on the website. We will print the entire report for the meeting tonight and it will be available to the public and at the dais for the City Council. Table D that you attached in your last email was modified to reflect the deletion of the upper canyon lining. Here is the summary of the changes to the attached tables: No report figures were edited (Fig 1 to Fig 14). The 4 tables were edited as shown in the attached documents. • Table 1-ltem 17 and 18 had an agency name change. • Table 2 -Added the Coastal Erosion Control - Coastal Offshore Low: Effective in dispersing High: Proven and readily available High: Significant This option is not Erosion Breakwater shoreline wave energy and technology. engineering, permitting, retained due to low Control reducing wave-cut coastal construction, and effectiveness and high bluff erosion but does not maintenance costs cost. address landslide dewatering or PBLC movement. • Table 3. Detailed Analysis of Remedial Alternatives-there are 2 changes to the Community Acceptance scoring for: o Liner and Channel System-score changed from 2 to 1 changing the total for that category from 31 to 30 o Seal Surface Fractures-score changed from 2 to 1 changing the total for that category from 30 to 29. I ables. ueta11ee1 Anaiysis ot t<emee11a1 Alternatives Nternative ----------·---·--· --.. -· ----·----------------· ----· ·------·-----· -· -·--· --·------------·---·-_._ Eliminate Septic Stormwater Control Dev.•aterin.g System Discharge ---·-----·---···---·------------·---------·--·---------------------··---· -----------·----- Liner and Sea! Groundwater Directional Concrete Channel Surface Exiraction Subsurface Centralized Criterion Channels System Fractures ·wells Drains Sewer 8'/stem Overall protection of human health and the environment 1 2 2 3 3 3 Compliance with ARARs 1 3 3 3 3 3 Long-term effectiveness and permanence 3 3 3 2 3 3 Short-term effectiveness 3 3 3 2 3 3 Protection of communit' during remedial actions " 3 3 3 3 3 ' Protection of workers during remedial actions 2 3 3 3 3 3 Em<jronmental impacts 0 2 2 3 '"' ,j 3 Time until remedial response objectives are achieved 3 3 3 2 3 3 J.l:l1P!e:r:rumt9.!:zillt'J.. 3 3 3 2 3 3 Technical feasibility 3 3 3 2 2 3 Administrative feasibilit'f 2 3 2 3 3 3 Availability of services and materials 3 3 3 3 3 3 State acceptance 1 2 2 3 3 3 Community acceptance 0 ~' c)··'-3 3 2 Score 23 ;,.:;.:;" .. ;;); 28 32 33 Cost High Medium Low Medium Medium High I Conclusfon I rnscard I Retain I Retain I Retain I Retain I Retain I • Table 4 . Was changed as noted be low. Table 4. Approximate Order-0f-Magnitude Costs for Preferred Alternatives Eliminate Septi c Stormwater Control Dewatering System Discharge ----------------------------------------------------------------------------------------------------------- Liner and Channel Seal Sur'iac e Groundwater Directional Centralized Sewer Scope Item System Frac tu res Extraction Wells Subsurface Drains System Data Gap Investigation and Pilot Testing Data g ap i nvestigation work plan so $0 $25,000 S25,000 so Data gap investigation field work so $0 $125,000 $125,000 so Dat a gap investigation data analysis/reporti ng so $0 $25,000 S25 ,000 so Pilot testi ng work plan development S50 ,000 $15 ,000 S25 ,000 S25 ,000 so Pilot test permitting S10 ,000 $10,000 $10,000 S10 ,000 so Pilot test field work $250 ,000 $25,000 $160,000 $240,000 $0 Pi lot test data analysis/re portin g S50 ,000 $15,000 $50 ,000 $50,000 so Fu ll-sca le design report 550 ,000 $15,000 $25 ,000 $25,000 $0 Contingency (25%) $102 ,500 $20,000 $1 1 1,250 $131 ,250 $0 Data Gap Investigation and Pilot Testing Su btotals $512 ,500 $100,000 $556,250 $656,250 so Subtotal IQtaµor Data Gap Investigation and Pilot Testing $1 ,825,000 ; ; Fu/I-Scale Planning_. Permitting, Construction, and Reporting ; ; Fu ll-scal e planni ng $150,000 $25 ,000 S100,000 $100,000 $150,000 Full-sca le permitting S75 ,000 $25,000 $50,000 S50 ,000 S50 ,000 Full-scal e fi eld construction (mid and lower canyons) so $100,000 $0 $0 so Fu ll-sca le fi eld construction (upper, mid , and lower ca nyons) $10,400 ,000 $0 $0 $0 so Full-sca le fi eld construction (10 drains i n 3 areas to 1,200 feet) so $0 $0 $4,800,000 so Fu ll-scal e fi eld construction (30 wells to 200 f eet) (extraction and monitori ng) so $0 $3,000,000 $0 so Full-sca le field construction (18 ,480 f eet of residential lines) so $0 $0 $0 $3,696,000 Reporting and proj ect management $175,000 $50,000 $200,000 $200,000 $200,000 Contingency (25%) $2 ,700 ,000 $50 ,000 $837,500 $1 ,287,500 $1 ,024,000 Full-Scale Plan ning , Permitting , Construction , and Reporting Subtotals $13 ,500 ,000 $250 ,000 $4, 187,500 $6,437,500 $5,120,000 Subtotal ~for Planning_. Pe.rmitting, Construction_. and Reporting $29,495,000 Operation and Maintenan ce Ann1.1al Operation and maintenance (!!@!: }'.ear ~i nc l ud ing monitori ng) SS0 ,000 $25,000 $250 ,000 5100,000 $50,000 Annua Reporti n g~ $25 ,000 $25 ,000 $75,000 $25,000 so Operation a nd maintenance (1 O years) so $250 ,000 so $0 $0 Operation and maintenance (30 years) $1 ,500 ,000 $0 $7,500 ,000 $3,000,000 $1 ,500,000 Reporting (10 years ) so $250,000 $0 $0 so Re portin,g (30 years) $750,000 $0 $2,250,000 $750,000 so Contingenc y (25%) $562 ,500 $125,000 $2,437 ,500 $937,500 $375,000 Operation and Maintenance Su btotals $2,812,500 $625 ,000 S12 ,187,500 $4,687,500 $1 ,875,000 Subtotal ~for Operation and Ma intenance $22, 187_.500 ; Alternative S1111uii111sTotals $16,825,000 $975,000 $16,931,250 $11,781,250 $6,995,000 Tora/ for Preferred Remedy $53,5-07,500 Appendix A is new. This was added based on a comment from the public to explain basic landslide terminology regarding the term "Landflow". This information is provided by the U.S. Geological Survey Landslide Program. The contents of Appendix Band Care the same as before (but the appendix letters are new since we added a new Appendix A. Appendix Band C were formerly Appendix A and B). Appendix D (former Appendix C) has been edited to remove the upper canyon liners and the Burma Road cutoff channel. Thank you for requesting additional clarification on these items before the meeting. VeborcifvCu.Uevv VweaorofF~ C lfy of RCU'\Cho-Potloy Ve¥~ From: Eva Cicoria [mailto:cicoriae@aol.com ] Sent: Tuesday, August 07, 2018 12:18 PM To: Deborah Cullen <DCullen@rpvca.gov >; Doug Willmore <DWillmore@rpvca.gov>; Eli as Sassoon <esassoon@rpvca.gov >; Ara Mihranian <AraM@rpvca.gov > Cc: CC <CC@rpvca.gov > , Subject: Re: missing pages Thank you, Deborah, but do you not consider the tables and diagrams part of the FS? Apparently they have changed, but there was no indication of that by showing them as part of the redline nor by exp lanation in the Staff Report. See attached, for examp le. I have found at least one other change to a table and have no idea whether there are more changes . Do any of you know? Eva .. " I :·: ... -. -----O riginal Message----- From: Deborah Cullen <DCullen@rpvca.gov > To: 'Eva Cicoria' <cicoriae@aol.com >; Doug Willmore <DWillmore@rpvca.gov>; Elias Sassoon <esassoon@rpvca .gov >; Ara Mihranian <AraM@rpvca.gov > Cc: CC <CC@rpvca.gov > Sent: Tue, Aug 7 , 2018 12:03 pm Subject: RE: missing pages Eva, Please see below for an explanation of your confusion regarding the Feasibility Study (draft, red -lined and final): We seem to be work ing with incomplete documents related to the Landslide Feasibility Study coming before City Counci l this evening. The Staff Report with attachments is 144 pages . The final FS included therein stops at p. 81 (B -88 ). B-88 stops at page 81 of th e Feasibility Study. This is the final version which deletes all the edits in the red-lined version which does change the pagination but this is a complete report. This index is the last few pages of the study in all the versions. The red -line of the FS, which is what I have relied upon to show any and all changes in the FS, stops at p. 83 (p .79 or Section 4 .6 .4.6 of the text), leading me to believe that was the extent of the revisions. You are correct that is the extent of the revisions to the report however there are some revis ions to the references (pgs. 80-83). The red-lined version stops at p.83. This is a complete report. I just downloaded the red-lined version that is on our website and have attached it to th is email. If you scroll to the end of the report you will see that the report ends at page 83 . Deborah Cullen Director of Finance City of Rancho Palos Verdes From: Eva Cicoria [ma i lt o:ci cori ae@a ol.com ] Sent: Tuesday, August 07, 2018 8:04 AM To: Doug Willmore <DWi llm o re@rpv ca .go v>; Elias Sassoon <esass o o n @rpv ca .go v>; Deborah Cullen <DCu ll e n @r pv ca .gov> Cc: CC <CC@ r pvca .go v > Subject: missing pages Hi all, We seem to be working with in complete documents related to the Landslide Feasibility Study coming before City Council this evening. The Staff Report with attachments is 144 pages. The final FS included therein stops at p. 81 (B -88 ). The red -line of the FS, which is what I have relied upon to show any and all changes in the FS, stops at p. 83 (p . 79 or Section 4 .6.4.6 of the text), leading me to believe that was the extent of the revisions. Come to find out there is more to it. Is the general public on ly getting part of the materials? Did City Council get a more complete red -line? Can you please provide the public with a complete red -line reflecting all changes to the FS ASAP? Eva ~ , , ~Daniel R. Stephen.~-&--Associates, lnc. --.. :;, No. ARAR? Date Agency 1 Applicable 1961 CDFG 2 Applicable 1968 CA 3 Applicable 1969 SWRCB 4 Applicable 1970 CA 5 To-be-1970 CDFG considered (TBC) 6 Applicable 1972 USEPA 7 TBC 1973 USFWS/NOAA 8 Applicable 1973 USFWS 9 TBC 1993 USEPA Table 1. Applicable or Relevant and Appropriate Requirements (ARARs) Page 1 of 3 Name Title Goals/Objectives/Features DFG Lake and DFG Lake and Streambed Fish and Game Code section 1602 requires an entity to notify CDFW prior to commencing any activity that may Streambed Alteration Alteration Program substantially divert or obstruct the natural flow of any river, stream or lake; substantially change or use any material Program, amended from the bed, channel or bank of any river, stream, or lake; or deposit debris, waste, or other materials that could pass into any river, stream, or lake. Anti-degradation Policy Resolution 68-16 State water discharges be regulated to achieve the "highest water quality consistent with maximum benefit to the people of the state." Satisfies federal CWA 40 CFR 131.12. Incorporated into Basin Plans. Porter-Cologne Act Porter-Cologne Water Quality Act Porter-Cologne grants the SWRCB and RWQCBs the authority to implement and enforce the water quality laws, (CA Water Code) regulations, policies, and plans to protect the groundwater and surface waters of the state, The Act is the principal law governing water quality control in California and establishes comprehensive program to protect water quality and the beneficial uses of waters of the State. The Act applies broadly to all State waters, including surface waters, wetlands, and ground water, waste discharges to land, surface water, and groundwater, and applies to both point and nonpoint sources of pollution. CEQA, amended 1983 California Environmental Quality Requires state and local agencies to identify the significant environmental impacts of their actions and to avoid or Act mitigate those impacts, if feasible, CEQA applies to certain activities of state and local public agencies who must comply with CEQA when it undertakes an activity defined by CEQA as a "project" A project is an activity undertaken by a public agency or a private activity for which the agency has the authority to deny the requested permit or approval that may cause either a direct physical change in the environment or a reasonably foreseeable indirect change in the environment. Environmental review requires at a minimum an initial review of the project and its environmental effects. A more substantial review may be conducted as an environmental impact report (EIR), Requires feasible alternatives or mitigation measures to substantially lessen the significant environmental effects of the project California Endangered California Endangered Species The goal of CESA, Section 2050 of the California Fish and Game Code, is to conserve, protect, restore, and enhance Species Act (CESA) Act(CESA) any endangered or threatened species and its habitat Regarding the birds likely to nest or feed in the area, most of (Fish and Game Code Sections those that are listed as endangered or threatened by the state are also listed federally. If presence of endangered/ 2050-2116) amended 1984 threatened species on the PBLC, the substantive requirements of the California Endangered Species Act, Section 2080 of the California Fish and Game Code, may be applicable. Federal Clean Water Act Federal Water Pollution Control Section 403 of the Clean Water Act, 33 U.S.C. 1343 and associated regulations at 40CFR Part 125, Subpart M (CWA) Act of 1972 regulate discharges into marine waters that have the potential to degrade the marine environment These provisions (Clean Water Act amended 1977, prohibit discharges unless limits can be established to prevent unreasonable degradation or irreparable harm to the 1981, 1987, 1988) marine environment The substantive requirements of the Section 403 may be applicable for remedial alternatives that involve dredging, placement, or dewatering of sediment Federal Endangered Federal Endangered Species Act The goal of the Endangered Species Act of 1973, 16 U.S.C. Section 1531 et seq. is the conservation and recovery of Species Act (ESA) (ESA) amended 1982 species of fish, wildlife, and plants that are threatened with extinction. EPA has consulted with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service to identify threatened and endangered species and ensure that any response action is not likely to jeopardize listed species or adversely modify critical habitat Because of the presence of endangered/threatened species on the PV Shelf, the substantive requirements at Sections 7 and 9 of the Endangered Species Act may be applicable. 16 U.S.C. §§1536 & 1538. Section 10(a)(1)(B) Habitat Conservation Plans Habitat Conservation Plans (HCPs) under section 1 O(a)(1)(8) of the Act provide for partnerships with non-Federal parties to conserve the ecosystems upon which listed species depend, ultimately contributing to their recovery, EPA NPS Management Guidance Specifying Guidance specifying management measures for sources of nonpoint pollution in coastal waters Guidance Management Measures For Sources Of Nonpoint Pollution In Coastal Waters ,., ... _/ ~- ~- /Janie/ B. Stephens & A,\',\'tJciate,\·, Inc. No . ARAR? Date Agency 10 TBC 1995 SWRCB 11 TBC 1998 California Fish and Game Code 12 Applicable 2002 SWRCB 13 TBC 2004 SWRCB 14 Applicable 2007 RWQCB 15 Applicable 2011 USEPA 16 Applicable 2015 SWRCB 17 Applicable 2015 SWRCB/RWQCBGal- ~ 18 Applicable 2015 s10.1~GQl~lo.lQGBCal - OSHA Table 1. Applicable or Relevant and Appropriate Requirements (ARARs) Page 2 of 3 Name Title Goals/Objectives/Features Water Quality Policy Water Quality.Control Policy for Water quality principles and guidelines to prevent water quality degradation and to protect the beneficial uses of waters Enclosed Bays and the Enclosed Bays and Estuaries of enclosed bays and estuaries (does not apply to wastes from land runoff except as specifically indicated for siltation Estuaries of CA as Adopted by Resolution (Chapter Ill 4.) and combined sewer flows (Chapter Ill 7)). Discharge of municipal wastewaters and industrial process No . 95-84 11/16/95 waters (exclusive of cooling waste discharges) to enclosed bays and estuaries (except San Francisco Bay-Delta) shall be phased out. Persistent or cumulative toxic substances shall be removed from waste to the maximum extent practicable through source control or adequate treatment prior to discharge. Nonpoint sources of pollutants shall be controlled to the maximum practicable extent. Requires self-monitoring/reporting. Section 307(c)(1) Coastal Zone Management Act Section 307(c)(1) of the CZMA requires that federal agencies conducting or supporting activities affecting land and 40 CFR 300 .5 , water resources of the coastal zone do so in a manner that is consistent with approved state coastal zone 300.430(1)(1 )(ii)(B) management programs. Lake and Streambed Lake and Streambed Alteration Prohibits the substantial diversion or obstruction of the natural flow or substantial changes to the bed, or bank of any Alteration Program Program Notification/Agreement river, stream, or lake designated by the Department of Fish and Game, or the use of any material from the streambeds , Section 1602 without first notifying the Department and otherwise complying with the statute . Water Quality Policy Water Quality Enforcement Creates framework for identifying and investigating instances of noncompliance and taking enforcement actions that Enclosed Bays and Policy February 19 , 2002 are appropriate in relation to the nature and severity of the violation , and for prioritizing enforcement resources to Estuaries achieve maximum environmental benefits. Other state agencies (Fish and Game) can enforce water quality provisions and state law allows for members of the pub lic to bring enforcement matters to the attention of the state and authorizes aggrieved persons to petition the state to review most actions or inactions by the RWQCB . In addition, state and federal statutes provide for public participation in the issuance of most orders , policies, and water quality control plans. Basin Plan Los Angeles Regional Water Establishes comprehensive program to preserve, enhance , and restore water quality in all water bodies within the state Quality Control Board Basin Plan as master planning document for each RWQCB . Designates beneficial uses of surface water and groundwater, as well as water auality objectives (WQOs). Nonpoint Source Po licy for Implementation and NPS Plan implementation. RWQCBs have primary responsibility for ensuring that appropriate NPS control Pollution Control Policy Enforcement of the Nonpoint implementation programs are in place throughout the State. RWQCB responsibilities include, but are not limited to, Source Pollution Contro l issuing WDRs or a waiver of WDRs for individua l discharges or a category of NPS discharges, or adopting a basin Program 5/20/04 plan amendment that addresses NPS discharges. Provides guidelines for development of third-party NPS control programs such as a mix of public and private partnership efforts. 40 CFR 122.44(a) National Pollutant Discharge Use of best available technology (BAT) economically achievable is required to control toxic and non-conventional Elimination System pollutants. Use of best conventional pollutant control techno logy (BCT) is required to control conventional pollutants. Technology-based limitations may be determined on a case,by-case basis . Applicable federally approved state water quality standards must be complied with; these standards may be in addition to or more stringent than other federal standards under the CWA. Discharge limitations must be established at more stringent levels than technology-based standards for toxic pollutants . 303(d) Listing Policy of Water Quality Contro l Policy Establishes standardized SWRCB/RWQCB approach and process for developing listing requirements of section 2004 , amended 2015 Developing CA CWA Section 303(d) of CWA. CWA section 303(d) requires states to identify waters that do not meet, or are not expected to meet by 303d List the next listing cycle, applicable water quality standards (WQOs or beneficial uses) after the application of certain techno logy-based controls, and schedule such waters for development of total maximum daily loads (TMDLs). States are required to assemble and evaluate water quality data and information to develop the list and to provide documentation for listing or not listing a state's waters. Estab lishes methodology to develop list including Listing Factors and Delisting Factors, the process for gathering and evaluating readily available data and infonmation , and TMDL scheduling. CA Division of Various regulations regarding Protects workers from health and safety hazards in the workplace in California. Sets permissible exposure levels Occupational Safety and safety (PELs) and other numerical values. Numerous requirements for worker safety and health. Health (DOSH) regulations (various) A-~-~7 Daniel-R.---Stepltens & A.--.rnciates,-lnc. No. ARAR? Date Agency 19 Applicable 2015 SWRCB/RWQCB 20 Applicable 2017 City of Rancho Palos Verdes 21 Applicable 2017 California Fish and Wildlife; USFWS; City of Rancho Palos Verdes .,. Name 401 WQC Program Table 1. Applicable or Relevant and Appropriate Requirements (ARARs) Page 3 of 3 Title Goals/Objectives/Features 401 Water Quality Certifications Regulates discharges of fill and dredged material under CWA Section 401 and the Porter-Cologne Water Quality and Wetlands Program Control Act. Protects all waters with special responsibility for wetlands, riparian areas, and headwaters of high resource value; protection of special-status species; regulation of hydromodification impacts; pollutant removal; flood water retention; and habitat connectivity. Grading Code 17.76.030 Grading Permits A minor grading permit is required for an excavation, fill, or combination thereof in excess of 20 cubic yards but less than 50 cubic yards, in any two-year period, on a slope of less than 35 percent, or an excavation 3 feet or more, but less than 5 feet, below natural grade or a fill 3 feet or more, but less than 5 feet, above natural grade on a slope of less than 35 percent. A major grading permit is required for an excavation, fill or combination thereof, in excess of 50 cubic yards in any two-year period; an excavation 5 feel or more below natural grade or a fill 5 feet or more above natural grade; any excavation or fill that encroaches on or alters a natural drainage channel or watercourse, and unless otherwise exempted by subsection C of this section, an excavation or fill on an extreme slope (35 percent or more). Code Section 2800 Natural Community Conservation NCCP identifies and provides for the regional protection of plants, animals, and their habitats, while allowing Plan (NCPP) compatible and appropriate economic activity. Working with landowners, environmental organizations, and other interested parties, a local agency oversees the numerous activities that compose the development of an NCCP. CDFW and the U.S. Fish and Wildlife Service provide the necessary support, direction, and guidance to NCCP participants. The City of Rancho Palos Verdes is included in the plan area for NCCPs/HCPs . General Response Action Storm water Control Subsurface Dewatering Daniel B. Stephens & Associates, Inc. Remedial Technology Repair Existing Corrugated Piping System Concrete Channels Liner and Channel System Seal Surface Fractures Groundwater Extraction Pits Table 2. Screening Evaluation of Remedial Technologies Page 1of4 Effectiveness Implementability Cost Low: Does not adequately High: Readily implemented with Low: Lowest cost capture regional surface industry standard equipment, option. stormwater. Prone to damage materials, and labor. and high maintenance. High: Highly effective in Low: Displaces habitat or open High: Standard capturing and controlling space. Not readily permitted. Prone technology subject to surface water flow and to damage with land movement. market rate bidding. infiltration. High: Highly effective in High: Can be partially integrated into Moderate/High: Lower capturing and controlling native or engineered habitat. Can be material costs surface water flow and permitted under stream restoration or compared to standard infiltration. engineered habitat regulations. concrete channeling. Flexible components can be installed Design costs can be in areas prone to land movement if significant. needed. High: Highly effective in High: Readily implemented with Low: Relatively low capturing and controlling industry standard equipment, annual costs for work in surface water infiltration. materials, and labor. before rainy season. Medium/Low: Effective in Medium/Low: Established Medium: Relatively low low-permeability formations technology. Simple construction and cost construction. but extraction rate can be low. operation. Can be high maintenance Permanent shoring or Can be installed across broad due to clogging. Can occupy sheet piling around the areas if needed. Effective in relatively large areas for several perimeter can escalate highly permeable formations. years. Deep pits can be hazardous. costs. Poor regional groundwater capture. Can promote slope instability. Retained for Detailed Screening Analysis? Not retained due to poor effectiveness. Not retained due to poor implementability. Retained due to high implementability. Retained due to high implementability and relatively low cost. Not retained due to poor effectiveness and implementability. General Response Action Subsurface Dewatering (cont.) Engineered Slope Stabilization Measures Daniel B. Stephens & Associates, Inc. Remedial Technology Groundwater Extraction Wells Directional Subsurface Drains Buttressing (engineered fill) Table 2. Screening Evaluation of Remedial Technologies Page 2 of 4 Effectiveness Implementability Cost High: Actively lowers Medium: Established technology. High/Medium: Well groundwater table where Requires permeable geology but drilling costs escalate subsurface geology is some portions of project area have with multiple wells relatively permeable and low permeability. Pump clogging is needed to develop an appropriate horizontal and common. Continual land movement extraction well field. vertical spacing can be damages wells. Could be installed in Costs increase with maintained. key areas only. depth also. Subject to competitive market- based cost control. High/Medium: Passively High: Established technology. Active Medium: Multiple removes groundwater through pumping not required. Low drains can be installed gravity drainage. Can be maintenance. Can be installed across at one location with one installed in radial clusters with relatively long horizontal distances. work area setup. Costs of long casing segments Readily implementable. increase if working covering relatively large depth is problematic areas. Flow can be slow in due to site geometry. some areas. Medium: Could be effective Low: Such a large single buttress High: Substantial costs for some sub-areas of the would be needed that PVDS would are associated with this Site, however, one large be shut down for months while option due to major site buttress may not be effective excavations and fill emplacement is preparation, deep in resisting the entire mass of completed. Deep excavation and excavation, soil the PBLC. In addition, this construction dewatering below the stockpiling, and technology alone would not basal rupture surface would be roadway management. address groundwater which is difficult. a primary driver for slope failure at PBLC. . .. Retained for Detailed Screening Analysis? Retained since some project area locations may be suitable. One of few dewatering technologies available. Retained due to high effectiveness and implementability plus medium costs. One of few dewatering technologies available. Not retained due to medium effectiveness in combination with low implementability and high cost. General Response Action Engineered Slope Stabilization Measures (cont.) Eliminate Septic System Discharge Daniel B. Stephens & Associates, Inc. Remedial Technology Mechanically stabilized earth (MSE) walls Driller piers (caissons) Centralized Sewer System Table 2. Screening Evaluation of Remedial Technologies Page 3 of 4 Effectiveness Implementability Cost Low: Not effective for slope High: This is a standard technology Low: This is a relatively stability projects as large and that is relatively easy to install as low-cost alternative due as deep as PBLC. In modular components. to readily available addition, this technology products, materials and alone would not address labor. groundwater which is a primary driver for slope failure at PBLC. Medium/Low: Caissons can Medium: This is a readily Medium: This is be effective, however, implementable technology but would typically a fairly numerous caissons would be be somewhat complicated by the reasonable cost needed at substantial depth substantial depth required at the alternative, however, to be sufficiently effective at PBLC. costs would escalate the PBLC. In addition, this with the depths required technology alone would not at PBLC. address groundwater which is a primary driver for slope failure at PBLC. High: Highly effective in High: Readily implemented with High: Septic tank removing septic tank industry standard equipment, removal on private discharge since tanks are materials, and labor. property and centralized removed. sewer system installation involves significant engineering planning, design permitting, and field construction. Can be cost-prohibitive for any one organization without significant funding assistance. Retained for Detailed Screening Analysis? Although this is a low- cost and readily implementable option, it is not retained because it would not be effective for a slope stability problem as large and as deep at the PBLC. This option is not retained due to the total estimated number of caissons and the depth of the caissons that would be required for this technology to be effective. Retained due to high effectiveness and implementability. Also permanent over the long term. Ge neral Res po nse A cti o n Coastal Erosion Contro l • Daniel B. Stephens & Associates, Inc. Re medi a l T ec hn o logy Offshore Breakwater Table 2. Screening Evaluation of Remedia l Technologies Page 4 of 4 Effective ness Impleme nt a bility Cos t Low: Effective in disgersing High: Proven and readily available High: Significant shoreline wave energy and techno logy. engineering, germitting , reducing wave-cut coasta l construction, and bluff erosion but does not maintenance costs address landslide dewatering or PBLC movement. Reta in ed for Deta il ed Scree ning An alys is ? This ogtion is not retained due to low effectiveness and high cost. 1·:·:. _ ... _ Daniel B. Stephens & Associates, Inc. Table 3. Detailed Analysis of Remedial Alternatives Criterion Overall protection of human health and the environment Compliance with ARARs Long-term effectiveness and permanence Short-term effectiveness Protection of community during remedial actions Protection of workers during remedial actions Environmental impacts Time until remedial response objectives are achieved Implementability Technical feasibility Administrative feasibility Availability of services and materials State acceptance Community acceptance Score Cost I Conclusion I Criterion scoring: 3 = Excellent 2 =Good 1 = Fair o =Poor Stormwater Control Liner and Concrete Channel Channels System 1 2 1 3 3 3 3 3 2 3 2 3 0 2 3 3 3 3 3 3 2 3 3 3 1 2 0 2'1 23 J.'.1-30 High Medium Discard I Retain I Alternative Dewatering Seal Groundwater Directional Surface Extraction Subsurface Fractures Wells Drains 2 3 3 3 3 3 3 2 3 3 2 3 3 3 3 3 3 3 2 3 3 3 2 3 3 2 3 3 2 2 2 3 3 3 3 3 2 3 3 2'1 3 3 W29 28 32 Low Medium Medium Retain I Retain I Retain Eliminate Septic System Discharge Centralized Sewer System 3 3 3 3 3 3 3 3 3 3 3 3 3 2 33 High I Retain I ~•D --a-,-.,-.e-l-B~.-5-·1_e_p_l_ze-n~s -&~A~s -s _o _c -ia_l_e-,--,-J-n~c .~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ v Ta ble 4. Approximate O rder-of-Magnitude Costs for Preferred Alte rnatives Eliminate Septic Stormwater Control Dewatering System Discharge Liner and Channel Seal Surface Groundwater Directional Centralized Sewer Scope Item System Fractures Extraction Wells Subsurface Drains System Data Gap Investigation and Pilot Testing Data gap investigation work plan $0 $0 $25,000 $25 ,000 $0 Data gap investigation field work $0 $0 $125 ,000 $125 ,000 $0 Data gap investigation data analysis/reporting $0 $0 $25 ,000 $25 ,000 $0 Pilot testing wo rk plan development $50 ,000 $15,000 $25 ,000 $25 ,000 $0 Pilot test permitti ng $10 ,000 $10,000 $10 ,000 $10 ,000 $0 Pilot test field work $250 ,000 $25,000 $160,000 $240,000 $0 Pilot test data analysis/reporting $50 ,000 $15,000 $50 ,000 $50 ,000 $0 Full-scale design report $50.000 $15,000 $25,000 $25,000 $0 Contingency (2 5%) $102,500 $20,000 $111,250 $131,250 $0 Data Gap Investigation and Pilot Testing Subtotals $512,500 $100,000 $556 ,250 $656 ,250 $0 Subtotal #J#H-for Data Gap Investigation and Pilot Testing $1,825,000 F ull-Scale Planning, Permitting, Construction, and Reporting Full-scale planning $150,000 $25 ,000 $100 ,000 $100,000 $150,000 Full-scale pe rmitti ng $75 ,000 $25 ,000 $50 ,000 $50 ,000 $50 ,000 Full-scale field construction (mid and lower canyons) $0 $100 ,000 $0 $0 $0 Full-scale field construction (upper, mid , and lowe r canyons) $10,400 ,000 $0 $0 $0 $0 Full-scale field const ruction (10 drains in 3 areas to 1,200 feet) $0 $0 $0 $4 ,800 ,000 $0 Full-scale .field construction (30 wells to 200 feet) (extraction and monitoring) $0 $0 $3 ,000 ,000 $0 $0 Full-scale field construction (18,480 feet of residential lines) $0 $0 $0 $0 $3,696,000 Reporting and project management $175,000 $50,000 $200 ,000 $200,000 $200 ,000 Continge ncy (2 5%) $2,700,000 $50,000 $837,500 $1,287,500 $1,024,000 Full-Scale Planning , Permitting , Construction, and Re porting Subtotals $13 ,500 ,000 $250 ,000 $4,187 ,500 $6,437,500 $5 ,120,000 Subtotal #J#H-for Planning, Permitting, Construction, and Reporting $29 ,495,000 Operation and M aintenance Annual Operation and maintenance (l!fil..Yfil!L..aRRlla!;-i ncluding monitoring) $50 ,000 $25 ,000 $250 ,000 $100 ,000 $50 ,000 Annual Reporting ~~ $25 ,000 $25,000 $75 ,000 $25 ,000 $0 Operation and maintenance (1 O years) $0 $250,000 $0 $0 $0 Operation and maintenance (30 years) $1,500 ,000 $0 $7 ,500 ,000 $3 ,000 ,000 $1 ,500 ,000 Reporting (10 years) $0 $250 ,000 $0 $0 $0 Reporting (30 years) $750 ,000 $0 $2 ,250 ,000 $750 ,000 $0 Contingency (25%) $562 ,500 $125,000 $2,437,500 $937 ,500 $375 ,000 Operation and Maintenance Subtotals $2 ,812 ,500 $625,000 $12,187,500 $4,687,500 $1 ,875,000 Subtotal +eial-for Operation and Maintenance $22 , 187, 500 Alternative ~Totals : $16 ,825,000 $975 ,000 $1 6 ,93 1,250 $11,781,250 $6 ,995,000 Total for Preferred Remedy $53,507,500 ,: ... ,.· ... ..•. ·f Teresa Takaoka From: Sent: To: Cc: Subject: Attachments: Eva, Deborah Cullen Tuesday, August 07, 2018 12:04 PM 'Eva Cicoria'; Doug Willmore; Elias Sassoon; Ara Mihranian cc RE: missing pages DRAFT 2017 Portuguese Bend Feasibility Study w edits -Presented to Council 20180807.pdf Please see below for an explanation of your confusion regarding the Feasibility Study (draft, red-lined and final): We seem to be working with incomplete documents related to the Landslide Feasibility Study coming before City Council this evening. The Staff Report with attachments is 144 pages. The final FS included therein stops at p. 81 (B-88). B-88 a·1 is the which edits in red··lined this is a is The red-line of the FS, which is what I have relied upon to show any and all changes in the FS, stops at p. 83 (p.79 or Section 4.6.4.6 of the text), leading me to believe that was the extent of the is the revisions to From: Eva Cicoria [mailto:cicoriae@aol.com] Sent: Tuesday, August 07, 2018 8:04 AM To: Doug Willmore <DWillmore@rpvca.gov>; Elias Sassoon <esassoon@rpvca.gov>; Deborah Cullen <DCullen@rpvca.gov> Cc: CC <CC@rpvca.gov> Subject: missing pages Hi all, We seem to be working with incomplete documents related to the Landslide Feasibility Study coming before City Council this evening. The Staff Report with attachments is 144 pages. The final FS included therein stops at p. 81 (B-88). The red-line of the FS, which is what I have relied upon to show any and all changes in the FS, stops at p. 83 (p. 79 or Section 4.6.4.6 of the text), leading me to believe that was the extent of the revisions. 1 Come to find out there is more to it. Is the general public only getting part of the materials? Did City Council get a more complete red-line? Can you please provide the public with a complete red-line reflecting all changes to the FS ASAP? 2 i Daniel B. Stephens & Associates, Inc. Table of Contents Section Page Executive Summary .................................................................................................................. 11 1. Introduction ......................................................................................................................... 11 1.1 Site Background .......................................................................................................... 11 1.1.1 Overview and Problem Statement ..................................................................... 11 1.1.2 Regulatory Background ..................................................................................... 44 1.1.3 Recent Community Involvement ....................................................................... 88 1.2 Project Area Definition ................................................................................................. 99 1.3 Purpose and Overview ............................................................................................. 1111 1.4 Document Organization ........................................................................................... 1212 2. Summary of Previous Work ............................................................................................. 1414 2.1 Historical Documents, 1957-1997 ............................................................................ 1414 2.2 1997 Ehlig and Yen Feasibility Study ....................................................................... 1717 2.3 2000 Leighton Feasibility Study ............................................................................... 2020 3. Physical Characteristics of the PBLC Vicinity .................................................................. 2222 3.1 Topography ............................................................................................................. 2222 3.2 Watershed Hydrology .............................................................................................. 2424 3.3 Soils ......................................................................................................................... 2626 3.4 Geology ................................................................................................................... 2929 3.5 Landslide Characterization ....................................................................................... 3131 3.6 Hydrogeology........................................................................................................... 3434 3.6.1 Groundwater Recharge ................................................................................. 3535 3.6.2 Groundwater Occurrence .................................................................................. 38 3.6.3 Water Wells .................................................................................................. 4040 3.7 Geotechnical Modeling ............................................................................................ 4141 4. Feasibility Study .............................................................................................................. 4545 4.1 ARARs ..................................................................................................................... 4545 4.1.1 Definitions ..................................................................................................... 4545 4.1.2 Identified ARARs ........................................................................................... 4646 4.2 Remedial Action Objective ....................................................................................... 4747 4.3 General Response Actions ...................................................................................... 4848 4.3.1 Stormwater Control ........................................................................................... 49 4.3.1 Subsurface Dewatering ..................................................................................... 49 4.3.2 Stormwater Control ........................................................................................... 49 4.3.1 Engineered3 ................................................ Enineered Slope Stabilization Measures 51 4.3.24 Eliminate Septic System Discharge ................................................................... 52 4.3.5 Coastal Erosion Control .................................................................................... 53 4.4 Identification and Screening of Technology Alternatives .......................................... 5353 4.4.1 Stormwater Control Option 1 – Repair Existing Corrugated Piping System ....... 53 4.4.1.1 Description ...................................................................................... 5353 4.4.1.2 Screening Summary ............................................................................54 Table of Contents (Continued) Section Page ii Daniel B. Stephens & Associates, Inc. 4.4.2 Stormwater Control Option 2 – Install Concrete Channels ................................ 54 4.4.2.1 Description ..........................................................................................54 4.4.2.2 Screening Summary ............................................................................54 4.4.3 Stormwater Control Option 3 – Install Liner and Channel System ..................... 55 4.4.3.1 Description ..........................................................................................55 4.4.3.2 Screening Summary ............................................................................55 4.4.4 Stormwater Control Option 4 – Seal Surface Fractures ..................................... 56 4.4.4.1 Description ..........................................................................................56 4.4.4.2 Screening Summary ............................................................................56 4.4.5 Subsurface Dewatering Option 1 – Groundwater Extraction Pits ................... 5656 4.4.5.1 Description ...................................................................................... 5656 4.4.5.2 Screening Summary ............................................................................57 4.4.6 Subsurface Dewatering Option 2 – Groundwater Extraction Wells .................... 57 4.4.6.1 Description ..........................................................................................57 4.4.6.2 Screening Summary ........................................................................ 5757 4.4.7 Subsurface Dewatering Option 3 – Directional Subsurface Drains ................ 5858 4.4.7.1 Description ...................................................................................... 5858 4.4.7.2 Screening Summary ........................................................................ 5858 4.4.8 Engineering Slope Stabilization - Buttressing (Engineered Fill) ..................... 5959 4.4.8.1 Description ...................................................................................... 5959 4.4.8.2 Screening Summary ........................................................................ 6060 4.4.9 Engineering Slope Stabilization Measures - Mechanically Stabilized Earth Wall ................................................................................................................... 60 4.4.9.1 Description ...................................................................................... 6060 4.4.9.2 Screening Summary ............................................................................61 4.4.10 Engineering Slope Stabilization Measures – Drilled Piers (CaissionsCaissons) ......................................................................................... 61 4.4.10.1 Description ..........................................................................................61 4.4.10.2 Screening Summary ............................................................................61 4.4.11 Centralized Sewer System ................................................................................ 62 4.4.11.1 Description ..........................................................................................62 4.4.11.2 Screening Summary ............................................................................62 4.4.12 Coastal Erosion Control (Breakwater) ............................................................... 63 4.4.12.1 Description ..........................................................................................63 4.4.12.2 Screening Summary ............................................................................63 4.4.13 Summary of Retained Technologies ................................................................. 