CC SR 20260407 01 - Landslide Water Reuse Feasibility Study
CITY COUNCIL MEETING DATE: 04/07/2026
AGENDA REPORT AGENDA HEADING: Regular Business
AGENDA TITLE:
Consider a report from the joint Infrastructure Management Advisory Committee (IMAC)
and Financial Advisory Committee (FAC) subcommittee on the feasibility of reusing water
extracted from Landslide Complex dewatering wells.
RECOMMENDED COUNCIL ACTION:
(1) Receive and file a report prepared by a joint subcommittee of IMAC and FAC on
the feasibility of reusing water extracted from Landslide Complex dewatering wells;
and,
(2) Determine whether Staff should return to the City Council at a future date with an
estimated cost and impact analysis on other Capital Improvement Program
projects in order to perform a detailed legal, regulatory, environmental,
infrastructure, operational, staffing, and financial study on landslide water reuse by
subject matter experts, in partnership with other public agencies to the extent
possible.
FISCAL IMPACT: There is no fiscal impact related to the staff recommendation.
Amount Budgeted: N/A
Additional Appropriation: N/A
Account Number(s): N/A
ORIGINATED BY: Russ Bryden, Principal Engineer
REVIEWED BY: Ramzi Awwad, Public Works Director
APPROVED BY: Ara Mihranian, AICP, City Manager
ATTACHED SUPPORTING DOCUMENTS:
A. Joint IMAC/FAC Subcommittee Report on Landslide Water Reuse Proposal
(page A-1)
B. Palos Verdes Groundwater Beneficial Reuse Study (page B-1)
BACKGROUND:
Dewatering wells have been used to control land movement in the Greater Portuguese
Bend-Ancient Altamira Landslide (Landslide Complex) since the late 1970s. Historically,
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groundwater extracted by these wells has been discharged to the ocean. Over the years,
particularly recently, questions have been raised as to whether that extracted water could
be used for a beneficial purpose (i.e. irrigation, etc.), especially during periods of extended
drought.
In 2009, the Water Replenishment District of Southern California hired a consultant to
prepare a feasibility study for reusing the extracted groundwater (Attachment B). The
study concluded that the cost to produce usable irrigation water from the existing
dewatering sources was substantially higher than the purchase cost of potable water and
recycled water; therefore it was not cost effective at that time.
Years later, the region received record amounts of rainfall during the FY 2023-24 storm
season. This resulted in unprecedented acceleration of land movement in the Landslide
Complex. In response, the City constructed various emergency stabilization measures
including deep dewatering wells, which significantly increased groundwater pumping
(approximately 550 gallons per minute with a total of approximately 460 million gallons of
water extracted from the ground to date since September 2024).
The City’s emergency stabilization deep dewatering wells led to a resurgence of
questions from the community regarding whether it would now be cost effective to reuse
the extracted groundwater. In 2024, then-Mayor John Cruikshank had informal
discussions at the City’s Mayor’s Breakfast on whether the extracted groundwater could
be reused. During this period, the accelerated land movement and associated response
efforts required substantial staff resources, which limited the City’s ability to independently
evaluate potential reuse of the extracted groundwater. Recognizing these resource
constraints, then-Mayor Cruikshank requested the Infrastructure Management Advisory
Committee (IMAC) to take the lead on investigating the feasibility of reusing the extracted
groundwater.
In response to then-Mayor Cruikshank’s request, in December 2024, IMAC and FAC
formed a joint ad hoc subcommittee (Subcommittee). The Subcommittee’s members
included John McAllister (FAC Chair), Rocky Weber (FAC Member), Peter Shaw (IMAC
Chair), Fred Smalling (IMAC member), and Nic Grillo (IMAC Member).
DISCUSSION:
The Subcommittee began its work by identifying the technical requirements, potential end
uses, and high-level economic considerations associated with developing a water reuse
system. The analysis included review of prior studies, historical groundwater data, and
current dewatering operations in order to better understand water quality characteristics,
available supply, and system constraints. It also included consultation with subject matter
experts from the Water Replenishment District of Southern California, which is the agency
that manages local groundwater resources for the region to ensure that a reliable supply
of high-quality groundwater is available through replenishment with recycled water and
stormwater capture. Additionally, the Subcommittee held discussions with
representatives from a company specializing in renewable water systems, Water
Harvesting Solutions, Inc. (WAHASO), to better understand available treatment
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technologies. Finally, outreach was also conducted with potential end users, including
local golf courses, to assess potential demand and revenue opportunities .
The Subcommittee found that groundwater in the Landslide Complex is brackish,
containing elevated levels of dissolved solids, and would require reverse osmosis
treatment in order to be reused for irrigation and other non -potable applications. While
the treatment technology itself is widely used, the Subcommittee found that the primary
challenge associated with this approach is cost. Reverse osmosis is energy -intensive and
results in significant electricity usage and high ongoing operations and maintenance
costs. Another major cost barrier identified was the substantial capital investment required
to construct the transmission infrastructure necessary to deliver water to potential
customers. This includes pipelines, storage, pumps, and related system components,
which would be required to connect the treatment system to end users.
After extensive research and investigation, the Subcommittee prepared a Joint
IMAC/FAC Subcommittee Report on Landslide Water Reuse Proposal (Attachment A),
which determined that the reuse of groundwater extracted from the Landslide Complex is
largely an economic question. While technically feasible, financial viability remains
uncertain and represents a major constraint to implementation. Additionally, the
Subcommittee identified a number of other areas they were unable to fully evaluate, which
require further analysis before a determination of viability could be made.
Building upon the viability points raised in Subcommittee report, Staff have developed the
following areas requiring further detailed analysis to determine viability of reusing
groundwater extracted from the Landslide Complex:
• Legal Authority and Water Rights – Questions remain regarding ownership of the
extracted groundwater and whether the City has the legal authority to treat, distribute,
and sell the water. Addressing this uncertainty would require a formal legal analysis
of applicable water rights and coordination with regulatory agencies to confirm
jurisdiction and any limitations on reuse or sale.
• Environmental and Regulatory Requirements – The treatment and reuse of brackish
groundwater, as well as disposal of the resulting brine concentrate, would be subject
to a range of environmental regulations and permitting requirements. Reducing this
uncertainty would involve identifying all applicable regulatory agencies, conducting a
detailed permitting analysis, and defining water quality standards, discharge
requirements, and compliance pathways associated with both treatment and disp osal
processes.
• Water Production Reliability – The amount of groundwater that can be consistently
produced and made available for sale over time is uncertain. This uncertainty creates
risk in forecasting and sustaining revenue, which could affect the ability to recover
capital and operational costs associated with a reuse system. Additional analysis
would require evaluation of long-term groundwater production under varying
conditions, including how changes in landslide activity and hydrologic conditions may
affect the quantity of water that can be reliably extracted and supplied for reuse.
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Infrastructure and Site Constraints – The Subcommittee conducted a foundational
analysis to identify the general infrastructure needs and site considerations associated
with implementing a treatment and distribution system, including potential
requirements for pipelines, storage, pumps, and related facilities in a geologically
sensitive area. Building on this initial work, the City would need to engage credentialed
engineering and technical professionals to advance the analysis to a level sufficient
to support preliminary engineering, cost estimating, and scheduling requirements
common to most grant programs.
• City Staffing and Operational Capacity – Development and operation of a treatment
system would require technical expertise, staffing resources, and ongoing
administrative functions. Further evaluation would include an organizational
assessment to determine staffing and skill set needs, as well as consideration of
whether these functions would be performed by new City staff, consultants, or through
partnerships with other agencies. Potential fiscal impacts would need to be furthered
studied.
Financial Viability –
The Subcommittee conducted a foundational analysis of financial feasibility using
available data and real-world cost assumptions to evaluate potential capital,
operational, and maintenance costs, as well as preliminary revenue considerations.
Building on this analysis, further evaluation by credentialed subject matter experts
would be necessary to refine life-cycle cost estimates, validate assumptions, and
develop the level of detail required to support project planning and competitive
applications for grant programs.
• Customer Demand Certainty – The Subcommittee’s report identified potential end
users and provided preliminary information regarding anticipated demand, usage
patterns, and pricing considerations. Building on this baseline, further vetting of
customer commitment is needed to determine the overall financial viability. This would
include confirming the terms and conditions required by potential customers to enter
into long-term agreements, as committed demand is necessary to provide a reliable
revenue stream to support the capital and operating costs of a reuse system .
The Subcommittee’s report indicates that reuse of groundwater extracted from the
Landslide Complex may be technically feasible; that is to say, it is possible for it to be
done. However, whether it is viable or can succeed remains uncertain based on the
information currently available. Additional investigation is necessary to properly identify
and quantify risk.
Addressing this uncertainty will require additional analysis from subject matter experts
from legal, regulatory, environmental, infrastructure, operational, staffing, and financial
fields. Embarking on these detailed technical studies will also require re-directing Staff
resources currently committed to other projects. Therefore, the City Council is being
asked to determine whether to direct Staff to proceed with obtaining, for the City Council’s
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consideration at a future meeting, the estimated costs for contracting with subject matter
experts to perform these studies and the impact re-directing Staff resources will have on
existing Capital Improvement Program (CIP) projects. This information could determine
whether to proceed with the subject matter expert studies.
ADDITIONAL INFORMATION:
IMAC Chair Peter Shaw will attend the April 7 City Council meeting to present the
Subcommittee’s report and answer City Council questions.
CONCLUSION:
The City Council is being asked to receive and file the Subcommittee’s report and to
determine whether to direct Staff to proceed with obtaining, for the City Council’s
consideration at a future meeting, the estimated costs for contracting with subject matter
experts to perform these studies and the impact re -directing Staff resources will have on
existing CIP projects.
ALTERNATIVES:
In addition to Staff recommendations, the following alternative actions are available for
the City Council’s consideration:
1. Defer a detailed study by subject matter experts until a future date as directed by
the City Council.
2. Take other action, as deemed appropriate.
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Joint IMAC/FAC Subcommittee Report on Landslide Water Reuse
Approved by FAC 1/15/26 and IMAC 1.21.26
Page 1 of 21
Executive Summary
This report documents the joint IMAC/FAC Subcommittee findings and recommendations
on the feasibility of reusing landslide water from Greater Portuguese Bend Landslide
Complex dewatering wells to produce a meaningful income stream that would help the
City of Rancho Palos Verdes mitigate the landslide remediation expense. The report has
two parts. The first is this Executive Summary which has been compiled primarily for the
decision makers. It identifies our fundamental conclusions, recommendations, and
challenges that we have identified without delving into the details that led to our findings.
The remaining section of the report describes the specifics of our study - what we identified
and how we got there. It covers past studies; discussions with the Water Replenishment
District, the specialist water reuse experts of Water Harvesting Solutions (“Wahaso”) and
the two main golf courses located on the Palos Verdes Peninsula ; definition of a
conceptual modular and scalable treatment system; capital cost estimate development;
potential for income; the challenges the City might face and finally, our conclusions and
recommendations. This second section of the report provides the City with a baseline to
plan for a future water treatment system should the Council decide it to be a worthwhile
endeavor.
The extracted landslide water is brackish and contains too much dissolved solids (mostly
salt) to be of any use without treatment. The levels of salt are too high for a dilution
approach, and a treatment system is needed. Water harvesting systems are used routinely
today to remove sediment through stage filters and the dissolved solids through a process
known as Reverse Osmosis (“RO”). About 80% of the input is turned into what is
essentially distilled water and the remaining 20% is highly brackish waste. The treated
water could become either potable or “Purple” water for irrigation use only. The water
treatment technology per se is not a challenge.
The technology to produce potable and irrigation grade water is similar. Producing potable
water has advantages because it can be piped directly into nearby water mains thereby
reducing capital cost for storage tanks and water distribution piping. Yet, even though we
could produce twice as much as we would not be limited by a small customer base, that
does not overcome the difference between selling potable water at wholesale versus
irrigation at retail. Further, experts have told the team that the regulatory issues with
potable water will be onerous and agonizingly slow; hence, we are recommending
considering only irrigation usage. Distilled water has zero dissolved solids and that is not
conducive to promoting photosynthesis so we would need to add back some water with
dissolved solids to essentially mimic the quality of the CWS water currently used. We also
need to dilute the brine waste. Collectively, these two measures reduce the net yield is
about 68% usable irrigation water with 32% being a brine waste roughly equivalent to
ocean water.
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A conceptual water treatment and distribution system was developed as a baseline for the
financial analysis. Two leased and mobile treatment modules in shipping containers would
be located adjacent to the landslide – one on the east side and the other on the west.
Customers would be the three golf courses, the Robert E. Ryan Community Park and to-be-
determined potential commercial customers along the coastal region of the City.
Collectively, the system would be required to produce 250,000 ccf’s per year (equivalent to
574 acre feet per year) to meet those customer needs. (Note: a ccf is the standard unit
California Water Service (“CWS”) uses for billing customers and is equal to 100 cu ft of
water). To produce the needed amount, 366,000 ccf’s of water would need to be extracted
from the landslide dewatering system. Currently the City, ACLAD and KCLAD wells
combined pump just over 750,000 ccf/year so we have some needed margin since we
anticipate the long -term steady state extraction rate will decline, as KCLAD is already
experiencing. With the land still moving, wells are still sheering so a reliable water supply
over the long term also will be important.
Although the actual treatment systems could be leased, there will be significant additional
system components to produce and distribute irrigation water. Typically, golf course
irrigation is conducted through the night whereas the extracted water is produced
24/7/365. Storage tanks large enough for a maximum day’s usage would be needed at each
golf course. Additionally, to mimic the CWS
supply, pumps would need to increase the
pressure and raise the water to the needed
elevation – not significantly on the east side
but over 600 feet on the west. The other major
infrastructure would be the combined 5.6
miles of pipe to transport the irrigation water.
As shown in the Capital Infrastructure table,
the estimated capital cost for a distribution
system is about $7.2M.
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Currently, as shown on
the Operations table,
the CWS non-
residential rate for
potable water is $9.42
per ccf but on top of
that there are
connection fees, taxes
and other surcharges
that make the total cost
about $11.50 per ccf.
Our estimate of the
City’s cost to produce
irrigation quality water
is $6.98 per ccf. As an
incentive to potential users, we have included a 20% discount in our forecasts. Doing so
results in annual n et revenue to the City of $555K per year. That revenue stream assumes
that the City would not be obligated to add on any taxes or surcharges, a potential
requirement under some levels of regulation . It also does not include amortization of the
capital expenditure which over 15 years would be $480K per annum.
On the face of it, with such a small income stream and all the associated uncertainty, it
hardly seems worthwhile pursuing this approach. However, the Water Replenishment
District facility in Torrance has received substantial grants for their recently approved
expansion program. Wahaso believes that grant monies are available at both state and
federal levels and that many of their customers have received grants for a variety of water
harvesting projects. Wahaso has offered to provide contact information for experts who
specialize in this area. If, for example, we could get a grant to pay for the infrastructure
there would be no capital amortization to account for. Then, if we could secure additional
grants for some, or maybe even all, of the operational costs then the maximum possible
annual income could hypothetically be as high as $2.3M.
The bottom line is that treating landslide water and using it for irrigation is a
worthwhile endeavor as long as we can get somebody else to pay for much of the
capitalization and treatment costs. Our initial recommendation to the City is to
investigate federal and state grant opportunities to determine how much of these
costs can be covered by grant authorities in the pursuit of avoiding 574 acre feet of
potable water currently being used per annum for irrigation.