63 4.5 Detailed Analysis of Remedial Technologies ............................................................... 63 4.5.1 Concrete Channels ........................................................................................... 64 4.5.2 Liner and Channel System ................................................................................ 65 4.5.3 Seal Surface Fractures ..................................................................................... 66 4.5.4 Groundwater Extraction Wells ........................................................................... 67 4.5.5 Directional Subsurface Drains ........................................................................... 68 4.5.6 Centralized Sewer System ................................................................................ 70 Table of Contents (Continued) Section Page iii Daniel B. Stephens & Associates, Inc. 4.6 Preferred AlternativeOptions ........................................................................................ 71 4.6.1 Description and Conceptual Design .................................................................. 71 4.6.1.1 Seal Surface Fractures........................................................................72 4.6.1.2 Directional Subsurface Drains .............................................................72 4.6.1.3 Liner and Channel System ..................................................................73 4.6.1.4 Groundwater Extraction Wells .............................................................75 4.6.1.5 Centralized Sewer System ..................................................................75 4.6.2 Data Gaps ......................................................................................................... 76 4.6.3 Pilot Testing ...................................................................................................... 77 4.6.4 Approximate Implementation Costs ................................................................... 77 4.6.4.1 Seal Surface Fractures........................................................................77 4.6.4.2 Directional Subsurface Drains .............................................................77 4.6.4.3 Liner and Channel System ..................................................................78 4.6.4.4 Groundwater Extraction and Monitoring Wells .....................................78 4.6.4.5 Centralized Sewer System ..................................................................78 4.6.4.6 Total Estimated Project Cost ...............................................................79 References ........................................................................................................................... 8080 List of Figures Figure 1 Regional Site Location 2 Aerial Photograph with Geographic Features 3 Landslide Subareas 4 Measured Horizontal Movement, 2013-2014 5 Watersheds 6 Topography 7 Major Utilities 8 Regional Geology 9 Stratigraphic Column, Monterey Formation List of Figures (Continued) Figure iv Daniel B. Stephens & Associates, Inc. 10 Onshore/Offshore Faults and Folds 11 Existing Dewatering Wells 12 Slope Stability Model 13 Modeled Increase in Factor of Safety with Decline in Groundwater Elevation 14 Conceptual Horizontal Drains, Extraction Wells, and Monitoring Wells List of Tables Table 1 Applicable or Relevant and Appropriate Requirements (ARARs) 2 Screening Evaluation of Remedial Technologies 3 Detailed Analysis of Remedial Alternatives 4 Approximate Order-of-Magnitude Costs for Preferred Alternatives List of Appendices Appendix AA USGS Landslide Types and Processes B Custom Soil Resource Report for Los Angeles County, California, Southeastern Part, Portuguese Bend BC Geotechnical Modeling Figures C D ............................................................. Conceptual Liner and Channel Specifications v Daniel B. Stephens & Associates, Inc. ES-1 Daniel B. Stephens & Associates, Inc. Executive Summary Daniel B. Stephens & Associates, Inc. has prepared this feasibility study (FS) update to address remediation of ongoing land movement in the Portuguese Bend Landslide Complex (PBLC) using the results of past environmental, engineering, and hydrogeologic work completed to address regional slope failure on the greater Palos Verdes Peninsula. This FS is an update to efforts completed primarily in 1997 and 2000 that characterized the hydrogeologic and geotechnical conditions driving landslide activity and proposed a variety of various approaches and technologies to abate slope failure in the PBLC. Remedies appropriately Earlier remedies focused, in part, on the removal of subsurface water (groundwater) and the elimination of continued stormwater loading to groundwater in key areas. Some proposed recommendations were implemented after the 1997 FS was drafted, including installation of dewatering wells, mass regrading, and surface water infiltration control with an above-grade piping system. However, land movement was largely unabated, and slope failure continues today at rates of up to approximately 8 feet per year. Slope failure is continually managed by a City of Rancho Palos Verdes (City) maintenance program, with significant cost and effort to maintain area utilities and the nearby roadway in a functional state. Additional measures, including a major excavation for a buttress extending nearly half a mile along the coast, were proposed in 2000, but were not implemented. This FS update focuses on implementable, effective, andimplementing cost-effective technologies as options for stormwater the City to consider regarding storm water control and groundwater extraction to achieve manageable and sustainable land stability. TraditionalOther geotechnical engineering solutions, such as buttresses, were also considered with other options, but were screened out due largely to poor overall implementability. The selected remedy consists of installing a flexible liner system in the upper and lower canyons in the watershed where stormwater directly infiltrates to groundwater in the FS remedies focus on the southern PBLC area and directing flow to a stormwater mainly within the control channel discharging to the ocean. Groundwater extraction is proposed to be completed with several ES-2 Daniel B. Stephens & Associates, Inc. subsurface directional gravity drains (horizontal drains or hydraugers). Drains would be installed from the coast extending north under Palos Verdes Drive South into and under the area of greatest of the City that is subject to a relatively high level of land movement , where the surface water drainage currently is not functioning properly, and where groundwater extraction is most needed. Once drains take effect and the groundwater surface is lowered in key areas, groundwater extraction with a traditional but expanded extraction well network is also proposed to supplement the horizontal drains where needed. Preliminary three-dimensional slope modeling confirms that a reasonable reduction in the elevationAn engineering analysis and evaluation of the groundwater surface existing stormwater drainage system of 5 to 15 percent would result in a significant reduction in land movement in the PBLC area. Annualthis area should be completed to assist in the design and construction of an updated system to convey runoff to the ocean and eliminate ponding areas which have been created over the years due to land settlement. At the same time, efforts need to be made for design and installation of groundwater extraction drains (horizontal drains or hydraugers). Hydrauger design and installation can be tested and modified based on results obtained. These horizontal drains could be installed, for example, into the coastal bluff and extend north under PVDS, and directly drain into the ocean. Further, it is recommended to perform an engineering analysis of the watershed including the northern canyon areas (upper Portuguese, Ishibashi, and Paintbrush Canyons) to identify where, how and to what extent stormwater infiltrates into groundwater in the PBLC. Subsequently, efforts could be made for design and installation of an environmentally friendly flexible liner system in the watershed canyons where the stormwater significantly infiltrates to groundwater in the PBLC in an attempt to minimize this infiltration and allow the stormwater to be discharged to the ocean in a controlled manner. Further, it is recommended to identify existing surface fractures throughout the PBLC area and install land surface fracture sealing is also a component of the selected remedy. Surface fractures in the PBLC should also be filled in before the rainy season each year to preventwith environmentally friendly material to minimize direct, uncontrolled stormwater infiltration, deep percolation, and groundwater recharge. which currently percolates into groundwater. These ES-3 Daniel B. Stephens & Associates, Inc. sealed surface fractures in the PBLC should be checked and maintained annually prior to the rainy season. Finally,Sanitary sewer septic systemssystem effluent in the area haveupslope areas has long been recognized as a source of groundwater recharge in the PBLC area that needs to be eliminated. AIn addition to the above options, it is recommended that the City consider working with its neighboring city, Rolling Hills, to construct a centralized sanitary sewer system is proposedand a storm water drainage system for the Portuguese Bendresidential neighborhood andat the uppertop of the watershed above the Portuguese, Ishibashi, and Paintbrush Canyon areas in the adjacent City of Rolling Hills at the top of the watershed, as well as within the City’s Portuguese Bend neighborhood. Importantly, the selected remedy options identified can be implemented in accordance with the Palos Verdes Land ConservancyCity’s Natural Communities Conservation Plan./Habitat Conservation Plan (NCCP/HCP). Several stormwater control and groundwater extraction remedy elements, as envisioned, can be designed to be largely integrated into the native habitat. Estimated order-of-magnitude costs for implementation of the selected remedyrecommended remedies total approximately $31.3 million, with additional operating, maintenance, and monitoring costs totaling $22 million approximately over 30 years. Additional hydrogeologic and geotechnical data are needed, however, before full-scale design can proceed.will be collected as an integral step leading to final design and implementation. In addition, remedy construction is proposed to be completed incrementally and iteratively starting with a pilot test program for directional subsurface drains. Drain pilot testing costs (included in above estimates) are estimated to total approximately $350,000 over about 12 to 18 months. ES-1 Daniel B. Stephens & Associates, Inc. Stakeholder participation has been identified as a key pathway to project success and community acceptance. It is recommended that public workshops be scheduled at various stages of project implementation which could include the design phase, pre-construction, any pilot testing implementation and post construction phases of the project. 1 Daniel B. Stephens & Associates, Inc. 1. Introduction This report has been prepared by Daniel B. Stephens & Associates, Inc. (DBS&A) to present the methods, results, and conclusions of the Portuguese Bend Landslide Complex (PBLC) feasibility study (FS) update. This FS update has been completed to summarize the physical characteristics of the PBLC and vicinity, and to systematically compile historical PBLC investigation work, related vicinity geologic and hydrologic studies, previous efforts toward achieving land movement stabilization, and regulatory drivers that will impact implementation of PBLC stabilization measures. The currently available information has been presented and analyzed in this FS update in order to identify techniques and technologies that can be implemented to stabilize the PBLC. PBLC stabilization will be considered achieved when a significant reduction in land displacement is recorded, as measured by the land survey monitoring system currently in place or a successor land survey methodology. The format of this FS broadly follows the U.S. Environmental Protection Agency (U.S. EPA) FS format (U.S. EPA, 1988) developed under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). That is, this document is a CERCLA-analogue FS. The time-tested CERCLA FS approach is a systematic, methodical, and thorough concept-level process widely accepted in the engineering industry to develop, analyze, and select cost effective mitigation alternatives that can be accepted by federal, state, and local regulators and community stakeholders. This introductory section presents site background information, regulatory history, the purpose and objectives of the FS, and a summary of community involvement opportunities. 1.1 Site Background 1.1.1 Overview and Problem Statement The PBLC is located along the south central section of the Palos Verdes Peninsula within the City of Rancho Palos Verdes in Los Angeles County, California (Figure 1).. The terminus of the active landslide complex, and generally the southwest boundary of the PBLC, is the Pacific 2 Daniel B. Stephens & Associates, Inc. Ocean. In this location, the shoreline runs in a generally northwest to southeast direction along the coastal coves known as Portuguese Bend on the east and Smuggler’s Cove (Sacred Cove) and Abalone Cove on the west. (Figure 1). Two other prominent features on the coastline at the terminus of the PBLC are Inspiration Point and the more westerly Portuguese Point. The eastern border of the PBLC is formed by an approximate line that runs northward from western Yacht Harbor Drive to the confluence of Ishibashi and Paintbrush Canyons. The northern boundary of PBLC is a small distance south and subparallel to Burma Road, a trail that was established along the path of the former proposed Crenshaw Boulevard extension. Construction for the Crenshaw Boulevard extension was begun in the 1950s but was never completed. The western boundary of PBLC is an approximate north-south line located a small distance west of Peppertree Drive in a residential neighborhood. The western boundary terminates south of Palos Verdes Drive South (PVDS) and west of Portuguese Point. Ehlig (1992) describes PBLC as being divided into two parts. The main part is described as moving towards Portuguese Bend (Figure 2). The western segment is described as moving into Sacred Cove between Inspiration Point and Portuguese Point. The main landslide has an area of about 190 acres and the western segment has an area of about 70 acres. Later, as reported by Douglas (2013), the PBLC was further divided into several subslides: (1) inland, (2) eastern, (3) central, (4) seaward, and (5) western subslides (Figure 3). Douglas (2013) reports that the PBLC (along with the Abalone Cove landslide to the west of PBLC) is a reactivated part of an approximate 2-square mile ancient landslide mass termed the Altamira Landslide Complex on the overall south flank of the Palos Verdes Peninsula. Douglas (2013) states that the landslide mass is a composite of numerous slides ranging from small slumps to large translational block slides that have occurred over the last approximately 800,000 years. Contrary to this view, Ehlig (1992) states that the slide originated about 120,000 years before present and was a megaslide that started moving as a unit but fragmented as movement progressed. A guide to landslide terminology, such as earthflow or landslide complex, is included as Appendix A for reference. Regardless of the original movement of the larger landslide mass, in 1955, reactivation of the PBLC was initiated when Los Angeles County was constructing an extension to Crenshaw 3 Daniel B. Stephens & Associates, Inc. Boulevard with the goal of extending the road down the south side of the Palos Verdes Hills to an intersection with PVDS. A relatively small landslide was triggered in 1956 during the road construction, and approximately 160,000 cubic yards of material was removed and placed at the head of the PBLC. MacKintosh and MacKintosh (1957) concluded that the sliding area had a very low factor of safety (FOS) prior to movement in 1955, and that the immediate cause of movement in 1956 and 1957 was the placement of approximately 3 million cubic feet of fill upon which to build the Crenshaw Boulevard extension. Consistent with antecedent instability noted by MacKintosh and MacKintosh (1957), Douglas (2013) reported that evidence of movement in historical aerial photographs had been discovered as early as 1948, and slide damage to the Portuguese Bend Club pier had been noticed as early as 1946. MacKintosh and MacKintosh (1957) observed that the most rapidly moving portion of the slide, on the eastern side of the slide, traveled about 22 feet in the seven months between September 17, 1956 and April 26, 1957. Douglas (2013) reported at the time of Crenshaw Road extension project that houses in the area were using septic waste systems that recycled household water into the subsurface, and that the neighborhoods did not have storm drains. Both of these factors had been contributing to groundwater recharge in the PBLC area by the time the road construction began. Douglas (2013) also stated that Converse Consultants concluded that increased pore water pressure that resulted from elevated groundwater levels was a significant causal factor. Since the reactivation in 1956, the slide has moved at various rates. In general, the area of greatest movement has stayed the same and is focused in the eastern and seaward subslide areas as reported by Douglas (2013) and described above. Figure 4 presents a map of the horizontal displacement that occurred between October 8, 2013 and September 19, 2014. Horizontal displacement of over 8.5 feet per year was measured within the eastern and seaward subslides. Continued land movement in the PBLC area over the last several decades has resulted in significant infrastructure damage to homes, utilities, and roadways. The City of Rancho Palos Verdes has expended nearly 50 million dollars over the years repairing and maintaining the 4 Daniel B. Stephens & Associates, Inc. damage and addressing the overall technical and administrative issues associated with managing such a complex problem. 1.1.2 Regulatory Background Historically, the primary driving force for conducting projects to stabilize the PBLC has not been of regulatory origin. Preservation of infrastructure, preservation of private property, preservation of open lands, preservation of the natural vegetation and recreational attributes of the Palos Verdes Nature Preserve (Preserve), reduction in soil erosion losses, restoring the water clarity in Portuguese Bend Cove, reduction in the cost of operation and maintenance of infrastructure, and health and safety concerns related to maintenance of the integrity of the key road system, the sewer system, and other infrastructure have been the leading drivers that have motivated the City of Rancho Palos Verdes and citizens to strive to achieve stabilization of the PBLC. As a result, there is little in the record that involves regulatory action with respect to the PBLC. Nonetheless, the following is a summary of applicable regulatory based actions taken relative to historical PBLC projects that may influence future work in the PBLC. In September 1987, the Rancho Palos Verdes Redevelopment Agency (RDA) proposed a grading and drainage project as part of a series of projects designed to contribute to the stabilization of the PBLC. The project was examined on a general basis in previous environmental impact reports (EIRs) prepared by the RDA. This particular EIR provided an analysis of environmental impacts associated with grading, drainage, and relocation of PVDS. The final proposed project incorporated alterations that mitigated non-significant short-term negative impacts. The Community Development Commission for the County of Los Angeles also completed a National Environmental Policy Act (NEPA) environmental assessment and the project was found to be in compliance with applicable laws and regulations and did not require an environmental impact statement (EIS). A finding of no significant impact (FONSI) was made stating that the project would not significantly affect the quality of the human environment (City of Rancho Palos Verdes, 1987). 5 Daniel B. Stephens & Associates, Inc. In 1988, a general investigation study by the U.S. Army Corps of Engineers (USACE) was authorized by Public Law 99-662, Section 712 of the Water Resources Development Act of 1986, to study the feasibility of constructing shoreline erosion mitigation measures in order to provide additional stabilization for the PBLC and adjacent landslide areas (USACE, 1998). The authorization read that the Army was “. . . authorized to study the feasibility of constructing shoreline erosion mitigation measures along the Rancho Palos Verdes coastline and in the City of Rolling Hills, California for the purpose of providing additional stabilization for the Portuguese Bend landslide area and adjacent landslide areas.” The study focus was on controlling sedimentation and turbidity in the nearshore and offshore zones that result from erosion at the shoreline, which impacts the marine species and habitat of the area. Additional fish and wildlife enhancement studies were authorized in the Water Resources Development Act of 1990, Section 116 which read “. . . investigative measures to conserve fish and wildlife (as specific in Section 704 of the Water Resources Development Act of 1986), including measures to demonstrate the effectiveness of intertidal marine habitat.” The reconnaissance study was initiated in October 1988 and completed in 1990, with a recommendation to proceed to a feasibility study based on a plan to help stabilize the landslide. However, a decision by the Assistant Secretary of the Army stated in a letter dated October 28, 1991 that “Landslide stabilization is outside the purview of the Army Civil Works program.” The reconnaissance report was revised in 1992 to reflect that decision, and no further study was recommended. In anticipation of another proposed Portuguese Bend Grading Project located within the City of Rancho Palos Verdes Redevelopment Area, an initial study was prepared in September 1994 in accordance with the provisions of the California Environmental Quality Act of 1970 (CEQA) as amended (Public Resources Code Section 21000 et seq.), and the State CEQA Guidelines for Implementation of the California Environmental Quality Act of 1970 as amended (California Code of Regulation Section 15000 et seq.). The project site was comprised of three vacant non-contiguous areas located on the eastern portion of the PBLC. This report of the initial study complied with the rules, regulations, and procedures for implementation of CEQA adopted by the City of Rancho Palos Verdes (the Local CEQA 6 Daniel B. Stephens & Associates, Inc. Guidelines). The project grading activity, specifically cutting and filling within the PBLC, proposed the removal of approximately 50,000 cubic yards of earth material from a cut area approximately 6.25 acres in size located in the southeastern portion of the PBLC. The project also proposed redistribution of the 50,000 cubic yards of earth material to two previously graded/disturbed fill areas. The reported purpose of the proposed project was to reduce driving forces in an active portion of the PBLC by moving earth from a driving force area to a neutral area of driving force (EDAW, 1994). In accordance with Section 15050 and 15367 of the State CEQA Guidelines, the City of Rancho Palos Verdes was designated as the lead agency, defined as the public agency that has the principal responsibility for carrying out or approving a project. The project was funded by the RDA and implemented by the City working for the RDA. After implementation of the initial study, it was concluded that although the proposed project could have a significant effect on the environment, there would not be a significant effect in this case because of mitigation measures that were added to the project. As a result, a mitigated negative declaration was prepared. Mitigations required as a component of the approved project included the following: • Control of construction-generated dust • Cessation of vehicular traffic when the wind speed exceeds 15 miles per hour (mph) • Appropriate NO x emission controls on construction vehicles • Minimization of footprint for construction vehicle routes • Identification of optimum construction vehicle routes to avoid areas of sensitive vegetation • Preparation and review of erosion control plans by the Director of Public Works and a qualified biologist to protect sensitive plant species and minimize disturbance to non- sensitive plant species • Post-construction re-establishment of vegetation 7 Daniel B. Stephens & Associates, Inc. • Prohibition of grading/construction during the mating/breeding/nesting season for the California gnatcatcher and the coastal cactus wren (mid-February through July) • Limitation of construction hours to Monday through Saturday, 7:00 a.m. to 5:00 p.m. (noise control) • Equipment of construction equipment with mufflers (noise control) An extensive biological assessment of the Rancho Palos Verdes development area was attached to the study that was based on a literature review and field surveys of the study area and, in some cases, surrounding areas. It is noteworthy that the study concluded that the proposed project would not impact the quality of existing recreational opportunities and that the project was not located in an area of existing recreational use, or designated for recreational activity. That conclusion may require re-evaluation to consider current uses of the area. Another initial study to evaluate a proposed erosion control project was conducted in 1994 (EDAW, 1994). The proposed project consisted of the placement of three drainage inlets and a 48-inch corrugated metal pipe (CMP) at the bottom of Portuguese Canyon, from PVDS to a point in the canyon approximately 1,600 feet north of PVDS. Approximately 350 linear feet of 1211 CMP was to be placed on the surface and staked down at each joint or at intervals not to exceed 15 feet. The proposed project also involved minor grading and brush removal at the bottom of the canyon, as necessary for installation of the drainage pipe and inlets. A finding was issued that, although the proposed project could have a significant effect on the environment, there would not be a significant effect because the mitigation measures described on an attached sheet have been added to the project. Preparation of a negative declaration was recommended (EDAW, 1994). Subsequent to the Secretary of the Army declining to participate in a landslide study, Congress added funds for a feasibility study to develop a shore protection project that would provide for restoration of the natural marine habitat at Rancho Palos Verdes. An agreement between the City of Rancho Palos Verdes and the USACE to perform the study was signed in December 8 Daniel B. Stephens & Associates, Inc. 1994. The alternative selected as the proposed recommended plan in the feasibility study was to construct a dike 400 feet offshore with natural removal of sediment deposits in the restoration area by wave action. 1.1.3 Recent Community Involvement The Landslide Subcommittee of the Rancho Palos Verdes City Council organized and held a series of public meetings on June 1, June 20, June 29, and July 6, 2017. The purpose of the meetings was to invite the community to participate in creating and identifying goals for the PBLC and to discuss the path forward in addressing the challenges faced by the community with respect to the PBLC. At the first public meeting, held on June 1, 2017, goals were identified that included the following: • Control of the PBLC and attendant costs • Stabilize residences • Retain use of PVDS • Protect the integrity of the Preserve and preserve the marine ecology • Restore the ecology of the ocean and land resources • Explore the possible of a geological hazard abatement district (GHAD) • Identify plausible potential solutions • Provide the basis of a design-build proposal to solicit federal funding The June 20, 2017 public meeting focused on potential solutions and/or actions for intercepting water on the PBLC. The meeting discussions were wide-ranging, and emphasized (1) the need to fully understand the hydrology of the watershed in which the PBLC is located, (2) the need to re-establish and maintain an effective stormwater control system, (3) the importance of capturing and controlling water before it gets into the PBLC, and (4) to minimize impacts to Preserve land. 9 Daniel B. Stephens & Associates, Inc. The June 29, 2017 public meeting addressed the effects of the PBLC on the surf zone. Consensus of the participating public focused on (1) hiring competent engineers to implement recommendations, (2) early communication with relevant regulatory agencies (e.g., Coastal Commission) regarding any planned PBLC projects, (3) use of road maintenance funds to underwrite the necessary technical work needed to slow the PBLC movement, and (4) assessment of the environmental impacts to the Preserve land and ocean ecology plus restoration of potentially damaged habitat to its original condition. The July 6, 2017 meeting focused on major actions that could be considered as a means of addressing the PBLC problem. As with a previous meeting, the public consensus focused on understanding the hydrology of the PBLC, understanding the occurrence of groundwater as it relates to the movement of the PBLC, and understanding and completing previous work on surface drainage. On October 17, 2017, a meeting was held between representatives of the City, DBS&A, the PVPLC, and the PVPLCWildlife Agencies to discuss potential impacts of PBLC solutions within the context of the City’s draft Natural Community Conservation Plan and /Habitat Conservation Plan (NCCP/HCP) (URS, Undated). The purpose of the meeting was to discuss potential impacts of PBLC solutions within the context of the NCCP/HCP.). The City’s goal for the meeting was to develop a programmatic policy that ensuredensuring that, while the probability for successfully resolving the PBLC problem was maximized, all appropriate measures were being considered to minimize potential impacts to biological resources within the Preserve. 1.2 Project Area Definition This FS focuses on significantly reducing land movement in the defined Red Zone area (project area) of the PBLC, where land movement has consistently been measured at the greatest rates. As shown in Figure 2, in addition to PBLC, landslides in the southern Palos Verdes Peninsula include the Abalone Cove, Portuguese Bend, Flying Triangle, Klondike Canyon, and most of the Ancient Altamira Landslide. All of these landslides are located within the City of Rancho Palos Verdes except for the majority of the Flying Triangle Landslide, which is in Rolling Hills. 10 Daniel B. Stephens & Associates, Inc. As described by Douglas (2013), two of the landslides, Portuguese Bend and Abalone Cove, are reactivated parts of a much larger and older slide mass that covers over 2 square miles and extends from the crest of the peninsula, near Crest Road, to the shoreline. Douglas (2013) named this ancient landslide mass the “Ancient Altamira Landslide Complex.” Douglas (2013) reported that the Abalone landslide and surrounding area, including portions of the ancient landslide complex, has been largely stabilized through the use of groundwater dewatering using vertical wells. The Klondike and Flying Triangle Landslides are closely related in space and time to the PBLC and Abalone Landslides, and are also part of the Ancient Altamira Landslide Complex, but they are commonly considered separate failures (Douglas, 2013). The PBLC project area within which land movement is being addressed by this FS is the area of greatest movement within the PBLC. As shown in Figure 4, the area in which measured horizontal movement has ranged from 1 foot, 10 inches to 8 feet, 7 inches is the area of greatest PBLC movement (the Red Zone). As mapped, the Red Zone is approximately 86 acres in area. This Red Zone area comprises what Douglas (2013) delineated as the eastern, central, and seaward landslide subareas of the PBLC, along with a small portion of the western PBLC landslide subarea, south of PVDS to the ocean. The total PBLC area is approximately 250 acres (101 hectares) in area. However, the area of land on which conditions that contribute to landslide instability exist is much greater. Numerous hydrologic, geologic, and engineering reports of the PBLC have concluded that controlling the water that enters into and is stored in the PBLC subsurface is critical to achieving landslide stabilization. Therefore, this FS considers that the selected landslide stabilization solution will be implemented over an area larger than the PBLC or the Red Zone itself. Water can move into the PBLC subsurface, where it contributes to instability, via three pathways. The first pathway is via rainfall and stormwater that runs off and subsequently infiltrates and percolates into the subsurface. Water is also introduced into the subsurface through residential use and disposal via onsite wastewater treatment systems (e.g., septic systems), a second pathway. The third pathway is via groundwater underflow. Groundwater underflow occurs 11 Daniel B. Stephens & Associates, Inc. when groundwater that has percolated to the water table in one location migrates laterally to another location. In the PBLC location, previous contouring of groundwater levels indicates that groundwater is moving in the subsurface from upslope areas to the north of PBLC toward the south. As a result, the larger area that is being considered when targeting a PBLC landslide stabilization solution is the watershed. A watershed is defined as the area of land bounded peripherally by a divide and draining ultimately to a particular watercourse or body of water. For example, in Portuguese Canyon, the watershed is defined as the land area from which all water that drains will ultimately drain into Portuguese Canyon. Based on review of topographic and drainage maps along with the use of field observations and aerial photographs, subsurface water in the PBLC is being impacted by water from Portuguese, Ishibashi, and Paintbrush Canyons. Figure 5 depicts the combined watershed boundary of the three canyons. 1.3 Purpose and Overview This FS report has been prepared consistent with methodologies that have been developed pursuant to CERCLA, also known as Superfund. Specifically, this FS was prepared using methodologies presented in the Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA (U.S. EPA, 1988). The CERCLA FS process is typically used to abate the risk of exposure to toxic environmental contaminants. In this project, toxic contamination is not an issue, and the criterion related to reduction of contaminant toxicity is removed from consideration. The resulting FS process represents a systematic methodology established for characterizing the nature and extent of complex problems, evaluating potential remedial options, and selecting the optimum remedial solution. options for the City’s consideration. The overall goal of the FS process is to gather sufficient information to make an informed management decision regarding potential remedial actions, and to develop a comprehensive, reliable, restoration strategy that satisfies community and regulatory requirements. The specific purpose of this FS is to identify and select aviable conceptual solution options that will accomplish the following project goals: 12 Daniel B. Stephens & Associates, Inc. • Provide the geotechnical conditions that significantly reduce the risk of damage to public and private property and would allow for the significant improvement of roadway infrastructure, safety, and stability. • Significantly reduce human health risk and improve safety in the City of Rancho Palos Verdes. • Significantly reduce sediment dispersal and deposition into the Pacific Ocean that is causing unacceptable turbidity in the coastal and marine environment. • Make all reasonable efforts to identify aSelect remedy options that will be consistent with the Natural Communities Conservation Plan (NCCP) and the Habitat Conservation Plan (/HCP, specifically Section 4.1.2).. 1.4 Document Organization This FS document generally follows the methodology and organizational format of the CERCLA feasibility study process (U.S. EPA, 1988). Section 1 presents an introduction that includes project background, history, project purpose, projection area definition, and a description of community involvement with the project. Section 2 provides a summary of the relevant previous work related to the PBLC and vicinity that forms a foundation for moving forward toward remedy selection and implementation options. Section 3 present a description of the physical characteristics of the project area including topography, watershed hydrology, soils, geology, groundwater, and landslide characteristics. Taken together, Sections 1 through 3 represent a characterization of the current information and data available to use in defining the PBLC setting and problem. Using the information and data presented in Sections 1 through 3 as the basis, Section 4 presents the remedial FS section of the report. Sections 4.1 and 4.2 present the introduction and purpose of the FS and the summary of infrastructure concerns related to the PBLC, respectively. Section 4.3 presents the applicable or relevant and appropriate requirements (ARARs) potentially governing remedy implementation. Section 4.4 establishes the remedial action objectives (RAOs). Section 4.5 establishes general response actions (broad classes of 13 Daniel B. Stephens & Associates, Inc. available technologies) to control movement of the PBLC. Section 4.6 identifies and screens the identified technologies appropriate to achieve the RAOs. Section 4.7 provides a more detailed discussion and analysis, presenting the pros and cons, of the technologies most suitable to achieve RAOs. Finally, the preferred alternative(s) is selected and options are identified in Section 4.8 as the most appropriate technology and methodology to address RAOs. An analysis of remaining data gaps, the need for pilot testing, and an estimate of the cost of implementation of the selected remedy are also presented. 14 Daniel B. Stephens & Associates, Inc. 2. Summary of Previous Work As noted by Douglas (2013), numerous geologic, hydrogeologic, environmental, and engineering studies have been completed and numerous reports have been produced by several authors over the years since the PBLC was first recognized. Not all of the documents have been digitally archived and some information has likely been permanently lost over the years. However, some key documents are available that describe past efforts and designs for land stabilization that are useful to review and form a foundation for moving forward toward a solution. These documents, supplemental to those described in Section 1.1.2, are summarized below. 2.1 Historical Documents, 1957-1997 In 1957, a report was written that described the ground movement of an approximately 200-acre area of land extending from above a major body of fill on Crenshaw Boulevard southward to the Pacific Ocean (MacKintosh, 1957). The report recommended that immediate emergency action be undertaken “. . . to protect the large investment in homes, streets, sewers, communication lines, and other utilities and improvements.” As of 1989, over 140 homes have been destroyed. Of the residents that remain, home utilities and foundation structures must be maintained continuously. It was also reported that over 10 million tons of mud and rock were deposited in the ocean. Disruption of vital community transportation and utility transmission lines is continuously threatened and millions of dollars have been spent to maintain community safety and services. Between March and August 1957, the County of Los Angeles and Palos Verdes Properties installed a group of 22 reinforced concrete caisson “shear pins” across the active failure surface in an effort to stabilize the PBLC. Each of these caissons was 4 feet in diameter, 20 feet in length, and embedded 10 feet into the material underlying the “failure surface” as it was understood at that time. The landslide reportedly slowed by approximately 65 percent (from 0.8 to 0.25 inch per day) following the installation of these shear pins. This reduced rate of movement was only maintained for approximately five months. In early 1958, the landslide abruptly returned to its pre-shear pin displacement rate of nearly 0.8 inch per day. Several 15 Daniel B. Stephens & Associates, Inc. intact shear pins have since been displaced to, and deposited on, the shoreline by subsequent landslide movement and wave action (Ehlig and Yen, 1997). From the late 1950s through the mid-1980s a series of geologic and engineering studies were conducted to understand and characterize various aspects of the PBLC and related landslide complexes in the vicinity. In 1972, Palos Verdes Properties provided financial support for a dissertation that analyzed the reasons for the movement of the PBLC (Vonder Linden, 1972). The report stated that “If movement were halted by eliminating infiltration of water, lowering the existing water table, and regrading parts of the slide surface, the factor of safety thereby would be raised to a value of at least unity.” The City of Rancho Palos Verdes was incorporated in 1973, and at that time the City took over the maintenance of roads and utilities in the PBLC area within the City limits. It was reported that approximately 20 percent of the City budget for street maintenance was spent for the 0.8± mile of PVDS through the landslide (Ehlig and Yen, 1997). In September 1978, the Rancho Palos Verdes City Council adopted Urgency Ordinance No. 108U, which established the Landslide Moratorium Area in and around the PBLC. In February 1981, the City Council adopted Ordinance No. 139U, which added the area known as Klondike Canyon to the Landslide Moratorium Area. In 1984, the City put a landslide stabilization plan of control (POC) into operation. In 1984, it was reported that the PBLC was moving over 40 feet per year. The stabilization plan consisted of installation of dewatering wells, major surface drainage, and regrading redistribution of earthen mass. This initial effort has since been called Phase I (Ehlig and Yen, 1997). It was reported that 5 years after initiation of the POC, the PBLC was moving less than 1 foot per year. The RDA proposed a grading and drainage project in September 1987, as Phase II of the POC intended to stabilize the PBLC (Ehlig and Yen, 1997). The grading portion performed in January and March 1988 involved redistribution of 500,000 cubic yards of earth from areas 16 Daniel B. Stephens & Associates, Inc. where the slide plane was steep to areas where the slide plane was relatively level so that the weight of the landslide material acted as a resisting force rather than a driving force. Generally speaking, the rate of slide movement responded positively to dewatering, regrading, and surface drainage improvements in Phase I and II, but these were not ultimately able to stop the slow movement. In fact, the rate of movement increased in subsequent years as earlier work deteriorated. Following a period of severe wave erosion and shoreline regression in early 1988, rock-filled wire baskets (gabions) were installed along the western shoreline of the landslide in 1988 in an attempt to reduce the rate of wave erosion. Although this temporarily abated the erosion, the gabions were essentially destroyed within an 18- to 24-month period by the combination of wave action, corrosion of the wire baskets, and landslide deformation (Ehlig and Yen, 1997). In January 1989, the USACE held a public information workshop to present to the community a study it was beginning in order to identify the federal interest in solutions to problems associated with shoreline erosion mitigation measures and storm damage along the coast of Rancho Palos Verdes, including consideration of how such a solution would contribute to landslide stabilization. In June 1993, the Assistant City Manager of Rancho Palos Verdes wrote a memorandum describing an upcoming workshop on the RDA’s interaction with the USACE on a feasibility study for shoreline protection and marine environmental restoration. The discussions centered on the need for shoreline protection, not landslide abatement. Grading (Phase Ill) grading was completed during August and September 1990. This phase of grading involved the relocation of approximately 60,000 cubic yards of soil from the central uphill margin of the landslide to the eastern portion of the failure immediately upslope of PVDS. Following this unloading, perceptible movement of the Landward Zone appears to have stopped until the heavy rainfall of January 1995. Between the completion of the 1990 Phase III grading and 1995, the rate of landslide movement gradually increased to approximately 0.25 inch per day (Ehlig and Yen, 1997). In 1991, Rancho Palos Verdes staff gave a presentation to the City Council on the progress of the stabilization plan. The progress reported included the performance of extensive geologic 17 Daniel B. Stephens & Associates, Inc. investigations using the services of 25 experts in the fields of geology and engineering. In addition, $1.5 million had been spent to implement grading, dewatering wells had been installed, and drainage structures had been constructed to control and convey water through the PBLC. In September 1994, a consultant proposed a grading project to the City of Rancho Palos Verdes in which several areas of the PBLC slide area were identified as “cut” zones where 50,000 cubic yards was to be removed, and other areas of lower elevation were identified as “fill” zones. As with the earlier proposed grading project of 1987, the purpose was to reduce driving forces in an active portion of the PBLC by moving earth from a driving force area to a neutral area of driving force. In 1997, the City of Rancho Palos Verdes and the USACE commissioned a study to determine the impact of the PBLC on the ocean environment (Abbott Associates, 1997) that concluded that 3,589,000 cubic yards of earth had entered into the ocean as a result of landsliding. 2.2 1997 Ehlig and Yen Feasibility Study A preliminary geologic and geotechnical engineering report was jointly prepared by Perry Ehlig (Ehlig) and Bing Yen & Associates, Inc. (BYA) which was presented to the City Council of Rancho Palos Verdes in 1997. The report evaluated the feasibility of a POC developed in 1995 by Ehlig and BYA and amended it for the 1997 report. The POC was intended to minimize or arrest the movement of the more rapidly moving portion (East-Central Subslide) of the PBLC and if successful, would provide valuable insight on the feasibility of stabilizing the western portion of the PBLC. The scope of work of the study incorporated compilation and evaluation of the historical surface and subsurface data to determine where additional exploration was needed to develop a preliminary geotechnical model for analysis. The study also consisted of installation of 13 additional monitoring wells to characterize groundwater, drilling of 18 large-diameter, 8 rotary-wash, and 4 rotary-core boreholes for subsurface mapping of the slide plane(s), and collection of slide plane samples for additional laboratory testing. Back calculation of the slide behavior was performed on the slide model to calibrate the soil parameters and confirm the 18 Daniel B. Stephens & Associates, Inc. validity of the model. Assessment of the proposed POC in mitigating the slide movement was done using the model to identify primary and supplemental mitigation techniques and their effectiveness. Based on the results of the POC assessment, conclusions and recommendations were presented in a formal report. Based on movement patterns, geologic, and/or geomorphic features, the PBLC was subdivided into subslides. The subslides were classified on increasing displacement rates which include, from the lowest to greatest rate of movement, the Landward, the West-Central, the East- Central, and the Seaward subslides. The study estimates that for the period from 1956 to 1996, rates of displacement range of the subslides range from 0.2 to more than 1.5 inches per day, and that the higher rates are associated with periods of above-average rainfall. The Ehlig/BYA POC recommended removal of approximately 450,000 cubic yards of slide plane clay from the upper portions of the Landward and East-Central subslides of the PBLC. This plan requires the excavation and removal of approximately 2.65 million cubic yards of landslide materials. They estimate that roughly 100,000 cubic yards of the landslide materials would consist of bentonitic (slide plane) clay, which could be used as a blanket fill to retard surface water infiltration. The remainder of the removed materials would be exported off-site and replaced with compacted fill. The POC also included installation of subdrain systems in the removal areas, construction of impervious drainage channels in selected canyons, installation of dewatering wells, and re- establishment of surface drainage within the developed portion of Portuguese Canyon. The study evaluated three scenarios where no reduction in groundwater levels occurred, lowering of the groundwater level of 25 feet, and lowering of groundwater level of up to 35 feet south of the regraded area. The increase in the factor of safety was estimated to range from 7 percent to 16 percent. After discussing the benefits of dewatering and its positive effect on increasing the factor of safety, the report stated: 19 Daniel B. Stephens & Associates, Inc. However, engineering analysis also revealed that the Seaward subslide, exacerbated by its steep and dilated bluff and erosion at its toe, will have a lower factor of safety than the regraded northeast PBL. Hence, the Seaward subslide may move first and, consequently, pose the risk that the EastCentral subslide may lose its lateral support towards the ocean. Engineering analysis shows further that the reduction of lateral support will reduce the factor of safety of the East- Central subslide to 1.04. This means that, while it appears to be theoretically feasible that the proposed POC [plan of control] can improve the current state of stability in eastern PBL, the margin of safety for the East-Central subslide (at a factor of safety of 1.04) is too small and the East-Central subslide will have an intermittent slow movement and periodic acceleration following heavy precipitation. Thus, the authors indicate their opinion that the avoidance of the addition of water to the subsurface in this area is critical. However, the authors stated that even in the best case, the proposed POC would only be capable of improving the stability marginally and that the landslide may still creep intermittently and be susceptible to reactivation. Conditions cited which could contribute to reactivation of the landslide included shoreline erosion, successive years of above average rainfall, lapses in the de-watering or surface drainage maintenance programs, and continued movement of the Seaward and/or West-Central subslides. Thus the authors evaluated supplemental stabilization measures that included (1) slide plane clay strength enhancement, (2) the construction of a revetment along the shore line, and (3) a more extensive dewatering program. The evaluation indicated that the tests conducted for this report regarding slide plane clay strength enhancement via lime injection were promising but not extensive, nor was the method of field implementation proven. A pilot test was recommended. The construction of a revetment along the shore line was assumed to be implemented in combination with strength reduction due to slow movement. In this scenario, the revetment was deemed a successful approach, but it was recognized that any construction in the vicinity of the existing shoreline would require permits from federal and state regulating agencies, and that obtaining these permits might be a long and costly process with uncertain outcome. Regarding supplemental dewatering, the authors stated that the benefits of lowering the groundwater elevation would be theoretically significant, particularly in the eastern portion of the landslide. However, to lower the water table an average of more than 20 feet may not be feasible because of the high cost associated with 20 Daniel B. Stephens & Associates, Inc. lowering groundwater within the low permeability material. At the time, the authors believed that one could not practically expect to lower the water table an additional 20 feet below the October 1996 level across the PBLC as a whole (Ehlig and Yen, 1997). Ehlig and Yen (1997) also reported on a global positioning system (GPS) satellite survey network that the City of Rancho Palos Verdes established that showed that the eastern portion of the slide moving about twice as fast as the western portion. The report stated that the rate accelerates when groundwater rises and/or when the landward (northern) portion of the slide exerts additional driving forces due to local slope failures or debris accumulations. Erosion of the toe of the slide along the shore exacerbates the instability of the seaward portion of the slide. 2.3 2000 Leighton Feasibility Study In a report prepared for the Palos Verdes Portuguese Bend Company, Leighton and Associates (Leighton) (2000) reviewed the 1997 POC (Ehlig and Yen, 1997) and recommended revisions. The report was prepared for the proposed construction of an 18-hole golf course and related facilities. The report presented a revised POC termed the Palos Verdes Portuguese Bend (PVPB) POC. The PVPB POC included all but the lime injection aspects of the 1997 POC, supplemented with a more extensive removal and capping of the landslide area, and extensive shear keys, as well as additional subdrains, monitoring wells, and dewatering wells. Grading for the property, including Peacock Hill and the active PBLC, was presented in a proposed grading plan. The PVPB POC was planned in phases, sequenced to limit the probability of major accelerations in the rate of landslide movement. The scope of work for the study included determination of the subsurface geologic structure, the ancient and active rupture surfaces, the gross stability of the site, and a groundwater analysis. The work performed included review of past geological, geotechnical, and hydrogeological reports and maps, aerial photograph analysis, and geologic mapping of the field area. Analyses of GPS survey and monitoring well data were also completed for the study. Subsurface exploration included drilling of 9 large-diameter and 11 continuous-core borings with downhole wireline geophysical logging, in addition to logging of 3 exploratory trenches. All of the core 21 Daniel B. Stephens & Associates, Inc. borings were converted to monitoring wells, and 4 additional monitoring wells were constructed with nests of piezometers. Laboratory testing of slide plane materials was conducted to establish chemical and physical properties for utilization in the slope stability analyses. Slope stability analysis was performed of the present stability and to determine the impacts of the proposed development, and the implementation of the proposed POC was also included. Other remedial measures proposed by Leighton include construction of two additional large shear keys to support buttresses of recompacted fill with subdrainage. The largest of the shear keys was proposed to be constructed near the toe of the PBLC and a toe protection system consisting of a riprap revetment was also recommended. An elaborate system of subdrainage of horizontal wells would intercept subsurface flow below Paintbrush and Ishibashi Canyons and direct flow to the ocean. Also, permeable drainage membranes, remedial grading, and construction of a drainage culvert would reduce surface water infiltration and facilitate gravity flow for the subdrainage system. Other remedial measures include more extensive capping of the landslide area, a short sheet pile wall at the western Klondike Canyon landslide boundary adjacent to the Beach Club, and construction of a dewatering pit to permit the development of a system of hydroaugers. The slope analysis conducted by Leighton estimates that the factor of safety for the most active portions of the PBLC would increase by approximately 50 percent. The factor of safety for the less active portions would increase by approximately 20 percent. They also conclude that the slide movement of the active portions of the PBLC located east of Inspiration Point would be arrested. 22 Daniel B. Stephens & Associates, Inc. 3. Physical Characteristics of the PBLC Vicinity This section provides information describing PBLC area topography, hydrology, soils, geology, and hydrogeology, as well as landslide characteristics. 3.1 Topography The regional topography of the ancient Altamira Landslide Complex is mapped in the U.S. Geological Survey (USGS) Redondo Beach, Torrance, and San Pedro quadrangles (USGS, 1963 and 1964). More recently, the Los Angeles Region Imagery Acquisition Consortium (LAR- IAC) developed a digital terrain model (DTM) using LiDAR and generated 2-foot and 5-foot digital contour elevation for Los Angeles urban project areas and Catalina Island, which includes the City of Rancho Palos Verdes (circa 2015) (Figure 6). The PBLC is located in the southeast portion of the larger and older Altamira Landslide Complex, is completely mapped within the San Pedro, California quadrangle (USGS, 1964), and is part of the LAR-IAC DTM. The Altamira landslide covers over 2 square miles extending from the crest of Palos Verdes peninsula near Crest Road at elevations of approximately 1,200 feet above mean sea level (feet msl) to the shoreline (Douglas 2013, Vonder Linden 1972). The perimeter of the Altamira Landslide Complex is generally bounded by an unnamed canyon adjacent to Barkentine Canyon to the west and the Klondike Canyon to the east and has the overall shape of a rotational landslide. The Altamira Landslide Complex is characterized by rolling hills with numerous gullies and canyons oriented generally perpendicular to the shoreline. Landward, the head of the ancient landslide is the prominent Valley View Graben, which sharply declines in elevation by 145 feet into a relatively flat surface of approximately 400 feet in width. The extension zone of the Altamira Landslide covers over 50 percent of the area and has a stepwise series of scarps and platforms with the major scarp dropping from 1,200 feet msl to the first head at 900 feet msl. The head scarp of the landslide contains some of the steepest slopes, with between 150 percent and 280 percent gradient. The last “platforms” are at approximately 500 feet msl, where there begins a relatively flat surface in the central portion of 23 Daniel B. Stephens & Associates, Inc. the ancient landslide, south of Narcissa Drive, that extends to the head of the Abalone Cove Landslide. The area of relatively flat terrain covers half a square mile in the central portion of the Altamira Landslide Complex. This area is characterized by rolling hills with slope gradients generally less than 60 percent. The Altamira Canyon cuts through this relatively gentle sloping surface with elevations falling from 400 feet msl to approximately 250 feet msl over a distance of 100 feet. The Altamira Canyon is the longest canyon (8,800 feet) that extends from the crest of the slide to the shoreline, just west of Inspiration Point. Throughout the Altamira landslide there are a series of canyons that run parallel to each other and range between 800 to 8,800 feet in length. From west to east these arethere is the unnamed canyon that bounds the landslide, as well as Vanderlip, Altamira, Kelvin, Portuguese, Ishibashi, Paint Brush, and Klondike Canyons, with slope gradients that range between 100 percent and 280 percent. Abalone Cove Landslide and the PBLC are generally within the compression zone or toe of Altamira Canyon and are characterized by a hummocky topography with rounded hills and some smooth valleys with a maximum elevation of 500 feet msl. On average, there is about 7 degrees dip in topography from the crest to the shoreline (Ehlig and Yen, 1997; Mackintosh, 1957). The crest of the PBLC is approximately 500 feet msl and the toe of the slide extends to the shoreline. In this compression zone, PVDS runs generally east to west, parallel to the shoreline. The elevation of PVDS ranges from approximately 160 to 220 feet msl and is about 800 feet from the shoreline. Pronounced sea cliffs and narrow beaches are present at the shoreline. The most noticeable features along the shoreline include two promontories that are present in the Western and western Seaward subslide areas of the PBLC (Figure 3), the westerly Inspiration Point and the easterly Portuguese Point with elevations up to 135 feet msl. 24 Daniel B. Stephens & Associates, Inc. 3.2 Watershed Hydrology A watershed is defined as a region or area bound peripherally by a divide and draining ultimately to a particular watercourse or body of water. In this case, the bodies of water of interest are the canyons that convey surface water, to one degree or another, through the area of the PBLC. It is also of interest to characterize the areas from which stormwater drains thatand ultimately runs off into the PBLC canyons. Water from those areas ultimately flows into the PBLC canyons and, in turn, into the PBLC. The PBLC receives water (both surface water and groundwater) from the watersheds of Portuguese Canyon, Ishibashi Canyon, and Paintbrush Canyon. These canyons are generally ephemeral, meaning that surface water does not flow through them throughout the year. Rather, these canyons generally have flowing water when and after it rains and they convey stormwater from the high ground in the watershed toward the Pacific Ocean. Collectively, they are referred to herein as the PBLC Canyons. Klondike Canyon is considered herein separate from the PBLC but, as described below, water from Klondike Canyon likely flows as underflow across the watershed divide at the lower southwest end of the Klondike Canyon watershed. Klondike Canyon is also an exception in that perennial water is observed flowing in the lower reaches of Klondike Canyon. The PBLC Canyons are shown in Figure 5 with their collective watershed boundaries. The PBLC Canyons are located in what is identified as the “Ocean South South” (sic) drainage area in the Master Plan of Drainage (MPD) (RBF Consulting, 2015), a part of the Santa Monica Bay Watershed defined by the County of Los Angeles Department of Public Works. The PBLC Canyons are directly tributary to the Pacific Ocean. The PBLC Canyons have storm drain systems located in their upper reaches that discharge into the canyons that, in turn, drain ultimately into the ocean. The area of the Portuguese Bend watershed that drains into the PBLC Canyons is approximately 627 acres. Over significant reaches of these canyons, notably the portions which direct water to and through the PBLC, the drainage systems consist mostly of canyon bottoms that are unimproved open channels. The surface of the ground within much of the PBLC is generally hummocky, 25 Daniel B. Stephens & Associates, Inc. irregular, and locally fissured due to the landslide activity. Previous drainage structures constructed to control and convey stormwater runoff have failed. The MPD (RBF Consulting, 2015) found that the CMP structures were undersized for the calculated flow they would receive. As a result, surface drainage within the landslide is generally poor and difficult to maintain. Infiltration of the runoff conveyed through these canyons is a source of recharge for the groundwater within the landslide (Ehlig and Yen, 1997). As described in the MPD (RBF Consulting, 2015), Ocean South South has three major canyons: Altamira Canyon, Portuguese Bend Canyon, and Paint Brush Canyon. While a part of the delineated Ocean South South drainage area, surface water from Altamira Canyon does not drain directly into PBLC like the other adjacent canyons and will not be discussed further herein. Groundwater that originates from Altamira Canyon infiltration may, however, flow into the PBLC area. Portuguese Canyon is located on the westerly side of the PBLC and generally forms the boundary of two subslides termed by Ehlig and Yen (1997) as the West -Central and East- Central slides. This boundary, and Portuguese Canyon, is defined by a near vertical fault that extends in a north-south direction along the general alignment of Portuguese Canyon (Ehlig and Yen, 1997). The upper reaches of Portuguese Canyon are steep and convey stormwater quickly to the lower reaches where water moves more slowly in the low gradient terrain. Smaller in size, Ishibashi Canyon, located east of Portuguese Canyon, drains into Paint Brush Canyon which, in turn, drains into an undeveloped mountain-front alluvial fan area of the PBLC. Paint Brush Canyon includes two debris basins in series upstream of the confluence of Ishibashi and Paint Brush Canyons before discharging to the upper end of the PBLC, where evidence in the field indicates that stormwater readily infiltrates. Klondike Canyon is located east of Paintbrush Canyon and the PBLC. The area of the Klondike Canyon W atershed is 680 acres and a smaller portion of that area drains into Klondike Canyon itself. The southwest margin of the Klondike Canyon Watershed, where Klondike Canyon stormwater empties into the Pacific Ocean, is within the mapped boundary of the PBLC. Though it appears likely, based on its location relative to the PBLC boundary and the generally low-lying surface terrain, it is unknown whether groundwater is moving from the lower Klondike Canyon Watershed into the PBLC Watershed. This is a complicated area where the Klondike 26 Daniel B. Stephens & Associates, Inc. Canyon Watershed abuts the PBLC Watershed and the Klondike Canyon Landslide abuts the PBLC in an area of maximum PBLC movement. As mentioned above, there are several swales and storm drains that drain the upper reaches of the watershed into the PBLC Canyons and Klondike Canyon where the water is then conveyed to the Pacific Ocean (Figure 7). The upper watershed areas contributing to water flow into the PBLC and Klondike Canyon landslides are located within the City of Rolling Hills. This may represent legal and/or jurisdictional access challenges with respect to the implementation of landslide abatement solutions that involve stormwater control and conveyance. Of the combined approximately 1,300-acre area of the PBLC and Klondike watersheds, approximately 360 acres (28 percent) lies within Rolling Hills. The balance of the watershed areas (940 acres, or 72 percent) lies within the City of Rancho Palos Verdes. There are currently no known stream gage data based on monitoring of either dry weather or storm water flow in the canyons that convey water into the PBLC and the Klondike Canyon Landslide. These canyons have a bottom generally 10 to 20 feet wide and fall 15 to 20 feet in a 100-foot run. A hydrologic study for this area is not within the scope of this study. Based on information in the MPD, it is estimated that the 100-year storm runoff for each of the above canyons would be approximately 200 cubic feet per second (cfs). This is not a rigorously derived design value, but rather an estimate to provide a basis to establish the rough sizing and feasibility of improvements being considered as part of a conceptual landslide stabilization solution. 3.3 Soils The U.S. Department of Agriculture (USDA) SSURGO database (USDA, 2015) was used to access information about the surficial soils at the PBLC (Appendix AB). The SSURGO database contains information about soil as collected by the Natural Resources Conservation Service (NRCS) over the course of a century. The information is typically displayed in tables or as maps and is available for most areas in the U.S. The information was gathered by walking over the land and observing the soil. In many cases, soil samples were analyzed in laboratories. The maps outline areas called map units. The map units describe soils and other 27 Daniel B. Stephens & Associates, Inc. components that have unique properties, interpretations, and productivity. The information was collected at scales ranging from 1:12,000 to 1:63,360. More details were gathered at a scale of 1:12,000 than at a scale of 1:63,360. The mapping is intended for natural resource planning and management by landowners, townships, and counties. The soil survey information came from the Soil Survey of Los Angeles County, California, Southeastern Part (CA 696), mapped at a scale of 1:24000, using aerial images dated May 25, 2010 to November 24, 2014. The predominant soil unit symbol in the PBLC is 1168 with a mapping unit name of Haploxerepts, 10 to 35 percent slopes. Rather than a typical association of soil series, the name Haploxerepts refers to the soil taxonomic classification of surficial soils that predominantly occur in the PBLC. Haploxerept soils typically occur at an elevation of 0 to 1,210 feet msl in an annual precipitation zone that typically ranges from 13 to 17 inches. Mean annual temperature typically ranges from 62 to 63 degrees Fahrenheit (°F). In this mapping unit, Haploxerept soils make up about 90 percent of the landscape, with the minor component of 10 percent composed of the Lunada soil that typically occurs on hillslopes. Haploxerepts generally occur on landslides in mixed slide deposits derived mostly from calcareous shale. The typical soil profile of a Haploxerept is as follows: 0 to 7 inches, loam; 7 to 20 inches loam with the incipient development of soil structure; 37 to 79 inches, channery loam. A channery soil is a soil that is, by volume, more than 15 percent thin, flat fragments of sandstone, shale, slate, limestone, or schist as much as 6 inches along the longest axis. A loam is soil composed mostly of sand (particle size > 63 micrometers [µm]), silt (particle size > 2 µm), and a smaller amount of clay (particle size < 2 µm). By weight, its mineral composition is about 40/40/20 percent concentration of sand/silt/clay, respectively. These proportions can vary to a degree, however, and result in different types of loam soils: sandy loam, silty loam, clay loam, sandy clay loam, silty clay loam, and loam, depending on which particle size predominates. Haploxerepts typically occur on slopes that range from 10 to 35 percent, are well drained (internally), and have moderately high to high capacity to transmit water. Typical saturated 28 Daniel B. Stephens & Associates, Inc. hydraulic conductivities (K sat ) of Haploxerepts range from 0.60 to 2 inches per hour. Depth to first water is typically greater than 80 inches. Soils are also typically classified as lying within a hydrologic soil group that, when considered with land use, management practices, and hydrologic conditions, determine a soil’s associated runoff curve number. Runoff curve numbers are used to estimate direct runoff from rainfall (NRCS, 2007). Soils were originally assigned to hydrologic soil groups based on measured rainfall, runoff, and infiltrometer data. As the initial work was done to establish these groupings, assignment of soils to hydrologic soil groups has been based on the judgment of soil scientists. Assignments are made based on comparison of the characteristics of unclassified soil profiles with profiles of soils already placed into hydrologic soil groups. Most of the groupings are based on the premise that soils found within a climatic region that are similar in depth to a restrictive layer or water table, transmission rate of water, texture, structure, and degree of swelling when saturated, will have similar runoff responses. The Haploxerepts mapped at the PBLC are classified as falling within the characteristic of Hydrologic Group B (NRCS, 2017). Soils in this group have moderately low runoff potential when saturated, and water transmission through the soil is not impeded. Group B soils typically have between 10 percent and 20 percent clay and 50 percent to 90 percent sand and have loamy sand or sandy loam textures (USDA, 2015). Douglas (2013) also characterized PBLC area soils as commonly comprising soils that are “expansive” in character. Douglas states that weathering and erosion of the Altamira bedrock produced a soil that is rich in clay minerals with distinctive properties. These clays have the ability to absorb and expel water so that they can swell (expand) or shrink (contract). When it rains, the clays in the soil absorb water, expand and become sticky. In the summer, they dry out and the clays lose water and contract. In the dry months, the soils in the area develop cracks, sometimes more than an inch across and up to a foot deep. In the rainy months, the cracks disappear as the clays absorb water. In the process of wetting and drying, expansion and contraction, the soils on the slopes respond to gravity and slowly migrate downslope. This is called soil creep. Expansive soils can also be a problem for slabs or foundations or anything that is placed in or on the ground without proper footing. Expansive soil movement is related to 29 Daniel B. Stephens & Associates, Inc. rainfall patterns and can amount to tenths of an inch to inches per year (Douglas, 2013). Douglas (2013) pointed out that in locations where GPS measurements indicate that land displacement is minimal, there is the possibility that the slow movement is due to slope creep from expansive soils. In summary, surficial soils on the PBLC are generally loamy in texture with a proportion of sand, silt, and clay of about 40/40/20 percent. They can take in and percolate water readily. They are relatively deep and have a moderate to high water-holding capacity. They develop deep, wide cracks during the dry summer and provide channels for later infiltration during the rainy season. Once water has infiltrated and is stored in the soil profile, the presence of expansive clays causes the soils to expand (or swell), closing the soil cracks. The cycle of expansion and contraction is a source of soil creep. Without a pathway for surface water to runoff to the Pacific Ocean, the infiltration of runoff water sourced from slopes higher on the PBLC readily occurs and exceeds the storage capacity of surficial soils. The excess water then percolates into underlying formations, beyond the reach of transpiring plants, where it potentially provides a mechanism to facilitate more significant slide movements. 3.4 Geology The PBLC is located on the northwest trending Palos Verdes Peninsula, which is formed on the hanging wall of the southwest-dipping Palos Verdes fault (Douglas, 2013) (Figure 8). The Peninsula is the result of uplift and formation of a doubly plunging anticline. The anticline plays an important role in the presence of the PBLC, which is located on the southern flank of the fold. The head of the landslide coincides with the crest of the anticline and the south limb is gently inclined in the seaward direction. The sedimentary rocks that form the Peninsula include the Mesozoic Catalina Schist, Monterey Formation, marine terrace deposits, alluvium, and landslide deposits. The oldest rocks of the Peninsula consist of Mesozoic Catalina Schist, which forms the core of the anticline (Ehlig, 1992). Middle to Late Miocene marine sediments of the Monterey Formation unconformably overlie the schist, and these sediments were deposited in an ocean basin (Douglas, 2013). Widespread volcanism occurred in the early phase of deposition of the 30 Daniel B. Stephens & Associates, Inc. Monterey Formation, which contributed volcaniclastic sediments to the Monterey Formation (Conrad and Ehlig, 1987). Conrad and Ehlig (1987) subdivided the rocks of the Monterey Formation into three main members, from lower to upper: the Altamira Shale, Valmonte Diatomite, and Malaga Mudstone (Figure 9). In the Pliocene, the ocean basin was subsequently folded into an anticline and uplifted what is now the Peninsula, producing an island separated from the mainland by a shallow sea (Douglas, 2013). Erosion of the uplifted island resulted in sedimentation of the shallow sea, forming a peninsula connected to the mainland. Fluctuations of sea levels in the Pleistocene simultaneous with uplift resulted in preservation of 13 marine terraces that circumscribe the Peninsula. Modern day sea level produces near vertical sea cliffs almost 150 feet high and erodes the landslide toe at relatively high rates. The two upper members of the Monterey Formation are mostly composed of biogenic materials such as diatomite, diatom-rich shale, and phosphate-rich mudstones. The Altamira Shale member is further subdivided into lower and middle tuffaceous shale and upper cherty and phosphatic lithofacies (Figure 9) (Douglas, 2013). The tuffaceous shale is rich in volcanic ash that contains interbeds of clay and bentonite that are inherently weak. The bentonite beds are the slip surfaces of most landslides in the peninsula (Ehlig, 1992; Douglas, 2013). The clay and bentonite interbeds form aquitards or aquicludes that permit the buildup of pore water pressure. Outcrops of the tuffaceous lithofacies in the ancient Altamira Landslide Complex are predominantly composed of tuffaceous shales with interbeds of cherts, silty sandstone, and intrusive basalt sills (Douglas, 2013). The Altamira Shale member also contains beds of tuff turbidite, ash fall, and debris flow tuffs that vary in thickness and are discontinuous over short distances (Douglas, 2013). Two distinctive tuff units occur within the tuffaceous lithofacies including the Miraleste Tuff and the Portuguese Tuff (Douglas, 2013). The Miraleste tuff is positioned in the upper part of the facies and the Portuguese tuff occurs approximately 450 feet below the top of the tuffaceous facies. The Portuguese Tuff ranges in thickness from approximately 20 to 60 feet with an average thickness of approximately 50 to 60 feet in the PBLC (Leighton and Associates, 2000). The variable thickness is the result of deposition on a hummocky sea floor interpreted to be caused by a single eruptive event (Ehlig, 1992). Most of the tuff has been converted to montmorillonite 31 Daniel B. Stephens & Associates, Inc. clay (bentonite) due to groundwater and heat (Douglas, 2013). The Portuguese Tuff functions as a zone of low shear strength and as an aquiclude in the PBLC (Ehlig, 1992). In the upper and middle portions of the PBLC, the landslide shear zone is positioned in a range approximately 50 feet above the tuff to coinciding with the top of the tuff. In the lower portion of the PBLC, the shear zone is positioned near the base of the tuff (Ehlig, 1992). Several folds and faults occur in the PBLC and offshore areas, the largest of which are anticlinal folds (Figure 10). All of the folds are asymmetric, east-west trending, and anticlinal. None of the onshore folds are exposed at the surface but are identified with subsurface data. The folds are significant in that they have influenced the direction of movement of the subslides of the PBLC (Douglas, 2013). Ehlig and Yen (1997) described the western edge of the east central subslide to be defined by a near vertical fault which extends in a north-south direction along the general alignment of Portuguese Canyon. The canyon probably developed along the fault. The fault is controlled by a discontinuity in the underlying bedrock structure. All of the geologic structures were formed during uplift and folding of the Peninsula. The crests of the anticline located at the head of the PBLC trends westward to Altamira Canyon where it underlies the hills of “Peacock Flats.” This anticline retards seaward movement of the ancient Altamira Landslide. Subsurface data reveal two flexural faults in the bedrock under the PBLC that trend west to east (Douglas, 2013). One of the flexures coincides with the boundary of the eastern and inland subslides (Figure 3). These flexures cause undulations in the slip zone of the PBLC, which creates large tension cracks in the slide mass as it moves over them. 3.5 Landslide Characterization The PBLC is the reactivated portion of a bowl-shaped area that encompasses approximately 2 square miles on the Palos Verdes Peninsula in the Ancient Altamira Landslide Complex (Figure 3). The Ancient Altamira Landslide Complex was first mapped by Woodring et al. (1946). More recent studies have moved the head of the landslide northward to include the Valley View graben (Douglas, 2013). There are differing hypotheses that postulate on the initiation and evolution of the Ancient Altamira Landslide Complex. Jahns and Vonder Linden (1972) believed that the Ancient Altamira Landslide Complex was the result of a series of semi- 32 Daniel B. Stephens & Associates, Inc. independent slides that formed in three separate time intervals during the 500,000 years. The oldest slides are located inland and the slides became progressively younger toward the coast. Ehlig (1992) proposed that the Ancient Altamira Landslide Complex initiated as a megaslide that moved as a simple translational glide block unit and, with continued displacement, the original slide block became fragmented. Furthermore, he concluded that the megaslide occurred sometime prior to 125,000 years ago and was no older than 200,000 years ago. Douglas (2013) argued that the AALC contains terrace remnants that are older than 200,000 years and therefore, its origin is older. He proposed that the upper block of landslide complex separated from a paleo sea cliff dated at 780,000 years and initial movement began shortly after this date. Douglas (2013) also believes that movement occurred in episodes with the oldest block at the head and the youngest at the coast which is consistent with the Jahns and Vonder Linden (1972) model. Given that borings drilled through the PBLC have determined that the ancient rupture surface is mostly at or the near the top of the Portuguese Tuff and the rupture surface is stratigraphically continuous, Leighton and Associates (2000) favor initial translational movement as a single sheet that subsequently broke up into large blocks consistent with the Ehlig (1992) model. The active PBLC encompasses approximately 250 acres with a maximum width of 3,600 feet and maximum head-to-toe length of approximately 4,200 feet (Douglas, 2013). The PBLC, together with the Abalone Cove and Klondike Canyon Landslides are reactivated portions of the Ancient Altamira Landslide Complex (Ehlig, 1992; Douglas, 2013). The western margin of the PBLC is poorly defined and transitory with respect to the Abalone Cove Landslide, whereas the east margin is well-defined. The internal structure of the landslide is established to be a series of randomly oriented large blocks separated by fractures and grabens (Ehlig and Yen, 1997; Leighton and Associates, 2000). Five large, semi-independent blocks or subslides were identified by Ehlig (1992), including the Landward, East-Central, West-Central, and Seaward subslides (Figure 3). The Abalone Cove Landslide Abatement District (ACLAD) is the first Geologic Hazard Abatement District (GHAD) created (in 1981) under the Beverly Act of 1979 (SB1195). The ACLAD is governed by a board of directors elected from property owners in the district area and 33 Daniel B. Stephens & Associates, Inc. assesses property owners to pay for the construction and maintenance of abatement measures in the Abalone Cove Landslide area, such as groundwater dewatering wells. The ACLAD maintains an extensive dewatering well network in the area. The well network has reportedly lowered water levels in the slide area up to a maximum of approximately 60 feet (Douglas, 2007) and helped to promote overall relative land stability in the ACLAD area. Ehlig and Yen (1997) supplemented their subsurface exploration data set with data acquired from previously drilled borings to construct a structure contour map of the basal rupture surface in the PBLC. The contour map estimates and maps the elevation of the rupture surface for the Landward, West-Central, and Seaward subslides. However, lack of subsurface data (data gap) east of Portuguese Canyon permits only inferred mapping of the rupture surface in this area. The undulating shape of the rupture surface is controlled by the structure of the underlying bedrock. The dips of the rupture surface range from approximately 15 to 25 degrees beneath the Landward subslide and flatten to less than 5 degrees in an anticlinal undulation along the southern margin near the West-Central and East-Central subslide boundaries (Ehlig and Yen, 1997; Leighton and Associates, 2000). One significant characteristic of the basal rupture surface is the trough shaped basin formed along the eastern part of the East-Central subslide (Appendix BC). The rupture surface steepens to 17 degrees at the northern flank of the trough with the central portion of the trough positioned just below sea level. The southern flank of the trough is gently inclined to the north and the rupture surface rises back up above sea level. Ehlig and Yen (1997) reported that a near vertical, north-south tear fault forms the boundary between the West-Central and East- Central subslides. The rupture surface of the West-Central subslide is generally uniformly gently dipping at approximately 7 degrees. An anticlinal undulation produces a 30 to 40 foot rise in the rupture surface which produces a buttressing effect on the subslide as the mass must climb to reach the crest of the fold (Leighton and Associates, 2000). The rupture surface of the Seaward subslide generally dips 5 degrees seaward and accommodates rotation of the slide blocks as wave erosion removes the toe of the active PBLC. Geologic cross-sections presented by Ehlig and Yen (1997) show that the topography (as of 1995) was nearly parallel to the underlying active rupture surface. The sections indicate that the 34 Daniel B. Stephens & Associates, Inc. thickness of the landslide mass is relatively uniform and averages approximately 100 feet above the rupture surface. However, Douglas (2013) states that, in places, the landslide complex is over 200 feet thick. Ehlig and Yen (1997) estimated that the total volume of PBLC mass is approximately 40 million cubic yards. Subsurface data indicate that the rupture surface is underlain by bedrock east of Portuguese Canyon and Ancient Altamira Landslide Complex debris west of Portuguese Canyon (Leighton and Associates, 2000). As a result, there are deeper slide and multiple slide planes present beneath the subslides located west of Portuguese Canyon, which coincides with the West-Central and East-Central boundary. Borings drilled by Ehlig and Yen, 1997 indicate that the Portuguese Tuff is at depth beneath the rupture surface throughout the northern portion of the PBLC. The portion of strata that are positioned between the rupture surface and the underlying Portuguese Tuff consists of relatively stronger strata derived from Catalina Schist debris and siliceous biogenic material. The rupture surface occurs along a sheared bentonite bed approximately 30 to 40 feet above the top of the Portuguese Tuff in the PBLC except for the northernmost portion and at the coast (Ehlig and Yen, 1997). The clay material of the rupture surface consists of both calcium-rich and sodium- rich montmorillonite clay (Ehlig and Yen, 1997; Leighton and Associates, 2000). The sodium- rich clay holds more water and is weaker than clay calcium-rich clay. Due to this fact, Ehlig and Yen (1997) proposed a lime injection program to increase the amount of calcium cations in the clay, which would strengthen the rupture surface clay. However, Leighton and Associates (2000) determined that the rupture surface consists of a substantial amount of calcium-rich clay and the lime injection may not yield desired stabilization results. 3.6 Hydrogeology Studies of the PBLC have consistently concluded that water moving in the subsurface is a significant contributing factor to the PBLC landslide instability. Subsurface water exists in the pores of soils and unconsolidated sediments and in fractures that exist in both unconsolidated sediments and hard rock. When water does not completely fill the pores that exist in soils, the moisture condition is referred to as “unsaturated.” The balance of the pore space is filled with soil vapor, which is typically in communication with the surface. When water completely fills the pores spaces, the moisture condition is termed “saturated.” Like any other free water surface 35 Daniel B. Stephens & Associates, Inc. (such as a pond or lake surface), a water table surface has a pore pressure, or static head, of zero. The water pressure increases linearly with depth below the water table. Water pressure can also build up as groundwater rises and encounters an overlying low-permeability zone that “confines” the groundwater. In this case, water in a drilled borehole would rise up above the level at which it was first encountered. If the water rose sufficiently high enough to encounter the surface, the water pressure would be termed “artesian.” Subsurface water includes water in soils that exists under conditions less than saturation above a water table and water that exists under saturated conditions below a water table or below a confining layer. Subsurface water is part of the continuous circulation of water between the ocean, atmosphere, and land called the hydrologic cycle. 