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1. Background and Introduction
The City, along with Abalone
Cove Landslide Abatement
District (ACLAD) and the
Klondike Canyon Landslide
Abatement District (KCLAD)
have been using dewatering
wells for decades in an
attempt to keep the
Portuguese Bend Landslide
Complex at bay. Past studies
have looked at reusing the
extracted water, but the
salinity was too high for direct
use. Reference 1 is the most
comprehensive report we have identified for one such study conducted in 2009. The graph
below, taken from that report, shows the total City/ACLAD well production from 1980 until
2006 had an average daily production of 150,000 GPD with an uptick in the 1996/2006
decade to an average of 206,000 GPD.
The table below, also from Reference 1, shows
ACLAD water composition where the average
salinity was 3,045 ppm. The study cited two
approaches for creating usable water – dilution
and filtration. With dilution, they identified
ratios of potable water to la ndslide water
ranging from 2:1 up to 23:1 depending upon the
TDS content of the output stream. They
recognized the quality could never match that
of potable water and it was a concern to the golf
courses which are accustomed to the TDS of
potable water. For filtration, they proposed a
microfiltration with reverse osmosis facility.
They looked at two scenarios – serving one golf
course and three courses. Both the dilution and filtration concepts were analyzed, and
Capitalization and Operations & Maintenance (O&M) costs were estimated. Adding in the
amortized capital cost over 25 years to all the other costs, they concluded it was not
feasible to produce the water at a competitive rate. Not unexpectedly, this never went past
the initial report.
Water Units
There is a plethora of units being used in the literature
varying from gallons per minute to ccf per month to
acre-feet per year and it’s difficult to relate them all.
Throughout this report, we have elected to use either
Gallons per Day (GPD) or Gallons per Minute (GPM) as
the water flow rates. When we get to the financial
analysis, we mostly use ccf (100 cubic feet) for cost
comparisons as that is the pricing unit we all see on our
residential and business bills. Occasionally, Acre-Feet
is also referred to since that is the unit the water
authorities use.
ACLAD Historical Water Extraction
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Given that history,
what has changed
that might provide a
different perspective
and outcome today?
First, the quantity of
water being extracted
is about an order of
magnitude higher
which should lead to
greater efficiency and
no need for “topping
up” with potable
water in the summer
months when the
supply from ACLAD was insufficient. Second, there appears to be increased government
and industry emphasis or reusing wastewater as a means of reducing potable water usage.
This improves the possibility for grant s to support the production costs – both
capitalization and O&M. Finally, the price of water has risen ~60% in the last decade and
likely will increase at an even higher rate over the next decade as water becomes a scarcer
commodity.
In 2024, Mayor Cruikshank asked IMAC to take
another look at whether there was now something
we could do with all the water being pumped out
of the landslide. Initially, IMAC looked at
Reference 1 that concluded that there really
wasn’t a cost-effective means of treating the water
to make it usable even for irrigation purposes.
Then, a brochure from the Water Replenishment
District (WRD) was distributed with the local
newspaper describing their treatment facility in
Torrance that is treating brackish water and
producing potable water. This put a different
perspective on treatment and opened up the question “If they can do it, why can’t we?”
With Mayor Cruikshank’s encouragement, IMAC agreed to study the feasibility of creating
an income stream from this landslide water. With a local brackish water treatment facility
already operating, IMAC felt the feasibility was as much a financial question as a technical
one. This led IMAC to invite the FAC to be part of a joint IMAC/FAC ad hoc subcommittee to
explore the possibilities and develop a feasibility opinion. After the formalities of IMAC and
FAC approvals, the subcommittee was formed. It comprised John McAllister (FAC Chair),
ACLAD Historical Water Analysis
Salinity
Salinity is a term that encompasses
all the dissolved solids that are in
the water of which salt is the most
prevalent. Per the Consumer
Confidence Report (CCR), the
potable water CWS provides to the
Palos Verdes District has a Total
Dissolved Solids (TDS) count that
averages 307 ppm.
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Rocky Weber (FAC Member), Peter Shaw (IMAC Chair). Fred Smalling (IMAC member) and
Nic Grillo (IMAC Member).
The following summarizes our interactions with WRD, Wahaso and the two major local golf
courses. We then provide a conceptual configuration that was used to provide a basis for
estimating both capital and Operations & Maintenance (O&M) costs. We provide a
summary of some of the challenges we still face and some ideas on how they might be
reconciled. Finally, we provide our overall conclusions, recommendations and suggested
next steps.
2. WRD Visit
The subcommittee visited the WRD Robert W. Goldsworthy facility in Torrance in early
April, 2025. The staff were very hospitable and gave us a lot of information . Salient points
from the visit were:
2.1 The freshwater aquifer throughout South Bay was a significant source of potable
water but during the early 1900’s it was over pumped and sea water intrusion
contaminated the water. The aquifer has recovered its water tables, but the water
remains brackish. The compromised aquifer area is about 14 square miles across
the South Bay, and it is referred to as a “saline plume”.
2.2 Fresh water was pumped into the coastal edge of the aquifer and the freshwater
pressure maintains a barrier to further seawater penetration.
2.3 Water is pumped from multiple wells distributed over the South Bay and
transported to the facility in Torrance via a network of underground pipes. The
aquifer is refreshed with both stormwater and wastewater that is encouraged to
permeate through the ground from a variety of percolation fields throughout the
South Bay.
2.4 The extracted water currently has an average TDS of 2,700 ppm.
2.5 Prefilters remove sediment before it is pressurized to flow through a bank of
Reverse Osmosis filters that remove almost everything else to produce essentially
distilled water. Chemical injection follows to create the desired properties (pH
balance, chlorine, etc.) before it can be delivered as potable water to the Torrance
Water District.
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2.6 The system produces 5 million GPD of potable water that represents about 25% of
the City of Torrance’s daily water consumption.
2.7 WRD’s primary objective is to clean up the aquifer such that in the future it will
become usable without treatment, but they recognize this will be a long-term
project. The salinity has been reduced since the plant commenced operations but
not yet to a level that avoids treatment and they have recently received the go ahead
to double the capacity of the treatment plant.
2.8 WRD sells the water at wholesale rates to the Torrance Water District, but they
don’t make much money doing so. The revenue helps to defray the O&M costs and
amortize some of the initial capital investments.
2.9 Their costs include all the extraction, transportation, and treatment but they did not
break them down for us.
2.10 The facility commissioned in 2001 is
owned by WRD. A substantial portion of the
funding came from the district’s Capital
Improvement Program which is supported by
replenishment assessments levied on water
pumpers within its service area. But, they were
also supplemented by various state grants from
Proposition 50, Proposition 1 and State Drought
Funds along with Federal grants through the U.S.
Bureau of Reclamation (USBR).
2.11 The expansion program was just
approved in November 2025 for $168M of which
$24M was provided under a grant from the
USBR. Much of that expansion cost we were told
pays for significantly more underground piping
that within dense urban areas now costs in
excess of $1M per mile to install.
Overall, this visit and discussion with WRD was very helpful in giving us a fundamental
understanding of what treating brackish water entails and how much it might cost.
3. Wahaso Interaction
Mayor Cruickshank told us about a mobile treatment system and a company that had
briefed him on wastewater reuse. That company is WAter HArvesting Solutions, also
known as Wahaso. We contacted their Vice President of Sales who set up virtual meetings
with two of their key engineers on the east coast. They were extremely helpful and
enthusiastic about helping us, but obviously for them they also saw a business
opportunity. Key points from these discussion s are summarized as follows:
Reverse Osmosis (RO)
This is a water purification process
that uses high pressure to force water
through a very fine semi-permeable
membrane. This membrane acts as a
barrier, allowing only pure water
molecules to pass through while
leaving behind larger molecules and
ions, such as dissolved salts, heavy
metals, most organic contaminants
and bacteria/viruses. Typically, about
80% of the water gets purified and the
remaining 20% containing all these
unwanted components becomes, by
a factor of 5, a now more
concentrated brine waste drain.
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3.1 Wahaso has implemented numerous wastewater harvesting and treatment facilities
throughout the country. They specialize in all aspects of a project from the technical
to the regulatory.
3.2 Their fundamental approach is referred to as Modified Ultra-Filtration (MUF) to
remove most of the undesirable content follow ed by a lower and variable pressure
Reverse Osmosis stage when dissolved solids also need to be removed. The
modified approach allows much quicker membrane cleaning, backwashing in 30-45
seconds versus the
typical 45-60 minutes.
Variable RO pressure
(nominally, 30 psi versus
typical 100 psi) provides
the opportunity to
minimize power used.
3.3 Wahaso designed the
portable system that
Mayor Cruikshank
referred to. It is portable
in the sense that the
treatment system is built
into a 40-foot shipping
container. It has an input
pipe for the raw water,
an output for the treated
water, another output for
the waste brine, and a
panel for connecting 200
amp, three-phase, 480-
volt electrical power. The
system is modular so
that units could be
situated close to the
water sources rather
than everything
transported to and from
one large facility.
3.4 Depending upon customer need, there are add-on options such as pH balancing, UV
sterilization and chemical injection. Also, there is a second shipping container
module they produce that can treat the brine waste so that there is only solid waste
that needs to be disposed of. This is useful if there is no other way for disposing of
the concentrated brine byproduct.
Potable or Irrigation Quality?
Early in our study we kept the options of both potable
and irrigation quality water. Potable water had many
advantages in that we could easily hand it off to CWS
(assuming they would be interested) without needing
short-term storage tanks, extra boost pumps and long
delivery pipes. We could utilize every gallon we could
pump out of the landslide. There would be no seasonal
element to the demand and if we have dry years where
the production rate drops we don’t have an issue with
not enough water to meet customer demand. However,
all the experts we spoke with cautioned us on the
regulatory requirements of producing drinking water.
Despite the high water quality the treatment facility
could produce, there seemed to be a quagmire of
regulatory requirements we would have to negotiate
our way through. In fact, they are so onerous that
Wahaso, for insurance reasons, essentially will not
provide a unit for producing water that is classified as
potable. From a value standpoint, potable water would
produce less revenue per ccf because we could only
sell it at discounted wholesale rates whereas irrigation
water could be sold at discounted retail rates. Based
on this assessment, we made the decision for the study
to only focus on producing irrigation quality water that
could be used by the three golf courses and potentially
other users, e.g., Ryan Park.
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3.5 We explained to them the damage the landslide had done, the emergency program
of deep dewatering wells, the quantity of water we are extracting and that currently
we are simply letting it flow into the ocean. In response, they offered to collect two
samples and then pass them through their test facility to demonstrate to us the “art
of the possible”. Once we received City approval, they took one sample from the
deep dewatering wells the City operates and another from the not -so-deep KCLAD
wells. We selected those two because one is below the deep slide plane and the
other in between the two slide planes. They are also in the region where the highest
TDS levels have been measured ~ 10,000 ppm per the water analysis reports the City
has published. Wahaso observed that the water samples were very clear so they did
not have a lot of suspended matter. Once those samples were treated, the output
TDS level was 10 ppm which is the lowest their testing techniques could measure. In
essence, the product from their treat ment was close to distilled water.
3.6 Wahaso’s business model is to lease the treatment system and be responsible for
all quality control and maintenance. Maintenance is not significant but many of the
prefilters have to be backwashed weekly and water tested for TDS and turbidity
(opaqueness) on a periodic basis. If anything breaks, then they would be responsible
for fixing it. The lease cost covers everything so there is no “per gallon” fee.
3.7 We discussed a lot of detailed technical information to better understand
parameters such as reliability, pumping requirements from the wells and to the
customer along with tank storage to accommodate mostly nighttime irrigation
schedules. Wahaso also provided rough order of magnitude costs for leasing a
treatment module. We factored all the information we learned into the conceptual
system and the financial analysis.
Overall, our discussions with Wahaso and their demonstration treating our landslide water
samples convinced us that a modular and tailorable approach to brackish water treatment
was technically the most effective way forward for our situation.
4. Discussions with Potential Customers
We met separately with senior leaders of the two larger golf courses – Trump National and
Los Verdes. In both cases they were very enthusiastic about receiving treated landslide
water if it could reduce their significant water bills. We discussed the technical aspect of
what we might propose to the City and they both gave us data on where they would need
the water delivered, the flow rates, their daily usage cycle, the delivery pressure and most
importantly, the water quality. Both were somewhat reticent about funding the
capitalization of such a system.
Both courses currently use potable water delivered by CWS that, based on the 2023 CCR
indicated the TDS range was 209 to 367 ppm. For quality grass, the optimal TDS range is
200 to 500 ppm. If it’s too low, like distilled water, then the nutrients needed for
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photosynthesis would need to be added using fertilizer. If it is too high, the additional salt
can lead to foliage damage and extra effort will be needed to manage the excess salt
through chemical means and/or leaching techniques, all of which make the irr igation of a
golf course much harder and potentially risky . It is reasonable to conclude, therefore, that
current TDS levels from CWS are acceptable, although we did hear that Los Verdes
conducts regular soaks of the greens to lower the salt level at the roots. The advantage of a
treatment facility that produces water with almost no dissolved solids is that the delivery
TDS level can be tailored to the customer needs by adding in a small amount of untreated
water to bring up the level needed for healthy photosynthesis so they can use it with
confidence without having to change their irrigation and grass welfare procedures.
Both golf courses were very open about how much they pay for water and that has helped
us in estimating potential revenues based on an equitable arrangement. We were given
permission to use this data but at the same time treat it as proprietary.
5. Conceptual Configuration for Estimation Purposes
We obtained estimated costs of the treatment facility , i.e., two containers, but we needed
to also consider what additional components would be needed to transport the raw water
to the treatment plant and from there to the customers – over a mile to Trump National and
nearly five miles to Los Verdes, the latter with an extra elevation gain of about 620 feet. We
also had to consider the daily usage profile which essentially is 8 hours overnight while we
would be producing water at a constant rate 24/7/365. To estimate both the acquisition
and running costs, we had to develop an approximate size for this additional equipment
and that necessitated developing a conceptual modular configuration that is shown below.
Our approach was to consider a system that would meet the needs of Trump National and
since it was all modular and localized, we could replicate the system and then add the
extra pipe lengths and pumping capacity to estimate the costs for supplying Los Verdes,
Terranea and potentially other large-user customers on the way.
Conceptual Modular Water Transportation, Treatment and Storage System
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The conceptual water treatment plant would be a modular, portable unit constructed and
contained within a 40 foot shipping container. The output capacity of the unit would be
nominally 205 gallons per minute of treated groundwater. The discharge lines from the
cities deep dewatering wells (DDW) 1 through 6 as well as possibly the discharge from the
KCLAD wells located at the west end of the Portuguese Bend Beach Club could be
consolidated and fed to a tank that would be approximately 5 ,000 gallons capacity,
located at or near the shoreline where the wells are located. Such a tank would be roughly
10 feet high and 10 feet in diameter. A pump would draw water from this feed tank and
forward it to the treatment unit located most probably on the hill overlooking the west end
of the PBBC. The treatment unit will have a series of filters which will remove suspended
solids, TSS (silt and other particulate matter) and biological contaminants such as bacteria
and viruses if they exist. After solids/particulate filtration, the water will pass through a
Reverse Osmosis unit which will remove total dissolved solids, (TDS ) along with any
remaining bacteria and viruses. The RO unit will remove TDS salts to a very low level, about
10 parts per million PPM. This is too low to be used for golf course irrigation, which requires
a TDS content of 200 to 500 ppm. To achieve customer recommended TDS concentration,
a small stream of water which passes through the initial filtration portion of the treatment
unit will bypass the RO portion of the treatment unit and be blended with the output stream
from the RO unit. The amount of water which will bypass the RO will depend on the
concentration of TDS in the untreated groundwater, but it is expected to be roughly 10%
to15% of the total water fed into the treatment unit. Also, the RO unit only treats about 80%
of the water fed into it. The remaining 20% becomes a concentrated brine stream which
will be discharged to the ocean. If the initial TDS is higher than around 6,000 ppm, the brine
waste will be more brackish than the ocean water. Another bypass line can be used to
dilute this waste down to TDS levels consistent with ocean water. From 300 GPM going into
the unit, 205 GPM of usable water is produced giving a net yield of 68%.