3.6.1 Groundwater Recharge At the PBLC, water enters the subsurface by: • Direct precipitation and infiltration through soils • Drainage of surface water from locations upslope and subsequent infiltration and percolation • Percolation of water from private residential on-site wastewater treatment systems such as septic systems • Groundwater flow from upgradient locations, termed “underflow” A preliminary groundwater balance was developed for a golf course project proposed for an area in the east-southeastern PBLC (Leighton and Associates, 1998). The information available to support this analysis was limited but deemed sufficient to provide a first order approximation of the amount of water entering and leaving the proposed project site (the golf course project was never completed). Rainfall data from the Los Angeles County Fire Station at the top of the watershed on Crest Road were used for the water balance calculations. Based on historical precipitation data for 36 Daniel B. Stephens & Associates, Inc. the years 1947 to 1996, the average annual rainfall at the station was estimated to be 14.1 inches. This represents the amount of water (after deductions for the amounts that runoff, evaporate, or transpire from plants) that can potentially infiltrate and percolate into the subsurface of the PBLC. The area of the PBLC watershed is approximately 620 acres (Section 6.2) (Figure 5). The resulting volume of water that falls on the PBLC watershed in an average year is approximately 728 acre-feet of water (1.175 feet x 620 acres), the equivalent of about 234 million gallons of water. As calculated from the estimates presented in Leighton and Associates (1998), approximately 10 percent of the rain that fell on their proposed project area in an average rainfall year recharges and becomes groundwater. Extrapolating that percentage to the case of the PBLC area results in approximately 71.8 acre-feet, or 23.4 million gallons, of recharge. In addition, Leighton and Associates (1998) also determined for their proposed project site that the average annual rainfall of the 10 wettest years was 26.3 inches. In the 10 wettest years, Leighton and Associates (1998) calculated that approximately 29 percent of the rain that fell recharged and became groundwater. Using a wet-year rainfall of 26.3 inches for the PBLC, the recharge to groundwater that results on the PBLC watershed area would be about 388 acre-feet, or 127 million gallons. These recharge estimates do not separate the rainfall water that infiltrates and percolates directly from water that runs off from upgradient locations and subsequently infiltrates and percolates into the Red Zone of the PBLC. Rather, these values represent estimates of the recharge that occurs over the entire watershed. These recharge values are likely conservative, and a more detailed analysis would likely reveal that the percentage of rainfall that results in recharge is higher than estimated by Leighton and Associates. This is because an important limitation of the method used by Leighton and Associates (1998) is the assumption that rainfall stored within the soil is subject to evapotranspiration until the soil moisture capacity is exceeded. However, existing conditions at Portuguese Bend include desiccation cracks, fractures, and fissures caused by landslide movement that may permit water to migrate beyond the depth of evapotranspiration before the soil reaches its moisture capacity. This limitation in the method may result in an underestimate of groundwater recharge. Leighton and Associates (1998) also estimated the contribution to groundwater recharge by septic systems based on (1) the presence of 80 homes upslope of the project, (2) an estimated 37 Daniel B. Stephens & Associates, Inc. annual indoor consumption of 1,350 cubic feet of water per month, and (3) the assumption that all indoor water flowed to the septic system. The resulting contribution to subsurface water by percolation from private septic systems was estimated to be about 30 acre-feet per year. Based on the estimates for total project area recharge presented by Leighton and Associates (1998), septic tanks contribute about 30 percent of the total groundwater recharge in dry years, and about 7.2 percent of the total groundwater recharge in the 10 wettest years. While additional study of the PBLC groundwater budget is merited to clarify the water budgets of both shallow and deep groundwater, the preliminary water budget work suggests that there is a substantial amount of recharge into the PBLC, particularly in wet years, and that groundwater recharge from septic tanks can be significant in dry to average water years. During periods of heavy rainfall, large quantities of runoff flow onto the landslide from the tributary canyons. Field observation indicates that, although the water from these canyons was conveyed across the landslide through a combination of natural and improved drainage courses, it appears that significant sections of CMPcorrugated metal pipe (CMP) used for surface drainage are broken and inoperable and that significant quantities of runoff infiltrate and percolate into the ground within and around the periphery of the PBLC. Douglas (2013) stated that “In Portuguese and Paint Brush Canyons, the lower reaches of the canyons have been destroyed and 100 percent of the storm water from these canyon flows directly into the head of the Portuguese Bend landslide.” Our field observations are consistent with this statement. Leighton and Associates (1998) estimated the amount of recharge contributed by irrigation. Because the northern border of their project area was at the upper end of the watershed, it represented a no flow groundwater (and surface water) boundary in their analysis. In other words, no water flowed south into the area from north of the boundary. As a result, all groundwater flowing south into their proposed project site was the result of groundwater recharge from areas between the north end of the study area (and watershed) and the project site itself. The same is true for the PBLC. All groundwater inflow into the PBLC results from recharge occurring upslope. Leighton and Associates (1998) estimated that up to 77 acre-feet per year could be entering their project area from upslope irrigation recharge. Extrapolated to the PBLC, and similar to septic tanks, irrigation return flow represents a significant source of 38 Daniel B. Stephens & Associates, Inc. groundwater recharge to the PBLC. This component of recharge should be investigated further in a water balance study developed to support the final design of a land stabilization solution. 3.6.2 Groundwater Occurrence Groundwater generally occurs in two water-bearing zones at the Site. “Shallow” groundwater typically flows above the bentonite layers (shear zones) that form the main slip or rupture zones (failure surfaces) and is fed by general recharge, preferential recharge through local fractures, recharge through the canyon bottoms, and recharge that occurs where the canyons dump storm water onto alluvial fans, head slopes, sag ponds, and hummocky areas of the slide area. Douglas (2013) reported that wells pumping from this layer respond quickly (days to weeks) to major rain storms. A second water-bearing zone consisting of “deep” groundwater originates in the upper part of the drainage basin and is largely confined to below the rupture zones. This deep groundwater is confined and groundwater builds up pressure over time. Douglas (2013) also reported that wells drilled deep enough often encounter pressurized groundwater zones below the basal rupture surface. Leighton and Associates (1998) reported that unconfined groundwater of the shallow water- bearing zone occurs across the Site, and that it has historically been observed at depths ranging from approximately 5 to 15 feet below ground surface (bgs), at monitoring wells PBS-7, B88-4, and B96-12, to approximately 90 to 110 feet bgs, at monitoring wells PBS-2, PBS-3, C-4, C-5, and C-6. In general, the shallowest occurrences of groundwater have been observed in the Landward subslide, above the heads of the East-Central and West-Central subslides. The deepest occurrences of groundwater have been observed north of the active landslide area (monitoring wells C-4 through C-6), and underlying the north-south trending topographic ridge where monitoring wells PBS-2 through PBS-4 are located. The horizontal hydraulic gradient of the unconfined groundwater of the shallow water-bearing zone trends north to south and has a magnitude of approximately 0.10 foot of vertical head loss per horizontal foot (Leighton and Associates, 1998), similar to the general site topographic gradient. Experience indicates that, in general, horizontal groundwater hydraulic gradients typically range from 0.01 to 0.00001. By comparison, the gradient at the PBLC is therefore 39 Daniel B. Stephens & Associates, Inc. unusually high. High horizontal hydraulic gradients can be indicative of low-permeability conditions, areas of intensive groundwater recharge, high topographic relief, and/or groundwater extraction. Under homogeneous conditions, the direction of groundwater flow is generally parallel to the direction of the hydraulic gradient, in this case north to south. Appendix BC shows the contoured piezometric surface of the water table at the site based on interpolation of groundwater elevations measured in wells at the site. The occurrence of groundwater in the deep water-bearing zone beneath the rupture zone is less well understood and additional characterization of site deep groundwater is needed to facilitate a clear understanding of the hydraulic forces that deep groundwater is exerting on PBLC land stability. Ehlig and Yen (1997) reported that nested piezometers have been completed on the PBLC at four locations, and that at each location pneumatic pressure transducer readings indicate that groundwater occurs below the slide plane. Ehlig and Yen (1997) also reported that vertical hydraulic head measurements indicate that a downward vertical gradient occurs within the landslide mass and an even greater downward vertical gradient exists across the slide plane. The presence of these downward vertical gradients at the lower end of the hillslope was potentially attributed to increased groundwater recharge rates along the landscape of the landslide, including the presence of extensional ground fractures. Ehlig (1992) (as cited in Ehlig and Yen, 1997) reported on a well that was constructed and screened at the toe of the Klondike Canyon landslide and yielded artesian groundwater flow. The interpretation was given that slope stability analyses pertaining to the Seaward subslide need to consider that confined groundwater conditions occur beneath the slide plane. Ehlig and Yen (1997) generally concluded that groundwater occurrence beneath the site slide rupture plane was consistent with groundwater recharge occurring at the upper end of the hill slope and subsequent deeper migration beneath the slide plane towards the ocean. Groundwater occurrence at the regional scale is shown in Appendix BC. Crest Road located north of the PBLC is approximately located at the topographic crest of the hill and is the approximate location of the surface water and groundwater flow divide. Surface water and groundwater that occurs north of Crest Road generally flows inland towards the Pacific Coast 40 Daniel B. Stephens & Associates, Inc. Highway. Surface water and groundwater that occurs south of Crest Road generally flows southward, through the PBLC, and toward the Pacific Ocean. Surface water that falls or flows south of Crest Road has the opportunity to infiltrate and percolate into the subsurface of the PBLC and become groundwater. This is the water that is the focus of concern regarding PBLC land stability. Leighton and Associates (2000) present a detailed cross-sectional view (UU-UU’) that traverses through the main body of the PBLC from the upland area where the scarp of the slide headwall is located to the Pacific Ocean. The relationship is shown between the existing surface topography (existing grade), the interpreted water table (indicated by inverse triangles), and the interpreted recent below-grade active failure surface of the PBLC, as interpreted in 1999. As depicted, the water table surface is located above the interpreted active failure surface with a gradient that roughly mimics the gradient of the surface topography. The area of greatest thickness of the saturated zone within the PBLC was reported to be located inland (north) of PVDS. The maximum interpreted saturated zone thickness is approximately 90 feet, and the top of the saturated zone, at the point of maximum saturated zone thickness, was reported to be located about 100 feet bgs (Leighton and Associates, 2000). Though additional work needs to be accomplished to evaluate and delineate the specific occurrence of groundwater in the PBLC, the previous work done to evaluate the occurrence of groundwater in the PBLC provides the conceptual basis to evaluate and select technologies that can be used to stabilize land movement. 3.6.3 Water Wells Limited documented information is available on the number, construction details, and spatial distribution of the water wells in the PBLC. Information provided by the City of Rancho Palos Verdes indicates that up to 20 water wells have been constructed and installed within the PBLC. Except for four recent wells installed in 2016, no information could be located which documents the well construction details, last surveyed location, purpose of well (monitoring or dewatering), date of installation, well temporal monitoring data, or the current status of the well. That limitation represents a significant data gap that should be aggressively addressed moving forward. A map of currently known extraction well locations is presented as Figure 11. 41 Daniel B. Stephens & Associates, Inc. A well inspection survey should be conducted, including well soundings and video survey where necessary, in order to construct one consolidated, comprehensive database of site water well information and to provide the basis to initiate a monitoring program moving forward. An assessment should be prepared of the adequacy of the well network for spatial and temporal monitoring of groundwater within the PBLC. Based on that assessment, the monitoring well network should be augmented and a monitoring program initiated and maintained to provide data that will guide and evaluate the performance of the selected program to stabilize the PBLC. Regular, periodic well inspection surveys are also recommended to evaluate the impact of land movement on the monitoring network and the need for monitoring network maintenance. Ehlig and Yen (1997) report that groundwater elevations in the East-Central subslide area are thought to have risen about 50 feet between the slide activation in 1956 and 1968. They attributed the rise in groundwater elevations to an increase in the rate of groundwater recharge within the landslide area caused by the disruption of drainage patterns and the opening of fissures and cracks following the 1956 onset of movement. Water well elevation data presented for four PBLC wells with close correlation of groundwater elevation increases to high rainfall months indicate that groundwater recharge is occurring within a month of high rainfall events. In other wells, particularly one located in the East-Central subslide area, the lag between rainfall occurrence and water elevation response was longer, up to 5 months. Changes in groundwater elevation with time and in relation to rainfall events vary depending upon the well (Leighton and Associates, 2000). This suggests that multiple processes are involved in the delivery and removal of groundwater from the site and highlights the need to institute and formalize a monitoring program with the ability to record short and long term cyclic events. Such a formalized monitoring program and the resulting database would facilitate the collection, storage, and data interpretation critical to developing a detailed comprehensive understanding of the mechanisms which control the stability of the PBLC. 3.7 Geotechnical Modeling Slope stability evaluations of the PBLC have been performed in the past in support of development of various remedial measures (e.g., Ehlig and Yen, 1997; Leighton, 2000). Past 42 Daniel B. Stephens & Associates, Inc. studies, however, were subject to significant limitations. For example, prior models of the PBLC were two-dimensional cross sections and hence could not capture the true three-dimensional nature of the PBLC. Stability evaluations could not replicate the observed conditions. Attempts were made to back-calculate shear strength parameters, but different results were obtained for each two-dimensional cross section evaluated, further impeding development of viable remedial measures. Recently (over the past five years), significant advances have been made in three-dimensional modeling of slope stability. It is now possible to develop a three-dimensional stability model of a multi-acre site such as the PBLC based upon three-dimensional surfaces rather than two- dimensional cross sections. Review of available studies as discussed Sections 2 and 3 indicates that, with reasonable data processing, available information is suitable and sufficient to develop a preliminary 3D stability model of the PBLC using the following surfaces: • Ground surface (topography) • Groundwater elevation surface • Basal shear plane surface The ground surface topography of the PBLC was provided by the City (Section 2). The groundwater surface map produced by Ehlig and Yen (1997) was selected as the most comprehensive and representative for the modeling effort. Groundwater elevations were laterally extrapolated to the perimeter of the model area (approximately 10 percent of the lateral model area) based on the mapped water level data measured within the PBLC area. The 1997 basal rupture surface map also from Ehlig and Yen (1997) was selected as the most appropriate basal shear plane map for the modeling effort. Basal rupture surface elevations were also laterally extrapolated (approximately 10 percent of the lateral model area) based on mapped data measured within the PBLC area. An image of the preliminary three-dimensional stability model of the PBLC is shown in Figure 12. This model image was generated using SVSlope from SoilVision, Inc. (https://www.soilvision.com/), which is the latest generation three-dimensional slope stability evaluation program. Additional imagery from the modeling effort is provided in Appendix BC, 43 Daniel B. Stephens & Associates, Inc. including the approximate mapped limits of landsliding, several lateral cross-sections (A-A’ to I-I’), and one transverse cross-section (1-1’). These images show that groundwater occurs above the basal rupture surface within the PBLC. DBS&A performed the following preliminary evaluations using the model software: • Back-analysis of the PBLC • Forward-analysis of the PBLC The back-analysis was performed to estimate shear strength parameters along the basal failure surface. Cohesion was set to zero, while friction angle was iterated until the calculated FOS reached 1 (unity), which corresponds to the incipient failure of the landslide complex. An FOS greater than 1.0 theoretically corresponds to the cessation of landsliding. Each model iteration consumed approximately 3 hours of computational time. Back-analysis modeling indicates the following: • Back-calculated friction angle equals 6.7 degrees, which is within the range of values reported in prior laboratory testing (Leighton, 2000). • The direction of sliding (roughly north to south) is consistent with observations. • The shape of the failure surface based on model calculations is consistent with observations and interpretations (i.e., Ehlig and Yen, 1997). Forward-analysis was performed to evaluate the effect of groundwater elevation on the stability of the PBLC. The results indicate, as expected, a strong correlation in which the FOS increases with a corresponding decrease in groundwater elevation (Figure 13): • An elevation decline of 5 feet results in an increase in the FOS of approximately 3 percent (FOS increases from 1 to 1.03). • An elevation decline of 40 feet results in an increase in the FOS of approximately 13 percent (FOS increases from 1 to 1.13). 44 Daniel B. Stephens & Associates, Inc. Model limitations include the following: • The 1997 groundwater elevation map may not be representative of current conditions; it especially may not be representative of rainy periods that precede accelerated landsliding. • The steady-state seepage option within the three-dimensional stability model was not used due to the lack of data and their interpretation. • It was assumed that groundwater elevation (i.e., surface) is not affected by artesian pressures, although there is historical evidence that the basal failure surface may be subject to artesian pressure (Douglas, 2013). • As noted above, the 1997 groundwater and basal failure surfaces were laterally extended by extrapolation of existing data. Both groundwater elevation contour maps and contour maps of the basal rupture surface can be improved and refined based upon the results of supplemental investigation and data interpretation. • The elevation of the groundwater surface that will exist upon implementation of proposed remedial measures (Section 4.6) is not known at this point. Importantly, the preliminary three-dimensional slope modeling confirms that a reasonable reduction in the elevation of the groundwater surface (i.e., 10 to 20 feet) could result in a significant reduction in land movement in the PBLC area (an increase in FOS up to approximately 8 percent) (Figure 13). 45 Daniel B. Stephens & Associates, Inc. 4. Feasibility Study The FS presented below consists of the following sections: • ARARs • Remedial Action Objective • General Response Actions • Identification and Screening of Technology Alternatives • Detailed Analysis of Remedial Technologies • Preferred Alternative 4.1 ARARs In accordance with the CERCLA-analogous process for selecting an appropriate remedy being implemented in this document, remedial actions must meet the requirements of relevant federal environmental laws or more stringent state environmental laws referred to as ARARs. Remedial alternative screening must include ARARs evaluation. 4.1.1 Definitions As defined previously, ARARs is an acronym for applicableApplicable or relevantRelevant and appropriate requirementsAppropriate Requirements. Applicable requirements are those “cleanup standards, standards of control, and other substantive requirements, criteria, or limitations promulgated under federal environmental or state environmental or facility siting laws that specifically address a hazardous substance, pollutant, contaminant, remedial action, location, or other circumstance. Only those state standards that are identified by a state in a timely manner and that are more stringent than federal requirements may be applicable” (CFR 300.5). If a requirement is not applicable, it still may be relevant and appropriate and address issues at the site such that their use is well suited to the particular site (U.S. EPA, 1991b). As 46 Daniel B. Stephens & Associates, Inc. summarized by U.S. EPA, environmental laws and regulations can in part be broadly classified into three categories: • Laws and regulations that restrict activities at a given location • Laws and regulations that control specific actions There are therefore two types of ARARs: • Location-Specific ARARs: Intended to protect unique or sensitive areas, such as wetlands, riparian areas, historic places, and fragile ecosystems, and restrict or prohibit activities that are potentially harmful to such areas. • Action-Specific ARARs: Activity or technology based. These ARARs control remedial activities involving the design or use of certain equipment or technology or regulate discrete actions and are used in remedial technology alternatives screening. To-be-considered criteria (TBCs) are also identified in addition to ARARs. TBCs are advisories, guidance, policies, and/or proposed regulations or standards that might be applicable or applicable in the future. Finally, local permitting requirements and ordinances are also applicable when performing remedial actions. 4.1.2 Identified ARARs ARARs are summarized in Table 1 and include: 1. 1961 California Lake and Streambed Alteration Program 2. 1968 California Anti-degradation Policy 3. 1969 California Porter-Cologne Act 4. 1970 California Environmental Quality Act (CEQA) 5. 1970 California Endangered Species Act (CESA) 6. 1972 Federal Clean Water Act (CWA) 7. 1973 Federal Endangered Species Act (ESA) 47 Daniel B. Stephens & Associates, Inc. 8. 1973 USFWS Habitat Conservation Plans 9. 1993 USEPA Non-point Pollution (NPS) Management Guidance 10. 1995 SWRCB Water Quality Policy, Enclosed Bays and Estuaries 11. 1998 California Coastal Zone Management Act 12. 2002 SWRCB Lake and Streambed Alteration Program 1602 13. 2004 SWRCB Water Quality Enforcement Policy, Enclosed Bays and Estuaries 14. 2007 RWQCB Los Angeles Basin Plan 15. 2011 California NPS Pollution Control Policy 16. 2011 SWRCB NPDES Program 17. 2015 SWRCB 303(d) Listing Policy of 2004, amended 2015 18. 2015 California Division of Occupational Safety and Health regulations (Cal-OSHA) 19. 2015 SWRCB/RWQCB 401 Water Quality Certifications and Wetlands Program 20. 2017 City of Rancho Palos Verdes Grading permit program 21. 1991 Natural Communities Conservation Plan (NCCP) (draft) 4.2 Remedial Action Objective As discussed in Section 1.3, the specific purpose of this FS is to identify and select aviable conceptual solution options for the City’s consideration that will accomplish the following overall project goals: • Provide the geotechnical conditions that reduce the risk of damage to public and private property and would allow for the significant improvement of roadway infrastructure, safety, and stability. • Significantly reduce human health risk and improve safety in the City. • Significantly reduce sediment deposition into the Pacific Ocean that is causing unacceptable turbidity in the coastal and marine environment. • Make all reasonable efforts to identify aSelect remedy whichoptions that will be consistent with the City’s NCCP and the Habitat Conservation Plan (/HCP, specifically Section 4.1.2).. 48 Daniel B. Stephens & Associates, Inc. Remedial action objectives (RAOs) as defined by CERCLA and adapted for this FS are one or more defined, specific project end-points or specific goals. The single RAO defined for the Project Area is as follows: • RAO1: Significantly reduce project area land movement The project area is defined as the southeastern PBLC area (Red Zone) where land movement has consistently been measured at the greatest rate. A significant reduction in land movement in the project area would address each overall project goal. Infrastructure operation and maintenance, including repair, redesign, and stabilization of PVDS, could be conducted with a more regular, less frequent, and more cost-effective schedule. A stabilized roadway would clearly be much safer for motorists and ensure the expedited transit of emergency vehicles as necessary. Infrastructure in the project area could also be upgraded, including sewer, water, and electrical lines, with significantly reduced land movement. Once land movement is significantly reduced, the coastal shorecliffshore cliff would no longer be regularly driven into the surf zone by ongoing mass movement upslope; thus, sediment turbidity in the coastal and marine environmental would be decreased. In addition, the proposed remedy will stabilize the Preserve land. land within the City’s Palos Verdes Nature Preserve. Further, remedy options will be identified consistent with the NCCP/HCP. 4.3 General Response Actions General response actions (GRAs) as defined by CERCLA and adapted for this FS describe broad, general categories of technologies that will satisfy the RAO and provide a framework for identifying specific remedial technologies for screening and detailed analysis. The GRAs identified to address the RAO are: • Stormwater control • Subsurface dewatering • Stormwater control 49 Daniel B. Stephens & Associates, Inc. • Engineered slope stabilization measures • Eliminate septic system discharge 4.3.1 Subsurface Dewatering Preventing new water from entering the PBLC can be achieved by stormwater control and extracting existing groundwater in the subsurface as much as possible to reduce soil saturation and reduce continued landslide movement. Preliminary three-dimensional slope modeling confirms that a reasonable reduction in the elevation of the groundwater surface of 5 to 15 percent would result in a significant reduction in land movement in the PBLC area (Section 3.7). Subsurface dewatering through groundwater extraction should be conducted where surface water infiltration and groundwater recharge has historically had the greatest impact, such as in the head scarp area, the project area perimeter, and/or within the interior of the project area. Groundwater extraction could be coupled with regional stormwater capture as discussed below to optimize the effectiveness of the overall subsurface dewatering effort. Subsurface dewatering is typically conducted with either or both horizontal and vertical groundwater extraction wells. Horizontal groundwater extraction wells are also termed horizontal drains, directional drains, hydraugers, or hydro-augers. In geotechnical engineering, the term horizontal drains is typically used. Vertical groundwater extraction wells are also termed pumping wells or dewatering wells. Dewatering wells are installed using conventional well-drilling rigs using such drilling methods as air or wet rotary tri-cone, auger, percussion, or sonic. Extraction well installation needs to be designed and field-supervised by a licensed Professional Geologist, Engineering Geologist or Geotechnical Engineer. Wells would be located based on an understanding of area hydrogeology and stratigraphy. 4.3.14.3.2 Stormwater Control Preventing stormwater infiltration is a key to reducing overall slope failure and ongoing surface water loading to the project area. Stormwater originating upslope in upper Portuguese Canyon, 50 Daniel B. Stephens & Associates, Inc. upper Paintbrush Canyon, and upper Ishibashi Canyon (east of Peacock Flat) has historically been flowing directly into the head scarp of the PBLC just south of Burma Road where surface fractures are present. Stormwater infiltration also recharges groundwater, to varying degrees, in the upper, central, and lower canyon areas, which then flows in the subsurface downgradient to the southeastern PBLC area where land movement is the greatest. Stormwater with the potential to result in significant recharge in these areas mustshould be captured, and/or controlled, and discharged to the ocean to prevent future recharge to surface fractures and groundwater. Stormwater discharge from lower Klondike Canyon also recharges groundwater in the vicinity of the southeastern Red Zone near where land movement is typically occurring at the greatest rate. Stormwater in lower Klondike Canyon should be captured and discharged to the ocean to prevent further groundwater recharge to this area of the PBLC. GRAs that are used to address stormwater control can include typicalone or any combination of surface water infrastructure such as box culverts, channels, gabions, drainage ditches, subdrains, velocity or energy dissipation structures, sedimentation basins, pipes, and drainways. Much of this type of regional drainage infrastructure is typically constructed with concrete, supplemented with metal or plastic piping, and designed for gravity flow. GeotextilesHowever, due to the sensitive surrounding flora and fauna, alternatively, geotextiles and engineered composite materials, such as geosynthetic clay liners (GCLs), can also be used for stormwater control where applicable in areas requiring substantial infiltration control. GCLs and geotextiles can also be used in constructed or restored wetlands environments or stream restoration designs. Stormwater control GRAs also include segmented pre-fabricated channels that can be specified, transported to a work area, and connected in series to form a streamway or channel with controlled flow. Surface water control measures also includes infilling of surface fractures on an annual basis as a maintenance item before winter rains commence. Surface fractures in the PBLC head scarp area can be filled in a number of ways, for example a grouting operation involving a long-reach 51 Daniel B. Stephens & Associates, Inc. concrete boom pumping truck delivering a cement grout.slurried earthen filler material. The principal goal is to remove preferential pathways through which rain or runoff water can rapidly percolate to the deep subsurface past the zone of plant root uptake and subsequent transpiration. 4.3.1 EnineeredSubsurface Dewatering In addition to preventing new water from entering the PBLC by stormwater control, existing groundwater in the subsurface must be extracted as much as possible to reduce soil saturation and reduce continued landslide movement. Preliminary three-dimensional slope modeling confirms that a reasonable reduction in the elevation of the groundwater surface of 5 to 15 percent would result in a significant reduction in land movement in the PBLC area (Section 3.7). Subsurface dewatering through groundwater extraction should be conducted where surface water infiltration and groundwater recharge has historically had the greatest impact, such as in the head scarp area, the project area perimeter, and within the interior of the project area. Groundwater extraction should be coupled with regional stormwater capture as discussed above to optimize the effectiveness of the overall subsurface dewatering effort. Subsurface dewatering is typically conducted with either or both horizontal and vertical groundwater extraction wells. Horizontal groundwater extraction wells are also termed horizontal drains, hydraugers, or hydro-augers. In geotechnical engineering, the term horizontal drains is typically used. Vertical groundwater extraction wells are also termed pumping wells or dewatering wells. Dewatering wells are installed using conventional well-drilling rigs using such drilling methods as air or wet rotary tri-cone, auger, percussion, or sonic. Extraction well installation needs to be designed and field-supervised by a licensed Professional Geologist, Engineering Geologist or Geotechnical Engineer. Wells would be located based on an understanding of area hydrogeology and stratigraphy. 52 Daniel B. Stephens & Associates, Inc. 4.3.24.3.1 Engineered Slope Stabilization Measures Numerous engineering measures for slope stabilization are currently in use in California. The feasibility of implementation regarding a specific engineering measure depends upon several factors. For example, in some situations, an extent of landsliding, geologic and groundwater conditions, the composition of the landslide mass, and/or the thickness of the landslide mass may limit implementation of a certain measure, while in other cases, terrain, topography, the cost of implementation and maintenance and/or environmental constraints may be a deciding factor. Engineered slope stabilization measures that could be considered for PBLC include the following: • Buttressing (engineered fill) • Mechanically stabilized earth (MSE) wall • Drilled piers (caissons) 4.3.34.3.2 Eliminate Septic System Discharge SepticAs discussed in Section 3.6.1, septic tanks contribute a significant amount of groundwater recharge in relatively dry water years. A centralized sewer system that eliminates septic tanks in the PBLC area would significantly reduce future dry weather groundwater recharge. A centralized sewer system is needed in portions of both the City of Rancho Palos Verdes and the City Rolling Hills within the Portuguese Bend watershed (Figure 7). The properties within the PBLC area between Peppertree Drive and PVDS currently use septic tanks. A centralized sewer system would be beneficial in this neighborhood that is directly adjacent to the northwest portion of the project area. Recharged groundwater in this neighborhood flows downgradient directly into the project area. The properties northeast of the PBLC area and south of Crest Road, primarily in the City of Rolling Hills, currently use septic tanks. A centralized sewer system would be beneficial in this neighborhood that is directly upgradient of the PBLC. Recharged groundwater in this neighborhood eventually flows downgradient into the project area. It is recommended that the 53 Daniel B. Stephens & Associates, Inc. City of Rancho Palos Verdes encourage the City of Rolling Hills to construct a centralized sewer system. 4.3.5 Coastal Erosion Control An offshore breakwater could be installed in Portuguese Bend east or southeast of Inspiration Point to dissipate offshore wave energy and reduce coastal wave-cut bluff erosion. This option was studied in detail by the USACE to address marine habitat restoration in an FS dated 2000 (USACE, 2000). 4.4 Identification and Screening of Technology Alternatives This section describes technologies commonly used in industry to address the RAO. This section also provides an initial screening of these technologies to identify and eliminate technologies that have a sufficiently obvious flaw, based on known conditions, such that it can be determined early on in the remedy selection process that the technology could not be reasonably implemented. Technologies that are retained as the result of the analysis presented in this section are then carried forward to the detailed analysis of technology alternatives. Prior to implementation, the alternatives would require further engineering analysis, reports, and project plans. Screened technologies are discussed below are also compared to effectiveness, implementability, and cost criteria in Table 2. 4.4.1 Stormwater Control Option 1 – Repair Existing Corrugated Piping System 4.4.1.1 Description The existing CMP system in the PBLC area could be repaired to capture stormwater and direct discharge to the ocean. The piping network was appropriately installed in the areas of greatest stormwater flow along the axes of Paintbrush, Ishibashi, and Portuguese Canyons. The loose piping segments could be re-connected and refurbished and/or replaced so that the overall system would be reinstated in its original design. Repairing and refurbishing and/or replacing the piping would be a relatively straight-forward task with readily available equipment and labor. 54 Daniel B. Stephens & Associates, Inc. 4.4.1.2 Screening Summary The existing piping network has been out of maintenance for nearly 20 years. When originally installed, the piping segments were relatively easily dismantled by continuing land movement in the PBLC area. In addition, surface water flow in the PBLC was not fully captured by the piping network since the upslope headworks were apparently underdesigned.under-designed. The piping diameter may have been undersized as well. Also, the network likely did not cover enough area in the PBLC, including the upper canyons.. Though the original piping network was envisioned with the intention of capturing stormwater and preventing groundwater recharge, it was installed as a preliminary engineering solution. Resurrecting the former system does not address the design scale issues, and it would not fully capture stormwater. If rebuilt, the metal piping would again be subject to damage from ongoing land movement. A more substantially designed and flexible system is needed for full stormwater capture and control. As a result, this option has been eliminated from further consideration. 4.4.2 Stormwater Control Option 2 – Install Concrete Channels 4.4.2.1 Description Traditionally, stormwater and flood control infrastructure is constructed with concrete channels and associated metal or plastic piping. Stormwater flow is captured upslope and directed to flood control basins where it infiltrates to groundwater or passes downgradient under gravity flow to a supplemental basin or concrete channel or box culverts. Concrete channels and box culverts are highly effective in capturing and directing stormwater flow and controlling design floods of a pre-specified size and frequency. Concrete channels and culverts are an established technology with available equipment, materials, and labor. 4.4.2.2 Screening Summary Concrete channels and culverts are effective in geotechnically stable areas. However, where there is land movement, concrete structures are prone to damage from tensional cracking, shearing, subsidence, upheaval, and associated stresses. Once damaged, the channels would no longer prevent groundwater infiltration. Routine maintenance and repair would not be cost- effective in the long term. In addition, concrete structures do not typically allow for native habitat developmentto thrive nor do they receive widespread aesthetic acceptance. However, concrete 55 Daniel B. Stephens & Associates, Inc. structures are highly effective and efficient on controlling flow and may be appropriate in some portion of the PBLC area such as the upper canyons, along south of Burma Road, or in mid- canyon areas that are not prone to land movement. As a result, this option has been retained for further consideration. in limited areas of the PBLC. 4.4.3 Stormwater Control Option 3 – Install Liner and Channel System 4.4.3.1 Description A canyon liner system consisting of engineered flexible geotextile composite fabrics or GCLs would allow for both stormwater infiltration control and habitat development within the PBLC and Preserve properties. Some associated engineering components would also be needed in mid- canyon high-flow or flow-convergence areas such as velocity dissipation structures, flow control channeling, streambank stabilization, vegetated gabions, or subsurface piping. The upper portionsPortions of Portuguese, Paintbrush, and Ishibashi Canyons would be lined to direct flow away from the PBLC head scarp area and away from the Project Area. High-flow in the mid- canyon area near Burma Road would be captured and directed by gravity flow into a single channel downgradient that ultimately connects to piping under the PVDS that discharges into the ocean. The flexible composite fabrics are not prone to damage from land movement. The mid-canyon flow control structures would be installed where land movement is minimal and acceptable. Habitat could be partially integrated into the design of the upper and lower canyon linersliner system. This option could be installed with readily available equipment, materials, and labor, and designed to comply with the minimization measures set forth in the City’s NCCP/HCP. 4.4.3.2 Screening Summary This option would effectively prevent stormwater infiltration and groundwater recharge while allowing for habitat developmentestablishment within the PBLC and Preserve properties. This technology is readily available and could be cost-effectively installed and maintained., and could be designed to comply with the minimization measures set forth in the City’s NCCP/HCP. Once installed, the structures would be structurally flexible and not prone to damage from land movement. For these reasons, this option has been retained for further consideration. 56 Daniel B. Stephens & Associates, Inc. 4.4.4 Stormwater Control Option 4 – Seal Surface Fractures 4.4.4.1 Description This option involves using a long-reach boom truck and/or conventional cementpumping truck, or other method, to deliver a groutslurried earthen material to major surface fractures in the PBLC head scarp area and other key areas where surface water infiltration needs to be minimized. A survey of fractures and fracture sealing would be conducted on an annual basis as a maintenance item before winter rains commence. 4.4.4.2 Screening Summary This option could be conducted with limited or no disruptionimpacts to existing habitat, with staging placed in disturbed areas, and would help reduce groundwater recharge in the project area and in the head scarp area. This technology is readily available and could be implemented for reasonable cost with industry standard equipment, materials, and labor. For these reasons, this option has been retained for further consideration. 