The output stream from the treatment plant will be discharged into a storage tank
approximately 200,000 gallons in size. Such a tank is roughly 30 feet high and 35 feet in
diameter. This large tank is necessary because irrigation only occurs in a nighttime window
from about 9 PM to 5 AM. During that 8-hour period, flows could vary from 200 to 600 gpm,
averaging about 470 gpm. Since the output from the treatment unit cannot keep up with
this usage rate, water made during the day will need to be stored to acc ommodate the high
usage at night. The size of this storage tank could be adjusted downwards slightly as the
treatment unit will make about 100 ,000 gallons of treated water during the 8 hours of the
golf course’s watering regime, but a tank of this rough order of magnitude size will be
required. This tank would likely be located somewhere on the hill overlooking the west end
of the PBBC. Pumps would be located next to this tank to transport the water to the golf
course through a pipeline that would need to be installed. The most probable route for this
line would be to go upslope to Palos Verdes drive South where it would run parallel to the
Los Angeles County Sanitation District sewer lines and then past the entrance of the
Portuguese Bend Beach Club to tie into the golf course’s irrigation system near the
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intersection of Trump National Drive and PVDS. The connection would be downstream of
the backflow preventer required by CWS for all irrigation systems. The line would be
approximately 6,000 feet in length, have a diameter of 8” and would likely be constructed
using High Density Polyethylene. It would be very similar to the black pipelines just
installed by LACSD except it would be smaller in diameter.
The treatment unit as sized would be capable of producing almost 300,000 gallons per day
of treated water. Since the average demand is 225,000 gallons per day the unit would need
to be shut down for some period each day once the treated water storage tank is full. This
could take place during the peak electricity demand hours thus minimizing power costs.
The filter units would be backwashed periodically, and filter changes performed on a
routine basis. The filtrate is expected to be non -hazardous and filter media can be
disposed of in an ordinary land fill. Almost no chemical treatment of the water is
necessary, a few gallons per day of Sodium Hydroxide, Caustic Soda, might be needed to
adjust pH. Depending on local health department regulations, there might be a
requirement for an additional UV filter to destroy any bacteria and viruses that might leak
through the filtration but that would need to be based on more intense water testing to
determine what bacteria and/or viruses are present. The primary concern is Hepatitis given
a small amount of the water may come from septic tanks higher up the hill.
The main power demand for the treatment unit is the feed pump. Other power users are air
conditioning, instrumentation and control systems and possibly a UV sterilization light. The
overall power consumption of the treatment unit is estimated to be 100 KW for 18 hours
per day. The transfer pump to the golf course would be capable of forwarding between 200
and 600 gallons per minute at a pressure of about 150 pounds per square inch. This
provides the needed flow and pressure to lift the water from the hill a bove the beach club
to a higher elevation at the golf course, overcome the pressure drop through the 6,000-foot
transfer line and deliver the water at pressures needed to operate the golf course irrigation
systems. This pump would require about 50 KW on average, but it operates on a demand
basis, so it only runs at full power about 8 hours per day.
6. Financial Analysis
6.1 System Capacity
From a potential customer base along the coastal part of the City there are two full -size
golf courses (Trump and Los Verdes), a nine-hole par 3 course (Terranea), two parks
(Ladera Linda Community Center & Robert E. Ryan Community Park), one potential
commercial customer and possibly several housing tracts that could benefit from a
“purple” water supply. Each one has its unique requirements in terms of total water usage,
when the water is needed, how it could be delivered and what capital costs would be
needed. Summing all these potential customer needs, we estimated the total requirement
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for irrigation-quality water was 250,000 ccf/year (356 GPM) and that was the basis for
sizing the treatment modules and some of the distribution system.
6.2 Treatment Modules
We considered the buy option for a treatment module but soon rejected it on the basis we
do not believe the City would want to get into the water treatment business. The lease
option seemed more attractive for the City’s needs because Wahaso is promoting an all -in
lease program which covers Operation and Maintenance costs. Our estimates oversize
the treatment modules to give operational flexibility to avoid running the system during
peak electrical rates. The basic module provides 205 GPM and there would two of them in
total. The total lease cost per module was in the region of $45K per month and we need two
modules.
Total Lease costs for treatment are $1.08M per year.
6.3 Water Storage
The system envisioned includes a 200,000-gallon storage tank sized to accommodate one
day’s worth of customer usage. Tank costs vary almost linearly depending on storage
requirements. We plan to store irrigation water which simplifies the tank materials, but
seismic and other regulations will likely push the pri ce upwards. To account for these
possibilities, we elected to use a bolted steel tank that was mid-range at $2 per gallon. The
cost of the tank itself would be $400,000 based on these specifications. Additional costs
include: Foundation $20K, Site Delivery $10K, Installation Labor $45K, Permits $7.5K and
Site Preparation $12.5K. These sum to $495K per tank and $990K for two.
The inlet tank would be a 5,000 gallon prefabricated PolyTank that would cost about $6K to
purchase and about $20K to install. Total for two of these would be $52K.
Total cost for water storage: $1.042M.
6.4 Distribution Pumping
On the east side of the Complex, the pump to forward treated water to the customer would
be about a 100 HP motor to deliver the water at 50 psi. Since our potential customers
require all their irrigation water during an 8-hour period with varying flow rates during that
time, a variable speed unit is needed. Cost of one pump is around $10K, times 2 if we need
an inline spare to increase reliability. Cost to install both is about $30K.
Total pump expense for the east side $50K.
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For the west side, the pump has to send the water about four times f arther and up in
elevation almost 600 feet more than the east side. Our estimated cost for a 150HP motor
equipped pump is $18K. Assuming installation and redundancy is the same as the east
side, the total for west side pumping is $65K.
Total cost for distribution pumps: $0.115M.
6.5 Distribution Piping
On the east side we would need about 6,000 feet of piping (approximately one mile) to get
from the treatment site to the golf course. We estimated that an 8” HDPE line would be
more expensive to install than a smaller one but would have lower pressure drop and
hence lower operating cost for pump power. 4,000 feet could be laid above ground and
2,000 feet below. We assumed most of our costs would be toward the higher end so we
believe the cost for east side water delivery would be in vicinity of $370K to install.
On the west side, the distance is about 25,000 feet (+/- 5 miles) and drove us towards using
12” HPDE fusion-welded pipe. Additionally, almost all of the route would be underground
along PVDS and Hawthorne Blvd so the installation costs would also be higher. We
estimated ranges for all the sub-elements for installing such a pipe and the total ranged
from $180 to $340 per linear foot. When talking with WRD, they commented that their
extension plan included a lot of additional piping and their estimate was in excess of $1M
per mile which is $189 per foot. RPV is not as dense as an urban city such as Torrance and
that alone would simplify much of the installation. We wanted to be conservative but
realistic so we settled on a mid-range amount of $220 per foot. That made the piping costs
for the west side as $5.5M.
Total cost for distribution piping: $5.87M.
6.6 Power Requirements
The treatment modules require significant electrical power and that is not included in the
lease costs. We assumed by the time such a system might be implemented, electrical
power would be available at both east and west sites. We were given a power requirement
for the modules of 140 KW for treatment costs. Running 18 hours per day and assuming
$.30 per KWH, the annual electricity cost for one module would be $272K.
For the distribution pumps running 8 hours per day, the annual cost would be $43.2K on
the east side and $77.8K on the west side.
Total cost for electrical power: $0.665M per year
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6.7 Miscellaneous
The above covers what we believe are all of the major cost drivers, but we also understood
this cannot be accomplished without internal costs to the City. For these we estimated a
senior engineer for 9 months plus additional support of 5%.
Total Miscellaneous cost $172.5K
6.8 Operations
Per the CWS tariff document for the Palos Verdes Service Area, the current non-residential
usage cost of potable water is $9.4163 per ccf. But there are other charges that increase
the effective cost per ccf. Connection fees are applied based upon the delivery pipe
diameter. In addition, there are taxes and other surcharges that, for large water usage bills,
can be an additional 20 – 25%. All these add-ons bring the effective cost to around $11.50
per ccf.
If the City were to implement a treatment solution as outlined herein, t he two primary
operating costs are the lease of the treatment module and the electricity to run the module
and pump the water to the customers. Assuming we have a total customer demand of
250,000 ccf year, the lease rates on the two modules would impose a cost of $4.32 per ccf.
Likewise, the electrical costs of running the module and distributing the treated irrigation
water creates a cost of an additional $2.66 per ccf. Thus, the cost for the City to produce a
ccf of irrigation water is $6.98. If we are to sell this water to customers currently paying
$11.50 per ccf, we will need to provide an incentivization discount. If that were 20% for
example, then the selling cost would be $9.20. This leaves the City with a $2.22 profit that,
for 250,000 ccf per year, translates to an annual income stream of $555,000. One
significant assumption here is that City would not be required to add the taxes and
surcharges that CWS is obligated to collect. That is a question for the City legal team to
research. Also, that number does not reflect a need for amortization of capital which, if the
City had to pay the full cost, would amount to $480K per year, thereby reducing the net
income to $75K per year.
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6.9 Financial Summary
The following table summarizes the financial data discussed above.
Cost Notes
Capital Infrastructure
Storage tanks $1.042M Mid-Range
Pumps $0.115M
Piping $5.87M 6000 ft East; 25,000 ft West
Miscellaneous $0.173M
Total $7.2M
Operations 250,000 ccf per year maximum
Current Customer Cost $11.5 Per ccf
Lease $4.32 Per ccf
Electricity $2.66 Per ccf
Total $6.98 Per ccf
Discounted Cost to
Customer
$9.20 Per ccf
Net Profit $2.22 Per ccf
Annual Income $555,000 Without Capital Amortization
Net After Amortization $75,000 $480K per year over 15 years
Hypothetical Maximum
Potential Annual Income
$2,300,000 Grants Covering all Operational
Costs
Much of this data is from our own research and information provided by WRD and Wahaso.
We did not want to cite overly optimistic costs so we have erred on the conservative side. If
these costs can come down somewhat, then the picture gets more attractive. For
example, a one-dollar reduction in the ccf treatment cost would create $255,000
additional income and we believe there is likely some negotiating room to work with.
6.10 Irrigation Decision Validation
Early in the study, we elected to only look at irrigation water beca use of the onerous
regulations on potable water. At the time we made that decision, we had not started any
financial analysis as we were still in a data collection mode. We thought it might of
academic interest here to see what the financial difference might be.
As of 1 January, 2026, the Metropolitan Water District of Southern California wholesale rate
for potable water is $1,528 per acre foot, not including any surcharges that the wholesalers
might impose before it reaches CWS. This wholesale rate translates to $3.51 per ccf. We
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could not even generate water for that price and we would have to discount it as an
incentive for CWS or DWP to want to procure it. If we were able to secure grants for the
total operational costs of producing the maximum possible (522,000 ccf/year), then the
hypothetical maximum annual income would be $1.466M assuming the pumping capacity
is sustained. It does mean a $7M reduction in capital costs which almost eliminates any
amortization component, but the long-term hypothetical maximum income would still be
somewhat less than going the irrigation route. We believe this quick analysis validates that
early decision to focus on irrigation water only.
6.11 Grant Opportunities
When WRD received the go-ahead on the Robert W. Goldsworthy Desalter expansion in
Torrance, they received a grant from United States Bureau of Reclamation for $24M. Their
documentation suggests they also received other grants, bonds and low interest loans to
fund the expansion. Wahaso told us that many of their customers who are harvesting
wastewater obtained grants to defray the startup and operational costs. They were quite
optimistic the City would have a strong ca se to justify grants that could either pay all or
part of the capital costs or the operational costs or even both. They also offered to provide
us with contact information of experts who specialize in this area.
After the trials and tribulations the City has gone through trying to get help from State and
Federal entities on the landslide with very little to show for it, we share the City’s likely
cynicism that such grants could be easily obtained. But despite the limited success to
date, the City has shown a lot of persistence and we believe it is worth pursuing this
avenue as well
7. Challenges
7.1 Sustainability
At the present, we do not know how long the current extraction rates will last and what the
long-term steady state flow rate might be. This “known unknown” will have a significant
impact on reliable flow rates and how much in total the city would be comfor table
committing to customers.
Recently, the 5th November, 2025 City Manager’s report stated the City has been
consistently pumping around 1,000,000 GPD from the deep dewatering wells, KCLAD has
reached a level of about 400,000 GPD and ACLAD is presently around 165,000 GPD.
Therefore, the total extraction from the greater landslide area is presently in the region of
1,565,000 GPD. With a 68% recovery, that is equivalent to a usable irrigation water
production of 522,000 ccf/year. That total is more than enough for all three golf courses
and any other potential uses such as parks that we estimate cumulatively to be around
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250,000 ccf/year so we have quite a margin before any concern arises about not supplying
enough to meet all possible customer needs. However, we simply do not know how much
of the current extraction is legacy water accumulated over the last few heavy-rainfall years
or maybe even over decades. Once the accumulated water is removed and everything
stabilizes such that only future rainfall can recharge the water tables, we anticipate the
extraction rate will drop. KCLAD is already seeing the water table dropping and they
periodically turn off pumps to protect them until the well water level recovers. We look
forward to the recently initiated hydrology study shed ding some light on what this steady
state might look like over a range of dry to wet winters.
Another sustainability concern is the well reliability. Currently, we see failures due to land
movement frequently and these require redrilling quickly to recover the extraction rate. The
City has improved the drilling techniques with increased diameter drilling that mitigates
some of these issues and if the land movement can be brought down to manageable
levels, the failure rate should decrease significantly.
7.2 Publicly Owned Utilities
In California, our research suggests it is not possible for a City to sell treated non-potable
water for distribution and consumption without being assessed as a public utility . State
law defines any entity that sells or delivers water to the public as a public utility and
subjects it to oversight by either the California Public Utilities Commission (CPUC) or, in
the case of public entities, a locally elected governing body.
One expert we spoke with surmised the City would need to get a permit from the State
Water Resources Board and that might be sufficient to meet this legislative requirement.
We did not explore whether the City would be required to apply the various taxes that CWS
adds to both non-residential and residential bills. Being forced to do so would negatively
affect the potential revenue if it was deemed a legal requirement. To what extent becoming
a utility impacts that requirement is one of these regulatory issues that the City legal team
would have to research.
7.3 Compliance with Proposition 218
California's Proposition 218, or the "Right to Vote on Taxes Act," is a 1996 constitutional
amendment that restricts local governments' ability to impose, increase, or extend taxes,
assessments, and property-related fees without voter approval. The measure was
intended to provide taxpayer protection and limit excessive revenue increases by local
government agencies. Consequently, water agencies must base their rates on the actual
cost of providing water, including operation, maintenance, and infr astructure. They cannot
set rates higher than necessary to recover costs.