4.4.5 Subsurface Dewatering Option 1 – Groundwater Extraction Pits 4.4.5.1 Description This option involves completing semi-permanent linear excavations of subsurface soils below groundwater in order to facilitate groundwater extraction from low-permeability soils over the long term. Excavations would be completed with a roughly rectangular configuration where groundwater extraction is needed in the southeastern PBLC area within the project area. Extraction pits are effective in relatively low permeability formations as they allow for slow groundwater seepage into the pit and incremental extraction by automated pumping to the surface. Typically, multiple long pits aligned in parallel would be needed to effectively dewater a relatively large area. Groundwater extraction pits are typically installed where the depth to groundwater is less than 25 feet below grade so that excavation engineering and groundwater extraction is less complex. However, deeper pits are also possible. 57 Daniel B. Stephens & Associates, Inc. 4.4.5.2 Screening Summary Groundwater extraction pits can be effective over the long term in low permeability formations where groundwater extraction through traditional pumping wells is too problematic due to very low well yields. However, multiple pits would likely be needed in the relatively large project area and vicinity. Multiple aligned pits would be fairly disruptive to the existing properties. Excavations are also inherently hazardous and require significant safety engineering during design, implementation, oversight, and long-term maintenance. In addition, the depth to groundwater in the PBLC area exceeds 50 feet below grade, further complicating this option and significantly increasing the implementation cost. For these reasons, this option has been eliminated from further consideration. 4.4.6 Subsurface Dewatering Option 2 – Groundwater Extraction Wells 4.4.6.1 Description Vertical groundwater extraction wells are a proven and traditional technology for groundwater dewatering. Typically, multiple wells are installed by drilling rig in a network pattern to effectively extract groundwater from a design target area and depth. The radius-of-influence (ROI) of each individual well is estimated from field measurements and coupled with the ROI from adjacent wells so that the entire well network covers the target area with some ROI overlap. Downhole electrical submersible pumps would deliver groundwater to the surface for ultimate gravity flow or surface pump-assisted gravity flow to the ocean. Downhole pumps require electrical power. Wells installed in key areas and depths can relieve subsurface artesian pressure which can alleviate land movement. 4.4.6.2 Screening Summary While extraction wells have been successful in the adjacent Abalone Cove area, extraction wells have had limited success historically in the PBLC area due to low soil permeability, low well yields, and pump clogging due to fine sediments and probable iron bacterial growth. W ells are also prone to deformation or vertical shearing due to ongoing land movement. In addition, the depth to groundwater in some portions of the PBLC exceeds 100 feet, which significantly increases drilling, well installation, and operational costs. 58 Daniel B. Stephens & Associates, Inc. However, extraction wells can be very effective if installed in an area of little or no land movement or where groundwater is present in relatively high permeability soils. Wells would be more effective in historically slide-prone areas once land movement is significantly reduced through other technologies. Wells could effective if coupled with other technologies such as stormwater control. In addition, extraction wells are one of the few cost-effective technologies actually available for subsurface dewatering. Extraction wells also required a relatively low surface footprint for implementation, and less for operation, this being compatible with habitat conservation and aesthetic goals. For these reasons, this option is retained for further consideration. 4.4.7 Subsurface Dewatering Option 3 – Directional Subsurface Drains 4.4.7.1 Description Directional subsurface drains are also termed hydraugers, hydro-augers, horizontal wells, or horizontal drains. This technology involves the installation of relatively long, linear well casing inclined to grade and extending up to 1,500 feet in the subsurface where conditions allow. The casing is slotted like a vertical well screen so that groundwater passively enters the screen slots then flows under gravity to the wellhead where it is directed to a pipe to the ocean. Several lengths of slotted well casing can be installed from one work area as multiple runs of separate slotted casing are oriented in a radial fan-like pattern extending up and into subsurface soils. Horizontal extraction wells could be installed at several locations in the project area and in the greater PBLC area where subsurface groundwater needs to be extracted. Drain casing can also be installed with relatively large outer casing covering smaller inner casing to help promote longevity and stability of the drain in a subsurface environment prone to land movement. 4.4.7.2 Screening Summary Directional drains have a number of advantages for the PBLC area. Numerous drains can be installed from one work area, and the resulting infrastructure is below grade so that no surface habitat is disturbed at all above the casing. No pumps or electrical components are needed as groundwater passively enters the drains and flows under gravity to an exit point at the work area. Several drains could be installed from the coastal bluff south of PVDS that would extend beneath the road and into and under the project area and other key areas where groundwater 59 Daniel B. Stephens & Associates, Inc. needs to be extracted. Additional drains could be installed further north at the base of the slopes in the upper project area to extract groundwater in the mid-canyon areas. Drains could be installed to cover nearly the entire project area subsurface if needed at a specified depth or, perhaps, multiple depths. In addition, if aligned parallel with or sub-parallel to the primary direction of regional land movement, drain casing would be less susceptible to shearing and deformation due to land movement compared to vertical wells. As land movement eventually slows due to dewatering, however, both wells and drains would be more stable over time. The challenge would be where drains are needed at significant working depths such as depths approaching 100 feet below grade or more. The drilling and casing installation work area typically must be at the lowest point of elevation so that the casing can be inclined to grade to enable gravity flow. For example, if groundwater extraction is required at a significant depth below grade in relatively flat terrain, the work area must be designed within a temporary excavation in order to achieve the appropriate geometry during installation. In some cases, directional drilling from the surface can be used to help accommodate deeper casing depths. Although working depth can complicate casing installation, this technology is cost effective, has relatively little operation and maintenance, can cover large areas, and is highly effective in groundwater dewatering. In addition,Moreover, minimal habitat loss would occur with this option, and like vertical groundwater extraction wells, directional drains are one of the few cost- effective technologies actually available for subsurface dewatering. For these reasons, this option is retained for further consideration. 4.4.8 Engineering Slope Stabilization - Buttressing (Engineered Fill) 4.4.8.1 Description Landslide mitigation by buttressing is probably the most commonly used method of landslide stabilization in California. Depending on the size and shape of the landslide and borrow source materials available, a relatively large buttress might be required. In some cases, especially where space for construction of buttress fill is limited, other, complementary engineering measures might be required. These measures might include soil (i.e., engineered fill) reinforcement by means of geogrids and stabilization of temporary cuts for buttress fill 60 Daniel B. Stephens & Associates, Inc. construction by soil nails or rock anchors. These measures allow for construction of buttress fills with nearly vertical slopes and very steep temporary cuts required for construction of these slopes. Leighton (2000) proposed a major buttress along the coastline south of PVDS that is nearly half a mile across and a smaller buttress along the southern and northeastern perimeter of the project area. 4.4.8.2 Screening Summary Buttress fills, when properly sized, keyed, benched and constructed, in most cases, stabilize landslides for an extended period of time. Slope movements, including lateral displacements, settlement and creep are, in most cases, minimal. Past studies (e.g., Leighton, 2000) considered construction of a very large buttress fill to mitigate the PBLC. Based upon review of past studies and the results of preliminary evaluation of slope stability using a three-dimensional model, it was confirmed that a relatively large buttress fill would be required for the PBLC. Due to location and size constraints, such a buttress fill would require keying below groundwater which, in turn, would require dewatering during construction. Due to its relatively large size, a buttress fill would be significantly disruptive to protected habitat and residents during construction and would likely not be aesthetically acceptable after construction. Construction of a buttress would be burdensome and disruptive to regional transportation for an extended period of time. For these reasons, this option has been eliminated from further consideration. 4.4.9 Engineering Slope Stabilization Measures - Mechanically Stabilized Earth Wall 4.4.9.1 Description Mechanically stabilized earth (MSE) walls (gravity earth-retaining walls) are a common and effective technology when applied in the appropriate geotechnical setting. MSE walls have been successfully applied to mitigate slope failure at numerous locations in California. An MSE wall is basically surface soil stabilized with engineered components such as reinforcing geotextiles, panels, or precast blocks installed downslope as a support or anchoring structure to mitigate upslope land movement or to counter forces associated with an upslope containment (such as from water storage). One of the primary advantages of MSE walls is that they can be 61 Daniel B. Stephens & Associates, Inc. constructed as modular components in a relatively short period of time compared to other technologies. MSE walls are commonly constructed in roadside slope stabilization projects, as secondary tank containment, and in dams and levees. 4.4.9.2 Screening Summary MSE walls are cost-effective and can be rapidly constructed to mitigate slope failure or counter design forces upslope in appropriate environments such as where the rupture surface is relatively shallow, and/or where substantial footings or keying to stable bedrock is not required. At the PBLC, the depth to the basal rupture surface exceeds 60 feet in some areas. A surficial MSE wall would not stabilize land movement originating at depth. Although MSE walls are attractive from a cost perspective and are relatively simple to install, due to the depth to the basal rupture surface at the PBLC, along with the relatively large PBLC area that requires stabilization, MSE walls are not an appropriate alternative and will not be considered further. 4.4.10 Engineering Slope Stabilization Measures – Drilled Piers (CaissionsCaissons) 4.4.10.1 Description Soil improvement techniques like piles, rock anchors, soil nails, and drilled piers (caissons), are commonly used to stabilize slopes and/or to mitigate areas affected by landsliding. Given the size of the area affected by landsliding, the only potentially feasible, soil-improvement based slope mitigation option for the PBLC is mitigation with drilled piers. Drilled piers (caissons) are constructed by drilling and installing vertical reinforcement bars surrounded by poured concrete. Several rows of closely-spaced piers (typically separated by a distance equal to 1.5 to 3 pier- diameters) are installed along the bottom third of sliding mass below the basal rupture surface. Drilled piers must extend below the basal failure surface (the total depth depends on the mechanical properties of the material below the basal failure surface). Drilled piers with diameters of up to 8 feet and up to 60 feet long have been installed at various sites across coastal California in the past, including the PBLC (Section 2.1). 4.4.10.2 Screening Summary Drilled piers can be installed in areas where access is limited or where there is not enough room to construct a properly keyed and benched engineered buttress. Preliminary evaluation, 62 Daniel B. Stephens & Associates, Inc. consistent with past studies, indicates that numerous large diameter drilled piers would be required for PBLC mitigation. In addition, the required caisson depth, advanced below the basal failure surface, would be excessive (at many locations over 60 feet). Therefore, the cost of implementation of this measure, and the associated disruption to the environment, traffic, and residents, is a basis for elimination of this remedial measure from further consideration. 4.4.11 Centralized Sewer System 4.4.11.1 Description As discussed in Section 4.5.2, septic tanks contribute a significant amount of groundwater recharge in relatively dry water years. Septic tanks are located at properties in both the City of Rancho Palos Verdes and the City of Rolling Hills. A centralized sewer system that eliminates septic tanks in the PBLC area would significantly reduce future dry weather groundwater recharge. Residential septic systems would be incrementally and systematically removed only once a new centralized sewer is installed along public streets in the target neighborhoods. The new sewer system would be installed under the center or along the side of existing streets and connected by laterals to each home within the network. Sewer line flow would ultimately be directed to a centralized sewer treatment plant such as the Sanitation Districts of Los Angeles County Joint Water Pollution Control Plant (JWPCP) in Carson, California. This option would have to be fully evaluated in a separate engineering study to develop specific objectives, design options, costs, and regulatory requirements. for both the City of Rancho Palos Verdes and the City of Rolling Hills. 4.4.11.2 Screening Summary This option would help reduce groundwater recharge in both the immediate vicinity of the Project Area and in the upper canyon areas over the long term. This technology is readily available and could be installed and maintained with industry standard equipment, materials, and labor. For these reasons, this option has been retained for further consideration. 63 Daniel B. Stephens & Associates, Inc. 4.4.12 Coastal Erosion Control (Breakwater) 4.4.12.1 Description An offshore breakwater installed in Portuguese Bend east or southeast of Inspiration Point would dissipate offshore wave energy and reduce coastal bluff erosion. This engineered structure would consist of a containment dike or similar feature. This option was studied in detail by the USACE in their FS dated 2000 (USACE, 2000). 4.4.12.2 Screening Summary While this option would reduce wave erosion along the bluff south of PVDS, overall landslide mitigation would not be addressed. As a result, the landslide complex would continue to advance generally towards the south after breakwater construction. For this reason, a breakwater option has not been retained for further consideration. 4.4.124.4.13 Summary of Retained Technologies The following technology alternatives have been retained for detailed evaluation, after completion of the screening process: • Stormwater Control – Concrete Channels • Stormwater Control – Flexible Liner System and Components • Stormwater Control – Seal Surface Fractures • Subsurface Dewatering – Groundwater Extraction Wells • Subsurface Dewatering – Directional Subsurface Drains • Eliminate Septic System Discharge – Centralized Sewer System The detailed analysis of each option is presented in the following section. 4.5 Detailed Analysis of Remedial Technologies The evaluation criteria that were used to conduct an analysis of the candidate alternative technologies are listed below: 64 Daniel B. Stephens & Associates, Inc. • Overall protection of human health and the environment • Compliance with ARARs • Long-term effectiveness and permanence • Short-term effectiveness • Implementability • Cost • State and community acceptance The options presented in this section are ranked and numerically scored for each evaluation criteria (Table 3). The individual scores are summed to arrive at a total technology score. The options that received the higher total scores and relative lowest cost were selectedidentified as a component of the final selected option (preferred alternative).option for the City’s consideration. Approximate order-of-magnitude costs for each option are included in Table 4. 4.5.1 Concrete Channels • Overall Protection of Human Health and the Environment. Concrete channels are protective of human health but can impact the natural environment once constructed. Construction permanently displaces otherwise native habitat or openand has an adverse impact on the aesthetic value of the open Preserve land. • Compliance with ARARs. This alternativeoption would likely meet most of the requirements of the identified ARARs. However, converting a blue line stream such as the upper canyon, mid-canyon, or lower canyon areas into a concrete channel would likely not be a permitted project. • Long-Term Effectiveness and Permanence. Concrete channels would be effective and permanent in the long term if built in areas with little to no land movement. • Short-Term Effectiveness. Concrete channels would be effective in the short term if built in areas with little to no land movement. 65 Daniel B. Stephens & Associates, Inc. • Implementability. This option is standard technology that is easily implemented with readily available equipment, materials, and labor. • Cost. This option does not involve specialty equipment, materials, or labor and is routinely implemented for stormwater control in appropriate areas. As a result, the option should not be cost-prohibitive. • State and community acceptance. This option is likely unacceptable to the state and the community because it would significantly alter the appearance of the Preserve properties and permanently eliminate habitat acreage within the Preserve. This option would be effective and could be installed for manageable costs. Over the longer term, maintenance costs would be high to repair damage caused by land movement. However, it would likely not be permitted within a native habitat area. In addition, it is not aesthetically acceptable for placement within a habitat preserve with protected habitat. As a result of the detailed analysis of this option discussed above, it has been eliminated from further consideration. 4.5.2 Liner and Channel System • Overall Protection of Human Health and the Environment. Flexible material lining the upper canyons and mid-canyon, where appropriate, would be protective of human health and integrated into the environment after construction. Engineered substrate could be incorporated into the design to allow for acceptable habitat development within the lined stormwater channel network. • Compliance with ARARs. This alternativeoption would likely meet most or all of the requirements of the identified ARARs. It is anticipated that work within a blue line stream could be permitted in part under a stream restoration program. • Long-Term Effectiveness and Permanence. This option would be effective and permanent in the long term. The proposed materials are flexible and are not susceptible 66 Daniel B. Stephens & Associates, Inc. to damage from land movement. The surface area can be planted with native vegetation that can be designed to accommodate various root systems depending on the depth of the top soil. • Short-Term Effectiveness. This option would be effective and permanent in the short term. If land movement occurs early in the program before longer term land movement is significantly reduced, a flexible liner system is designed to withstand damage by allowing some liner movement. • Implementability. This option is standard technology that is easily implemented with readily available equipment, materials, and labor. • Cost. This option does not involve specialty equipment, materials, or labor and is routinely implemented for infiltration control in appropriate areas. As a result, the option should not be cost-prohibitive. • State and community acceptance. This option would likely be acceptable to the state and to the community because it partially integrates habitat and stream restoration into a design for stormwater capture and control. 4.5.3 Seal Surface Fractures • Overall Protection of Human Health and the Environment. Sealing surface fractures each year in the PBLC head scarp and project area, where appropriate, would be protective of human health and the environment as the contribution to overall land movement due to stormwater infiltration would be reduced. • Compliance with ARARs. This alternativeoption would likely meet most or all of the requirements of the identified ARARs. • Long-Term Effectiveness and Permanence. This option would be effective and permanent in the long term. Additional sealing may be needed each year if additional 67 Daniel B. Stephens & Associates, Inc. fractures are identified. Eventually as land movement is significantly reduced, the need to continue fracture sealing would become increasingly reduced. • Short-Term Effectiveness. This option would be effective and permanent in the short term once sealing material is introduced into fractures. • Implementability. This option is standard technology that is easily implemented with readily available equipment, materials, and labor. The staging area would take up relatively minimal surface area with minimal impact to protected habitat. • Cost. This option does not involve specialty equipment, materials, or labor and is routinely implemented for infiltration control in appropriate areas. As a result, the option should not be cost-prohibitive. • State and community acceptance. This option would likely be acceptable to the state and to the community because it does not significantly impact the surrounding surface environment or habitat., and provided that the staging area is located where little to no impact to protected habitat would occur. 4.5.4 Groundwater Extraction Wells • Overall Protection of Human Health and the Environment. Groundwater extraction wells are protective of human health and the environment when properly designed, installed, and maintained. Limited but manageable and temporary disruption ofThis option would result in relatively minimal impacts to the native habitat or open land is associated with well installation. • Compliance with ARARs. Well installation is routinely permitted and would meet requirements of the identified ARARs. • Long-Term Effectiveness and Permanence. Groundwater extraction wells have been problematic over the long term in the PBLC area due to clogging and damage due to 68 Daniel B. Stephens & Associates, Inc. land movement. Wells could be sustainable and permanent over the long term if the clogging issue can be resolved through such measures as periodic sterilization with oxidants and redevelopment. In addition, groundwater yield has been problematically low in the PBLC area due to naturally occurring low permeability soils in the subsurface. However, if installed in the appropriate area and at the appropriate depth where soils are sufficiently permeable and where groundwater is present, extraction wells are highly effective in removing subsurface groundwater. • Short-Term Effectiveness. Wells are effective over the short term if installed and maintained where groundwater is present in sufficiently permeabilitypermeable soils. • Implementability. This option is standard technology that is easily implemented with readily available equipment, materials, and labor. This technology is one of the few available for subsurface dewatering. However, low permeability soils can be problematic in the subsurface at the PBLC. • Cost. This option does not involve specialty equipment, materials, or labor and is routinely implemented for infiltration control in appropriate areas. As a result, the option should not be cost-prohibitive. • State and community acceptance. This option would likely be acceptable to the state and to the community because wells currently exist within the PBLC, and in adjacent areas, and are installed and maintained within a relatively small area footprint. 4.5.5 Directional Subsurface Drains • Overall Protection of Human Health and the Environment. Horizontal groundwater extraction wells are protective of human health and the environment because they are installed nearly entirely in the subsurface. Installation can be conducted within a relatively limited area footprint with manageable and temporary disruption ofrelatively minimal impacts to the native habitat or open land, and would not result in an adverse aesthetic value because the drains are mostly located below the surface. 69 Daniel B. Stephens & Associates, Inc. • Compliance with ARARs. Horizontal well installation is routinely permitted and would meet requirements of the identified ARARs. • Long-Term Effectiveness and Permanence. Horizontal groundwater extraction wells are effective over the long term because they are essentially a passive technology with no moving parts, relatively limited operation and maintenance, and are mostly underground where the potential for damage from surface activities is eliminated. Groundwater continues to be extracted as long as the well is not damaged from lateral land movement transverse to the well casing. Horizontal wells can be installed with concentric casings aligned parallel to prevailing land movement to help minimize damage from land movement. As the wells remove groundwater land movement is anticipated to be significantly reduced incrementally over time so that the potential for well damage is also incrementally reduced. As with vertical wells, horizontal wells could be sustainable and permanent over the long term if the clogging issue can be resolved through such measures as periodic sterilization with oxidants and redevelopment. If installed in the appropriate area and at the appropriate depth where soils are sufficiently permeable and where groundwater is present, horizontal extraction wells are highly effective in removing subsurface groundwater over the long-term. This technology has not been implemented in the PBLC area before, although it is highly effective when appropriately installed and monitored. • Short-Term Effectiveness. Horizontal wells are also effective over the short term if installed where groundwater is present. In some installations, groundwater flow into the horizontal wells can take up to several months before discharge is observed. • Implementability. This option is standard technology that is easily implemented with readily available equipment, materials, and labor. This technology is also one of the few available for subsurface dewatering. However, low permeability soils can be problematic in the subsurface at the PBLC. 70 Daniel B. Stephens & Associates, Inc. • Cost. This option does not involve non-standard specialty equipment, materials, or labor and is routinely implemented for groundwater extraction control in landslide repair or landslide-prone areas. Multiple horizontal wells, directed out radially and extending up to approximately 1,000 feet or more of lateral length, can be installed from one work area. As a result, this option is highly cost-effective. • State and community acceptance. This option would likely be acceptable to the state and to the community because horizontal wells are mostly underground, out of sight, do not displace or disruptimpact habitat or open space, and are installed and maintained within a relatively small area footprint. Only relatively minor surface piping would be associated with each wellhead to direct captured groundwater by gravity flow to a nearby surface water channel or pipe discharge to the ocean. 4.5.6 Centralized Sewer System • Overall Protection of Human Health and the Environment. Centralized sewer systems are protective of human health and the environment as they control and contain raw sewage flow to regional treatment plants instead of directing the liquid flow into the subsurface environment. • Compliance with ARARs. This alternative would likely meet most or all of the requirements of the identified ARARs. This option likely involves significant permitting from multiple jurisdictions, however. • Long-Term Effectiveness and Permanence. This option would be effective and permanent in the long term. Some periodic maintenance is required. • Short-Term Effectiveness. This option would be effective and permanent in the short term once constructed. • Implementability. This option is standard technology that is easily implemented with readily available equipment, materials, and labor. 71 Daniel B. Stephens & Associates, Inc. • Cost. This option does not involve specialty equipment, materials or labor and is routinely implemented in new developments and in retro-fit areas. This option involves significant planning, permitting, design engineering, and construction work, and, as a result, costs are relatively high. Moreover, permitting and construction would occur in the City of Rancho Palos Verdes and the City of Rolling Hills. • State and community acceptance. This option would likely be acceptable to the state due to the elimination of ongoing liquid infiltration that contributes to regional land movement. While the community will understand and support cessation of land movement, conversion costs from OWTS to city sewer will likely be an issue that would need to be addressed by City of Rancho Palos Verdes and the City of Rolling Hills. 4.6 Preferred AlternativeOptions 4.6.1 Description and Conceptual Design Based on the evaluation and discussion presented in the previous sections, the following alternativespreferred options have been selected asidentified for the preferred remedyCity’s consideration: • Seal Surface Fractures • Directional Subsurface Drains • Flexible Liner System and Components • Groundwater Extraction Wells • Centralized Sewer System The sequence of the remedy componentsoptions has been organized to correspond with an iterative construction cycle or a phased-approach to overall design, construction and installation. That is, sealing surface fractures a relatively straight-forward and cost-effective remedy that could be readily implemented before other options are pursued or while other options are in design, permitting, or construction. Second, directional drains are a conventional and cost- effective solution that could be installed while the more complex stormwater control liner and 72 Daniel B. Stephens & Associates, Inc. channel system would be in design, permitting, or construction. Directional drains would be installed in a phased manner to allow for additional drains installed over time once earlier designs are installed, pilot-tested, and assessed on its effectiveness. Finally, onceafter key fractures are sealed, directional subsurface drains are in place, and stormwater control is in place, the remedy program may be supplemented with an expansion of the existing groundwater extraction well network. Wells would be installed last in the sequence so that potential well damage from ongoing land movement would be minimized as the earlier components incrementally take effect. The first three remedy componentsoptions (sealing fractures, directional drains, and stormwater liner/channel system) would be pilot-tested before full-scale design and construction to allow for design refinement and adjustment as needed based on field conditions. Pilot testing is discussed below in Section 4.6.3. Each remedy component is further described in the following subsections. 4.6.1.1 Seal Surface Fractures This technology consists of in-filling existing surface fractures on an annual basis primarily in the vicinity of the project area (Red Zone) and in the PBLC head scarp area to reduce stormwater infiltration to groundwater. Other areas of the PBLC such as south of PVDS or within the interior of the slide area itself could also be included if appropriate. Relatively large fractures would be infilled before the rainy winter season each year using a long-reach concrete pumping truck, conventional grout pumping rig, or other method. Surface fractures would be identified in advance each fall through an on-site visual inspection survey, recent aerial photograph review, or potentially, with photographic data collected with an aerial drone fly-over. 4.6.1.2 Directional Subsurface Drains Directional drains have the potential to have a significant effect on lowering the groundwater surface within the PBLC project area. Drains would be installed in a phased approach to target groundwater removal in the southern project area where land movement has historically been measured at the greatest rate. Drains could be installed at two or more locations at the southern edge of the coastal bluff south of Palos Verdes Drive, for example, and would be 73 Daniel B. Stephens & Associates, Inc. drilled radially approximately 1,200 to 1,500 feet northwest, north, and northeast extending beneath PVDS (Figure 14). Drains in this area would be installed using a conventional, track- mounted horizontal drilling rig that can safely and reliably access the rocky beach area. Other drains could be installed north of the beach from low-lying areas south of PVDS. The drain design would have to include infrastructure to collect and discharge groundwater flow from the drains, such as piping runs to an ocean discharge location on the beach. A site investigationAn engineering study would need to be conductedprepared to determinesupport identification of exact drilling locations and drain installation geometry. Additional data gaps related to this and other options are discussed in Section 4.6.2. 4.6.1.3 Liner and Channel System This technology consists of the following components (Appendix CD): • Canyon Liner • Collector Channel Junction • Collector Channel • Outlet Channel (through active slide area) • Lapped Liner System • Lapped Channel Liner Under-Drain System • Native Vegetation Islands The ultimate goal of this technology is to minimize or eliminate stormwater infiltration and percolation to groundwater in the Portuguese Bend watershed and in the PBLC Project Area. The upper canyon liner would extend just north of the Burma Road Trail at an appropriate distance upgradient into the upper reaches of Portuguese, Paintbrush, and Ishibashi Canyons in order to capture and control stormwater surface flow and direct it into a collector channel and outlet channelto the ocean (described below) (Appendix CD). The upper canyon liner system as envisioned would be an impervious layer with an underdrain and an armored stone riprap surface. in relatively high surface water flow segments. Lower Portuguese Canyon in the northern Project Area would also be lined and connected to an outlet channel (described below). Both the upper and lowerthe canyon liners can be vegetated to blend into the native 74 Daniel B. Stephens & Associates, Inc. habitat. The depth of the top soil will determine the size of the feasible root system supporting the native habitat. The subsurface liner material, such as engineered geomembrane, could be expected to have a lifetime expectancy of at least several hundred years (Benson, 2014). The upper canyon liner would connect to a collector channel junction installed at Burma Road where the three major canyons (Portuguese, Paintbrush, and Ishibashi) converge near the PBLC head scarp area. The collector channel junction would slow stormwater flow and then redirect it into a main collector channel constructed along Burma Road and flowing southeastward under gravity. The collector channel junction would be constructed of vegetated rock gabions, half-round concrete piping (or equivalent) around the bend in the stream way, and associated rock armoring of the streambank. The main collector channel would be constructed of riprap, rock gabions, and an underlying lapped geotextile liner. Like the canyon liners, the collector channel junction and the main collector channel can be vegetated to blend into the native habitat. The main collector channel would direct flow into an outleta lower channel installed across the northeasternnorthern edge of the PBLC area and leading under gravity flow to a road culvert under PVDS (Appendix CD). Similar to the upper canyon liner and main collector channel, the outlet channel would be installed with an underlying lapped geotextile liner and surface rock armoring (Appendix C).. The outlet channel could also be vegetated to blend into the native habitat. Vegetation islands can be installed mid-stream where the overall design and flow conditions allow (Appendix C).. This option would also include a drainage and engineering study to support a final design that will promote surface water flow along the northern roadside of PVDS where storm water has historically been ponding and infiltrating to groundwater in the Red Zone area. Ultimately, additional areas in the adjacent watersheds could also be lined, such as eastern Altamira Canyon or lower Klondike Canyon, where stormwater continues to infiltrate to groundwater in the vicinity of the project area. The described liner and channel system is only a 75 Daniel B. Stephens & Associates, Inc. conceptual design. A full engineering and hydrologic study would be needed to appropriatelysupport final design and sizesizing of the liner and channel system. 4.6.1.4 Groundwater Extraction Wells Supplemental groundwater extraction wells would be installed in the project area once drains and stormwater control are in place (Figure 14). Groundwater extraction wells would be installed with conventional track-mounted or truck-mounted well drilling rigs using sonic drilling methods. The sonic method is preferred since soil sampling and characterization can be continually conducted while drilling commences, groundwater is readily observed, and well installation can proceed without the potential for drilling-induced permeability reduction associated with other methods such as mud rotary. Companion borings for geologic or geotechnical investigation may also need to be completed in advance by other methods to collect well design information such as geologic, stratigraphic, or hydrogeologic data. Groundwater monitoring wells will also need to be installed to routinely monitor groundwater levels in the PBLC area. At this conceptual stage of the overall project, based on the areal extent of the PBLC area and historical well yields, it is estimated that approximately 25 extraction wells would be needed in the project area with a network of approximately 10 to 15 additional monitoring wells within and adjacent to the project area. The number, depth, and design of the extraction and monitoring wells would be based on site-specific aquifer testing conducted to determine well design parameters as well as overall hydrogeologic and stratigraphic data based on historical work or supplemental site investigation. 4.6.1.5 Centralized Sewer System Approximately 2 miles of new subsurface sewer lines and associated manholes and junctions need to be installed in the Portuguese Bend neighborhood east of lower Altamira Canyon and west of lower Portuguese Canyon. This area includes those roads generally southeast of Peppertree Drive and north of Palos Verdes Drive South (Figure 7). In addition, approximately 1.5 miles of new subsurface sewer lines are needed in the upper Portuguese Canyon Watershed. New sewer lines are needed in this area where upper Portuguese Canyon extends north to the northern watershed boundary at Crest Road and where upper Ishibashi Canyon splits into four sub-canyons that extend east-northeast to the northern watershed boundary. Both upper Portuguese Canyon and upper Ishibashi Canyon are located within the City of 76 Daniel B. Stephens & Associates, Inc. Rolling Hills. The new sewer line installation would need to be synchronized with private lateral installation and connection as well as septic system removal in both neighborhoods. The new lines would likely be connected to nearby exiting lines that direct sewage to the Los Angeles County Joint Water Pollution Control Plant (JWPCP) in Carson. New sewer line installation and septic tank removal would have to be fully designed in a separate engineering study to develop specific objectives, design options, costs, and regulatory requirements. 4.6.2 Data Gaps In addition, the following pre-final design input is needed, at a minimum, to develop a detailed scope of work and engineering cost estimate for construction bidding for the City’s consideration: • Hydrologic analysis and floodplain mapping • Geologic, hydrogeologic, and stratigraphic characterization Hydrologic analysis, floodplain mapping, and watershed modeling are needed to appropriately characterize and specify the design flood for canyon lining and channel sizing engineering. These data include stream flow measurements, flood frequency, rainfall data analysis, and related tasks. Geologic, hydrogeologic, and stratigraphic data are needed to understand subsurface conditions before drain and well drilling commences. Historical data are also needed, if available, including extraction well construction data, extraction well production records, boring logs, a master soil boring and well location map, groundwater elevation data (historical and current), and groundwater quality sampling data. Data gap information is typically further specified in a data gap investigation work plan that outlines the required information and how it can be collected before final design engineering commences. 77 Daniel B. Stephens & Associates, Inc. 4.6.3 Pilot Testing Selected components of the preferredThe remedy options selected by the City should be pilot tested before full-scale implementation. Pilot testing should be completed to simulate full-scale implementation as much as possible while obtaining the design data needed to scale-up and cost the remedy for complete implementation. Pilot testing should be completed before full- scale implementation of the canyon liner and collector channel system, the surface fracture sealing, and subsurface drain remedy componentsoptions. Pilot testing and associated baseline and performance monitoring is typically specified and detailed in a separate plan. The pilot test plan could be combined with the data gap investigation work plan discussed above. 4.6.4 Approximate Implementation Costs The approximate order-of -magnitude costs (20172018 dollars) associated with the preferred alternative is provided in Table 4. Estimated costs are based on industry literature where possible and from professional experience with similar projects. 4.6.4.1 Seal Surface Fractures Pilot testing for a surface fracture sealing program is estimated to cost approximately $100,000. Planning, permitting, construction and initial reporting for a full-scale program is estimated at approximately $250,000. Operation and maintenance (O&M) (fracture sealing, monitoring, and reporting each year thereafter) costs are estimated at approximately $50,000. Extended for 10 years (20172018 dollars), O&M would cost approximately $625,000. The total cost for this option is thus approximately $975,000. 4.6.4.2 Directional Subsurface Drains Directional drains require a data gap investigation to characterize groundwater and identify the appropriate stratigraphic zone for drain installation. Data gap investigation and pilot testing for a drain program is estimated to cost approximately $656,000. Planning, permitting, construction and reporting of a full-scale program of 10 drains extending 1,200 feet is estimated at approximately $6.4 million. O&M (including monitoring and reporting each year thereafter) is estimated at approximately $125,000. Extended for 30 years (20172018 dollars) (without major 78 Daniel B. Stephens & Associates, Inc. reconstruction) this component would cost approximately $11.7 million. Major reconstruction for additional drains or replacement drains would be basically comparable to the initial program cost rates and total costs. 4.6.4.3 Liner and Channel System Pilot testing for a liner and channel system is estimated at approximately $512,000. Planning, permitting, and construction of a full-scale program of lining the upper canyons (Portuguese, Paintbrush and, Ishibashi) and lower Portuguese Canyon with a perimeter channel and culvert directing flow to the ocean is estimated to cost approximately $13.5 million. O&M (including monitoring and reporting each year thereafter) is estimated at approximately $75,000. Extended for 30 years (20172018 dollars) (without major reconstruction) this component would cost approximately $16.8 million. 