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Prop 218 was never intended, we believe, for the situation the City is dealing with but
nevertheless we are potentially bound by these rules. To be financially compliant, the City
must conduct a detailed cost-of-service analysis to justify its recycled water fees. The
analysis must show that the revenue collected from the fees does not exceed the cost of
providing the service.
Presently, the City is budgeting $3.4M in FY25/26 for the dewatering wells; it is our belief
that the City passes the basic test just from the dewatering well operations and
maintenance so long as the cost of water extraction from the landslide can be included as
part of the cost of providing water. If the initial capitalization costs of installing the
dewatering wells can also be recouped through amortization, then the basis for assessing
“profit” would be more than sufficient to meet the Prop 218 “reasonableness test” for
many years to come.
Let us emphasize, these are our thoughts and opinions based upon cursory research and
have no legal standing. If KCLAD and ACLAD provide some of the pumped water then that
adds another level of complexity that has the potential for unintentional consequences
that are way beyond our expertise to comment on.
7.4 Water Ownership
This was an issue ACLAD identified and it relates to who “owns” the water beneath their
property. It might not be an issue for the Portuguese Bend Landslide because there are no
private properties within the landslide boundary. But it could be an issue for ACLAD and
KCLAD where private property and public lands coexist. We have no opinion on the issue
but felt it needed to be highlighted for the City legal team to review.
7.5 Integration with KCLAD and ACLAD
Both ACLAD and KCLAD have supported this study, and both would like to participate in
any efforts going forward. They have expended significant investment in the dewatering
wells within their district and continue to spend their resources with operations and
maintenance of those wells. It seems to us that maybe a joint venture could be a viable
and equitable approach.
7.6 The “Complacency” Factor
There is another rather intangible benefit to having an income stream that is dependent
upon the reliability of the landslide dewatering system. None of us want a repeat of the
disaster that the landslide caused in 2023 and 2024. In decades to come, it will be
historical landmark in the City’s history. New generations will populate the City and the
City workforce and City Council will all comprise people that likely did not experience this
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event. Without this landslide water treatment system, what happens if a pump fails or a
well shears? As is normal, CIP budget is limited and because the landslide doesn’t provide
immediate feedback, it is human nature to prioritize the near -term projects. Then, if there
were no apparent consequences and the next well fails, the same response will be
justified. Eventually t he system will decay through this complacency. With its effectiveness
almost eliminated when we get another series of wet winters, the la ndslide will likely rear
its ugly side again and we will back in the same situation. Having City income depending on
keeping all the wells and pumps in good working order will mitigate this effect because the
repairs can always be justified as cost effecti ve. There is no way of quantifying this
justification for a water treatment system, but we believe it is a concern and a factor that
needs be part of the decision-making process.
8. Conclusions & Recommendations
The following is a summary of the study’s major conclusions:
1) Technically, producing high quality water from the lan dslide dewatering wells is not
an issue. Desalters are working on a much higher scale today in Torrance and water
harvesting is a thriving and expanding industry.
2) Trying to sell potable water is not only an onerous regulatory quagmire but is also
less financially beneficial than producing and selling irrigation quality water.
3) The landslide water is too brackish for practical use without reverse osmosis
treatment to remove the dissolved solids, mostly salt.
4) The customer base is limited but if all get onboard, then the City could advertise
they are saving 574 acre feet of potable water per year.
5) Mobile treatment modules built into shipping containers are available for lease and
used in venues across the nation today.
6) Significant infrastructure beyond the treatment modules is needed to handle the
irrigation schedules and distribute the water to the various customers, mostly the
three golf courses in the City. Total cost of that infrastructure is estimated at $7.2M.
7) Without grants, the costs of producing irrigation water including amortization of the
capital expenditure produces an annual income stream of $75K.
8) With grants covering all capital and operational costs, the hypothetical annual
income could be as high as $2.3M.
9) If grants can only be obtained for defraying capital costs, then the City might want to
revisit the lease/buy option for the treatment units. If the two units could be
purchased with a long-term, all-inclusive warranty and operation al contract, all of
which qualifies as a component of a grant covering required capital, then that would
save $4.32 cost per ccf and eliminate the amortization . This would lead to a
hypothetical maximum annual income of $1.635M per annum.
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Based on the foregoing, our recommendations are:
1) Without grants to defray either capital and/or operational costs, this simply isn’t
worth the effort to pursue.
2) There are a number of legal and regulatory challenges identified that we are
unqualified to make recommendations on but we suggest the City look into these as
a first step. We would hope they are inconsequential, but there could be a project
killer among them even if grants could be obtained.
3) If that step has a positive outcome, then we would suggest the City explore the
opportunities for grants. The City could use our data in this report to provide an
approximate cost estimate to help quantify the magnitude of grants needed to make
this a financially viable proposition.
4) With the above information at hand, the City Council can make a reasoned decision
on whether it is worth the effort to proceed.
9. Acknowledgements
The joint IMAC/FAC Subcommittee wish to than k the following for their help and support in
conducting the research and analysis that led to this feasibility study report.
• Mayor John Cruikshank for his incessant questioning “why we can’t we use this water
for something”, his encouragement for the subcommittee to pursue this feasibility
study and introducing us to Wahaso.
• Public works Department in general and deputy director Dave Copp and Principal
Engineer Russ Bryden in particular for their help and support. Their experience with
water projects before joining the City has been invaluable and helped us immensely in
maintaining focus.
• Water Replenishment District for their citizen’s brochure that provided the initial
impetus and for giving the subcommittee a tour of their Torrance facility and providing
valuable technical and cost data.
• Wahaso for their overall support, especially in taking and treating water samples to
show us the “art of the possible” and for being available to educate us and answer our
numerous questions.
• Trump National and Los Verdes golf courses for their enthusiasm for the project and
help with how they use water and what constraints we needed to consider.
10. References
1. Palos Verdes Groundwater Beneficial Reuse Study, Kraig Erickson, P.E. and John
Thayer, P.E. (RMC Water and Environment), August 6, 2009
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FINAL Technical Memorandum
Palos Verdes Groundwater Beneficial Reuse Study
Subject: Abalone Cove Project and Malaga Cove Plaza Project Conceptual Evaluation
Prepared For: Water Replenishment District and West Basin Municipal Water District
Prepared by: Kraig Erickson, P.E. and John Thayer, P.E. (RMC Water and Environment)
Reviewed by: Scott Goldman, P.E. (RMC Water and Environment)
Date: August 6, 2009
Reference: RMC Job No. 0130-004.03
The purpose of this preliminary study is to develop a project concept for collection, treatment, and
delivery of extracted nuisance groundwater for non-potable irrigation and other beneficial uses within the
Palos Verdes Peninsula. This technical memorandum (TM) is organized as follows:
1 Background ______________________________________________________________ 2
1.1 Abalone Cove _______________________________________________________________ 2
1.2 Malaga Cove Plaza ___________________________________________________________ 4
1.3 Potable and Recycled Water Supply _____________________________________________ 5
2 Abalone Cove Assessment __________________________________________________ 5
2.1 Existing Conditions and Infrastructure ___________________________________________ 5
2.2 Nuisance Groundwater Quality _________________________________________________ 8
2.3 Nuisance Groundwater Supply _________________________________________________ 9
2.4 Potential Users ______________________________________________________________ 9
2.5 Fatal Flaw Analysis __________________________________________________________ 11
2.6 Conceptual Evaluation _______________________________________________________ 14
3 Malaga Cove Plaza Assessment _____________________________________________ 20
3.1 Existing Conditions and Infrastructure __________________________________________ 20
3.2 Nuisance Groundwater Quality ________________________________________________ 21
3.3 Nuisance Groundwater Supply ________________________________________________ 21
3.4 Potential Users _____________________________________________________________ 23
3.5 Fatal Flaw Analysis __________________________________________________________ 25
3.6 Conceptual Evaluation _______________________________________________________ 28
4 Summary of Findings and Conclusions ________________________________________ 34
4.1 General ___________________________________________________________________ 34
4.2 Potential Obstacles and Opportunities for Abalone Cove ___________________________ 35
4.3 Potential Obstacles and Opportunities for Malaga Cove ____________________________ 36
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1 Background
The Palos Verdes Peninsula is a unique setting in Los Angeles County because of an abundance of
artesian groundwater and unstable soil conditions. The City of Palos Verdes Estates has implemented
dewatering measures to prevent nuisance groundwater from damaging homes and businesses. In the City
of Rancho Palos Verdes, continuous-withdrawal dewatering wells have been installed to slow the
progression of the Abalone Cove Landslide and the Portuguese Bend Landslide. The nuisance
groundwater removed from these dewatering sites is discharged into the local storm drain system and/or
to the nearby Pacific Ocean.
Figure 1-1: Palos Verdes Peninsula Location Map
1.1 Abalone Cove
In the City of Rancho Palos Verdes, the Portuguese Bend and Abalone Cove areas of Palos Verdes
Peninsula have undergone consistent landslide movement since the mid-1950s. Figure 1-2 shows the
locations of active and inactive landslides in the area. The Abalone Landslide Abatement District
(ACLAD) was formed to govern and assess property owners in the Abalone Cove landslide area to pay
for construction and maintenance of landslide abatement measures. The ACLAD is governed by an
elected Board of Directors comprised of property owners in the District.
ACLAD maintains 18 dewatering wells within their district. The average total daily well production for
all wells for the period between 1996 and 2006 is 206,000 gallons-per-day (gpd) (see Figure 2-2 for
annual well production from 1980-2006). These dewatering wells are successfully preventing movement
of the Abalone Cove Landslide except during very wet years.
In the mid-1950’s, over 10-million cubic yards of earth was removed from the Portuguese Landslide area
and transferred to the beach to thwart further landslide movement. The landslides are geologically
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classified as debris flows moving laterally along a subsurface bentonite clay layer. The landslides speed
up (flow) during wet years; typically 0.5 inches-per-year at the toe of the Portuguese Bend Landslide.
However in the last 1½ years the Portuguese Bend Landslide has moved roughly 5-6 feet at the toe. The
Portuguese Bend Landslide area has no landslide abatement currently in place other than previous transfer
of earth. The Abalone Cove Landslide has some creep at the toe of landslide; roughly 1/10 inch per day in
wet years. It is important to understand the geological setting of both the Abalone Cove Landslide and
Portuguese Bend Landslide due to their impact on the location of the dewatering wells with respect to
potential end irrigation users (such as Trump National Golf Course; see Section 2.4 for discussion of
potential users). The location of potential conveyance pipelines, storage facilities, treatment facilities, and
pumping facilities could be a fatal flaw as these facilities would be impacted by landslide movement.
Figure 1-2: Abalone Cove Landslide Map
Photos of Abalone Cove Area
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1.2 Malaga Cove Plaza
Geological conditions cause groundwater to concentrate and discharge near the surface in the area of
Malaga Cove Plaza (see Figure 1-3). The source of the water has been studied by the City of Palos
Verdes Estates and is believed to be a combination of rainfall and irrigation. As early as 1978, wells were
installed in the alleyway behind the Plaza to alleviate problems due to the groundwater. The main
problem was water seeping through the walls of adjacent buildings, damaging items inside the buildings
and creating risk of structural damage. Similar problems have been prevalent throughout the Plaza over
the years.
In 1993, the groundwater discharge at the ground surface reached a very high volume and caused the City
to develop an emergency mitigation plan. The City drilled nine wells to provide immediate dewatering
relief for the commercial buildings in the Plaza.
In 1997, the City installed a perforated pipe sub-drain within Malaga Lane (alleyway). Since the sub-drain
was installed, there have been frequent occurrences of sinkholes in the street along the sub-drain’s
alignment.
Figure 1-3: Malaga Cove Plaza Area Map
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Photos of Malaga Cove Plaza
1.3 Potable and Recycled Water Supply
Table 1-1 shows the existing local costs of potable and recycled water supplied by California Water
Service Company (Cal Water), the water retailer for Palos Verdes Peninsula.
West Basin Municipal Water District (West Basin MWD), a water wholesaler and service provider of
recycled water to the South Bay region of Santa Monica Bay, owns and maintains a recycled water
system that extends into the City of Torrance. Recycled water is not currently available on the Palos
Verdes Peninsula.
Table 1-1: Existing Local Costs of Water
Type of Water Supply Average Retail Cost
Potable Water Supplied by Cal Water in Palos Verdes $1,229 per acre-foot
Recycled Water Supplied by Cal Water in Palos Verdes1 $873 per acre-foot
Footnote 1: Recycled water producer and wholesaler for communities adjacent to Palos Verdes is West Basin MWD.
2 Abalone Cove Assessment
The following is an assessment of infrastructure, water quality, supply and demand for the
implementation of beneficial reuse of groundwater in Abalone Cove.
2.1 Existing Conditions and Infrastructure
Active dewatering wells in the Abalone Cove/Portuguese Bend Area exist only within ACLAD’s
boundaries. There are three City wells that ACLAD has assumed operation of within their boundary.
ACLAD operates a total of 18 dewatering wells plus the three City dewatering wells (as shown in Figure
2-1). The three City dewatering wells discharge to the ocean at a different location.
In addition to the dewatering wells, there are additional monitoring wells in the Abalone Cove and
Portuguese Bend areas. These wells are either owned by private developers or the City of Rancho Palos
Verdes. These wells are only for monitoring and are not equipped to serve as dewatering wells. Sampling
data from the monitoring wells and the active dewatering wells is the basis for the water quality data
reported in this study.
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Figure 2-1: Abalone Cove Active Well Locations Map
All dewatering wells use submersible pumps at the bottom of the well. Wells run 24 hours a day, 7 days a
week. Typical well depth is 100-150 feet. Some wells have been re-drilled to depths of 300 feet. In the
future, ACLAD is planning to have well depths at 500 feet to maximize flow by maximizing draw-down.
Water depths for the ACLAD wells vary widely but are in the range of 30 to 500 feet including well
drawdown. Each well discharges into above-ground 3-inch PVC piping. Piping joins together as it moves
down the hill southward to the ocean and eventually becomes a 4-inch PVC pipe. The 4-inch PVC piping
then discharges into a manhole at ACLAD’s boundary off Palos Verdes Drive (the Coast Highway). The
existing PVC piping is above-ground. From the manhole, flows travel underneath Palos Verdes Drive
through steel piping inside a drainage culvert before discharging onto the beach. ACLAD operates and
maintains the existing dewatering infrastructure (wells, pumps, and piping). The average total daily well
production for all wells for the period between 1996 and 2006 is 206,000 gallons-per-day (gpd) (see
Figure 2-2 for annual well production from 1980-2006).
The City of Rancho Palos Verdes owns all land to the south of Palos Verdes Drive in the landslide areas.
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Figure 2-2: ACLAD Annual Dewatering Well Production
Source: Bob Douglas, ACLAD.
Photo of Dewatering Well and PVC Piping Photo of Above-Ground PVC Piping
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Photo of Common Collection Manhole Photo of Discharge Point to Ocean
2.2 Nuisance Groundwater Quality
Table 2-1 provides an overview of groundwater quality in Abalone Cove. Water quality is based on
available data from active dewatering wells and monitoring wells from ACLAD from 1980-2006. As
shown in the table, the high constituent levels do not meet potable water standards and treatment would
be required for potable water use.
Table 2-1: Abalone Cove Nuisance Groundwater Quality
Parameter Units
Typical
Observed
Range 1
Average 1 Drinking Water
Limits 2
Potable
Water
Quality
(Avg.) 3
Total Dissolved
Solids (TDS) mg/L 2,700 to 3,300 3,045 1,000 SMCL 436
Sulfate mg/L 1,700 to 2,300 2,040 500 SMCL 134
Nitrate (as
Nitrogen) mg/L 5 to 28 17 10 MCL 0.6
Calcium mg/L 411 to 561 464 none 44
Sodium mg/L 258 to 463 351 none 78
Magnesium mg/L 248 to 323 276 none 19
Potassium mg/L 16 to 22 19 none Not reported
Chloride mg/L 389 to 563 450 500 SMCL 86
Bicarbonate mg/L 410 to 517 462 none Not reported
Silicon Dioxide mg/L 29 to 36 32 none Not reported
Conductivity Umhos/cm 3,900 to 4,800 4,298 none 747
Footnotes:
1. Data provided by Bob Douglas of ACLAD. 1997-1998.
2. MCL = Maximum Contaminant Level. SMCL = Secondary Maximum Contaminant Level.
3. Data provided by Cal Water per 2008 Water Quality Report.
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2.3 Nuisance Groundwater Supply
The current dewatering wells are necessary to prevent future landslide movement. An analysis done by
ACLAD (ACLAD, 2007) suggests that the dewatering wells are an effective tool in reducing groundwater
within the Abalone Cove landslide and adjacent upslope area. The data suggests that groundwater
recharge greater than 200,000 gpd, which occurs when rainfall exceeds 19 inches per year, exceeds
current well production and permits the build-up of groundwater within and below the Abalone Cove
landslide. The pumping capacity per well varies but a typical well capacity is roughly 50 gpm. In years
when rainfall exceeds 25 inches, the build-up of groundwater and pore-fluid pressure causes slow
movement in the landslide. During years of average rainfall, well production approximately equals
groundwater infiltration and during dry years (less than 10 inches per year of rainfall), dewatering well
production exceeds groundwater infiltration and groundwater storage is reduced. The dewatering wells
are abating landslide movement except during very wet years. The dewatering wells are effective in
preventing future landslides and are currently maximizing dewatering production to match infiltration
rates.
Table 2-2 summarizes the groundwater supply from the 18 Abalone Cove dewatering wells. There is not
a significant seasonal fluctuation in groundwater production; changes to the groundwater production rate
occur slowly over a period of many months/years and are mostly linked to long-term climatic shifts
occurring in the Eastern Pacific.
Table 2-2: Abalone Cove Nuisance Groundwater Supply
Parameter Value Value Notes
Maximum Annual
Average Production
Between 1996 and
2006
300,000 Gal/day 336 AFY
Maximum occurred
during 1998-1999
El Niño Year
Minimum Annual
Average Production
Between 1996 and
2006
100,000 Gal/day 112 AFY Minimum occurred
in 2003
Average Production
Between 1996 and
2006
206,000 Gal/day 231 AFY --
2.4 Potential Users
Within the vicinity of Abalone Cove there are three golf courses that could be potential candidates for
using non-potable water supplies for irrigation: Trump National Golf Course, Terranea Golf Course, and
Los Verdes Golf Course. There are also a number of parks that are within the vicinity as shown in Figure
2-3. Abalone Cove Shoreline Park is the closest park; however the park does not currently have any
irrigation. Due to low water demands and potential for high forecasted retrofit costs, parks were not
evaluated as potential users. At this time median irrigation along Palos Verdes Drive was also not
evaluated due to low water demands. However, other potential irrigation users, including median
irrigation, should be evaluated in the future if the project moves forward.
An additional demand suggested by Robert Douglas of ACLAD is the potential for supplemental non-
potable water for firefighting uses. The fire flow system would potentially have a high cost and cross-
connection issues. The high cost would be associated with the need for a separate piping system, which
would be isolated from Cal Water’s existing fire flow system, which is currently tied in with their potable
water system. A non-potable system would be a supplemental system involving a separate storage tank,
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pumps, piping, and separate fire hydrants. Currently, Cal Water has fire hydrants in the Abalone Cove
area to meet projected fire flow demands. Due to the high cost, potential cross-connection issues, and that
fire flow does not necessitate a continuous demand, a separate non-potable firefighting system for
Abalone Cove was not evaluated further as part of this study.
Figure 2-3: Map of Potential Irrigation Users Near Abalone Cove
2.4.1 Water Demand
Table 2-3 provides an overview of the estimated demands of potential users.
Table 2-3: Abalone Cove Potential Users and Demands
Demand # of Golf Holes /
Approx. Acreage
Estimated Max.
Day Summertime
Demand
Estimated
Max. Day
Summertime
Demand
Currently
Dual Plumbed
Los Verdes
Golf Course
18 holes / 112
acres 698,000 Gal/day 782 AFY no
Trump National
Golf Course 18 holes / 68 acres 424,000 Gal/day1 475 AFY no
Terranea
Golf Course 9 holes / 33 acres 206,000 Gal/day1 231 AFY no
Footnote 1: These demands are interpolated based on acreage and demands from Los Verdes G.C. (6,232 GPD/acre). Trump and
Terranea were contacted but did not provide demand information.
Abalone
Cove
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There is potential for using non-potable water for fire fighting in the Abalone Cove. Because of the lack
of continuous water demand for firefighting, the projected high cost and cross-connection issues, it will
not be evaluated further in this study. If funding becomes available to construct a separate piping and
storage system for a non-potable fire suppression system, then this option could be evaluated further.
2.4.2 Existing Conditions and Infrastructure
The following is a summary of the available information for each potential user. Further evaluation is
required to properly evaluate each user. The evaluation should include specifics on each user’s booster
pumps and irrigation meters as well as any operational storage requirements.
Trump National Golf Course 1
Trump National Golf Course is interested in a lower cost source of water. Currently Trump receives all
their water from Cal Water. Trump National Golf Course is not a dual-plumbed system. There is a single
main potable water line that supplies golf course irrigation. Trump does not have an onsite storage
tank/reservoir but does have ponds on their golf course. Trump National is an 18-hole golf course.
Terranea Golf Course
No specific information is available for Terranea Golf Course at this time. This is a 9-hole golf course
that was recently constructed. The Terranea Resort opened in June 2009.
Los Verdes Golf Course 2
Los Verdes Golf Course is also interested in a lower cost source of water. Currently Los Verdes receives
all their water from Cal Water off connections along Hawthorne Boulevard and Los Verdes Drive. Los
Verdes Golf Course is not a dual-plumbed system. Los Verdes does not have any onsite
storage/reservoir/ponds. Los Verdes is an 18-hole golf course.
2.4.3 Potential User Requirements
Per communications with Los Verdes Golf Course 2, the observed TDS levels from Cal Water are roughly
500-600 mg/L. Cal Water reports TDS levels of 283-678 mg/L with an average TDS level of 436 mg/L.
Los Verdes leaches their greens approximately once a month to control salt levels on greens.
2.5 Fatal Flaw Analysis
2.5.1 Permitting
In preparing this TM the following public agencies were contacted to discuss the potential
implementation of this project and any major permitting requirements:
California Department of Public Health 3
California Department of Public Health’s (CA-DPH) main concern with any project is the protection of
public health. Protection of the existing potable water system and groundwater supplies will need to be
accurately addressed during the design phase. The reuse of nuisance groundwater should be considered a
non-potable water supply. CA-DPH will require installation of backflow prevention devices on both
potable water pipelines and on non-potable water pipelines as well as an air gap separation for potable
1 Per personal communications with Martin Howard, Trump National Golf Course. June 9, 2009.
2 Per personal communications with Bruce Duenow, Los Verdes Golf Course. June 10, 2009.
3 Per personal communications with Paul Williams, CA-DPH. June 8, 2009.
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water connections to blending basins. CA-DPH deferred to Los Angeles County Department of Public
Health’s (LA-DPH) stormwater reuse guidelines for reference. These guidelines include pipeline
separation requirements. CA-DPH recommended contacting LA-DPH as well as Los Angles Regional
Water Quality Control Board (LA-RWQCB) for further permitting requirements.
Los Angeles County Department of Public Health
Protection of potable water supply on-site is the main concern of LA County DPH. Testing may be
required to assure that there are no cross connections with the existing potable water system.
Cal Water 4
Per communications with Cal Water, protection of their potable water system is their main concern. Steps
(such as backflow protection, cross connection testing, pipe separation, proper signage, etc.) will need to
be taken to make sure their system is protected.
Los Angeles RWQCB
The LA-RWQCB was contacted during preparation of this report; however, no response has been
received to date.
2.5.2 Environmental Restrictions
The discharge of the nuisance water is at the beach. The nuisance water is piped all the way to the ocean
discharge location; there is no streambed. Based on site visits it can be determined that no streambed
would be altered by depleting flows from this discharge location. There is no riparian habitat at the
discharge location.
In evaluating the preliminary environmental impacts it was determined that a negative declaration (ND)
report may be sufficient to meet CEQA requirements for constructing the alternatives in Section 2.6.5 of
this report. However, for planning purposes, cost estimates for a potential project should assume that a
mitigated negative declaration (MND) would be required. California Department of Fish and Game and
the California Coastal Commission should be included in the review of the initial study that precedes the
ND or MND. A lead public agency will need to step forward in order for the permitting process to begin;
other public agencies can be contributing responsible agencies in the CEQA process.
2.5.3 Water Quality Requirements
Some form of treatment or blending will be required to reduce the TDS levels of the nuisance
groundwater. For Abalone Cove the TDS levels average about 3,000 mg/L. Table 2-4 provides a
summary of TDS levels for potable water, recycled water, and groundwater.
Table 2-4: TDS Comparison – Abalone Cove Area
Type of Water Units TDS - Typical Observed
Range Average TDS
Potable Water mg/L 500 to 6001
283 to 6782 4362
Recycled Water Supplied by West Basin
MWD in Neighboring Communities mg/L 750 to 850 790
Groundwater mg/L 2,700 to 3,3003 3,0453
Footnotes: 1. Data reported by Los Verdes Golf Course.
2. Data reported by Cal Water.
3. Dated provided by Bob Douglas of ACLAD.
4 Per personal communications with Carmelo Sorce, Cal Water. June 4, 2009.
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Blending of potable water with the nuisance groundwater will be required to achieve the required TDS
levels by the end users. A TDS level of 1200 mg/L is the maximum threshold suitable for golf course
irrigation purposes. TDS levels of 1200 mg/L will require additional maintenance (such as leaching the
greens of golf courses). A TDS level of 700 mg/L is the preferred threshold for irrigation purposes5.
Based on the average TDS levels as shown in Table 2-4, Table 2-5 summarizes the required blending
ratios of potable water to nuisance groundwater to meet end user water quality requirements.
Table 2-5: Abalone Cove Blending Ratios
TDS Level
Required by User
Potable
Supply
Non-Potable
Supply
Ratio
(Potable range to
Non-Potable)
1200 mg/L 400 – 600 mg/L 3,045 mg/L (2.3 – 3.1) to 1
700 mg/L 400 – 600 mg/L 3,045 mg/L (7.8 – 23.5) to 1
As shown in Table 2-5, in order to achieve a TDS level of 700 mg/L, the required blending range is 7.8 to
23.5 parts potable water to one part non-potable nuisance groundwater from Abalone Cove. In order to
achieve a TDS level of 1200 mg/L, the required blending range is 2.3 to 3.1 parts potable water to one
part non-potable nuisance groundwater from Abalone Cove.
2.5.4 Constructability
The geographic location of Abalone Cove impedes construction. There is the issue of constant land
movement in the area caused by the landslides. All piping in the Abalone Cove area is above-ground
(potable water, sewer, gas, dewatering). All piping that crosses the landslide areas has multiple joints to
allow for flexing at bend points. Periodic maintenance is required to add more joints as needed to
accommodate the constant land movement.
2.5.5 Municipal Concerns
No municipal concerns were encountered during this study. The City of Rancho Palos Verdes has
expressed interest in the results of this study.
2.5.6 Customer Concerns
The golf courses are interested in the results of this study as well as in obtaining a lower cost water supply
to supplement their irrigation demands. The golf courses’ main concern is the quality of water and any
impacts to their vegetation. The TDS levels are higher than the golf courses are used to receiving from
Cal Water.
Property owners within ACLAD are concerned with water rights by distributing nuisance groundwater.
Based on communications with Robert Douglas, Chairman of the ACLAD Board of Directors, the rights
to groundwater in the Abalone Cove area are not precisely known. It is assumed the individual property
owners have the rights to groundwater underneath their property. This is the current interpretation of the
ACLAD Board of Directors. As this project moves forward groundwater rights must be investigated
further.
5 Per personal communications with Patrick Gradoville, Palos Verdes Golf Club. May 11, 2009.
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2.6 Conceptual Evaluation
This section provides a conceptual evaluation of how to consolidate nuisance groundwater flows, provide
treatment of the non-potable water, and deliver the non-potable water to end irrigation users. In addition,
this section evaluates the cost of each alternative to the amount of non-potable water produced.
2.6.1 Consolidating Flows
In Abalone Cove all the ACLAD dewatering flows converge at an existing point in the manhole off Palos
Verdes Drive. Flows can be captured at this point and pumped as shown in Figure 2-4. Capturing the
three City wells’ flows was not evaluated since they discharge to the east in the Portuguese Bend
Landslide area.
Figure 2-4: Schematic of Manhole and Submersible Pumps
2.6.2 Treatment
Two alternatives are available for reducing the TDS levels of the nuisance groundwater: (1)
microfiltration with reverse osmosis (MF/RO) treatment or (2) blending the captured groundwater with
potable water.
Treatment would require a site location to house the MF/RO facilities, including storage facilities,
pumping facilities, and connection to a local sanitary sewer system to dispose of brine. Due to high
mineral content it can be assumed that a portion of the captured groundwater will be lost during brine
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removal. It is assumed that the sidestream MF/RO facilities would have a product water recovery of
70 percent6.
Blending would require a blending basin and potable water connection. If the blending basin is located
onsite at the golf course it could potentially be tied into their existing irrigation system, provided that the
irrigation system undergoes a dual-plumbed retrofit. Utilizing existing ponds/basins at the golf course
would greatly reduce the capital costs of the project, but might require continuous mixing mechanism (i.e.
water circulation).
2.6.3 Conveyance
Figure 2-5 provides an overview of the three potential pipeline alignments to convey water to local golf
courses in the Abalone Cove vicinity. Pipeline alignments are assumed to be mostly along Palos Verdes
Drive. Traveling westerly along Palos Verdes Drive there is minimal impact from active landslides. To
the east, however, the pipeline alignments would cross active landslides (Portuguese Bend Landslide).
Pipelines in active landslide areas would need to be above-ground with restrained or flexible joints.
The figure also identifies a potential location for off-site MF/RO treatment, blending, or storage. There is
land north and south of Palos Verdes Drive in the vicinity of Abalone Cove Shoreline Park. In particular,
there is an abandoned fruit stand with a level parking lot that could be evaluated as potential treatment site
location. The parking lot has approximate dimensions of 50 feet by 200 feet (10,000 square feet of area)
and is located within a large parcel encompassing Abalone Cove Shoreline Park (maintained by City of
Rancho Palos Verdes). This parking lot has two existing paved vehicle entrances off the south edge of
Palos Verdes Drive. According to Bob Douglas of ACLAD, the parking lot is not within an active
landslide area.
Figure 2-5: Abalone Cove Schematic of Conveyance Alternatives to Golf Courses
6 70 percent is a conservative estimate. The system should be designed to maximize recovery to the largest extent
possible. 75 to 90 percent recovery may be attainable.
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2.6.4 Site Retrofit
It is assumed for preliminary cost estimating that ACLAD will maintain all facilities upstream of the
existing collection manhole on Palos Verdes Drive South.