4.6.4.4 Groundwater Extraction and Monitoring Wells Groundwater extraction wells require a data gap investigation to characterize groundwater and identify the appropriate stratigraphic zone(s) for well installation. Data gap investigation and pilot testing for supplemental groundwater extraction wells is estimated at approximately $556,000 (supplemental to the drain data gap investigation). Planning, permitting, and construction of a full-scale program (20 wells to 200 feet with 10 companion monitoring wells [30 wells total]) is estimated to cost approximately $4 million. O&M (including monitoring and reporting each year thereafter) is estimated at approximately $325,000. Extended for 30 years (20172018 dollars) (without major reconstruction) this component would cost approximately $12 million. 4.6.4.5 Centralized Sewer System Residential sewer costs are approximately $200 per linear foot overall including manholes and related infrastructure. Approximately 1.5 miles of sewer line are needed in the Portuguese Bend neighborhood and approximately 2 miles of sewer line are needed in the upper Portuguese Bend watershed area (within the City of Rolling Hills) (total of approximately 18,480 feet). Planning, permitting, and construction of a full-scale program in both the City of Rancho Palos Verdes and Rolling Hills is estimated to cost approximately $5 million. O&M (including monitoring and reporting each year thereafter) is estimated at approximately $50,000. 79 Daniel B. Stephens & Associates, Inc. Extended for 30 years (20172018 dollars) (without major reconstruction) this component would cost approximately $7 million. 4.6.4.6 Total Estimated Project Cost The estimated order-of-magnitude cost for all components of the preferred remedy totals $31.3 million for initial planning, permitting, data gap investigation, pilot testing, design, and construction. With O&M, monitoring, and reporting extended for 30 years (20172018 dollars) (without major reconstruction) the estimated order-of-magnitude cost totals $53.5 million. 80 Daniel B. Stephens & Associates, Inc. References Benson, Craig H., 2014. Performance of Engineered Barriers: Lessons Learned. University of Wisconsin Madison, 2014, accessed July 2018 at https://www.energy.gov/. California Stormwater Quality Association (CASQA). 2003. Stormwater best management practice handbook: New development and redevelopment. January 2003. Charles Abbot Associates, Inc., 1997. Portuguese Bend Shore Protection Feasibility Study, Analysis of Landslide Material Loss. Prepared for City of Rancho Palos Verdes, California, and the U.S. Army Corps of Engineers. Chesapeake Stormwater Network (CSN). Undated. Session 4: Retrofit costs, delivery and maintenance. Workshop presentation available at <http://chesapeakestormwater.net/wp- content/uploads/downloads/2012/06/Session-4-Retrofit-Costs-Delivery-and- Maintenance_060112.pdf>. City of Rancho Palos Verdes, 1987. Draft Environmental Impact Report for a Grading, Drainage, and Road Relocation Project, September, 1987. Clary, J., M. Leisenring, A. Poresky, A. Earles, and J. Jones. 2011. BMP performance analysis results for the International Stormwater BMP Database. American Society of Civil Engineers. World Environmental and Water Resources Congress 2011, Palm Springs, California, United States. May 22-26, 2011. Douglas, Robert, 2007. Abalone Cove Landslide Abatement District (ACLAD). Unpublished presentation. Douglas, Robert, 2013. The Creepy (Slow Moving) Landslides of Portuguese Bend. The Association of Environmental & Engineering Geologists, AEG Special Publication, v. 24, Los Angeles, California. 81 Daniel B. Stephens & Associates, Inc. EDAW, 1994a. Initial Study, Portuguese Bend Grading Project, Rancho Palos Verdes, California. Lead Agency: City of Rancho Palos Verdes, California, September 9, 1994. EDAW, 1994b. Initial Study, Portuguese Canyon Erosion Control Project, Rancho Palos Verdes, California. Lead Agency: City of Rancho Palos Verdes, California, August 5, 1994 Ehlig, Perry L., 1992. Evolution, mechanics and mitigation of the Portuguese Bend Landslide, Palos Verdes Peninsula, California. In (Pipkin, Bernard W. and R. J. Proctor, eds.) Engineering Geology Practice in Southern California, Special Publication No. 4, Association of Engineering Geologists, Southern California Section. Ehlig, Perry L., and B.C. Yen, 1997. A Joint Preliminary Geology and Geotechnical Engineering Investigation Report: Feasibility of Stabilizing Portuguese Bend Landslide, March 3, 1997. Leighton and Associates, 2000. Updated feasibility study for the Portuguese Bend Landslide remediation project at Peacock Hill and Portuguese Bend, City of Rancho Palos Verdes, California. Project No. 1881922-26; prepared for Palos Verdes Portuguese Bend Company, 25200 La Paz Road, Suite 210, Laguna Hills, California 92653, January 19, 2000. MacKintosh & MacKintosh, 1957. Report of Earth Movement, Portuguese Bend, California, April 26, 1957. MacKintosh & MacKintosh, Consulting Engineers, Los Angeles 4, Calilfornia. Maestre, A., R. Pitt, and Center for Watershed Protection. 2005. The National Stormwater Quality Database, Version 1.1, A compilation and analysis of NPDES stormwater monitoring information. U.S. Environmental Protection Agency Office of Water. September 4, 2005. National Weather Service (NWS). 2015. Climate Prediction Center, Frequently asked questions about El Niño and La Niña. Accessed June 4, 2015. <http://www.cpc.ncep.noaa.gov/ products/analysis_monitoring/ensostuff/ensofaq.shtml>. Natural Resources Conservation Service (NRCS), 2007. Chapter 7: Hydrologic soil groups. Part 630 Hydrology, National Engineering Handbook. 210–VI–NEH. May 2007. 82 Daniel B. Stephens & Associates, Inc. National Resources Conservation Service (NRCS), 2017. Custom Soil Resource Report for Los Angeles County, California, Southeastern Part, Portuguese Bend. Downloaded from <https://websoilsurvey.sc.egov.usda.gov> on November 6, 2017, PDF copy of report for custom area on file with DBS&A. RBF Consulting, 2015. City of Rancho Palos Verdes Master Plan of Drainage, Final Report. Prepared for the City of Rancho Palos Verdes Public Works Department, June 5, 2015, by RBF Consulting, a Michael Baker International company. Regional Water Quality Control Board, San Diego Region (RWQCB). 1994. Water quality control plan for the San Diego Basin (9). As amended. RWQCB, 2009. Clean Water Act Section 305(b) and Section 303(d) Integrated Report for the San Diego Region, Staff Report. December 2009. State Water Resources Control Board (SWRCB), 2004. Policy for implementation and enforcement of the Nonpoint Source Pollution Control Program: Guidance for developing an integrated program for implementing and enforcing the “Plan for California’s Nonpoint Source Pollution Control Program”. May 20, 2004. SWRCB, 2013. Resolution No. 2013-0003: Adoption of an amendment to the policy for water quality control for recycled water concerning monitoring requirements for constituents of emerging concern. January 22, 2013. SWRCB, 2015. State Water Boards bacterial objectives. <http://www.waterboards.ca.gov/bacterialobjectives/>. Last updated February 19, 2015. U.S. Army Corps of Engineers (ACOE), 1998USACE), 2000. Rancho Palos Verdes, Los Angeles County, California, Draft Feasibility Study and Environmental Impact Statement, prepared for F-4 Technical Conference by theReport, Los Angeles District, South Pacific Division, January 1998June. 83 Daniel B. Stephens & Associates, Inc. U.S. Environmental Protection Agency (USEPA), 1988. Guidance for conducting remedial investigations and feasibility studies under CERCLA (Interim final). EPA/540/G89/004, October 1988. Vonder Linden, Karl, 1972. An analysis of the Portuguese Bend Landslide, Palos Verdes Hills, California, A Dissertation submitted to the Department of Geology, Stanford University, in partial fulfillment of the requirements for the degree of Doctor of Philosophy, 271 pp. URS, undated. Draft Report entitled, Natural Community Conservation Plan and Habitat Conservation Plan. URS Project No. 27644296.08000, prepared for the City of Rancho Palos Verdes. Water Environment Research Foundation (WERF). 2015. International Stormwater BMP Database. <http://www.bmpdatabase.org/>. Teresa Takaoka From: Sent: To: Cc: Subject: Attachments: Eva Cicoria <cicoriae@aol.com> Tuesday, August 07, 2018 12:18 PM Deborah Cullen; Doug Willmore; Elias Sassoon; Ara Mihranian cc Re: missing pages 2018-07-Table D.pdf Thank you, Deborah, but do you not consider the tables and diagrams part of the FS? Apparently they have changed, but there was no indication of that by showing them as part of the red line nor by explanation in the Staff Report. See attached, for example. I have found at least one other change to a table and have no idea whether there are more changes. Do any of you know? Eva -----Original Message----- From: Deborah Cullen <DCullen@rpvca.gov> To: 'Eva Cicoria' <cicoriae@aol.com>; Doug Willmore <DWillmore@rpvca.gov>; Elias Sassoon <esassoon@rpvca.gov>; Ara Mihranian <AraM@rpvca.gov> Cc: CC <CC@rpvca.gov> Sent: Tue, Aug 7, 2018 12:03 pm Subject: RE: missing pages Eva, Please see below for an explanation of your confusion regarding the Feasibility Study (draft, red-lined and final): We seem to be working with incomplete documents related to the Landslide Feasibility Study coming before City Council this evening. The Staff Report with attachments is 144 pages. The final FS included therein stops at p. 81 (B-88). B-88 stops at page 81 of the Feasibility Study. This is the final version which deletes all the edits in the red-lined version which does change the pagination but this is a complete report. This index is the last few pages of the study in all the versions. The red-line of the FS, which is what I have relied upon to show any and all changes in the FS, stops at p. 83 (p. 79 or Section 4.6.4.6 of the text), leading me to believe that was the extent of the revisions. You are correct that is the extent of the revisions to the report however there are some revisions to the references (pgs. 80-83). The red-lined version stops at p.83. This is a complete report. I just downloaded the red-lined version that is on our website and have attached it to this email. If you scroll to the end of the report you will see that the report ends at page 83. Deborah Cullen Director of Finance City of Rancho Palos Verdes 1 From: Eva Cicoria [mailto:cicoriae@aol.com] Sent: Tuesday, August 07, 2018 8:04 AM To: Doug Willmore <DWillmore@rpvca.gov>; Elias Sassoon <esassoon@rpvca.gov>; Deborah Cullen <DCullen@rpvca.gov> Cc: CC <CC@rpvca.gov> Subject: missing pages Hi all, We seem to be working with incomplete documents related to the Landslide Feasibility Study coming before City Council this evening. The Staff Report with attachments is 144 pages. The final FS included therein stops at p. 81 (B-88). The red-line of the FS, which is what I have relied upon to show any and all changes in the FS, stops at p. 83 (p.79 or Section 4.6.4.6 of the text), leading me to believe that was the extent of the revisions. Come to find out there is more to it. Is the general public only getting part of the materials? Did City Council get a more complete red-line? Can you please provide the public with a complete red-line reflecting all changes to the FS ASAP? Eva 2 CONCEPTUAL DRAINAGE ROUTING CITY OF PALOS V£ROE: DRAINAGE FEASIBILITY STUDY PORTUGUESE BEND SLIDE AREA PRO.ECr: 06.17.1200.00 i DATF : I Q/20/17 ORAIWI 8Y : &40 OCSICN BY: 840 Teresa Takaoka From: Sent: Eva Cicoria <cicoriae@aol.com> Tuesday, August 07, 2018 10:46 AM To: Cc: Doug Willmore; Elias Sassoon; Deborah Cullen cc Subject: Re: Landslide Feasibility Study I We agree. Thanks, Doug. Always good to find the point where staff and the community agree. Eva -----Original Message----- From: Doug Willmore <DWillmore@rpvca.gov> To: Eva Cicoria <cicoriae@aol.com>; Elias Sassoon <esassoon@rpvca.gov>; Deborah Cullen <DCullen@rpvca.gov> Cc: CC <CC@rpvca.gov> Sent: Tue, Aug 7, 2018 10:32 am Subject: RE: Landslide Feasibility Study Hi Eva, ln answer to your comments below: (1) Our staff report proposes addressing issues one at a time especially by focusing on eliminating the existing ponds at the bottom of the slide. That is exactly what we propose and you say that makes sense. We agree. (2) Testing of the infiltration in the canyons makes sense even if the City doesn't consider lining. When you identify how much of a problem it is (or is not) and also where those problems might be in the canyons (again, if any), it helps you identify steps you should take with the entire slide and how much money you should spend on those steps. (3) It is indeed "a storm drain under PVDS and pilot test of hydro-augers" with larger installations included to be informed by the pilot tests. (4) Doing a hydrology test of the canyons now actually helps us identify runoff going into the canyons from RH. Doug From: Eva Cicoria [mailto:cicoriae@aol.com] Sent: Monday, August 06, 2018 4:18 PM To: Doug Willmore <DWillmore@rpvca.gov>; Elias Sassoon <esassoon@rpvca.gov>; Deborah Cullen < DCu lie n@rpvca.gov> Cc: CC <CC@rpvca.gov> Subject: Re: Landslide Feasibility Study Thank you, Doug. I very much appreciate you taking the time to respond. I've addressed each of your comments, embedded below. 1) The engineers were hired to express their professional opinion about an issue. While they want to listen to residents to see if the input can improve their methodology, or their thinking, it's not their job to change their professional recommendations because some members of the public want something different. If they did that, the City shouldn't hire them. The City wants their professional opinion. Their 1 job is to give their professional recommendation, based on available information, on what is needed to slow the movement of the slide down. That is what they have done. Partially, yes, insofar as the Study sticks to the consultants' area of expertise. But recall Table 3 in the FS that rates lining the channels down the canyons with concrete as O/poor for environmental impacts and community acceptance. Concrete channels were taken off the table in part because of this. The flexible liner system ought to be taken off the table as well. These consultants as far as I can tell are not experts in either native vegetation or our community, yet they included both in their Study. The flexible liner system was rated 2/good for environmental impacts, yet doesn't seem to be a whole lot different from the concrete as far as environmental impacts. PVPLC and other experts in the field of CA natives as well as members of the public with significant experience involving the PBLC and the Palos Verdes Nature Preserve identified a host of adverse environmental impacts anticipated with the flexible liner system. The consultants ought to at the very least acknowledge the input and their amended report ought to reflect the anticipated impacts they hadn't been aware of/understood. As for community acceptability, these consultants don't know our community, yet rated community acceptability of the flexible liner system as a 2/good. It would seem to be outside their area of expertise to rate what is acceptable in our canyons. With the majority of public comments indicating that the liner system would be unacceptable, it seems to me that the consultants ought to at the very least acknowledge it. The Staff Report starts out saying that the options for beginning to control the land movement are going to be addressed one at a time. In particular, Staff wants to begin by "focusing on eliminating any existing ponds which have been created over the years due to land settlement and/or relocation of pipes/culverts." That makes sense. Let's do that and see where we are. (2) The hydrologic studies of the canyons can be very valuable in many ways short of lining the entirely of all three major canyons in the PB preserve. For example, if infiltration in the canyons is occurring, where is it occurring? Is infiltration in the canyons even occurring at any significant rate? Can any infiltration in the canyons be ignored because others steps in other areas can make enough of a difference? In other words, a study in the canyons could tell us that it is not enough of an issue to worry about and that we could spend all of our efforts on other fixes and still be able to reach our goal. Or, it could tell us that it isn't the entirety of all three canyons that is the issue, but rather just three limited spots in the three canyons. Knowing the answers to these questions help the Council decide what to do about the slide in other avenues in coming years, if anything. I don't disagree that testing of water infiltration in the canyons could be worthwhile if lining the canyons were an acceptable option, but it's not, especially not at this time when there are other options that ought to be tried first. Staff recommends putting off extraction wells for a time and that makes sense; why not put off anything that will disturb the canyons as well? (3) The drainage and hydro-augers at the bottom of the slide need limited study and experimentation (and will be built into the engineering work). In addition, almost all of the work will be done on non-preserve property and will result in under the surface infrastructure. It's not clear what the drainage work and hydro-augers at the bottom of the slide actually consist of. Is the idea to build some sort of water conveyance from the head scarp down to PVDS or is it a storm drain under PVDS and pilot test of hydro-augers for possible larger installation later? Perhaps the presentation to City Council will make this clear, but if you have anything to add color, that would be appreciated. (4) Regarding an overall hydrology study for entire slide area (that you reference), we are not recommending one at this time. Before more extraction wells are installed, one will be needed. We are hoping that the drainage work at the bottom of the slide and working with RH to reduce runoff and infiltration from septic systems at the top can slow the slide enough to then do an accurate, up to date hydrology study that would allow the placement of extraction wells that won't get sheared off (because 2 movement has slowed). Fine, then let's please take the same approach with the canyons. Let's hope that the drainage work at the bottom of the slide as well as working with RH to reduce their runoff and septic system discharge makes a significant difference, then try extraction wells if that's warranted. Remember, we are living under drought conditions and taking out all of the water raises its own issues. Swinging too far to solve one problem invariably leads to other problems. Let's take it slow; one measure at a time and see where we are. Thanks again for engaging. Eva -----Original Message----- From: Doug Willmore <DWillmore@rpvca.gov> To: Eva Cicoria <cicoriae@aol.com>; Elias Sassoon <esassoon@rpvca.gov>; Deborah Cullen <DCullen@rpvca.gov> Cc: CC <CC@rpvca.gov> Sent: Mon, Aug 6, 2018 12:24 pm Subject: RE: Landslide Feasibility Study Hi Eva, Thanks again for expressing your thoughts. There were a couple of ideas you brought up that I thought I should speak to. (1) The engineers were hired to express their professional opinion about an issue. While they want to listen to residents to see if the input can improve their methodology, or their thinking, it's not their job to change their professional recommendations because some members of the public want something different. If they did that, the City shouldn't hire them. The City wants their professional opinion. Their job is to give their professional recommendation, based on available information, on what is needed to slow the movement of the slide down. That is what they have done. (2) The hydro logic studies of the canyons can be very valuable in many ways short of lining the entirely of all three major canyons in the PB preserve. For example, if infiltration in the canyons is occurring, where is it occurring? Is infiltration in the canyons even occurring at any significant rate? Can any infiltration in the canyons be ignored because others steps in other areas can make enough of a difference? In other words, a study in the canyons could tell us that it is not enough of an issue to worry about and that we could spend all of our efforts on other fixes and still be able to reach our goal. Or, it could tell us that it isn't the entirety of all three canyons that is the issue, but rather just three limited spots in the three canyons. Knowing the answers to these questions help the Council decide what to do about the slide in other avenues in coming years, if anything. (3) The drainage and hydro-augers at the bottom of the slide need limited study and experimentation (and will be built into the engineering work). In addition, almost all of the work will be done on non-preserve property and will result in under the surface infrastructure. (4) Regarding an overall hydrology study for entire slide area (that you reference), we are not recommending one at this time. Before more extraction wells are installed, one will be needed. We are hoping that the drainage work at the bottom of the slide and working with RH to reduce runoff and infiltration from septic systems at the top can slow the slide enough to then do an accurate, up to date hydrology study that would allow the placement of extraction wells that won't get sheared off (because movement has slowed). Doug From: Eva Cicoria [mailto:cicoriae@aol.com] Sent: Monday, August 06, 2018 10:06 AM To: Elias Sassoon <esassoon@rpvca.gov> 3 Cc: CC <CC@rpvca.gov> Subject: Re: Landslide Feasibility Study Thank you, Elias. I appreciate your comment. I actually did read the Staff Report and was happy to see that it is not recommending that the canyons be lined at this time. However, it does recommend that Staff develop a RFP "for performing hydrologic study and engineering analysis of the canyons [emphasis added] to identify where, how, and to what extent the stormwater infiltrates into the groundwater". Considering that the consultants neither removed canyon lining as an option in the Study, nor revised their rating of it as a "good" option, nor changed the costs to reflect any significant change in their original recommendation, concerns remain that at some point this will come back and what folks will remember will be what is in the Study, not the long list of criticisms of it. Moreover, City Council doesn't always follow the recommendations of staff reports. To be clear, I'm not opposed to spending money to study the slide more closely. I believe more should be spent on studying the lower reaches of the slide complex, not the canyons (which we should leave alone). At the last public meeting, I suggested that the City look into engaging a research institution to do the study. Was that pursued? A related matter is whether you can provide a little color on what the $150,000 for hydrologic study and engineering analysis would get us. A friend of mine, an expert in the field, tells me that the sort of data one really wants for a hydrologic study would be 1) a time series of several types of data at several locations within the watershed or drainage area: precipitation, streamflow (if any), outflow or ponding (if any), and any data on water that was extracted due to the various extraction wells RPV put in over the years. The time series should be long enough to form a picture of the hydrology in both wet and dry years. And since the extraction wells could have changed things, you'd want a time series that spans from before and across implementation of these wells. And you'd want it to extend to a relatively recent time. 2) soil type, slope, etc., which would involve drilling down in various locations to get soil types. The consultants have said that they have not taken any measurements on the land. Rather, they relied on historic data. Yet they have also indicated that there is insufficient data, aka data gaps. What do they propose to do to fill those data gaps on the ground? 4 My sense is that the Staff is recommending going forward with installing hydro-augers without completing study of what is going on in the slide. The need for a complete study is something the public and, I thought, the consultants agreed on. Eva -----Original Message----- From: Elias Sassoon <esassoon@rpvca.gov> To: 'cicoriae@aol.com' <cicoriae@aol.com> Cc: CC <CC@rpvca.gov> Sent: Mon, Aug 6, 2018 9:14 am Subject: RE: Landslide Feasibility Study Hi: Thank you for your email. Your email will be included in late correspondence. However, if you would, please read the staff report accompanying the fcasibil1ty study. The staff report is not rccomrncnding that the canyons be lined. Thanks: Elias K. Sassoon, Director Department of Public Works City of Rancho Palos Verdes 30940 Hawthorne Blvd. Rancho Palos Verdes, CA 90275 Tel: 310-544-5335 From: Eva Cicoria <cicoriae@aol.com> Sent: Sunday, August 5, 2018 8:00:56 AM To: CC Subject: Landslide Feasibility Study Dear Mayor Brooks, Mayor Pro Tern Duhovic, and Councilmembers Alegria, Cruikshank and Dyda, The early draft of the Landslide Feasibility Study recommended lining the canyons with a geotextile fabric and planting islands of native plants in sacks here and there to provide some "habitat" and make the canyons more aesthetically appealing. The consultants rated that aspect of their recommendations as "good" (a 2 on a scale of 0-3, 0 being unacceptable), both in terms of how environmentally sound it is and in terms of how acceptable it would be to the community. 5 At the last public meeting on the subject of the landslide, I asked the consultants how they could rate canyon lining as high as they have after all the feedback from the public, including experts in the field of California native plants and representatives of the PVP Land Conservancy and the Sierra Club, all of whom were critical of this approach both for its direct and indirect impacts to the vegetation, wildlife, erosion control, aesthetics, and more. The consultants' response? To paraphrase, "There's another 40,000 people who haven't weighed in and we think they would say the canyon lining is a good approach." In the edited Landslide Feasibility Study, geotextile lining of the canyons is still recommended. The report shows no indication that the "good" rating assigned to lining the canyons has been reduced either in terms of environmental soundness or in terms of community acceptability to reflect input received. Nor has the cost estimate for the work changed. So it seems that the consultants have disregarded the public's concerns. Ripping out the deep-rooted, long-established canyon vegetation and removing water flow to the land completely will bring a host of problems not addressed by the consultants' report. Please reject this study's recommendation regarding the canyon liner system and put no further resources toward implementing·that recommendation. There are other options to reduce the groundwater recharge in the area of land movement, including converting septic tanks to new sewer lines (including those in Rolling Hills), reducing excess irrigation affecting the watershed area, and installing horizontal drains under Palos Verdes Drive South to move the water out to the ocean. City Council has historically expressed interest in increased public input into decision making. Well, the public has shown up and weighed in on this issue and to have us utterly disregarded is not only disrespectful, it calls into question whether these consultants ought to be engaged by our city for any further work at all. Eva Cicoria 6 Teresa Takaoka From: Sent: To: Cc: Subject: Hi all, Eva Cicoria <cicoriae@aol.com> Tuesday, August 07, 2018 8:04 AM Doug Willmore; Elias Sassoon; Deborah Cullen cc missing pages We seem to be working with incomplete documents related to the Landslide Feasibility Study coming before City Council this evening. The Staff Report with attachments is 144 pages. The final FS included therein stops at p. 81 (B-88). The red-line of the FS, which is what I have relied upon to show any and all changes in the FS, stops at p. 83 (p.79 or Section 4.6.4.6 of the text), leading me to believe that was the extent of the revisions. Come to find out there is more to it. Is the general public only getting part of the materials? Did City Council get a more complete red-line? Can you please provide the public with a complete red-line reflecting all changes to the FS ASAP? 1 Teresa Takaoka From: Eva Cicoria <cicoriae@aol.com> Monday, August 06, 2018 4:18 PM Sent: To: Cc: Doug Willmore; Elias Sassoon; Deborah Cullen cc Subject: Re: Landslide Feasibility Study Thank you, Doug. I very much appreciate you taking the time to respond. I've addressed each of your comments, embedded below. 1) The engineers were hired to express their professional opinion about an issue. While they want to listen to residents to see if the input can improve their methodology, or their thinking, it's not their job to change their professional recommendations because some members of the public want something different. If they did that, the City shouldn't hire them. The City wants their professional opinion. Their job is to give their professional recommendation, based on available information, on what is needed to slow the movement of the slide down. That is what they have done. Partially, yes, insofar as the Study sticks to the consultants' area of expertise. But recall Table 3 in the FS that rates lining the channels down the canyons with concrete as O/poor for environmental impacts and community acceptance. Concrete channels were taken off the table in part because of this. The flexible liner system ought to be taken off the table as well. These consultants as far as I can tell are not experts in either native vegetation or our community, yet they included both in their Study. The flexible liner system was rated 2/good for environmental impacts, yet doesn't seem to be a whole lot different from the concrete as far as environmental impacts. PVPLC and other experts in the field of CA natives as well as members of the public with significant experience involving the PBLC and the Palos Verdes Nature Preserve identified a host of adverse environmental impacts anticipated with the flexible liner system. The consultants ought to at the very least acknowledge the input and their amended report ought to reflect the anticipated impacts they hadn't been aware of/understood. As for community acceptability, these consultants don't know our community, yet rated community acceptability of the flexible liner system as a 2/good. It would seem to be outside their area of expertise to rate what is acceptable in our canyons. With the majority of public comments indicating that the liner system would be unacceptable, it seems to me that the consultants ought to at the very least acknowledge it. The Staff Report starts out saying that the options for beginning to control the land movement are going to be addressed one at a time. In particular, Staff wants to begin by "focusing on eliminating any existing ponds which have been created over the years due to land settlement and/or relocation of pipes/culverts." That makes sense. Let's do that and see where we are. (2) The hydro logic studies of the canyons can be very valuable in many ways short of lining the entirely of all three major canyons in the PB preserve. For example, if infiltration in the canyons is occurring, where is it occurring? Is infiltration in the canyons even occurring at any significant rate? Can any infiltration in the canyons be ignored because others steps in other areas can make enough of a difference? In other words, a study in the canyons could tell us that it is not enough of an issue to worry about and that we could spend all of our efforts on other fixes and still be able to reach our goal. Or, it could tell us that it isn't the entirety of all three canyons that is the issue, but rather just three limited spots in the three canyons. Knowing the answers to these questions help the Council decide what to do about the slide in other avenues in coming years, if anything. I don't disagree that testing of water infiltration in the canyons could be worthwhile if lining the canyons were an acceptable option, but it's 1 not, especially not at this time when there are other options that ought to be tried first. Staff recommends putting off extraction wells for a time and that makes sense; why not put off anything that will disturb the canyons as well? (3) The drainage and hydro-augers at the bottom of the slide need limited study and experimentation (and will be built into the engineering work). In addition, almost all of the work will be done on non-preserve property and will result in under the surface infrastructure. It's not clear what the drainage work and hydro-augers at the bottom of the slide actually consist of. Is the idea to build some sort of water conveyance from the head scarp down to PVDS or is it a storm drain under PVDS and pilot test of hydro-augers for possible larger installation later? Perhaps the presentation to City Council will make this clear, but if you have anything to add color, that would be appreciated. (4) Regarding an overall hydrology study for entire slide area (that you reference), we are not recommending one at this time. Before more extraction wells are installed, one will be needed. We are hoping that the drainage work at the bottom of the slide and working with RH to reduce runoff and infiltration from septic systems at the top can slow the slide enough to then do an accurate, up to date hydrology study that would allow the placement of extraction wells that won't get sheared off (because movement has slowed). Fine, then let's please take the same approach with the canyons. Let's hope that the drainage work at the bottom of the slide as well as working with RH to reduce their runoff and septic system discharge makes a significant difference, then try extraction wells if that's warranted. Remember, we are living under drought conditions and taking out all of the water raises its own issues. Swinging too far to solve one problem invariably leads to other problems. Let's take it slow; one measure at a time and see where we are. Thanks again for engaging. Eva -----Original Message----- From: Doug Willmore <DWillmore@rpvca.gov> To: Eva Cicoria <cicoriae@aol.com>; Elias Sassoon <esassoon@rpvca.gov>; Deborah Cullen <DCullen@rpvca.gov> Cc: CC <CC@rpvca.gov> Sent: Mon, Aug 6, 2018 12:24 pm Subject: RE: Landslide Feasibility Study Hi Eva, Thanks again for expressing your thoughts. There were a couple of ideas you brought up that I thought I should speak to. (1) The engineers were hired to express their professional opinion about an issue. While they want to listen to residents to see if the input can improve their methodology, or their thinking, it's not their job to change their professional recommendations because some members of the public want something different. If they did that, the City shouldn't hire them. The City wants their professional opinion. Their job is to give their professional recommendation, based on available information, on what is needed to slow the movement of the slide down. That is what they have done. (2) The hydro logic studies of the canyons can be very valuable in many ways short of lining the entirely of all three major canyons in the PB preserve. For example, if infiltration in the canyons is occurring, where is it occurring? Is infiltration in the canyons even occurring at any significant rate? Can any infiltration in the canyons be ignored because others steps in other areas can make enough of a difference? In other words, a study in the canyons could tell us that it is not enough of an issue to worry about and that we could spend all of our efforts on other fixes and still be able to reach our goal. Or, it 2 could tell us that it isn't the entirety of all three canyons that is the issue, but rather just three limited spots in the three canyons. Knowing the answers to these questions help the Council decide what to do about the slide in other avenues in coming years, if anything. (3) The drainage and hydro-augers at the bottom of the slide need limited study and experimentation (and will be built into the engineering work). In addition, almost all of the work will be done on non-preserve property and will result in under the surface infrastructure. (4) Regarding an overall hydrology study for entire slide area (that you reference), we are not recommending one at this time. Before more extraction wells are installed, one will be needed. We are hoping that the drainage work at the bottom of the slide and working with RH to reduce runoff and infiltration from septic systems at the top can slow the slide enough to then do an accurate, up to date hydrology study that would allow the placement of extraction wells that won't get sheared off (because movement has slowed). Doug From: Eva Cicoria [mailto:cicoriae@aol.com] Sent: Monday, August 06, 2018 10:06 AM To: Elias Sassoon <esassoon@rpvca.gov> Cc: CC <CC@rpvca.gov> Subject: Re: Landslide Feasibility Study Thank you, Elias. I appreciate your comment. I actually did read the Staff Report and was happy to see that it is not recommending that the canyons be lined at this time. However, it does recommend that Staff develop a RFP "for performing hydro logic study and engineering analysis of the canyons [emphasis added] to identify where, how, and to what extent the stormwater infiltrates into the groundwater". Considering that the consultants neither removed canyon lining as an option in the Study, nor revised their rating of it as a "good" option, nor changed the costs to reflect any significant change in their original recommendation, concerns remain that at some point this will come back and what folks will remember will be what is in the Study, not the long list of criticisms of it. Moreover, City Council doesn't always follow the recommendations of staff reports. To be clear, I'm not opposed to spending money to study the slide more closely. I believe more should be spent on studying the lower reaches of the slide complex, not the canyons (which we should leave alone). At the last public meeting, I suggested that the City look into engaging a research institution to do the study. Was that pursued? A related matter is whether you can provide a little color on what the $150,000 for hydrologic study and engineering analysis would get us. A friend of mine, an expert in the field, tells me that the sort of data one really wants for a hydrologic study would be 1) a time series of several types of data at several locations within the watershed or drainage area: precipitation, streamflow (if any), outflow or ponding (if any), and any data on water that was extracted due to the various extraction wells RPV put in over the years. The time series should be 3 long enough to form a picture of the hydrology in both wet and dry years. And since the extraction wells could have changed things, you'd want a time series that spans from before and across implementation of these wells. And you'd want it to extend to a relatively recent time. 2) soil type, slope, etc., which would involve drilling down in various locations to get soil types. The consultants have said that they have not taken any measurements on the land. Rather, they relied on historic data. Yet they have also indicated that there is insufficient data, aka data gaps. What do they propose to do to fill those data gaps on the ground? My sense is that the Staff is recommending going forward with installing hydro-augers without completing study of what is going on in the slide. The need for a complete study is something the public and, I thought, the consultants agreed on. Eva -----Original Message----- From: Elias Sassoon <esassoon@rpvca.gov> To: 'cicoriae@aol.com' <cicoriae@aol.com> Cc: CC <CC@rpvca.gov> Sent: Mon, Aug 6, 2018 9:14 am Subject: RE: Landslide Feasibility Study Hi: Thank vou for vour email. ., •. Your email will be included in late correspondence. However, if you would, please read the staff report accompanying the feasibility study. The staff report is not recomrnending that the canyons be lined. Thanks: Elias K. Sassoon, Director Department of Public Works City of Rancho Palos Verdes 30940 Hawthorne Blvd. Rancho Palos Verdes, CA 90275 Tel: 310-544-5335 4 From: Eva Cicoria <cicoriae@aol.com> Sent: Sunday, August 5, 2018 8:00:56 AM To: CC Subject: Landslide Feasibility Study Dear Mayor Brooks, Mayor Pro Tern Duhovic, and Councilmembers Alegria, Cruikshank and Dyda, The early draft of the Landslide Feasibility Study recommended lining the canyons with a geotextile fabric and planting islands of native plants in sacks here and there to provide some "habitat" and make the canyons more aesthetically appealing. The consultants rated that aspect of their recommendations as "good" (a 2 on a scale of 0-3, 0 being unacceptable), both in terms of how environmentally sound it is and in terms of how acceptable it would be to the community. At the last public meeting on the subject of the landslide, I asked the consultants how they could rate canyon lining as high as they have after all the feedback from the public, including experts in the field of California native plants and representatives of the PVP Land Conservancy and the Sierra Club, all of whom were critical of this approach both for its direct and indirect impacts to the vegetation, wildlife, erosion control, aesthetics, and more. The consultants' response? To paraphrase, "There's another 40,000 people who haven't weighed in and we think they would say the canyon lining is a good approach." In the edited Landslide Feasibility Study, geotextile lining of the canyons is still recommended. The report shows no indication that the "good" rating assigned to lining the canyons has been reduced either in terms of environmental soundness or in terms of community acceptability to reflect input received. Nor has the cost estimate for the work changed. So it seems that the consultants have disregarded the public's concerns. Ripping out the deep-rooted, long-established canyon vegetation and removing water flow to the land completely will bring a host of problems not addressed by the consultants' report. Please reject this study's recommendation regarding the canyon liner system and put no further resources toward implementing that recommendation. There are other options to reduce the groundwater recharge in the area of land movement, including converting septic tanks to new sewer lines (including those in Rolling Hills), reducing excess irrigation affecting the watershed area, and installing horizontal drains under Palos Verdes Drive South to move the water out to the ocean. City Council has historically expressed interest in increased public input into decision making. Well, the public has shown up and weighed in on this issue and to have us utterly disregarded is not only 5 disrespectful, it calls into question whether these consultants ought to be engaged by our city for any further work at all. Eva Cico1'ia 6 Teresa Takaoka From: Sent: To: Subject: Elizabeth Sala <etsala@live.com> Monday, August 06, 2018 8:08 PM cc Landslide Feasibility Study Dear Mayor Brooks, Mayor Pro Tern Duhovic, and Councilmembers Alegria, Cruikshank and Dyda, Regarding the alternatives in the Landslide Feasibility Study, please remove the option of lining the canyons with a geotextile fabric. The lining proposed would alter the nature of the canyons in destructive ways. The process lined out in the Staff report seems reasonable. Thank you, Elizabeth Sala Teresa Takaoka From: Sent: To: Cc: Subject: Phil Adler <philatpv@gmail.com> Monday, August 06, 2018 4:21 PM So Kim Susan Brooks; George Zugsmith; CC; Ara Mihranian Re: RPV Notice of August 2, 2018 Hi there - I just wanted to thank you for the prompt and detailed reply. Sincerely, Phil Adler On Fri, Aug 3, 2018 at 10:22 AM, So Kim <SoK@rpvca.gov> wrote: Dear Mr. Adler, Currently, there is a total of 4 beach trail access from the Trump National Golf Club property, which will remain {see attached PDF file -existing beach trails shown in brown). The trail to be removed is shown in green in the image below. This was never part of the Public Amenities Plan and is not an official trail. A resident mentioned this path at the last City Council hearing and the Council asked Staff why this was not part of the trails plan. At the time, I did not have enough information other than the fact that it's an unofficial trail and it is too steep for safe access. Based on that, the Council directed Staff to add this to the trails plan. Since that time, I did more research and found that this trail/pathway traverses existing habitat areas and both the Coastal Commission and the CA Dept of Fish/Wildlife are not in support of making this an official trail for that reason. This is why this trail was never part of the original 1997 Public Amenities Plan. Additionally, one of the conditions tied to this tract is to have a 32' setback from the west property line to any trails. l<eeping this trail would not be in compliance with this condition. As a result, we will be requesting that the City Council consider removing this trail from the trails plan. I hope this helps and please feel free to contact me with additional questions. 