The three golf courses in Rancho Palos Verdes are not dual-plumbed. Costs are included for retrofits to
the golf courses as noted in each project alternative.
2.6.5 Evaluation Criteria
Five water supply alternatives were evaluated. The water supply alternatives are:
• No Project Alternative – serve three golf courses with potable water. No change.
• Alternative 1 – serve three golf courses with blending on golf course site. Facilities include:
a) Capture: weir structure in collection manhole, two 20-hp submersible supply pumps.
Includes O&M costs for powering pumps.
b) Blending: use existing irrigation pond at golf course for blending; no separate basin
required. Includes O&M costs for purchasing potable water used in blending operation.
Assumes 3.1 to 1 blending ratio of 639,000 gallons of potable water per day (715 AFY)
to produce 845,000 gallons of blended water per day with blended TDS of 1,200 mg/L.
Includes capital cost for hypochlorite dosing system and O&M costs hypochlorite.
c) Storage: use existing irrigation ponds at Terranea and Trump golf courses for blending. A
new storage facility would be constructed at Los Verdes golf course for blending
operations.
d) Pumping: use new submersible pumps for capture to provide required pressure to
irrigation ponds at each golf course.
e) Pipe: 26,000 feet of 8-inch PVC piping to all users.
f) Misc: Potable water connection and meter at each user location. Non-potable water meter
at each user location. Backflow protection. Includes costs for retrofitting each golf course
irrigation piping (assumes $1,000/AF).
O&M Costs: includes 15 percent of a Full-Time-Equivalent (FTE). 1 percent of capital costs
for electrical and chemical costs. Includes costs to purchase potable water for blending (715
AF). Also includes costs to purchase potable water to meet user’s full demands in summer
months (117 AF). The table below provides an analysis of supply versus demand:
Alternative 1: Supply and Demand
Groundwater Supply 231 AFY (206,000 GPD)
Potable Water Blend 715 AFY (638,600 GPD)
Blended Supply 946 AFY (844,600 GPD)
Total Average Irrigation Demand 611 AFY (199,200,000 Gals/Year)
Potable Water Supplement Required to meet
4 Summer Month Demands 117 AFY (1,162,000 GPD)
• Alternative 2 – serve three golf courses with new offsite blending structure. Facilities include:
a) Capture: weir structure in collection manhole, two 20-hp submersible supply pumps.
Includes O&M costs for powering pumps.
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b) Blending: Construct new offsite blending basin, 1.3-MG7. Includes O&M costs for
purchasing potable water used in blending operation. Assumes 3.1 to 1 blending ratio or
639,000 gallons of potable water per day (715 AFY) to produce 845,000 gallons of
blended water per day. Includes capital cost for hypochlorite dosing system and O&M
costs hypochlorite.
c) Storage: use new offsite blending basin for operational storage.
d) Pumping: Two 20-hp distribution pumps at treatment location. Includes O&M costs for
powering pumps.
e) Pipe: 29,000 feet of 8-inch PVC piping to all users .
f) Misc: Potable water connection and meter at blending basin only. Non-potable water
meter at blending basin. Backflow protection. Includes costs for retrofitting each golf
course irrigation piping (assumes $1,000/AF).
O&M Costs: includes 30 percent of a Full-Time-Equivalent (FTE). 1 percent of capital costs
for electrical and chemical costs. Includes costs to purchase potable water for blending (715
AF). Also includes costs to purchase potable water to meet user’s full demands in summer
months (117 AF).
Alternative 2: Supply and Demand
Groundwater Supply 231 AFY (206,000 GPD)
Potable Water Blend 715 AFY (638,600 GPD)
Blended Supply 946 AFY (844,600 GPD)
Total Average Irrigation Demand 611 AFY (199,200,000 Gals/Year)
Potable Water Supplement Required to meet
4 Summer Month Demands 117 AFY (1,162,000 GPD)
• Alternative 3 – serve one golf course with MF/RO product water. Facilities include:
a) Capture: weir structure in collection manhole, two 20-hp submersible supply pumps.
Includes O&M costs for powering pumps.
b) Treatment: Construct new offsite MF/RO sidestream treatment facility. No potable water
is used in treatment process and no supplemental potable supply. Includes costs for brine
disposal. Includes O&M costs for chemicals and powering facility. 70 percent of
sidestream feed water is recovered as product water (100,000 GPD of RO product water).
Assumes portion of feed water is bypassed (63,000 GPD) and blended with RO product
water at the treatment facility. Total facility output is 163,000 GPD of blended water.
c) Storage: Construct new offsite 0.25-MG8 storage. No potable water used.
d) Pumping: Two 20-hp distribution pumps at treatment location. Includes O&M costs for
powering pumps.
e) Pipe: 8,000 feet of 8-inch PVC piping to one user only.
f) Misc: Potable water connection and meter. Non-potable water meter. Backflow
protection. Includes costs for retrofitting the golf course irrigation piping (assumes
$1,000/AF).
7 Assumes 3.1 to 1 blending ratio of potable water to groundwater and peak demand factor of 1.5.
8 Assumes 70 percent recovery and peak demand factor of 1.5.
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O&M Costs: includes 30 percent of a Full-Time-Equivalent (FTE). O&M costs for MF/RO
facility which includes electrical, chemical, and brine disposal. Includes cost to purchase
potable water to meet user’s full demands in summer months (6 AF).
Alternative 3: Supply and Demand
Groundwater Supply 231 AFY (206,000 GPD)
Potable Water Blend 112 AFY (100,000 GPD)
Blended Supply 183 AFY (163,000 GPD)
Total Average Irrigation Demand 95 AFY (30,900,000 Gals/Year)
Potable Water Supplement Required to meet
4 Summer Month Demands 6 AFY (180,250 GPD)
• Alternative 4 – serve three golf courses with MF/RO product water. Facilities include:
a) Capture: weir structure in collection manhole, two 20-hp submersible supply pumps.
Includes O&M costs for powering pumps.
b) Treatment: Construct new offsite MF/RO sidestream treatment facility. No potable water
is used in treatment process but potable water is assumed to supplement water supplies to
all three golf courses. Includes costs for brine disposal. Includes O&M costs for
chemicals and powering facility. 70 percent of sidestream feed water is recovered as
product water (100,000 GPD of RO product water). Assumes portion of feed water is
bypassed (63,000 GPD) and blended with RO product water at the treatment facility.
Total facility output is 163,000 GPD of blended water.
c) Storage: Construct new offsite 0.25-MG9 storage. Potable water would supplement
supplies but no storage is required for potable water.
d) Pumping: Two 20-hp distribution pumps at treatment location. Includes O&M costs for
powering pumps.
e) Pipe: 29,000 feet of 8-inch PVC piping to all users.
f) Misc: Potable water connection and meter. Non-potable water meter. Backflow
protection. Includes costs for retrofitting each golf course irrigation piping (assumes
$1,000/AF).
O&M Costs: includes 30 percent of a Full-Time-Equivalent (FTE). O&M costs for MF/RO
facility which includes electrical, chemical, and brine disposal. Includes costs to purchase
potable water to meet user’s full demands in summer months (431 AF).
Alternative 4: Supply and Demand
Groundwater Supply 231 AFY (206,000 GPD)
RO Product Water 112 AFY (100,000 GPD)
Total RO Facility Output 183 AFY (163,000 GPD)
Total Average Irrigation Demand 611 AFY (199,200,000 GPD)
Potable Water Supplement Required to meet
4 Summer and 8 Winter Month Demands 431 AFY
Table 2-6 provides the anticipated costs for each project alternative.
9 Assumes 70 percent recovery and peak demand factor of 1.5.
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Table 2-6: Abalone Cove – Cost of Alternatives h
Alt. Facilities Approx. Capital Cost
($)
Approx. O&M
Cost ($/yr) b
Annualized
Cost ($/yr) c
Present Worth
Cost of Water
($/AF)
No
Proj None $ -- Cost to purchase
Potable Water $750,919 $1,229
AC
1
a) Capture
b) Blending
c) Storage
d) Pumping
e) Pipe
f) Misc.
¾ TOTAL
a) $85,000
b) $78,000
c) $ 463,500
d) $ --
e) $4,576,000
f) $620,322
¾ $10,220,000 a
15% of FTE,
+ 1% for elec. &
chem. e
+715 AFY
Potable.
+117 AFY
Potable.
= $1,148,000 /
year
$1,947,000
611 AFY yield
$3,185 / AF
AC
2
a) Capture
b) Blending
c) Storage
d) Pumping
e) Pipe
f) Misc.
¾ TOTAL
a) $85,000
b) $1,976,000
c) $ --
d) $80,000
e) $5,104,000
f) $620,322
¾ $13,805,000 a
30% of FTE,
+ 1% for elec. &
chem. e
+715 AFY
Potable.
+117 AFY Potable
= $1,206,000 /
year
$2,286,000
611 AFY yield
$3,739 / AF
AC
3
a) Capture
b) Treatment
c) Storage
d) Pumping
e) Pipe
f) Misc.
¾ TOTAL
a) $85,000
b) $501,000
c) $375,000
d) $80,000
e) $1,355,200
f) $97,829
¾ $4,378,000 a
30% of FTE,
+$800/AFY for
MF/RO f,
+6 AFY Potable.
= $199,000 / year
$542,000
95 AFY yield
$5,716 / AF
AC
4
a) Capture
b) Treatment
c) Storage
d) Pumping
e) Pipe
f) Misc.
¾ TOTAL
a) $85,000
b) $501,000
c) $375,000
d) $80,000
e) $5,104,000
f) $620,322
¾ $11,874,000 a
30% of FTE,
+$800/AFY for
MF/RO f,
+431 AFY
Potable.
= $721,000 / year
$1,650,000
611 AFY yield
$2,699 / AF
Footnotes:
a. Costs include Raw Construction Contingency of 30 percent and Engineering, Environmental, Construction
Management, ESDC, Legal, Admin, and Financial Costs of 35 percent. Does not include costs for potable water
used in blending operations.
b. Assumes FTE at $60,000 per year salary multiplied by a factor of 2.5 to account for overhead and administration, for
a total annual FTE cost of $150,000.
c. Assumes 25 year period at an inflation rate of 6 percent.
d. Not used.
e. Assumes 1 percent of total capital costs for electrical and chemical O&M.
f. O&M cost of $800/AFY includes electrical costs (pumping, treatment), chemical costs, brine disposal and
maintenance of MF/RO facility (112 AFY of sidestream product water).
g. Costs do not include land acquisition (including for storage, treatment, and piping locations).
h. All costs are reported in 2009 dollars and do not include inflation.
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3 Malaga Cove Plaza Assessment
The following is an assessment of infrastructure, water quality, supply and demand for the
implementation of beneficial reuse of groundwater in Malaga Cove Plaza.
3.1 Existing Conditions and Infrastructure
There is an existing 12-inch perforated storm drain pipeline
in the alleyway of Malaga Lane in between Via Corta and
Via Chico. This sub-drain is roughly 20-feet deep and
extends 500-feet to the west from Via Chico along Malaga
Lane. The perforated pipe is ‘burrito-wrapped’ with drain-
rock to allow for groundwater to enter the pipe and not soil.
The groundwater then enters the City’s storm drain system
and is discharged into the nearby creek before it discharges
into the ocean. Figure 3-1 shows the location of the sub-
drain along Malaga Lane.
There have been frequent sink-holes along the alleyway.
Video inspection has revealed roots and soil in the
perforated sub-drain pipeline. Without repairs and
maintenance, the life of the existing sub-drain is projected to
be less than 5 years.
Another dewatering activity occurring in Malaga Cove
Plaza, north of Malaga Lane, is the use of sump pumps to
remove groundwater. Each basement in the Malaga Cove
Plaza has anywhere from 1 to 3 sump pumps operating 24-
hours per day. The observed pumping capacity for one
pump was roughly 36 gpm. It is unknown at this time how
the sump pumps are installed or where they discharge, but it is a likely assumption that the sump pumps
currently discharge to the storm drain system.
Photo of Malaga Lane (alleyway) Photo of Sump in Basement of Malaga Cove Plaza
Photo of Discharge to Ocean
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Figure 3-1: Malaga Cove Plaza Sub-Drain Location Map
3.2 Nuisance Groundwater Quality
It is assumed some form of treatment or blending will be required to reduce the TDS levels of the
nuisance groundwater. For Malaga Cove Plaza the TDS levels of the groundwater average 2,100 mg/L.
Per communication with Palos Verdes Golf Course, TDS levels may need to be under 700 mg/L
otherwise additional maintenance or leaching of greens may be required. Table 3-1 provides an overview
of groundwater quality in Malaga Cove Plaza.
3.3 Nuisance Groundwater Supply
Rainfall, including runoff from it, is probably the
main source of the groundwater. Infiltration
throughout the area uphill from the plaza,
extending to the drainage divide near Via Acalones,
contributes to the groundwater problem at the
plaza. Imported domestic water, used for irrigation
contributing to runoff/infiltration, is a secondary
source of groundwater and may contribute to the
severity of the present groundwater problem. Table
3-2 shows the groundwater supply quantity for
Malaga Cove Plaza. Based on available
information and discussions with the City of Palos
Verdes Estates it is assumed that the flowrate is
constant throughout the year.
Photo o Surface Wate Spring upstream of
Plaza near Golf Course
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Table 3-1: Malaga Cove Plaza Nuisance Groundwater Quality
Parameter Units Sump Pump
Sample 1
Ocean
Discharge
Sample 1
Drinking Water
Limits 2
Potable
Water
Quality
(Avg.) 3
Total Dissolved
Solids (TDS) mg/L 2,182 2,016 1,000 SMCL 436
Sulfate mg/L 1,009 1,016 500 SMCL 134
Total Alkalinity mg/L as
CaCO3 404 440 none Not reported
pH -- 6.93 7.85 none 8.2
Hardness mg/L 1,793 1,558 none 187
Conductivity mmhos/cm 3.41 3.15 none 0.747
Calcium mg/L 391 326 none 44
Magnesium mg/L 197 180 none 19
Potassium mg/L 14 14 none Not reported
Sodium mg/L 113 142 none 78
Iron mg/L 4.5 2.2 none Not reported
Carbonate mg/L 0 0 none Not reported
Bicarbonate mg/L 493 537 none Not reported
Hydroxide mg/L 0 0 none Not reported
Chloride mg/L 528 447 500 SMCL 86
Manganese mg/L 0.588 0.045 none Not reported
Copper mg/L <0.02 0.022 1.3 Action Level <1.3 (Action
Level)
Zinc mg/L 0.082 0.088 none Not reported
Aluminum mg/L 0.286 <0.200 1.0 MCL
0.2 SMCL 0.10
Footnotes:
1. Data provided by Patrick Gradoville of Palos Verdes Golf Club and Allan Rigg of City of Palos Verdes Estates. Sump
Pump sample from basement pumps at Malaga Cove Plaza commercial building next to alleyway; sample date August 25,
2008. Ocean Discharge sample from Creek Discharge to Ocean at Malaga Cove; sample date August 25, 2008.
2. MCL = Maximum Contaminant Level. SMCL = Secondary Maximum Contaminant Level.
3. Data provided by Cal Water per 2008 Water Quality Report.
Table 3-2: Malaga Cove Plaza Nuisance Groundwater Supply
Parameter Value Value
Maximum Continuous Flowrate of Alley Drain
Behind Malaga Cove Plaza 576,000 Gal/day 400 Gal/minute
Assumed Value for Reliable Continuous Supply
from Alley Sub-Drain
216,000 Gal/day
(242 AFY)
150 Gal/minute
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It has been observed and recorded that the flow entering the ocean is consistently 400 gpm, however this
flowrate should be field-verified. This flow is assumed to be a combination of natural surface water
accumulating east of the plaza, discharge from the sub-drain, discharge from the sumps, and other
runoff/drainage. As such, it is assumed that the reliable value of continuous supply from the alley sub-
drain is 150 gpm (this flowrate should be field verified with location-specific metering).