1 Sincerely, So Kim, AJCP Deputy Director/Planning Manager Community Development Department City of Rancho Palos Verdes www.rpvca.gov (310) 544-5222 From: Phil Adler [mailto:philatpv@gmail.com] Sent: Thursday, August 02, 2018 8:36 PM To: So Kim <SoK@rpvca.gov> Cc: Susan Brooks <SusanB@rpvca.gov>; George Zugsmith <zuggielaw@gmail.com> Subject: RPV Notice of August 2, 2018 Ladies and Gentlemen, 2 This is in response to the Notice bearing today's date regarding the Application of V.H. Property Corp. There does not appear to be any number associated with the Application or the Notice. I have both a procedural issue and a fundamental issue concerning this matter: 1. From a procedural standpoint, as a retired attorney, I would point out that the Notice is highly defective, as there appears to be a number of paths down to the beach from what I believe to be the Trump property. Whether any or all are encompassed by this Notice is impossible to determine from this Notice. I have in fact hiked most of them, and I have no idea to which one this Notice refers. To protect the City from future litigation, I would certainly recommend as a concerned citizen that you provide a revised Notice to include a map showing exactly to which of the trails this Application refers and which are excluded. 2. From a fundamental perspective, as a long time resident (since 1972) who enjoys hiking the trails ofRPV, I cannot understand, at least from this Notice, what community benefit will be derived from the elimination of any such trails. I would encourage the City to deny any Application which would result in the revocation of beach access rights which are in the public domain. I thank you for your time and attention. Phil Adler 3 TO: FROM: DATE: SUBJECT: CITY OF RJ\NCHO PALOS VERDES HONORABLE MAYOR & CITY COUNCIL MEMBERS CITY CLERK AUGUST 6, 2018 ADDITIONS/REVISIONS AND AMENDMENTS TO AGENDA Attached are revisions/additions and/or amendments to the agenda material received through Monday afternoon for the Tuesday, August 7, 2018 City Council meeting: Item No. 1 2 Description of Material Email from Roma S. Khan Emails from: Noel Park; SUNSHINE; Al & Barbara Sattler; Eva Cicoria; Mike Kilroy; Joyce White; Kathy Hill; Ann Shaw; Dr. L. Varner; John R. (Rod) Jensen; Anita Caplan; Joan Kelly; David Berman; Tony Baker; and Kathy Nichols Respectfully submitted, W:\01 City Clerk\LATE CORRESPONDENCE\2018 Cover Sheets\20180807 additions revisions to agenda thru Monday.doc Teresa Takaoka From: Sent: To: Cc: Subject: Attachments: khanr@gtlaw.com Thursday, August 02, 2018 5:40 PM Susan Brooks; CC berkowitze@gtlaw.com Green Hills Memorial Park 133762110_v 1_2018.08.02 -Ltr from E. Berkowitz to City Council.PDF Dear Mayor Brooks and Honorable Councilmembers: Please see the attached correspondence. Thank you, RoVVtC! s. J<'.,VJC!V\, Assistant to E. Berkowitz, B. Corl, M. Neighbors & R. Tabura Greenberg Traurig, LLP 11840 Century Park East Suite 1900 I Los Angeles, CA 90067-2121 T +1 310 586 6543 1;unU I G ~-. ·----·----I PLEASE COi<SiUER THE ENV!RONAALH·r L\LFORE PRlt~·r!NG THlS ENlA!L If you are not an intended recipient of confidential and privileged information in this email, please delete it, notify us immediately at postmaster@gtlaw.com, and do not use or disseminate such information. 1 /. GreenbergTraurig Ellen Berkowitz Tel 310.586. 7763 Fax 310.586. 7800 berkowitze@gtlaw.com August 2, 2018 VIA E-MAIL AND FIRST-CLASS MAIL Mayor Susan Brooks and Honorable City Council Members City of Rancho Palos Verdes 30940 Hawthorne Boulevard Rancho Palos Verdes, California 90275 Susan.Brooks(O]rpvca.gov cc(ajrpvca.gov Re: Green Hills Memorial Park Dear Mayor Brooks and Honorable Councilmembers: This law firm represents Green Hills Memorial Park (GHMP). We are submitting this letter to request denial of the appeal (Appeal) filed by Sharon Loveys, challenging the Planning Commission's denial of her previous appeal challenging the Planning Director's approval of GHMP's grading permit for Area 2. Most of Ms. Loveys' appeals (presumably ghost written by her overly verbose attorney), consist of pages upon pages of arguments, exhibits, and supporting documentation, which -given sufficient time, energy and focus -ultimately reveal only about one or two basic arguments. (After all, why say in 3 or 4 pages what could be said in 40?) The Appeal is no exception. This time, however, we are spared the brain damage and pain of wading through every last syllable to reach the salient point: the Appeal contains a helpful and handy summary of its principal argument (albeit with a few unfortunate typographical errors) on the cover page. For those of us with short attention spans (and poor eyesight, who actually appreciate the use of all caps), we now know the essence of the Appeal is as follows: "THE CORE IDEA IS THAT THERE CAN NO [SIC] DEVELOPMEN'r OF OPEN SPACE IN THERE [SIC] CEMETERY UNTIL THERE IS A MASTER PLAN IN PLACE WHICH CONTEMPLATES DEVELOPMENT OF ANY SUCH OPEN SPACE ... JUST BECAUSE GREEN HILLS HAS A CONDITIONAL RIGHT TO DEVELOP SOME AREAS OF THE CEMETERY DOES NOT MEAN GREEN HILLS HAS THE UNCONDITIONAL RIGHT TO DEVELOP ALL AREAS OF THE CEMETERY ... " (Appeal cover page.) LA 133761579v1 GREENBERG TRAURIG, LLP • ATTORNEYS AT LAW • WWW.GTLAW.COM 1840 Century Park East, Suite 1900, Los Angeles, California 90067·2121•Tel:310.586.7700 •Fax 310.586.7800 ALgt\NY AMSTERDAM AEANlA NJST!N 3El1UN·, BOCA RATON CHiGt\GO 01\U.fS DEl.AWf\RE DLNVU FOET LAUDEROM.E HOUSTON LASVFCAS LONDON~ LOS ANGELES MEX!CO G\!'Y' NEWYtmK NORTHERN ViRG!Ni/\ ORf.NGt COUNTY ORLANDO HOMP"" Si\GHMM:Nrn SAN FRANCISC:C $t'OUL SHANGHAI SiUGON VAU ... f:Y TAl.LAHASS!~F TAMPA Tfl. A\JiV'' TOKYO" WASHINGTON, f).(:, Vl/f:STGHFSTLR COUNTY Mayor Brooks and Honorable Councilmembers August 2, 2018 Page 2 In other words, the Appeal claims that: (i) the Master Plan did not contemplate development in Area 2; and, (ii) as a result, GHMP must obtain a conditional use permit (CUP) to amend the Master Plan to grade Area 2 and add lawn crypts. Before we address the merits of this argument, indulge me in digressing in a brief aside. The concept "development of open space" (a phrase so loved by the author that it's been used twice in this short paragraph) typically requires two components: development and open space. Neither is present here, at least not in the sense that most people think of them. "Development" typically connotes construction of some type of structure. Think, for example, of the "development" of a shopping center or "development" of an airport. And "open space" typically connotes some kind of heretofore undeveloped greenfield or parkland. Think, for example, of destroying a forest or a meadow to build that shopping center or airport. For most people, such thoughts elicit an immediate and visceral negative response. Few would applaud the notion of bulldozing pristine wilderness to build an airport or put up a parking lot. That's the emotion the Appeal seeks to elicit. But here, the "development" involves the placement of burials within (and flush to) the ground, and the "open space" is the cemetery grounds itself. At the risk of stating the obvious, that's what happens in a cemetery: burials are placed in the ground. Least we accuse the Appeal of being manipulative, calling ground burials in a cemetery "development of open space" is a decided "spin" and choice of language that seems to us to be -if not deceitful -certainly manipulative. But enough of this. Back to the Appeal. The entire premise of the Appeal is faulty. The 2007 Master Plan very clearly, very explicitly and very deliberately contemplated and approved development of a mausoleum and placement of ground burials in Area 2. A look at the Master Plan map unequivocally depicts development in Area 2, as do the accompanying materials in the Master Plan booklet (the "Cut and Fill" map, the "Dirt Movement Chart," and pages 2A-G). The introductory pages of the Master Plan booklet, which contain the estimates of anticipated burials that may be accommodated within Area 2 (the estimates that the Appellant continually mischaracterizes as a "cap" on maximum density within the park) indicate that Area 2 is anticipated to have 388 single depth lawn crypts, 1820 double depth lawn crypts and 48 family estates (with an estimated capacity of 8-12 individuals each), for a total estimated capacity of 4404 burials (not including the mausoleum). Indeed, so obvious is the fact that Area 2 was called out for "development" that it is actually mystifying how the Appeal can repeatedly state that the Master Plan never contemplated development here. Moreover -and again at the risk of stating the obvious -GHMP is a cemetery. Cemeteries do not have "open space." Cemeteries use their open space to bury individuals. That's why Condition of Approval l.e. provides that: "Earth interments are permitted throughout the cemetery, including family estates." No additional CUP is required for earth interments. The Appeal is simply off-base and misguided. Given this, there is really no need to address the plethora of other arguments raised in the Appeal (for example, CUP findings are not necessary because a CUP is not necessary, the Master Plan is not being modified, the mediation LA 133761579v1 :\TTORNf."Y~;) 1\T I.A\/>/ VVVVVV,CTL./\\N,COf'.-l Mayor Brooks and Honorable Councilmembers August 2, 2018 Page 3 condition has been deemed fulfilled, and the claims that GHMP's CUP should be revoked are pure nonsense). Given our abhorrence to saying in 40 pages what can be said in 3-4, we will save a response to those issues for the public hearing should the Council have any questions. Before we close, however, there is one other point worth mentioning, and that is the concept of density. The 2007 Master Plan was intended to guide development of GHMP for decades into the future. As such, estimates were made of the total number of burials that could be accommodated within the mausoleums, within niches (although often these were noted as "to be determined"), and within single depth lawn crypts, double depth lawn crypts and family estates within the areas identified in the Master Plan for future development. GHMP is generations away from achieving those numbers. As noted, the Master Plan estimated that Area 2 alone would hold more than 4400 ground burials. The 44 interments that are the subject of this grading request are not 44 additional interments -they are part of the 4400. GHMP has developed only a fraction of the build-out contemplated in the Master Plan; in fact, it is unlikely that any of us here today will live to see that build-out completed. * * * * Again, we request that you deny the Appeal. Thank you for your consideration. As always, my clients and I will be present at the hearing next Tuesday and would be happy to answer any questions you may have. Sincerely, /"\ (\ le <s~•" .. <, ... '•,, : Ellen Berkowitz Shareholder EB:rk LA 133761579v1 Teresa Takaoka From: Sent: To: Subject: Noel Park <noelparkone@gmail.com> Saturday, August 04, 2018 2:36 PM CC; Doug Willmore; Elias Sassoon; Ron Dragoo; Andrea Vona; Allen Franz; Tony Baker Council Agenda of 8/7 /18, Item 2 On reflection, Tony Baker's suggestion to revisit Option 1, repairing or rebuilding the existing corrugated metal pipe (CMP) system, would seem to offer some intriguing possibilities. As Tony related, the Feasibility Study (FS) speculates that the failure of same may be partially due to under design. Maybe, but observation in the field makes it pretty clear that most, if not all, of the failure was due to land movement. I doubt if the original design assumptions are still available, but perhaps someone could make a rough estimate of the maximum flow using standard storm drain sizing methods. If, in the fullness of time, the existing pipe proved to be too small, I'm sure that creative minds can come up with a fix. Side boarding the pipe comes to mind or, if worst comes to worst, larger pipe. I would support doing such a thing under the guise of "maintenance", thus enabling it to be done in a quicker time frame than going through the rightfully lengthy studies recommended by the FS. Likewise, if the "inlet structure(s)" are thought to be under designed, possibly they could be supplemented with some expedient such as sand bags. Sand bags can be supplemented with cement to prolong their lives. Likewise, I would support repairing or replacing the storm drain under PV Drive South (PVDS) on a "maintenance", or even emergency, basis. Event if, God forbid, detailed hydrologic studies should prove it to be undersized, it wouldn't be the end of the world to replace it or add a second pipe. Modern "corrugated" plastic pipe is available in sizes up to at least 60". It would seem to offer more flexibility and survivability in a ground movement environment than more conventional conduits. Plastic pipe might also offer a viable option if the existing CMP is not preferred. I envision it being laid on the surface along the alignment of the existing pipe and secured with some version of the stakes and collars used for overside drains I submit that we could just go ahead and fill up the "fissures" around the "head scarp" with on site dirt as a temporary expedient. Not as good as pumped in slurry perhaps, but way better than nothing. All of these things could be done on an expedited basis, and with minimum damage to the existing plant habitat. The geotechnical fabric/riprap channel system proposed in Option 3 may be more resistant to ground movement than a surface pipe alternative. But, given the magnitude of the movement in the lower areas of the slide at issue here, it seems inevitable that, in the interim before the movement significantly slows, there will be maintenance issues. If (when) the channels deform, and/or the fabric is compromised, the repairs could arguably be more difficult than repairing pipe. 1 As you know, I have been "from Missouri" regarding this project from the beginning. I have a commitment to use my very best efforts to protect the irreplaceable remaining mature Coastal Sage Scrub habitat in the Nature Preserve. That said, the process has raised my consciousness about the need to get the water out of the "head scarp" and the ponds behind PVDS as a matter of urgency. I believe that Tony has given us an excellent starting point for doing so on an expedited basis and with minimum environmental damage. I hope that you will give these suggestions every consideration. Sincerely, Noel Park 6715 El Rodeo Road Rancho Palos Verdes CA 90275 562-413-5147 2 Teresa Takaoka From: Sent: To: Cc: Subject: Noel Park <noelparkone@gmail.com> Friday, August 03, 2018 10:59 AM cc Andrea Vona; Deborah Cullen; Elias Sassoon; woulfe@fws.gov; Tony Baker; Doug Willmore Re: Proposed Portuguese Bend Landslide Abatement Enclosed is the email which Tony Baker sent to you regarding the above. Please incorporate it by reference into my comments. Mr. Baker is entirely too modest in stating his qualifications. He is a recognized expert on California native plants. Through his business, Natural Landscapes, he has created many highly successful native plant gardens around Palos Verdes and elsewhere. He is a long time member of the Palos Verdes Peninsula Land Conservancy and a long time highly influential member and officer of the local chapter of the the California Native Plant Society. I ask that you pay particular attention to his comments. I would also point out that the same points about the impossibility of replacing old growth native plant communities at all, let alone with plants in some sort of "soil sacks" in an impermeable liner, have been made over and over in public meetings and written comments throughout this process. One or more of those commenters is PhD qualified in directly related fields. In my comment letter on the first draft of the Feasibility Study I made basically these same points. I proposed that it: God forbid, it was deemed necessary to convey water out of the canyons, an intensive study be made to find less disruptive ways to do it. I even submitted a few modest suggestions. It must also be kept in mind that removing all of the seasonal flow in the canyons is unacceptable. If that is done, the native plant communities, and the wildlife which depend on them, will surely die. The idea that this canyon lining idea is acceptable to stakeholders is just wishful thinking. Anyone who attended the most recent public meeting must realize that. I appreciate that the proposed hydrologic study may obviate the need for lining the upper canyons. God send that it shall be true. If not, any fair minded analysis of the public input to date will clearly show that the option #3 proposal is unsustainable and unacceptable. Sincerely, Noel Park 6715 El Rodeo Road Rancho Palos Verdes CA 90275 ,_ On Aug 2, 2018 2:39 PM, "tony baker" <tbake377(@,gmail.com> wrote: Dear City Council Members and City Staff 1 a. As a long time resident of Portuguese Bend (1949 to present) and observer/participant of the infamous creeping landslide, I wish to state my strong opposition to the Storm Water Control Option #3 (aka Liner Channel System). It is stated that the flexible liner option is designed to be sustainable and will withstand damage from movement until long term land movement is significantly reduced. So ifthe land movement is not significantly reduced, then it will not be sustainable and need to be reconstructed or become non-functioning. It is also stated that this option is cost effective. The estimate for pilot testing is $512,000. The estimate to construct the system is estimated at $13.5 million. Estimate for 30 years is $16.8 million (assuming no reconstruction is needed). This is not cost effective especially in view of the fact that it is not a guaranteed solution. The footprint of the liner system will destroy some of the best established vegetation/habitat in the Palos Verdes Preserve. The canyons are especially valuable because they were not impacted or disturbed by the early cattle grazing and later farming that removed large swaths of native vegetation. By cutting back the sides of the canyons to install the liner system, vegetation that serves to hold soil in place, transpire precipitation and provide habitat for wildlife will be replaced by bare soil prone to erosion. The idea that "native plant islands" planted in soil bags with "native soil" and "designed to be integrated into native habitat" can even come close to replicating what would be removed is----well, laughable. It is not, as stated, an environmentally friendly option even though it is presented that it will be done with --little disruption (?). Option # 1 was taken off the table as unworkable. I think this option should be revisited. It is stated that the previous drain structures that were put in place to control and convey storm water to the ocean where it exits the upper canyons have failed and were abandoned 20 years ago. It is stated that the calculated flows were underestimated and the structures were undersized and head-works were under designed. As a result surface drainage was poor. This is true. So re-design. This system failed also partly due to lack of maintenance. Pipes separated at faults and were left to drain storm water into the land. The half pipe system was laid out across the flat area of the "Sandbox" and quickly filled with silt. If the half pipe had been located just north on the slope above, it would have had a drop all the way to the pipe under P.V. Dr. South. Please re-think the destructive and ill conceived flexible liner option #3 and take it off the table. Thank you for your consideration Anthony Baker 16 Limetree Lane Portuguese Bend 2 Teresa Takaoka From: Sent: To: Subject: Noel Park < noelparkone@gmail.com > Friday, August 03, 2018 3:17 PM CC; Doug Willmore; Deborah Cullen; Elias Sassoon; Andrea Vona; Tony Baker; Allen Franz Council agenda for 8/7 /18, Item 2, Portuguese Bend Landslide As to the revised Feasibly Study, I offer the following. The added paragraph about the need for ongoing stakeholder participation going forward is appreciated. However, it does not go far enough. I have repeatedly asked for an advisory committee, similar to that established for the Civic Center, to be implemented for this proposed project. There is a clear need for an interactive process, involving experts from the PVPLC and the community to work together to design a project which will acceptable to the community. Obvious community choices would include people of the caliber of Alan Franz, Tony Baker, Cassie Jones and Eva Cicoria. I will remark further on the immediate need for such input below. The substitution of a soil based slurry for concrete in the filling of surface cracks is a great improvement. The accompanying proposals for design and study funding are confusing and lack sufficient detail for me to understand. The proposal for a hydrologic study is welcome and appropriate. The scope however is unclear. Is it for the entire watershed, or only for the canyons above the "head scarp" area, otherwise known as the "sand box". A study of the canyons, to determine whether or not some sort of artificial water conveyance is actually necessary, is clearly a good idea. With the blessing, this could make the most controversial aspect of the project unnecessary. But surely, a study of the entire watershed is necessary. The other part of the proposal is to design water conveyance structures for the lower portion of the slide. How can these things be designed without accurate information on the potential flows? The Feasibility Study mentions that the former water conveyance system appears to have been under designed, which contributed to it's failure. On the other hand, if a system is designed based upon some sort of rule of thumb assumptions, it may be over designed and unnecessarily expensive. Clearly, accurate information is vital to successful design. The hydrologic study should come first. I would support its implementation as a matter of urgency. As to the proposed design budget for the construction, the staff report raises many questions. The scope of the water conveyance work is unclear. Is it only to build adequate infrastructure to carry the water under Palos Verdes Drive South and prevent ponding upstream thereof? Or is it to include a channel from the"head scarp" area to the above? And would this channel be of the Option 3 configuration? And would the latter require some kind of collection is infrastructure at its upstream end? 1 It would be very useful to have some sort of a sketch or other graphic to depict what is envisioned. If it is too late to distribute such a thing to the public, maybe it could at least be shown at the Council meeting. And, if all of the above is envisioned, would it not be appropriate to begin the filling of the surface cracks at the same time? If all of this work is intended, the budget request would appear to be inadequate. The Feasibility Study estimates $512,000 for data gaps and pilot testing of the liner and channel system. It estimates $100,000 for data gaps and pilot testing of sealing of surface fractures. This is over double the design budget requested Surely these things need to be done before final design commences. While this area of the project is much less controversial than the upper canyons, there is still a high potential for destruction of mature Coastal Sage Scrub habitat. This just emphasizes again the urgent need to create a process whereby experts, in whom the community has confidence, can help to route any channel and/or water collection structures to minimize habitat disruption, and devise effective mitigation for any unavoidable impacts. An finally, once again, how can these features be properly designed in the absence of a professional hydrologic study? As to the horizontal drains, there appears to be consensus on going ahead with them. But, once again, the budget does not seem to take into account the data gap and pilot testing estimate in the Feasibility Study (FS). The amount for "groundwater extraction and monitoring Wells" is $556,000. Doesn't this need to be done before we proceed to actual design? In the FS the point is clearly made that there is not enough historical data to adequately map the underground configuration of the underlying bedrock and the clay layer(s) or slip plane. I assume that this is part of the data gap. Again, in the presence of these data gaps, how can the system be properly designed? There seems to be agreement on the value of these steps, if they are thoughtfully design to avoid damage to the habit. But, we would appear to be proceeding without complete information. Millions of dollars have been spent over the years to try to stop the landslide. All of the projects have failed. We need to do it right so it works this time. As to the septic tanks in Rolling Hills, I am in favor of having them removed by whatever means necessary. The FD also recommends removing the remaining septic tanks in Portuguese Bend. I see nothing about that here. Surely, that will be less complicated than dealing with Rolling Hills. It should be addressed as a matter of urgency. It appears from the FD that the amount of storm and/or irrigation runoff corning into the slide are from Rolling Hills is greater than the amount of septic tank effluent. In fact, it approximately equals the amount of rainfall that is deposited directly on the slide area annually. Clearly, this is an issue that should be addressed somehow. Finally, I can only stress again the critical need for a cooperative design effort taking advantage of the unique pool of knowledge in our community regarding Coastal Sage Scrub habitat. If we can resolve the issues as we go along, we won't have to fight about them at the end. Thank you for your consideration. Noel Park 6715 El Rodeo Road 2 Rancho Palos Verdes CA 90275 562-413-5147 3 Teresa Takaoka From: Sent: To: Subject: Noel Park < noelparkone@gmail.com > Monday, August 06, 2018 9:53 AM CC; Doug Willmore; Deborah Cullen; Elias Sassoon; Andrea Vona Landslide comments mistake In commenting on irrigation runoff from Rolling Hills I said something which was clearly wrong. Equating it to the total rainfall on the Preserve was wrong and doesn't pass the reasonableness test. I ether misunderstood or misquoted something I saw in Feasibility study. I apologize for this dumb and obvious error. Noel Park 6715 El Rodeo Road Rancho Palos Verdes CA 90275 562-4135247 1 Teresa Takaoka From: Sent: To: Cc: Subject: Attachments: SUNSHINE <sunshinerpv@aol.com> Friday, August 03, 2018 6:21 PM cc momofyago@gmail.com; Mickey Radich <mickeyrodich@gmail.com>; leneebilski@hotmail.com landslides v. habitat v. people. 8/7 /2018 Agenda Item 2 PV Dr South imgOOljpg; PV Dr South img002jpg; PV Loop n Lower Filiorum 044jpg PB RFP Council Policy messes overview MEMO FROM: SUNSHINE TO: RPV City Council DATE: August 3, 2018 RE: 8/7/2018 Council Meeting Regular Business Agenda Item 2. PB Landslide The omissions in this Agenda Report represent the 600 pound gorilla which I mentioned at your last meeting. What Staff is recommending does not address how, when and who will be providing design programming input to Design Consultants in relation to the Goals and Policies in the General Plan, The Coastal Specific Plan, The Parks Master Plan nor The Trails Network Plan. The only Plan which appears to be of interest is the NCCP. I repeat that I am concerned that the landslide and water flow engineering is to be compromised in deference to the existing vegetation. I am not seeing any specific analysis of the results of the hydroseeding and lack of infrastructure maintenance after the work done in the mid-eighties. All of our foundational documents were impacted and I don't mean well. Two photos are attached. See? The habitat grew back. We have an opportunity do get it "right" this time. It is good to have a plan to conserve "natural communities". "Pure habitat" (as in no human entry allowed on 90 percent of the earth's surface including the oceans) may be the over-riding Goal of the United Nation's Agenda to be accomplished by the end of the 21 51 Century (UN Agenda 21), however, we, the people, of the Palos Verdes Peninsula have some much more "human friendly" Goals for our piece of paradise. See our foundational documents. 1 In relation to the PVPLC's Work Plan for 2019, Ara made it perfectly clear that the Trails Network Plan Update will have nothing to do with the NCCP Trails Plan. Did you catch that? Each of the Nature Reserves are to be kept isolated from the rest of the Peninsula Wheel Trails Network, The California Coastal Trail the Palos Verdes Loop Trail and access from other jurisdictions. The existing Trails Network Plan is full of a lot of important stuff which is not "obsolete". Under IMPLEMENTATION PROCEDURES I PROGRAMS, Existing Policy #7. is Establish consistent intetface with surrounding jurisdictions regarding a regional trails network. Staff's recommendation is that a Council Subcommittee be established to negotiate with the City of RH about the waster intrusion. This is another case of Staff avoidance of "The big Picture". There are water flow issues at the north ends of the canyons as well as recreational trail issues, emergency access issues, emergency evacuation issues as well as private property issues. Does anybody know this? The PB Landslide Subcommittee's goal of reaching a "community consensus" about anything is totally bogus as long as most of RPV's foundational document's Goals/Polices and citizen input is kept outside of the PB Landslide, now multiple RFP's, Scopes of Work. Start work from the bottom, up. Who just fell off of the turnip truck? See Agenda Report page A-13. The project area has shrunk? How about the graphic on page A-31? What has this area to do with the landslides? This is private property. If someone has their eyes on it to add to the PV Preserve, why does it not show our interest in the Palos Verdes Loop Trail? See attached "ideal route" concept as of 1985. Once again, Staff is asking Council to "receive and file" and "provide direction" based upon 144 pages of substantially irrelevant words and graphics. At least Ara Mihranian and Cory Linder should have been consulted/named on this Agenda Report. Like I suggested, the 600-pound gorilla in the room is the division of interests. Forget the NCCP until the Feds and the State of California Approve it. What we need to spend at least $410,000.00 on, right now, is a comprehensive design for all four of our landslide complexes which includes all of our other public amenities, health, safety and welfare Goals AGENDA DESCRIPTION: Consideration and possible action to receive the Update to the Feasibility Study to remediate the Portuguese Bend Landslide, and to provide direction to begin implementing recommendations from the Feasibility Study. RECOMMENDED COUNCIL ACTION: (1) Receive and file the Feasibility Study Update; (2) Appropriate $260,000 and authorize Staff to develop a Request for Proposals for an engineering analysis, evaluation, and design for the lower portion of the landslide that would convey the drainage runoff to the ocean directly; as well as design of groundwater extraction horizontal drains (hydro-augers) for this lower area of the landslide; (3) Appropriate $150,000 and authorize Staff to develop a Request for Proposals for performing a hydrologic study and engineering analysis of the canyons to identify where, how, and to what extent the stormwater infiltrates into the groundwater in the Portuguese Bend Landslide Complex; and (4) Authorize the City Council to appoint a subcommittee to work with the City Manager and City Attorney in negotiating with the City of Rolling Hills to address and resolve the runoff as well as sanitary sewer effluent for 2 septic tanks and private treatment systems which are contributing to landslide movement from the City of Rolling Hills. FISCAL IMPACT: Funds for these recommendations have not been included in the FY18-19 budget. Amount Budgeted: $0 Additional Appropriation: $410,000 Account Number(s): 330-400-8304-8001. ORIGINATED BY: Ron Dragoo, PE, Principal/City Engineer Elias Sassoon, PE, Director of Public Works REVIEWED BY: Gabriella Yap, Deputy City Manager APPROVED BY: Doug Willmore, City Manager 3 -u :t> - :::> J) < Tl lJ :J Tl J) ::J D • Apha nisma o Ocean Locowee d • I.stand Green Oudle~a a Ca lifornia Gnatateher o Santa Catakna Island Desert-thom o Ca lifornia Crossosoma o Catalina Maripou lily Coasta l Cactus Wren : ~:=~:!:teutterfl1 (H i stonc--~-- 0 0e8f'W'98d a Pa los Verdes Blue Butte rfly (Historic) O South Coast Salt&cale • Vlk.IOI)' Seablight Rocky Shore/l nterjd al •ciirtFace •Coastal Sage Serub •Southern Coa""I Bluff Scrub Southern Cactu& Scrub •Ri parian Scrub Graosland Disru rbed Vegetation • Exobc Vlk>odland •AQricutbJfe Disturbed Developed •Saltbru &h Scrub CJNCCP/HCP Pla n Bo undary ea Presarvo Aro;J i:jJurisdlctional Boundary Potential Preserve for Lower Filiorum 5-3. Potential Preserve for Lower Filiorum • I JB f) T(c.l ( \ I 'y\ f' °'-( t7 s. 'V -e, -r o{ e,, s ------·---------------··-·-- (A,~ "' l J. eaJ , '(" t:J \A,'-f ·-e.-11 l V-0\.. I I . A-31 I'\) (]1 -< m )> JJ (f) r )> --1 m JJ Teresa Takaoka From: Sent: To: Cc: Barbara Sattler < bsattler@igc.org > Monday, August 06, 2018 2:25 PM Doug Willmore; Elias Sassoon; Mary Beth Woulfe CC; Al Sattler; Deborah Cullen Subject: Re: comments re Feasibility Study for Landslide Abatement Hi Doug, Thank you for your assurances. I am glad to hear that any proposed hydrology study would come back for public review. However, I still have significant concerns. I think there are major problems and additional risks with re-configuring and lining the canyons, even beyond the habitat impacts (which are likely to be major and much wider than the footprint of the project). The city will have destroyed the dense network of roots that stabilize the soil; will have removed the protective canopy of mature native vegetation that buffers the soil from impacts of intense rainstorms; and will have converted the refuge and habitat of shady canyon bottoms to a flat disturbed area which will be blasted by full day exposure to hot sun. The newly disturbed area is likely to become quickly infested by weedy non-native annual grasses, which the fire department characterizes as "fine fuels". It seems to me that these measures would also accelerate the flow of water down the channelized canyons to what the consultants characterize as "blocked" drainages below. None of those changes seem like a good idea to me. Why continue to entertain such a potentially destructive proposal? Even if the Council is not giving a go-ahead for lining the canyons at this particular meeting, that does not mean the threat of that action is removed. Studies are not always objective. Any hydrological studies done in this area should be performed by a consulting company that specializes in the ecological and biological impacts of modifications to blue line streams. Furthermore, any biological consultants must be pre-approved by the Wildlife Resource Agencies in accordance with the NCCP. No company having a conflict of interest of potentially profiting by a future engineering project worth tens of millions of dollars should be involved in the hydrological study. Barbara On 8/6/2018 12:27 PM, Doug Willmore wrote: Dear Barbara, I want to assure you that there is no thought amongst staff or Council to find a way to justify lining the canyons. It is simply a study to find out more information and how any infiltration impacts the amount of water in the slide as a whole. The hydrologic studies of the canyons can be very valuable in many ways short of lining the entirely of all three major canyons in the PB preserve. For example, if infiltration in the canyons is occurring, where is it occurring? Is infiltration in the canyons even occurring at any significant rate? Can any infiltration in the canyons be ignored because others steps in other 1 areas can make enough of a difference? In other words, a study in the canyons could tell us that it is not enough of an issue to worry about and that we could spend all of our efforts on other fixes and still be able to reach our goal. Or, it could tell us that it isn't the entirety of all three canyons that is the issue, but rather just three limited spots in the three canyons. Knowing the answers to these questions help the Council decide what to do about the slide in other avenues in coming years, if anything. Any proposed contract for a hydrology study in the canyons would come back to the City Council for consideration. Doug -----Original Message----- From: Barbara Sattler [1!1_<:1.il~t:_().:_}:)_':3~1tler@igc. orgl Sent: Monday, August 06, 2018 11:05 AM To: Elias Sassoon <::_~_'.?..?_~_soon@rpvca.gov::::_ Cc: CC <CC@rpvca.gov>; Al Sattler <alsattler@igc.org> Subject: Re: comments re Feasibility Study for Landslide Abatement Hi Elias, Thank you for your response. Although you are technically correct, I remain concerned that item 3 of the staff recommendations states: "Appropriate $150,000 and authorize Staff to develop a Request for Proposals for performing a hydrologic study and engineering analysis of the canyons to identify where, how, and to what extent the stormwater infiltrates into the groundwater in the Portuguese Bend Landslide Complex;" The report further states on page 2: "This information is needed prior to performing any work that may facilitate minimizing percolation of runoff into the landslide through the mass amounts of runoff that are transmitted through the natural canyons during rain events." I am concerned that such a study may be focused on trying to justify lining the canyons. The more I think about the option of lining the canyons, the more severely problematic it seems, to the extent that I think that the option should be entirely removed from any further consideration by the city. I am certainly not opposed to hydrological studies, however I would want to know the specific goals, parameters and methodology proposed for any studies before approving them. I think the public should be given the opportunity to weigh in on that at a future City Council meeting. Thank you for your willingness to discuss these concerns. Barbara Sattler On 8/6/2018 9:45 AM, Elias Sassoon wrote: Hi: Thank you for your email. Your email will be included in late correspondence. However, if you would, please read the staff report accompanying the feasibility study. The staff report is not recommending that the canyons be lined. 2 Thanks: Elias K. Sassoon, Director Department of Public Works City of Rancho Palos Verdes 30940 Hawthorne Blvd. Rancho Palos Verdes, CA 90275 Tel: 310-544-5335 Fax: 310-544-5292 -----Original Message----- From: Barbara Sattler [mailto_'._Q_?attler@igc.org] Sent: Saturday, August 04, 2018 5:58 PM To: cc <:_CC~F_PYS::!'l:_:_9:_Q_V>_; Elias Sassoon ~~-?!:l:.?..'32Q.0_~_i:::flVC_"'._.:_9:_0V>; Deborah Cullen <DCul_le_r_i_~XJ:lYC:::~-~-g()_Y:?:; Ron Dragoo <RonD@rpvca. goy.?_; Doug Willmore <DWiLLmore@rpvca.gov>; Ara Mihranian ~l_\raM@rpvca.gov>; Kit Fox _<Ki_tE'@!:fl_'LC:::~_:_9.?Y.?:; Mary Beth Woulfe ~!!!_~:ybeth ":'_()_ylfe@_fws.gov>; Ken Corey <Ken Corey@fws.gov>; Eric Porter <eric porter@fws.gov> Cc: Al Sattler ~3lsa~!::_le~@igc.org> Subject: Re: comments re Feasibility Study for Landslide Abatement Please accept this .pdf version of our comments as a substitute for the .docx file we submitted to you yesterday. The only change is the file format, the content remains the same. Al & Barbara Sattler On 8/3/2018 5:44 PM, Barbara Sattler wrote: To the RPV City Council and City Staff: Attached are our comments regarding the Feasibility Study for Landslide Abatement. Al & Barbara Sattler 3 August 3, 2018 re: Feasibility Study to remediate the Portuguese Bend Landslide Dear City Council and City Staff: Thank you for the opportunity to comment on the Feasibility Study for Landslide Abatement. Although the study seems to give a good overview of the landslide history and context and a broad discussion of various abatement options, we do not agree with one of the preferred options presented by the consultants. Our Preferred Options: We strongly urge the City Council to remove lining the canyons from further consideration. The following options make more sense and are less threatening to the Preserve: 1. Convert all existing septic tanks to new sewer lines (including those in Rolling Hills) 2. Reduce excess irrigation in the watershed area 3. Incorporate horizontal drains for the lower portion of the landslide as appropriate 4. Seal fractures only with compatible soil free of contaminants Discussion We believe that the Feasibility Study provides strong arguments for alternatives which would be effective and yet minimize impacts to the natural areas of the PV Nature Preserve. 1. Convert septic tanks to a central sewer line Conversion of existing septic tanks to a central sewer line should be the absolute first priority. The Feasibility Study states that these septic tanks contribute 30% of the groundwater in a dry year and 7.2% in the wettest years (p.37) and states that 11 A centralized sewer system that eliminates septic tanks in the PBLC area would significantly reduce future dry weather groundwater recharge." (p. 51) The Feasibility Study also states that 11 ... a reasonable reduction in the elevation of the groundwater surface of 5 to 15 percent would result in a significant reduction in land movement in the PBLC area" (p.49) If the total percentage of groundwater correlates with the elevation of the groundwater surface, then these statements seem to indicate that conversion from septic tanks to a central sewer system would easily surpass the needed reduction in ground water load in dry years, and fall well into a range of significant reduction even in the wettest years. In regard to converting from septic tanks to a sewage system, the Feasibility Study states that 11 Planning, permitting, and construction of a full-scale program in both the City of Rancho Palos Verdes and Rolling Hills is estimated to cost approximately $5 million." (p.77) There is no good reason not to do this conversion. Certainly, it would be optimal if the City of Rolling Hills would share the cost. But $5 million is less expensive than any of the other alternatives suggested by the consultant other than filling the fissures. It is still a reasonable option even if RPV has to foot the entire bill. 2. Reduce impacts from excess irrigation within the watershed Impacts coming from excess irrigation within the watershed are mentioned in the Feasibility Study. "Leighton and Associates {1998) estimated that up to 77 acre-feet per year could be entering their project area from upslope irrigation recharge. Extrapolated to the PBLC, and similar to septic tanks, irrigation return flow represents a significant source of groundwater recharge to the PBLC. 11 (p. 37-38) However, they make no recommendations other than further study. At the very least, the city should begin an educational campaign in an effort to persuade the public to reduce the use of excess irrigation. A more assertive effort might be to return to some sort of water rationing with fines for excessive water use. 3. Horizontal directional drains may be a viable option. We understand that such a drainage system was installed at White Point following the landslide in that location, and that the installation had very little impact to existing habitat at the White Point Preserve. It makes sense to us to concentrate drainage efforts in the Red Zone, particularly since it seems that much of the problem is caused by blocked drainage from that area to the ocean. 