3.4 Potential Users
Within the vicinity of Malaga Cove Plaza there is one golf course that could be a potential candidate for
using non-potable water supplies for irrigation: Palos Verdes Golf Course. There is also Malaga Park and
School that is a potential candidate. There are a number of smaller parks, grassy areas, and medians that
are within the vicinity. Due to their low water demands and potential retrofit costs, they were not
evaluated as potential users. The City of Palos Verdes Estates reports that the Palos Verdes Golf Course
and Malaga Cove Park/School are the only two potential users of interest. The Palos Verdes Golf Course
and Malaga Cove Park/School are shown in Figure 3-2.
Figure 3-2: Map of Potential Users near Malaga Cove Plaza
3.4.1 Water Demand
Table 2-3 provides an overview of the estimated demands of potential users.
It is observed at Palos Verdes Golf Course that their irrigation demands vary from other golf courses in
the Palos Verdes Peninsula due to location and more moderate temperatures resulting from cloud cover.
Malaga Cove
Plaza
MMaallaaggaa
PPaarrkk aanndd
SScchhooooll
PPaallooss Veerddeess
GGoollff CCoouurrssee
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Table 3-3: Malaga Cove Plaza Potential Users and Demands
Demand
# of Golf
Holes /
Approx.
Acreage
Estimated
Max. Day
Summertime
Demand
Average
Demand
3
Average
Summer
Demand
4
Average
Winter
Demand
5
Yearly
Average
Demand
Currently
Dual Plumbed
Palos
Verdes
Golf
Course
18 holes /
100 acres
400,000
Gal/day 1
200,000
Gal/day
350,000
Gal/day
75,000
Gal/day
224 AFY
yes
Malaga
Park and
School
N/A 25,000 2
12,500
Gal/day
21,875
Gal/day
4,688
Gal/day
14 AFY
no
Footnotes:
1. Demand for Palos Verdes G.C. based on personal communications with Patrick Gradoville (May 11, 2009).
2. Assumes 25,000 gpd of max day irrigation demand and 11,500 gpd average annual demand for the school and park site.
School and park site is approximately 6 acres (~2 feet/acre). These demands are based on typical planning numbers and
need to be verified with actual water meter data for the park and school.
3. Average demand is assumed to be 50 percent of peak day demand.
4. Average Summer demand is assumed to 75 percent above the average daily demand. Assumes a 4 month period.
5. Average Winter demand is assumed to 37.5 percent lower than the average daily demand. Assumes an 8-month period.
3.4.2 Existing Conditions and Infrastructure
The following is a summary of the available information for each potential user. Further evaluation is
required to properly evaluate each user. The evaluation should include specifics on each user’s booster
pumps and irrigation meters as well as any operational storage requirements.
Photo of Palos Verdes Golf Irrigation Pond Photo of Malaga Park and School Irrigated Area
Palos Verdes Golf Course 10
The Palos Verdes Golf Course and City of Palos Verdes Estates are very interested in supplementing the
golf course with non-potable water. The golf course is owned by the City. The golf course is already dual-
plumbed. Analysis of the golf course with the course’s superintendent indicates there is potential to
supplement the existing irrigation supply at the course’s irrigation ponds. The ponds currently serve as
10 Per personal communications with Patrick Gradoville, Palos Verdes Golf Club. May 11, 2009.
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storage for potable water and are drained down during irrigation at night. The ponds are already dual-
plumbed with an air gap on the potable water fill line and on the recycled water fill line. A new supply
pipeline would need to be installed to the irrigation ponds for the supplemental non-potable water supply
in addition to the existing potable and recycled water supply pipelines.
Malaga Park and School
The Malaga Park and School has an irrigated area of roughly 6.4 acres and is located to the northwest of
Malaga Cove Plaza. The park and school are not dual-plumbed and there are no storage tanks or
reservoirs on the campus.
3.4.3 Potential User Requirements
The main concern of the Palos Verdes Golf Course is the quality of the non-potable water supply;
specifically TDS levels. The target TDS level the golf course is comfortable with is 600-700 mg/L.
However Palos Verdes Golf Course believes blending potable water with non-potable water at a 1.5 to 1
ratio (60 to 40), respectively, is a potential solution. This blending ratio of 1.5 to 1 would bring TDS
levels to roughly 1,110 mg/L11. Because this TDS is higher than the TDS of the existing potable supply,
Palos Verdes Golf Course prefers to irrigate only fairways and roughs with non-potable. Greens and tee-
boxes, which are on a separate irrigation system and require a better water quality, would continue to be
irrigated with potable water. Palos Verdes Golf Course is in favor of adding operational storage onsite in
order to maintain the water level of their irrigation ponds.
3.5 Fatal Flaw Analysis
3.5.1 Permitting
In preparing this TM the following public agencies were contacted to discuss the potential
implementation of this project and any major permitting requirements:
California Department of Public Health 12
California Department of Public Health’s (CA-DPH) main concern with any project is the protection of
public health. Protection of the existing potable water system and groundwater supplies will need to be
accurately addressed during the design phase. The reuse of nuisance groundwater should be considered a
non-potable water supply. CA-DPH will require installation of backflow prevention devices on both
potable water pipelines and on non-potable water pipelines as well as an air gap separation for potable
water connections to blending basins. CA-DPH deferred to Los Angeles County Department of Public
Health’s (LA-DPH) stormwater reuse guidelines for reference. These guidelines include pipeline
separation requirements. CA-DPH recommended contacting LA-DPH as well as Los Angles Regional
Water Quality Control Board (LA-RWQCB) for further permitting requirements.
Los Angeles County Department of Public Health
Protection of potable water supply on-site is the main concern of LA County DPH. Testing may be
required to assure that there are no cross connections with the existing potable water system.
11 Note: this blending ratio is specific to Palos Verdes G.C. for nuisance groundwater from Malaga Cove Plaza.
12 Per personal communications with Paul Williams, CA-DPH. June 8, 2009.
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Cal Water 13
Per communications with Cal Water, protection of their potable water system is their main concern. Steps
(such as backflow protection, cross connection testing, pipe separation, proper signage, etc.) will need to
be taken to make sure their system is protected.
Los Angeles RWQCB
The LA-RWQCB was contacted during preparation of this report; however, no response has been
received to date.
3.5.2 Environmental Restrictions
In evaluating the preliminary environmental impacts it was determined that a negative declaration (ND)
report may be sufficient to meet CEQA requirements for constructing the alternatives in Section 3.6.5 of
this report. However, for planning purposes, cost estimates for a potential project should assume that a
mitigated negative declaration (MND) would be required. California Department of Fish and Game and
the California Coastal Commission should be included in the review of the initial study that precedes the
ND or MND. A lead public agency will need to step forward in order for the permitting process to begin;
other public agencies can be contributing responsible agencies in the CEQA process.
The main environmental impact from implementing this project is the loss of water to the drainage system
that discharges into the nearby creek. Development of this project as a feasible alternative will need to
evaluate the loss of water to the stream and any habitat impacts.
The creek is blue-line, intermittent stream. By definition, a blue-line-stream is any stream shown as a
solid or dashed blue line on 7.5 Minute Series quadrangle maps prepared by the U.S. Department of the
Interior Geological Survey (USGS). A blue line stream may be any creek, stream or other flowing water
feature, perennial or ephemeral, indicated on USGS quadrangle maps, with the exception of man-made
watercourses. The United States Army Corps of Engineers uses USGS blue line stream markings as a
preliminary indicator of “Waters of the United States”. Streams identified on USGS maps in such a
manner are therefore generally subject to federal environmental regulations.
The creek shows up on the USGS 7.5 minute quadrangle as a blue-line, dashed, intermittent stream. A
biologist may need to examine the stream to determine if a riparian habitat has developed and if the
hydrology of the stream would be impacted. This study could be part of the initial CEQA study.
Photos of Creek at Malaga Cove
13 Per personal communications with Carmelo Sorce, Cal Water. June 4, 2009.
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3.5.3 Water Quality Requirements
Table 3-4 provides a summary of TDS levels for potable water, recycled water, and groundwater.
Table 3-4: TDS Comparison – Malaga Cove Plaza Area
Type of Water Units TDS - Typical
Observed Range Average TDS
Potable Supplied by Cal Water mg/L 400 to 600 436
Recycled Water Supplied by West Basin
MWD in Neighboring Communities mg/L 750 to 850 790
Groundwater mg/L 2,000 to 2,200 2,100
Blending of potable water with the nuisance groundwater will be required to achieve the required TDS
levels by the end users. A TDS level of 1200 mg/L is the maximum threshold suitable for golf course
irrigation purposes. TDS levels of 1200 mg/L will require additional maintenance (such as leaching the
greens of golf courses). A TDS level of 700 mg/L is the preferred threshold for irrigation purposes14.
Based on the average TDS levels as shown in, Table 3-5 summarizes the required blending ratios of
potable water to nuisance groundwater to meet end user water quality requirements.
Table 3-5: Malaga Cove Plaza Blending Ratios
TDS Level
Required by User
Potable
Supply
Non-Potable
Supply
Ratio
(Potable range to
Non-Potable)
1200 mg/L 400 – 600 mg/L 2,100 mg/L (1.1 – 1.5) to 1
700 mg/L 400 – 600 mg/L 2,100 mg/L (4.7 – 14.0) to 1
As shown in Table 3-5, in order to achieve a TDS level of 700 mg/L, the required blending range is 4.7 to
14.0 parts potable water to one part non-potable nuisance groundwater from Malaga Cove Plaza. In order
to achieve a TDS level of 1200 mg/L, the required blending range is 1.1 to 1.5 parts potable water to one
part non-potable nuisance groundwater from Malaga Cove Plaza.
3.5.4 Constructability
Existing Sub-Drain
The existing sub-drain was installed in 1997. Since then the alleyway above the sub-drain has had
numerous sink-holes and other problems. It was observed that there are roots and soil inside the existing
perforated pipe of the sub-drain. The projected remaining life of the existing sub-drain is less than 5 years
from the date of this TM. As this sub-drain is essential to protecting the businesses in Malaga Cove Plaza
is it assumed that this sub-drain will be replaced. Costs for the replacement of the sub-drain are not
included in this project, because these costs are assumed to be necessary even if the beneficial reuse
project is not pursued.
It is recommended the sub-drain be replaced. An alternative to ‘burrito-wrapping’ a perforated pipe is to
install multiple vertical well screens with solid, non-perforated pipe connecting the wells. Further analysis
needs to be performed to properly evaluate the best solution for replacing the sub-drain.
14 Per personal communications with Patrick Gradoville, Palos Verdes Golf Club. May 11, 2009.
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3.5.5 Municipal Concerns
No municipal concerns were encountered during this study. The City of Palos Verdes Estates is very
interested in developing this project and providing water to the golf course and school.
3.5.6 Customer Concerns
The main concern of Palos Verdes Golf Course is the quality of water and any impacts to their vegetation.
The current TDS levels of the groundwater exceed Cal Water’s current water quality. The golf course
would also like to add operational storage in order to maintain a more constant level in their irrigation
ponds.
The rights to groundwater in the Malaga Cove Plaza are unknown. It is assumed the property owner has
the rights to groundwater underneath their property. As this project moves forward groundwater rights
will need to be further investigated.
3.6 Conceptual Evaluation
This section provides a conceptual evaluation of how to consolidate nuisance groundwater flows, provide
treatment of the non-potable water, and deliver the non-potable water to end irrigation users. In addition,
this section evaluates the cost of each alternative to the amount of non-potable water produced.
3.6.1 Consolidating Flows
Flows need to be captured prior to entering the City’s storm drain system. The storm drain system
contains upstream typical urban runoff and rainwater that would impact the water quality requiring
additional treatment. A new manhole would need to be constructed over the existing cleanout to capture
the sub-drain flows. Groundwater would then be pumped to the user location as shown in Figure 3-3.
The manhole would contain a weir structure to allow any flows greater than what is being pumped to
overflow into the storm drain system.
This concept assumes two submersible duplex pumps with level floats. Pumps will require stainless-steel
materials of construction to deal with the high levels of sulfate and salinity.
3.6.2 Treatment
Two alternatives are available for reducing the TDS levels of the nuisance groundwater: (1)
microfiltration with reverse osmosis (MF/RO) treatment or (2) blending the raw water with potable water.
Treatment would require a site location to house the MF/RO facilities, including storage facilities,
pumping facilities, and connection to a local sanitary sewer system to dispose of brine. Due to high
mineral content it can be assumed that a significant portion of the raw water will be lost during brine
removal. It is assumed that the sidestream MF/RO facilities would have a product water recovery of 70
percent15.
Blending would require a blending basin and potable water connection. If the blending basin is located
onsite at the golf course it could potentially be tied into their existing irrigation system if already dual
plumbed. Utilizing existing ponds/basins at the golf course would greatly reduce the capital costs of the
project. The blending basin needs to be sized to meet the maximum daily demands of the potential users.
15 70 percent is a conservative estimate. The system should be designed to maximize recovery to the largest extent
possible. 75 to 90 percent recovery may be attainable.
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As demand far exceeds potential supply, the blending basins need to be sized to store the maximum daily
flow of nuisance groundwater plus the necessary potable water to be blended.
Figure 3-3: Proposed System Schematic
3.6.3 Conveyance
Figure 3-4 provides an overview of the two project alternatives to convey water to Palos Verdes Golf
Course or to Malaga Park and School. Pipeline alignments are assumed to be mostly in City right-of-way.
To the golf course the pipeline alignment would increase in elevation to the existing irrigation ponds. To
the park and school the pipeline alignment would decrease in elevation.
3.6.4 Site Retrofit
It is assumed that the City will be replacing and maintaining the sub-drain in Malaga Lane. No retrofit
will be required to Palos Verdes Golf Course other than the installation of the distribution pipeline.
Malaga Park and School may need to have its irrigation system retrofitted to allow for a non-potable
supply. In addition, if a new blending basin was constructed onsite at the park, it could be sub-surface
beneath basketball courts. Costs are included for retrofits to the Malaga Park and School as noted in each
project alternative.
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Figure 3-4: Malaga Cove Plaza Schematic of Conveyance Alternatives
3.6.5 Evaluation Criteria
Three water supply alternatives were evaluated. The water supply alternatives are:
• No Project Alternative – serve Malaga Park and School and Palos Verdes Golf Course with
potable water. No change.
• Alternative 1 – serve Palos Verdes Golf Course utilizing existing onsite irrigation ponds as
blending basins. Facilities include:
a) Capture: new manhole with weir structure, two 110-hp submersible supply pumps.
Includes O&M costs for powering pumps. The two 110-hp submersible pumps will
supply the golf course irrigation ponds directly.
b) Blending: utilize existing irrigation ponds onsite at Golf Course as blending basins.
Includes O&M costs for purchasing potable water used in blending operation. Assumes
1.5 to 1 blending ratio or 99,000 gallons of potable water per day (111 AFY) to produce
165,000 gallons of blended water per day (185 AFY). Includes capital cost for
hypochlorite dosing system and O&M costs hypochlorite.
c) Storage: assumes no operational storage other than existing irrigation ponds.
d) Pumping: utilizes Golf Course’s existing pumps; no additional pumping is required.
Assumes no costs for existing pumping operations.
e) Pipe: 5,000 feet of 10-inch PVC piping to Golf Course.
f) Misc: Potable water connection and meter at blending basin only. Non-potable water
meter at blending basin. Backflow protection. No retrofit costs for golf course.
SSuubb--DDrraaiinn
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O&M Costs: includes 30 percent of a Full-Time-Equivalent (FTE). 1 percent of capital costs
for electrical and chemical costs. Includes costs to purchase potable water for blending
(111 AF). Also includes costs to purchase potable water to meet summer month demands
(68 AF).
Alternative 1: Supply and Demand
Groundwater Supply 74 AFY (66,000 GPD)
Potable Water Blend 111 AFY (99,000 GPD)
Blended Supply 185 AFY (165,000 GPD)
Total Average Irrigation Demand 184 AFY (60,000,000 Gals/Year)
Potable Water Supplement Required to meet
4 Summer Month Demands 68 AFY (350,000 GPD)
• Alternative 2 – serve Malaga Park and School and Palos Verdes Golf Course with new
blending/storage basin on School site. Facilities include:
a) Capture: new manhole with weir structure, two 10-hp submersible supply pumps.
Includes O&M costs for powering pumps.
b) Blending: construct new blending basin at School site (300,000 gallons). Includes O&M
costs for purchasing potable water used in blending operation. Assumes 1.5 to 1 blending
ratio or 105,000 gallons of potable water per day (118 AFY) to produce 175,000 gallons
of blended water per day (196 AFY). Includes capital cost for hypochlorite dosing system
and O&M costs hypochlorite.
c) Storage: use new blending basin (300,000 gallons) at school site for operational storage.
d) Pumping: Two 110-hp distribution pumps at blending site to supply water to Golf
Course. Includes O&M costs for powering pumps.
e) Pipe: 2,000 feet of 10-inch PVC piping to School site and 7,000 feet of 10-inch PVC
piping to Golf Course (9,000 feet total of pipe).
f) Misc: Potable water connection and meter at blending location. Non-potable water meter
at each user location. Backflow protection. Includes retrofit costs for School site
irrigation system.
O&M Costs: includes 30 percent of a Full-Time-Equivalent (FTE). 1 percent of capital costs
for electrical and chemical costs. Includes costs to purchase potable water for blending (118
AF). Also includes costs to purchase potable water to meet summer month demands (73 AF).
Alternative 2: Supply and Demand
Groundwater Supply 78 AFY (70,000 GPD)
Potable Water Blend 118 AFY (105,000 GPD)
Blended Supply 196 AFY (175,000 GPD)
Total Average Irrigation Demand 196 AFY (63,750,000 Gals/Year)
Potable Water Supplement Required to meet
4 Summer Month Demands 73 AFY (372,000 GPD)
• Alternative 3 – serve Palos Verdes Golf Course with MF/RO product water. Facilities include:
a) Capture: new manhole with weir structure, two 110-hp submersible supply pumps.
Includes O&M costs for powering pumps. The two 110-hp submersible pumps will
supply the golf course treatment plant directly.
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b) Treatment: Construct new offsite MF/RO sidestream treatment facility (location TBD).
No potable water is used in treatment process and no supplemental potable supply.
Includes costs for brine disposal. Includes O&M costs for chemicals and powering
facility. 70 percent of sidestream feed water is recovered as product water (80,000 GPD
of RO product water). Assumes portion of feed water is bypassed (102,000 GPD) and
blended with RO product water at the treatment facility. Total facility output is 182,000
GPD of blended water. One possible location for the MF/RO treatment facility is within
the existing “bone yard” located on the golf course, immediately to the north of the two
existing golf course ponds. This area is currently used by the golf course to store quite a
large amount of equipment and supplies. The advantage of using this area is that it is
completely obscured from view by large trees and shrubs and cannot be seen from any
other portion of the golf course.
c) Storage: Construct new offsite 0.3-MG16 storage. No potable water used.
d) Pumping: Two 10-hp distribution pumps at treatment location to pump to Golf Course.
Includes O&M costs for powering pumps.
e) Pipe: 5,000 feet of 10-inch PVC piping to Golf Course.
f) Misc: Potable water connection and meter. Non-potable water meter. Backflow
protection. No retrofit costs for golf course.
O&M Costs: includes 30 percent of a Full-Time-Equivalent (FTE). 1 percent of capital costs
for electrical and chemical costs. Includes costs to purchase potable water for blending (90
AF). Also includes costs to purchase potable water to meet summer month demands (62 AF).
Alternative 3: Supply and Demand
Groundwater Supply 242 AFY (216,000 GPD)
RO Product Water 90 AFY (80,000 GPD)
Total RO Facility Output 204 AFY (182,000 GPD)
Total Average Irrigation Demand 184 AFY (60,000,000 Gals/Year)
Potable Water Supplement Required to meet
4 Summer Month Demands 62 AFY (350,000 GPD)
Each project alternative for Malaga Cove Plaza is evaluated based on cost, permitting, environmental
impacts, and public/customer acceptability. Table 3-6 shows the anticipated costs for each project
alternative.
16 Assumes 70 percent recovery and peak demand factor of 1.5.
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Table 3-6: Malaga Cove Plaza – Cost of Alternatives i
Alt. Facilities Approx. Capital
Cost ($)
Approx. O&M
Cost ($/yr) b
Annualized
Cost ($/yr) c
Present Worth
Cost of Water
($/AF)
No
Proj None $ -- Cost to purchase
Potable Water $226,136 $1,229
MC
1
a) Capture
b) Blending
c) Storage
d) Pumping
e) Pipe
f) Misc.
¾ TOTAL
a) $453,000
b) $16,000
c) $ --
d) $ --
e) $1,100,000
f) $3,000
¾ $2,759,000 a
30% of FTE,
+ 1% for elec. &
chem. e
+111 AFY Blend.
+68 AFY Peak.
= $293,000 / year
$509,000
184 AFY yield
$2,764 / AF
MC
2
a) Capture
b) Blending
c) Storage
d) Pumping
e) Pipe
f) Misc.
¾ TOTAL
a) $53,000
b) $476,000
c) $ --
d) $440,000
e) $1,980,000
f) $48,000
¾ $5,261,000 a
30% of FTE,
+ 1% for elec. &
chem. e
+118 AFY Blend.
+73 AFY Peak.
= $331,000 / year
$743,000
196 AFY yield
$3,798 / AF
MC
3
a) Capture
b) Treatment
c) Storage
d) Pumping
e) Pipe
f) Misc.
¾ TOTAL
a) $453,000
b) $405,000
c) $450,000
d) $40,000
e) $1,000,000
f) $3,000
¾ $4,302,000 a
30% of FTE,
+$800/AFY for
MF/RO f,
+62 AFY Peak
= $284,000 / year
$621,000
184 AFY yield
$3,373 / AF
Footnotes:
a. Costs include Raw Construction Contingency of 30 percent and Engineering, Environmental, Construction
Management, ESDC, Legal, Admin, and Financial Costs of 35 percent. Does not include costs for potable water
used in blending operations.
b. Assumes FTE at $60,000 per year salary multiplied by a factor of 2.5 to account for overhead and administration, for
a total annual FTE cost of $150,000.
c. Assumes 25 year period at an inflation rate of 6 percent
d. Not used.
e. Assumes 1 percent of total capital costs for electrical and chemical O&M.
f. O&M cost of $800/AFY includes electrical costs (pumping, treatment), chemical costs, and maintenance of MF/RO
facility (90 AFY of sidestream product water).
g. For all costs it is assumed that no land acquisition will be required (including for storage, treatment, and piping
locations).
h. Capture includes pumping costs to supply Palos Verdes Golf Course.
i. All costs are reported in 2009 dollars and do not include inflation.
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4 Summary of Findings and Conclusions
4.1 General
Table 4-1 provides a summary comparison of each project’s alternatives as compared to the cost of
potable water.
Table 4-1: Cost Comparison of Water1
Alt. Alternative Cost of Wate
($/AF) 1
No
Project Potable Water Purchase (Cal Water) $ 1,229
Abalone Cove
AC
1
Serve Three Golf Courses
with Blending on Golf Course Site (blend ratio: 3.1 to 1) 2 $ 3,185
AC
2
Serve Three Golf Courses
with New Offsite Blending Structure (blend ratio: 3.1 to 1) 2 $ 3,739
AC
3
Serve One Golf Course
with MF/RO Treatment $ 5,716
AC
4
Serve Three Golf Courses
with MF/RO Treatment (supplement with supply of potable water) 2 $ 2,699
Malaga Cove Plaza
MC
1
Serve Palos Verdes Golf Course
(blending to be provided on-site in existing golf course ponds) (Blend ratio: 1.5 to 1) 2 $ 2,764
MC
2
Serve Malaga Park and School and Palos Verdes Golf Course,
and Install New Blending/Storage Basin on School Site (blend ratio: 1.5 to 1) 2 $ 3,798
MC
3
Serve Palos Verdes Golf Course
with MF/RO Treatment (includes storage) $ 3,373
Footnotes:
1. All costs are reported in 2009 dollars and do not include inflation.
2. Costs include costs for purchasing potable water for blending.
3. Recycled water is not considered as an alternative as recycled water is not currently available to the Palos Verdes
Peninsula.
As shown in the above table, costs to produce usable irrigation water from the existing dewatering
sources are substantially higher than the purchase cost of potable water and recycled water. For the
Abalone Cove and Malaga Cove Plaza project areas, the cost of new conveyance piping turned out to be
the most significant component of capital cost. The second most significant component of capital cost
was for new blending basins with the operational volume necessary to provide blending ratios that reduce
the TDS from 2,000 - 3,000 mg/L down to a level suitable for golf course irrigation. For the alternatives
involving multiple golf courses, the supply of groundwater available is only a small fraction of the total
golf course demand.
It should be pointed out that the estimated costs in Table 4-1 are conservative and incorporate ample
contingencies, piping costs, and volume allowances for blending structures.
The following conditions would lend themselves to making re-use of dewatering groundwater a more
cost-effective option for the Palos Verdes Peninsula:
• Irrigating with the re-used groundwater in the immediate vicinity of the source, thereby reducing
the length and extent of distribution piping required.
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• Adopting an “on-demand” operational scheme for blending, whereby the flowrate of blending
water from the potable system is constantly regulated and adjusted according to the incoming
groundwater volume and TDS characteristics. This is an instrumentation-dependent option that
could drastically reduce the required volume of new blending structures. The risks of failure of
an automatic system are mitigated by the backup potable source and the fact that the groundwater
supply is a relatively small fraction of overall golf course demand. An “on-demand” blending
system would reduce costs by reducing the amount of storage required for blending.
• Sharing the cost between multiple entities and taking advantage of any re-use subsidy programs
available from Metropolitan Water District or other water purveyors with an interest in reducing
potable water demand.
Cost is the biggest deterrent to implementing any of the above-listed alternatives. The permitting process
poses no major fatal flaws, although a consistent amount of agency effort would need to be devoted to the
permitting process. The CEQA initial study for new facilities would explore opportunities to pursue a
Negative Declaration (ND) if possible, or a Mitigated Negative Declaration (MND) if an ND is shown to
be insufficient. Permitting will require further investigation. Alternatives involving MF/RO would
require agency coordination to permit the disposal of small quantities of brine to the sewer system. Title
22 certification is not required for any of the alternatives, because the project does not involve recycled
wastewater effluent. There is no indication of public opposition to date.
4.2 Potential Obstacles and Opportunities for Abalone Cove
4.2.1 Obstacles
Aside from costs already quantified in this report, the following obstacles or possible additional costs
would need to be overcome if a groundwater reuse project were implemented for Abalone Cove:
• It is possible that ACLAD would choose to seek compensation for the groundwater supply, if an
agency other than ACLAD chose to implement groundwater recycling in Rancho Palos Verdes.
• Permitting for new treatment and/or blending facilities within the Coastal Zone could require
extra lead time for interaction with the Coastal Commission.
• There is additional effort and/or cost associated with the process of securing land or easements
for new treatment and blending facilities.
• Appropriate interpretation of groundwater rights would be necessary for project implementation.
• An additional project risk is the uncertainty of nuisance groundwater as a reliable supply of water.
Dewatering data is available from 1980 to present. The volume of water discharged by ACLAD
dewatering wells increases with high rainfall seasons, peaking in 1999 with over 300,000 gpd
pumped. In 1983, a dry year, less than 50,000 gpd were pumped. Note that additional upslope
dewatering wells were installed between 1987 and 1992 to increase pumping capacity. The
average pumping flowrate is now 150,000 gpd. In order to more accurately assess the Abalone
Cove dewatering as a reliable supply of water, additional studies should be conducted.
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4.2.2 Opportunities
Although the per-acre-foot cost of re-using the groundwater for golf course irrigation is high because of
transmission and blending costs, the opportunity exists for ACLAD to independently use the water within
their own residential jurisdiction as follows:
• For backup fire suppression supply, provided ACLAD and/or homeowners are willing to fund the
construction of the additional storage, piping, and pumping facilities necessary to create a
separate above-ground, non-potable fire suppression system.
• For local landscape irrigation uses, provided there is sufficient localized blending and/or MF/RO
treatment situated in the immediate vicinity of the ACLAD area.
4.3 Potential Obstacles and Opportunities for Malaga Cove Plaza
4.3.1 Obstacles
Aside from costs already quantified in this report, the following obstacles would need to be overcome if a
groundwater reuse project were implemented for Malaga Cove Plaza:
• CEQA permitting for the creek may entail additional complexity if it is determined that diverting
the existing discharge of groundwater into the creek impacts the creek habitat.
• There is additional effort and/or cost associated with the process of securing land or easements
for new treatment and blending facilities.
• Appropriate interpretation of groundwater rights would be necessary for project implementation.
• An additional project risk is the uncertainty of nuisance groundwater as a reliable supply of water.
Malaga Cove Plaza has a history of nuisance groundwater since the 1960’s. Artesian well
occurrences have increased with high rainfall seasons. Precise flow data is not available prior to
1993. In 1993, with the construction of the business sumps and drain, 100 gpm was observed at
the Via Chico drain and 300 gpm was observed at the storm drain outfall. In 1997, with the
construction of the perforated sub-drain along Malaga Lane, a peak flowrate of 400 gpm was
observed from just the sub-drain flows. The average flowrate is assumed to 150 gpm. In order to
more accurately assess the Malaga Cove Plaza dewatering as a reliable supply of water,
additional studies should be conducted.
4.3.2 Opportunities
• The cost of the least expensive alternative for Malaga Cove Plaza (Alternative 2) could be
significantly reduced if the City of Palos Verdes Estates and the city-owned golf course used a
groundwater source at or near the golf course, as opposed to the alley drain. Artesian
groundwater conditions also exist immediately adjacent to the golf course, in locations closer than
the alley sub-drain. This would reduce the capital and O&M costs of distribution piping and
pumping.
• Palos Verdes Estates may find that it can operate the new facilities utilizing existing staff, thereby
avoiding any additional labor cost.
• Palos Verdes Estates may also be able to justify the additional cost of water, because the existing
alley drain is gradually failing, and capital expenditure to provide a reliable alley dewatering
system will need to be incurred regardless of whether groundwater re-use is implemented. For
Palos Verdes Estates, the project is dual-purpose.
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