4. Sealing Surface Fractures Sealing surface fractures is recommended by the Feasibility Study, but is not among the recommendations by City Staff. Although we understand the logic of 11 sealing11 fractures in the ground, we do not have sufficient information to fully support this option. If used, it would be much more biologically appropriate to use a fill composed of natural soil rather than one including artificial material. We are concerned that any artificial materials included in the fill 11slurry11 would leave behind them a legacy of debris or contamination over the years. We would also want to have the assurance that any soil used for such fill be free of contamination (non-native seeds, incompatible micro-organisms, including disease organisms, etc.) and that the soils used would be fully compatible with the native soil structures. Please remove the option of Reconfiguring and Lining the Canyons Much of the storm water flow in the canyons may be the result of storm drainage infrastructure at the top of the watershed intentionally directing flow into the canyons. It would seem to be simpler and cheaper to capture and re-direct this storm water runoff, rather than constructing expensive destructive canyon linings. The consultant's claim that lining the canyons would be compatible with habitat preservation in the canyons of the Palos Verdes Nature Preserve has no basis in biological or ecological fact. To the contrary, recontouring and lining the canyons would cause severe permanent loss, disfigurement and fragmentation of existing prime natural ecological areas that serve as habitat, clearly in violation of the NCCP. Early configuration planning for the RPV NCCP focused on adhering to the California Natural Communities Conservation Planning Guidelines which emphasized the need for preserving habitat and habitat quality by keeping large areas of habitat contiguous and unfragmented. Eliminating and reducing "edge effects" was and remains a key goal in the establishment of the RPV Preserve configuration. Edge effect impacts can and often do extend far beyond a project footprint. Common detrimental edge effects include impacts such as: invasion of non-native plant and animal species; increased predation on vulnerable sensitive species; microclimate effects such as alterations of the soil, moisture, heat and wind conditions at the edges; increased stress on species at the edges leading to increased vulnerability to pests and diseases; etc. Although well-intentioned in the hopes of reducing the risks of excess water in a "100 year" storm event, the proposed channelization of the existing natural canyons would profoundly alter soil hydrology of the existing canyons in drought years as well as wet ones. This would exacerbate drought stress on the remaining adjacent plant community. A frightening unintended consequence of such clearing and reconfiguration of the currently healthy natural canyons could be the likelihood of the proliferation of non-native invasive species into the cleared area (particularly highly flammable non-native grasses). Coupled with aggravated drought stress of the remaining plant community, fire risks could increase substantially. Certainly this is not what anyone in the community desires. Before opting to continue consideration of the lining and channelization of the natural canyons, the city and the consultant need to be aware that edge effects such as those mentioned above need to be included in the acreage of impacts of the proposed channelization project. The actual extent of that edge impact acreage would have to be determined by qualified biologists and ecologists and the Wildlife Resource Agencies, but the area is likely to extend quite broadly beyond the footprint of the channels themselves. Thus it is quite likely that the total impact acreage of the proposed channels would be far in excess of the acreage allowable for such impacts within the Preserve. The Feasibility Study has recommended several other approaches to addressing landslide abatement within the Preserve. In view of the availability of those more benign approaches, there is no need for the drastic impacts which would be associated with channelizing the natural canyons. We respectfully request that the City Council remove the destructive and expensive option of lining the natural canyons from further consideration. As discussed above, there are other viable options that are far less destructive to habitat and far less expensive to implement. We do not currently support a Hydrological Study Staff has recommended providing funding to initiate a "hydrological study and engineering analysis of the canyons." At this point in time, we are opposed to such funding since the city's end goal for such studies seems to be to further the option of lining the canyons. It is also not evident what measures and methodologies would be used in such studies (active disturbances such as borings or some sort of non- invasive methodology) and in what time frame and conditions (rain or drought) such studies would be conducted. We also suspect that any hydrological studies might be of more value if they are conducted after addressing the impacts of septic tanks and excess irrigation in the watershed. If the city wishes to pursue additional studies, then biological and ecological studies of the Preserve hydrology as related to the flora and fauna of the Preserve would be warranted. Conclusion We urge the City Council to remove the option of lining the natural canyons from further consideration. Likewise we urge the council to move forward as soon as possible to convert the septic tanks in the region to a central sewage line, even if that means the city will absorb most of the costs. We further believe that horizontal directional drains are worth further investigation. Finally, we encourage the city to begin efforts to reduce the impacts of excessive irrigation on the landslide area. Sincerely, Alfred and Barbara Sattler via email Teresa Takaoka From: Sent: To: Cc: Subject: Mr. Sassoon, Thank you very much. Al Sattler <alsattler@igc.org> Monday, August 06, 2018 12:22 PM Elias Sassoon; CC; Doug Willmore; Ara Mihranian; Deborah Cullen; Ron Dragoo Mary Beth Woulfe; Eric Porter Re: Sierra Club Comments on Landslide Remediation Feasibility Study attached I very much appreciate that the city staff is not including a recommendation that the canyons be lined. However, since staff is recommending $150,000 to study the issue, it is important to reiterate the major issues with this approach. We would not want to have this initial expenditure be part of a slippery slope of increasing expenditures that give a sense of inevitability to lining the canyons. The consultants have prioritized the lining of the canyons, and seem totally ignorant of the biological/ecological damage it would cause. Alfred Sattler On 8/6/18 10:00 AM, Elias Sassoon wrote: >Hi: > >Thank you for your email. > >Your email will be included in late correspondence. However, if you would, please read the staff report accompanying the feasibility study. The staff report is not recommending that the canyons be lined. > >Thanks: > > Elias K. Sassoon, Director > Department of Public Works >City of Rancho Palos Verdes > 30940 Hawthorne Blvd. > Rancho Palos Verdes, CA 90275 >Tel: 310-544-5335 >Fax: 310-544-5292 > > > > >-----Original Message----- > From: Al Sattler [mailto:alsattler@igc.org] >Sent: Saturday, August 04, 2018 2:00 PM >To: CC <CC@rpvca.gov>; Doug Willmore <DWillmore@rpvca.gov>; Elias >Sassoon <esassoon@rpvca.gov>; Ara Mihranian <AraM@rpvca.gov>; Deborah >Cullen <DCullen@rpvca.gov>; Ron Dragoo <RonD@rpvca.gov> >Cc: Mary Beth Woulfe <marybeth_woulfe@fws.gov>; Eric Porter > <eric_porter@fws.go> 1 >Subject: Sierra Club Comments on Landslide Remediation Feasibility > Study attached > >To the Rancho Palos Verdes City Council and City Staff: > >Attached are the Sierra Club comments on the Staff Report and Update to the Feasibility Study to remediate the Portuguese Bend Landslide for the City Council meeting August 7, 2018. > >Alfred Sattler >Chair > Palos Verdes -South Bay Regional Group Sierra Club 2 Teresa Takaoka From: Sent: To: Cc: Subject: Attachments: Al Sattler <alsattler@igc.org> Saturday, August 04, 2018 2:00 PM CC; Doug Willmore; Elias Sassoon; Ara Mihranian; Deborah Cullen; Ron Dragoo Mary Beth Woulfe; Eric Porter Sierra Club Comments on Landslide Remediation Feasibility Study attached Sierra Club Comments_RPV Landslide 20180807.pdf To the Rancho Palos Verdes City Council and City Staff: Attached are the Sierra Club comments on the Staff Report and Update to the Feasibility Study to remediate the Portuguese Bend Landslide for the City Council meeting August 7, 2018. Alfred Sattler Chair Palos Verdes -South Bay Regional Group Sierra Club 1 Palos Verdes-South Bay Group I Angeles Chapter August 4, 2018 Re: Feasibility Study to remediate the Portuguese Bend Landslide To the Rancho Palos Verdes City Council and City Staff: The Sierra Club understands the city's desire to reduce the progression of the Portuguese Bend landslide. We request that the city omit the option of lining the canyons of the Preserve from any further consideration, and that instead, the city move forward on more benign options of removing excess ground water from the landslide area, including the conversion of septic tanks to a central sewer system; reduction of excess irrigation in the watershed; and the consideration of horizontal drains in the "Red Zone" to allow effective water drainage to the ocean. Please remove the proposal to modify the canyons with liners from any further consideration -it is not consistent with the Rancho Palos Verdes Natural Communities Conservation Plan (NCCP) We are strongly opposed to any artificial recontouring, grading, filling or lining of the natural canyons in the Portuguese Bend Nature Preserve. We strongly disagree with the claims made in the Feasibility Study that such destruction of the natural configuration of the canyons would in any way be consistent with habitat preservation or allowable under the RPV NCCP. The Feasibility Study has provided absolutely no biological basis to justify such claims. We are concerned that the city Staff Report concludes that lining the canyons, as proposed in the Feasibility Study, is consistent with the RPV NCCP. City Staff seems to be basing that conclusion solely on the contents of a single table (Table 5.1 of the NCCP) and cherry-picked phrasing that landslide abatement measures are "not limited to" those specifically listed in the NCCP in section 5.2.3. However, it is clear, from reading the full NCCP descriptions of allowable activities within the Preserve, that nothing of the scope and severity of impact of the current proposal to line the natural canyons and convert them to storm drains was ever envisioned in the drafting of the NCCP. For example, Section 5.2.14 of the NCCP regarding "Utility Maintenance and Repair" (including storm drains) states that such activities are "anticipated to permanently impact up to 10 acres ofCSS and 20 acres of non-native grassland throughout the life of the permits. lt is estimated that one-half of the impacts will occur within the Preserve." However, the Proposed Project Work Areas table on page A-10 of the Staff Report shows habitat loss for the various channels in the canyons. The impacts for the channels alone add up to loss of 11.2 acres of CSS within the Preserve. This is more than double what was envisioned in the NCCP. Even more importantly, City Staff neglects to cite the introduction to Section 5.1 of the NCCP which states, This NCCP/HCP assumes incidental take coverage for 17 Covered City Projects and Activities ... provided that the projects and activities are consistent with the applicable Habitat Impact Avoidance and Minimization Measures described in Section 5.5 of the NCCP/HCP." (Emphasis added) P. 0. Box 2464, Palos Verdes Peninsula, California 90274 Section 5.5, item # 19 then states, For Covered Projects/ Activities within the Preserve, the impact area ... shall be located on the least sensitive portions of the site as determined by existing site-specific biological and supporting information (emphasis added) It is also worth noting that Section 5.5.18, which focuses on trails, states that they should be "located in areas that minimize habitat fragmentation and edge effects" (emphasis added) Although this restriction was included in the context of trails, the concern about habitat fragmentation and edge effects is very important biologically and would also apply to the channelization of the canyons. Convert septic tanks to a central sewage system and reduce irrigation in the watershed Before even considering such destructive options as channelization of the canyons for removing water from the landslide watershed, the city must address the existing situation of imported water entering the landslide area. Imported water is water sourced from outside the Palos Verdes Peninsula, delivered by the Peninsula's water purveyor, California Water Service. The Feasibility Study names two very significant categories for discharges of imported water into the landslide watershed: The existing septic tanks in both Rancho Palos Verdes and Rolling Hills; and excess water from landscape irrigation within the watershed. Despite the political challenges involved, Rancho Palos Verdes must make eliminating all septic tank systems in the landscape watershed, both in Rancho Palos Verdes and Rolling Hills, a top priority if the city is at all serious about addressing the landslide issue. We note with approval that the Staff Report recommends: "(4) Authorize the City Council to appoint a subcommittee to work with the City Manager and City Attorney in negotiating with the City of Rolling Hills to address and resolve the runoff as well as sanitary sewer effluent for septic tanks and private treatment systems which are contributing to landslide movement from the City of Rolling Hills." The Feasibility Study states that these septic tanks contribute 30% of the groundwater in a dry year, and 7.2% in the wettest years. (p37) and states that "A centralized sewer system that eliminates septic tanks in the PBLC area would significantly reduce future dry weather groundwater recharge." (p. 51) It would be unconscionable to ignore this ongoing influx of imported water to the landslide watershed while considering expensive destructive options to remove water. Many, if not most, of the homes can be connected to sanitary sewers. Alternatively, a speaker at a recent community meeting pointed out that sewers can be problematic for homes in areas with constant land movement, and recommended holding tanks instead for areas with constant land movement. In addition to eliminating all septic tank systems, the city of Rancho Palos Verdes should also address the impacts of excessive landscape irrigation discharging imported water into the landslide watershed. At the very least, the cities of Rancho Palos Verdes and Rolling Hills should begin an education campaign with the goal of reducing this excessive and damaging water usage. Should voluntary reductions not suffice, it may become necessary at a future time to implement some sort of water rationing as has been done during our recent droughts. P.O Box 2464 • Palos Verdes Peninsula, California 90274 @ Printed on Recycled Paper Investigate the use of Horizontal Drains to convey excess water from the "Red Zone" to the ocean It does seem appropriate to focus on removal of excess water in the "Red Zone", where, according to the Feasibility Study, the natural drainage to the ocean has been destroyed. We are aware that a system of horizontal subsurface drains has been installed at the White Point Nature Preserve with minimal disruption to habitat. Horizontal drains of the "Red Zone" area extending under Palos Verdes Drive South seem to be a logical approach. Conclusion Many people and organizations, including the Sierra Club, have invested great amounts of money, time, and energy in the establishment of the Portuguese Bend Preserve. Removing the natural vegetation from the canyon bottoms and replacing it with impermeable membranes would irreparably damage the habitat value of the preserve. We support such measures as reducing inflow of water from septic tanks and irrigation in order to reduce the water load in the landslide area. Likewise, we support further study of potentially installing horizontal drains to improve outflow to the ocean. However, for the reasons stated above, we request that the Council remove the proposal to line the natural canyons from any further consideration. Sincerely, /S Alfred Sattler Chair Palos Verdes -South Bay Regional Group Sierra Club CC: Mary Beth Woulfe, U.S. Fish and Wildlife Service Eric Porter, U.S. Fish and Wildlife Service Submitted via email P.O Box 2464 • Palos Verdes Peninsula, California 90274 @ Printed on Recycled Paper Teresa Takaoka From: Doug Willmore Sent: Monday, August 06, 2018 12:24 PM To: Cc: Eva Cicoria; Elias Sassoon; Deborah Cullen cc Subject: RE: Landslide Feasibility Study Hi Eva, Thanks again for expressing your thoughts. There were a couple of ideas you brought up that I thought I should speak to. (1) The engineers were hired to express their professional opinion about an issue. While they want to listen to residents to see if the input can improve their methodology, or their thinking, it's not their job to change their professional recommendations because some members of the public want something different. If they did that, the City shouldn't hire them. The City wants their professional opinion. Their job is to give their professional recommendation, based on available information, on what is needed to slow the movement of the slide down. That is what they have done. (2) The hydrologic studies of the canyons can be very valuable in many ways short of lining the entirely of all three major canyons in the PB preserve. For example, if infiltration in the canyons is occurring, where is it occurring? Is infiltration in the canyons even occurring at any significant rate? Can any infiltration in the canyons be ignored because others steps in other areas can make enough of a difference? In other words, a study in the canyons could tell us that it is not enough of an issue to worry about and that we could spend all of our efforts on other fixes and still be able to reach our goal. Or, it could tell us that it isn't the entirety of all three canyons that is the issue, but rather just three limited spots in the three canyons. Knowing the answers to these questions help the Council decide what to do about the slide in other avenues in coming years, if anything. (3) The drainage and hydro-augers at the bottom of the slide need limited study and experimentation (and will be built into the engineering work). In addition, almost all of the work will be done on non-preserve property and will result in under the surface infrastructure. (4) Regarding an overall hydrology study for entire slide area (that you reference), we are not recommending one at this time. Before more extraction wells are installed, one will be needed. We are hoping that the drainage work at the bottom of the slide and working with RH to reduce runoff and infiltration from septic systems at the top can slow the slide enough to then do an accurate, up to date hydrology study that would allow the placement of extraction wells that won't get sheared off (because movement has slowed). Doug From: Eva Cicoria [mailto:cicoriae@aol.com] Sent: Monday, August 06, 2018 10:06 AM To: Elias Sassoon <esassoon@rpvca.gov> Cc: CC <CC@rpvca.gov> Subject: Re: Landslide Feasibility Study Thank you, Elias. I appreciate your comment. I actually did read the Staff Report and was happy to see that it is not recommending that the canyons be lined at this time. However, it does recommend that Staff develop a RFP "for performing hydrologic study and engineering analysis of the canyons [emphasis added] to identify where, how, and to what extent the stormwater infiltrates into the 1 groundwater". Considering that the consultants neither removed canyon lining as an option in the Study, nor revised their rating of it as a "good" option, nor changed the costs to reflect any significant change in their original recommendation, concerns remain that at some point this will come back and what folks will remember will be what is in the Study, not the long list of criticisms of it. Moreover, City Council doesn't always follow the recommendations of staff reports. To be clear, I'm not opposed to spending money to study the slide more closely. I believe more should be spent on studying the lower reaches of the slide complex, not the canyons (which we should leave alone). At the last public meeting, I suggested that the City look into engaging a research institution to do the study. Was that pursued? A related matter is whether you can provide a little color on what the $150,000 for hydrologic study and engineering analysis would get us. A friend of mine, an expert in the field, tells me that the sort of data one really wants for a hydrologic study would be 1) a time series of several types of data at several locations within the watershed or drainage area: precipitation, streamflow (if any), outflow or ponding (if any), and any data on water that was extracted due to the various extraction wells RPV put in over the years. The time series should be long enough to form a picture of the hydrology in both wet and dry years. And since the extraction wells could have changed things, you'd want a time series that spans from before and across implementation of these wells. And you'd want it to extend to a relatively recent time. 2) soil type, slope, etc., which would involve drilling down in various locations to get soil types. The consultants have said that they have not taken any measurements on the land. Rather, they relied on historic data. Yet they have also indicated that there is insufficient data, aka data gaps. What do they propose to do to fill those data gaps on the ground? My sense is that the Staff is recommending going forward with installing hydro-augers without completing study of what is going on in the slide. The need for a complete study is something the public and, I thought, the consultants agreed on. -----Original Message----- From: Elias Sassoon <esassoon@rpvca.gov> To: 'cicoriae@aol.com' <cicoriae@aol.com> Cc: CC <CC@rpvca.gov> 2 Sent: Mon, Aug 6, 2018 9: 14 am Subject: RE: Landslide Feasibility Study you your email. email will included in late correspondence. However, if you would, please read the staff report accompanying the feasibility study. The staff report is not recommending that the canyons be lined. Elias K. Sassoon, Director Department of Public Works _city of Rancho Palos Verdes 30940 Hawthorne Blvd. Rancho Palos Verdes, CA 90275 Tel: 310-544-5335 Fax: 310-544-5292 From: Eva Cicoria <cicor_@e@_9gl.com> Sent: Sunday, August 5, 2018 8:00:56 AM To: CC Subject: Landslide Feasibility Study Dear Mayor Brooks, Mayor Pro Tern Duhovic, and Councilmembers Alegria, Cruikshank and Dyda, The early draft of the Landslide Feasibility Study recommended lining the canyons with a geotextile fabric and planting islands of native plants in sacks here and there to provide some "habitat" and make the canyons more aesthetically appealing. The consultants rated that aspect of their recommendations as "good" (a 2 on a scale of 0-3, 0 being unacceptable), both in terms of how environmentally sound it is and in terms of how acceptable it would be to the community. At the last public meeting on the subject of the landslide, I asked the consultants how they could rate canyon lining as high as they have after all the feedback from the public, including experts in the field of California native plants and representatives of the PVP Land Conservancy and the Sierra Club, all of whom were critical of this approach both for its direct and indirect impacts to the vegetation, wildlife, erosion control, aesthetics, and more. The consultants' response? To paraphrase, "There's another 40,000 people who haven't weighed in and we think they would say the canyon lining is a good approach." 3 In the edited Landslide Feasibility Study, geotextile lining of the canyons is still recommended. The report shows no indication that the "good" rating assigned to lining the canyons has been reduced either in terms of environmental soundness or in terms of community acceptability to reflect input received. Nor has the cost estimate for the work changed. So it seems that the consultants have disregarded the public's concerns. Ripping out the deep-rooted, long-established canyon vegetation and removing water flow to the land completely will bring a host of problems not addressed by the consultants' report. Please reject this study's recommendation regarding the canyon liner system and put no further resources toward implementing that recommendation. There are other options to reduce the groundwater recharge in the area of land movement, including converting septic tanks to new sewer lines (including those in Rolling Hills), reducing excess irrigation affecting the watershed area, and installing horizontal drains under Palos Verdes Drive South to move the water out to the ocean. City Council has historically expressed interest in increased public input into decision making. Well, the public has shown up and weighed in on this issue and to have us utterly disregarded is not only disrespectful, it calls into question whether these consultants ought to be engaged by our city for any further work at all. 4 Teresa Takaoka From: Sent: To: Subject: Mike Kilroy <ml@kilroy.com> Sunday, August 05, 2018 8:33 AM cc Please Do Not Line the Canyons Honorable Mayor and Council Members: Please do not line the canyons in Portuguese Bend or anywhere else in Rancho Palos Verdes. It interrupts and impedes natural processes which have been found to reduce the risk of flood, enhances loss of beach by artificially boosting the speed and quantity of outflow, and destroys important habitat. Thank you. Mike Kilroy 1 Teresa Takaoka From: Sent: To: Subject: Joyce White <joyceborzoo@yahoo.com> Sunday, August 05, 2018 11:00 AM cc Please do not line the canyons with plastic!!!! Joyce White Sent from Yahoo Mail for iPhone 1 Teresa Takaoka From: Sent: To: Subject: Kathy H < katholeeno@gmail.com > Sunday, August 05, 2018 11:23 AM cc Landslide mitigation Dear Mayor Brooks, Mayor Pro Tern Duhovic, and Councilmembers Alegria, Cruikshank and Dyda, As a long-time local hiker in all of the PVP nature preserves, I am writing to voice my strong desire that you REJECT the recommendation put forth in the Landslide Feasibility Study to remove the long-established vegetation and line the canyons with geotextile fabric. To go forward with this proposal would not only ignore the overwhelmingly critical input from the public (your constituants) but, more importantly, would cause massive long-term damage to delicate wildlife habitat, not to mention erosion control. The natural beauty of the canyons would be turned into an eyesore (and planting a few islands of native plants in sacks to provide some "habitat" and make the canyons "more aesthetically appealing" is, in my opinion, laughable). I urge you to consider other, more sensible options to reduce the groundwater recharge in the area of land movement, such as converting septic tanks to new sewer lines, reducing excess irrigation affecting the watershed area, and installing horizontal drains under Palos Verdes Drive South to move the water out to the ocean. Please say NO to lining the canyons! Kathy Hill 1 Teresa Takaoka From: Sent: To: Subject: Ann Shaw <anndshaw@gmail.com> Sunday, August 05, 2018 11:26 AM cc Lining the canyons Please give up this idea now. As a person who has fought for open space since we founded the city I urge you to listen to the conservationist and others who are knowledgeable and do the right thing. Lets not destroy what we have. Ann Shaw 1 Teresa Takaoka From: Sent: To: Subject: outlook_75085E9AD219D739@outlook.com Sunday, August 05, 2018 11:43 AM cc URGENT REQUEST: DO NOT KILL the vegetation, and do NOT line the canyons-- Mayor Brooks and RPV City Council Members: I attended the last city council meeting and was shocked to learn that you and the consultants had not even analyzed the underlying problem of the landslides, yet-but in spite of that, you are leaping to a silly "solution" of geotextile lining that has NOT even been proven to work. At that meeting, I heard the consultants' explanation of the geotextile lining of the canyon walls, which they readily admitted were NOT A SOLID SOLUTION to containing the landslides-and, in ,fact, this approach has NO PROVEN EVIDENCE OF SUCCESS. You have heard from scientific and engineering EXPERTS from the PVPLC and The Sierra Club, who are in DIRECT OPPOSITION to your in-house consultants: They agree that vegetation and wildlife would not only be destroyed, but also the "geotextile method of erosion control" that is "Not a well-thought out or guaranteed solution" is UNTESTED. Hence, this approach is a WASTE OF TAXPAYER'S MONEY. And you will destroy the canyons for no reason other than you want to "do something now," instead of making the effort to understand what the problem really is, and what can realistically be done about it. Please abandon this insane geotextile lining approach and DO ONE THING NOW: ANALYZE THE SITUATION TO DETERMINE THE "UNDERLYING PROBLEM" CAUSING THE LANDSLIDES. THEN AND ONLY THEN CAN YOU PLOT A COURSE TO DETERMINE POTENTIAL "SUCCESSFUL" SOLUTIONS. Dr. Linda L. Varner 3 Santa Rosa Rolling Hills Estates, CA 90274-5405 310-483-9934 cell 1 Teresa Takaoka From: Sent: To: Subject: John R. (Rod) Jensen <jrodjensen@me.com> Sunday, August 05, 2018 12:58 PM cc Lining the Canyons Dear Mayor Brooks, Mayor Pro Tern Duhovic, and Councilmembers Alegria, Cruikshank and Dyda, I disapprove the suggestion to line the canyons. Other ways can be found. PS Please STOP the Helicopter and ultralight noise Regards, John R. (Rod) Jensen 21 Barkentine Road, RPV 90275 Sent from my iPad 1 Teresa Takaoka From: Sent: To: Subject: Anita or Bob Caplan <arcaplan2@gmail.com> Sunday, August 05, 2018 2:42 PM cc No to lining the canyons It seems risky and would look awful Anita Caplan Sent from my iPhone Teresa Takaoka From: Sent: To: Joan Kelly <katelinkelly649@gmail.com> Monday, August 06, 2018 6:22 AM cc I strongly oppose the removal of vegetation of canyons and lining them. Drainage is a problem. Please have the homes that are in the active landslide install holding tanks. Why are they still on septic?? That water is going down into the earth every day That needs to be done first. Use the money to do that initially/ PLEASE show us that you really want to help mitigate this landslide. Joan Kelly katel inkelly649@gmail.com 310 541 8582 Teresa Takaoka From: Sent: To: Cc: Doug Willmore Friday, August 03, 2018 4:06 PM David Berman CC; Andrea Vona; Deborah Cullen; Elias Sassoon; woulfe@fws.gov; Eric Porter; Ara Mihranian Subject: Re: Native plant society letter opposing Landslide Abatement Plan David, There is no plan to plan to install a liner and channel system n the canyons. Did you read the recommendations in the staff report? Doug Sent from my iPad On Aug 3, 2018, at 3:26 PM, David Berman <pvhome2002@yahoo.com> wrote: Please review this letter. A scanned copy is attached. August 2, 2018 Honorable Mayor, Members of the City Council, and Staff, The South Coast Chapter of the California Native Plant Society (SCCNPS} appreciates the city's desire to minimize ongoing land movement on the Palos Verdes Peninsula. However, any efforts to do so should not be to the detriment of the natural and intact canyons of the Portuguese Bend Nature Preserve. SCCNPS is strongly opposed to the proposed plan to install a "Liner and Channel System" in the canyons. Reconfiguring and lining Portuguese, Paintbrush and Ishibashi Canyons, and potentially also doing the same to Altamira and Klondike Canyons would destroy some of the highest value native vegetation in the Nature Preserve, in clear and dramatic violation of Section 5.5.20 of the Rancho Palos Verdes Natural Communities Conservation Plan/ Habitat Conservation Plan (NCCP/HCP}.i[1] That section of the plan states that "Total Loss of Habitat by Covered City Projects and Activities) shall be located on the least sensitive portions of the site as determined by existing site-specific biological and supporting information ... " Lining the canyons would destroy much of the highest value area within the preserve. Sacrificing the rich ecological and biological value of the canyons so that they can be transformed into engineered stormwater drains would not only permanently destroy the ecology and habitat of the canyons themselves, but also permanently divide the larger habitat area of the Preserve into isolated segments, introducing detrimental "edge effects" along the 1 full length of the proposed project areas. This would be a significant and permanent biological impact to the Preserve as a whole. These habitat areas have developed over thousands of years and cannot just be destroyed and replanted like one would redo a lawn. The proposed isolated decorative planting of the remnants of the altered canyons to "blend in with" surrounding habitat would not in any way constitute functional habitat restoration or replacement. Native plants in the canyons not only provide habitat value but also help to stabilize the land. They absorb water and prevent it from percolating into the lower layers. Roots from lemonade berry plants routinely go down 40 feet below the surface and have been found as deep as 90 ft. The Feasibility Study indicates that the replacement of existing septic tanks and the reduction of irrigation within the watershed could significantly reduce the potential for landslides. Those measures would be a much more benign and cost effective way of addressing landslide avoidance. Many efforts have been attempted over the years to tame the landslide and have failed. The city needs to consider the downside of this project which includes a high likelihood that money will be spent that will only end up making the problem worse. SCCNPS urges the city of RPV to remove the lining of the canyons from any further consideration. Sincerely, David Berman President, South Coast Chapter California Native Plant Society ii[l]The Feasibility Study specifies "remedy options that will be consistent with the Natural Communities NCCP/HCP, specifically Section 4.1.2." (p. 21). However there is no such section in the current version of the NCCP. <CNPS Aug 2018.pdf> 2 calif ornia Native Plant Societ~ Soutb Coast cbapter August 2, 2018 Honorable Mayor, Members of the City Council, and Staff, The South Coast Chapter of the California Native Plant Society (SCCNPS) appreciates the city's desire to minimize ongoing land movement on the Palos Verdes Peninsula. However, any efforts to do so should not be to the detriment of the natural and intact canyons of the Portuguese Bend Nature Preserve. SCCNPS is strongly opposed to the proposed plan to install a "Liner and Channel System" in the canyons. Reconfiguring and lining Portuguese, Paintbrush and Ishibashi Canyons, and potentially also doing the same to Altamira and Klondike Canyons would destroy some of the highest value native vegetation in the Nature Preserve, in clear and dramatic violation of Section 5.5.20 of the Rancho Palos Verdes Natural Communities Conservation Plan I Habitat Conservation Plan (NCCP/HCP).1 That section of the plan states that "Total Loss of Habitat by Covered City Projects and Activities) shall be located on the least sensitive portions of the site as determined by existing site-specific biological and supporting information ... " Lining the canyons would destroy much of the highest value area within the preserve. Sacrificing the rich ecological and biological value of the canyons so that they can be transformed into engineered stormwater drains would not only permanently destroy the ecology and habitat of the canyons themselves, but also permanently divide the larger habitat area of the Preserve into isolated segments, introducing detrimental "edge effects" along the full length of the proposed project areas. This would be a significant and permanent biological impact to the Preserve as a whole. These habitat areas have developed over thousands of years and cannot just be destroyed and replanted like one would redo a lawn. The proposed isolated decorative planting of the remnants of the altered canyons to "blend in with" surrounding habitat would not In any way constitute functional habitat restoration or replacement. Native plants in the canyons not only provide habitat value but also help to stabilize the land. They absorb water and prevent it from percolating into the lower layers. Roots from lemonade berry plants routinely go down 40 feet below the surface and have been found as deep as 90 ft. The Feasibility Study indicates that the replacement of existing septic tanks and the reduction of irrigation within the watershed could significantly reduce the potential for landslides. Those measures would be a much more benign and cost effective way of addressing landslide avoidance. 1The Feasibility Study specifies "remedy options that will be consistent with the Natural Communities NCCP/HCP, specifically Section 4.1.2." (p. 21). However there is no such section in the current version of the NCCP. Many efforts have been attempted over the years to tame the landslide and have failed. The city needs to consider the downside of this project which includes a high likelihood that money will be spent that will only end up making the problem worse. SCCNPS urges the city of RPV to remove the lining of the canyons from any further consideration. Sincerely, David Berman President, South Coast Chapter California Native Plant Society Teresa Takaoka From: Sent: To: Cc: Subject: tony baker <tbake377@gmail.com> Thursday, August 02, 2018 2:40 PM Deborah Cullen; Elias Sassoon; CC Andrea Vona; woulfe@fws.gov Proposed Portuguese Bend Landslide Abatement Dear City Council Members and City Staff As a long time resident of Portuguese Bend (1949 to present) and observer/participant of the infamous creeping landslide, I wish to state my strong opposition to the Storm Water Control Option #3 (aka Liner Channel System). It is stated that the flexible liner option is designed to be sustainable and will withstand damage from movement until long term land movement is significantly reduced. So if the land movement is not significantly reduced, then it will not be sustainable and need to be reconstructed or become non-functioning. It is also stated that this option is cost effective. The estimate for pilot testing is $512,000. The estimate to construct the system is estimated at $13.5 million. Estimate for 30 years is $16.8 million (assuming no reconstruction is needed). This is not cost effective especially in view of the fact that it is not a guaranteed solution. The footprint of the liner system will destroy some of the best established vegetation/habitat in the Palos Verdes Preserve. The canyons are especially valuable because they were not impacted or disturbed by the early cattle grazing and later farming that removed large swaths of native vegetation. By cutting back the sides of the canyons to install the liner system, vegetation that serves to hold soil in place, transpire precipitation and provide habitat for wildlife will be replaced by bare soil prone to erosion. The idea that "native plant islands" planted in soil bags with "native soil" and "designed to be integrated into native habitat" can even come close to replicating what would be removed is----well, laughable. It is not, as stated, an environmentally friendly option even though it is presented that it will be done with --little disruption (?). Option # l was taken off the table as unworkable. I think this option should be revisited. It is stated that the previous drain structures that were put in place to control and convey storm water to the ocean where it exits the upper canyons have failed and were abandoned 20 years ago. It is stated that the calculated flows were underestimated and the structures were undersized and head-works were under designed. As a result surface drainage was poor. This is true. So re-design. This system failed also partly due to lack of maintenance. Pipes separated at faults and were left to drain storm water into the land. The half pipe system was laid out across the flat area of the "Sandbox" and quickly filled with silt. If the half pipe had been located just north on the slope above, it would have had a drop all the way to the pipe under P.V. Dr. South. Please re-think the destructive and ill conceived flexible liner option #3 and take it off the table. Thank you for your consideration Anthony Baker 16 Limetree Lane Portuguese Bend 1 Teresa Takaoka From: Sent: To: Subject: Dear City Council Persons, my3000,V <my3000@verizon.net> Monday, August 06, 2018 3:24 PM cc City Council re DBS&A's Landslide Abatement Feasibility Study It was disheartening to see that the final edits to DBS&A's Feasibility Study failed to reflect the comments made in the June 28 meeting to review their Feasibility Study, responses to written questions, and seek public comment. For instance, most in the meeting made it abundantly clear that it was totally irresponsible to take actions like reengineering canyons (which risk the loss of homes, wildlife, habitat, public safety, and major RPV taxpayer money), before 1) correcting the obvious problem that the road dams water from reaching the ocean. And 2) Assessing whether proper drainage solves the problem!!!!! Nearly everyone agreed that work to create excellent drainage under the road in the lower part of the canyon already graded and moving is needed. It was shocking to learn that given the money that RPV has spent on repairing the road and monitoring the landslide, none of it was spent on building good or better drainage under the road or at least maintaining the old drainage/well system which is in total ruin. Can you imagine the impact of actually following this study's original recommendation of concurrently paving the canyons (currently heavily lined with thirsty, often deep rooted vegetation), if we have a "normal" rainy season or a particularly heavy rain. With nothing to absorb or block its flow, a massive, high speed river could be created in each canyon and the road damming it irreparably damaged. Many also pointed out that DBS&A's written responses to public questions basically said we don't know, we don't have that information, or was based on very old, unclear, biased data created by Hon's geologists long ago. They felt that DBS&A needed much better information before suggesting expensive, very risky solutions. Yet In their final copy to you, they continue to discuss reengineering and lining the canyons with an "impermeable" liner, ignoring numerous objections to 1) destroying much of the little remaining, high quality coastal sage scrub in the Preserve(s), 2) the inability for any liner in this area to be remain impermeable with ground squirrels, deep rooted vegetation etc, 3) the high, probably underestimated, cost of doing this, 3) the absence of good data of actual run-off levels in each canyon and 4) the high risk in this steep terrain, that the liner becomes a landslide plane in an earthquake and/or 5) the construction itself launches a bigger slide or causes it to move faster. If you look DBS&A examples of working liners, they show a hole in the ground that is lined. How many toxic dumps have you seen built in a canyon on the side of a steep, ancient landslide, hill 2000 feet high? There also has been no explanation of why the test canyon is Portuguese Bend Canyon which has very few houses draining into it other than Del Cerro which is on sewers and I believe drains into Rattlesnake Canyon. DBS&A in an earlier public meeting admitted that Portuguese Canyon drains well except in lower area dammed by the road and flattened by grading. The other canyons farther south have many more houses above them excluding Del Cerro. It was made very clear in the meeting that the biggest water problem was created by Ishibashi Canyon area and the area below called Ishibashi Lake. Which though recognized as a major water collection area is also totally dammed by the road from reaching the ocean. DBS&A mentioned that this water will reach the end of Portuguese Bend Canyon eventually, but why not drain it under the road immediately where the collects naturally. Thank you very much for your consideration. I understand that you have a problem which you need to solve if possible. Please take steps that are most likely to improve the situation without resulting in a real disaster and making the slide even larger and more severe. Also consider the cost of ongoing maintenance which I strongly believe will be much higher than estimated. A big problem here is that the basic maintenance of drainage systems has not been occurred due to the high cost and difficulty of doing so. The contemplated "solution" here will be extraordinarily difficult and expensive to maintain. Having been responsible for several construction projects worldwide, I can assure you of this. It always seems easier and "cheaper" in the plan than in the real world, even when that world is flat. Sincerely, Cathy Nichols, 14 Crest Rd W 2