8€PA
Palos Verdes Shelf
Superfund Site
U.S. Environmental Protection Agency $ Region 9
San Francisco, CA
June 2009
EPA Announces Proposed Plan
This Proposed Plan presents the United States Environmental Protection Agency's
(EPA's) Preferred Alternative to address risks to human health and the environment
posed by contaminated sediment at the Palos Verdes Shelf Superfund site (PV Shelf).
EPA is requesting written and oral comments on the Proposed Plan and Preferred Alter-
native and the information contained in the Administrative Record. The Preferred Alter-
native is Institutional Controls, Monitored Natural Recovery and a Cap over the area of
the shelf that has the highest contaminant levels and is most susceptible to erosion. This
is an Interim Remedial Action. After completion of this interim action and additional
studies, EPA may propose additional actions in a subsequent Record of Decision. This
Proposed Plan is being issued by EPA, pursuant to CERCLA §117(a) and the National
Contingency Plan (NCP) §300.430(f)(2).
The goal of the Proposed Plan is to facilitate public comment on all of the alternatives,
including the Preferred Alternative. The Proposed Plan provides a summary of the Palos
Verdes Shelf Superfund site, including risks to human health and the environment, and
the alternatives EPA evaluated to address these risks. It is based on the Remedial Investi-
gation (RI) and Feasibility Study (FS) and supported by documents in the Administrative
Record. EPA will make its decision after considering comments submitted during the
public comment period. Public comments will be addressed in a Responsiveness Sum-
mary that is issued with the Record of Decision.
The Administrative Record file, which contains the Remedial Investigation, Feasibility
Study, Risk Assessment and other information EPA used to develop the Preferred Alterna-
tive, is available at the following locations:
San Pedro Public Library
931 S. GaffreySt.
San Pedro, CA 90731
U.S EPA Superfund Record Center
95 Hawthorne Street
San Francisco, CA 94105
Redondo Beach Public Library
303 N. Pacific Coast Highway
Redondo Beach, CA 90277
NOAA/Office of General Counsel
501. W Ocean Blvd., suite 4470
Long Beach, CA 90802
Public Meetings
EPA will hold a series of public meetings to explain and discuss the alternatives presented in this Proposed Plan and to
answer questions about the information presented in the Feasibility Study. Oral and written public comments will also
be accepted at the meetings. The Proposed Plan presentation at each meeting location will be the same.
How to Submit
Public Comment
EPA will accept written com-
ments on the Proposed Plan
during the public comment
period. A 30-day public
comment period on this Pro-
posed Plan and information
contained in the administra-
tive record file begins on June
15, 2009 and closes on July
15, 2009- Written comments
postmarked no later than
July 15, 2009, should be sent
to:
C.R. White (SFD-8-2)
U.S. EPA, Region IX
75 Hawthorne Street
San Francisco, CA 94105
If requested, EPA may extend
the comment period. Any re-
quest for an extension must be
made in writing and received
by EPA no later than July 6,
2009-
Documents supporting this decision are avail-
able on-line at the EPA website: www.epa.gov/
region09/superfund/pvshelf.
Tuesday June 23rd
Open House 2:00-3:00 p.m.
Meeting 3:00 p.m. to 5:00 p.m.
Cabrillo Beach House
3800 Stephen M. White Dr.
San Pedro, CA
Wednesday June 24th
Open House 6:00-7:00 p.m.
Meeting 7:00 p.m. to 9:00 p.m.
Banning's Landing
100 E. Water Street
Wilmington, CA
Thursday June 25th
Open House 6:00-7:00 p.m.
Meeting 7:00 p.m. to 9:00 p.m.
Palos Verdes Library
701 Silver Spur Rd.
Rolling Hills Estates, CA
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Palos Verdes Shelf Superfund Site
Site Background
The Palos Verdes Shelf Superfund site (PV Shelf) is a large area of contaminated
sediment on the continental shelf and slope off the coast of Los Angeles, California.
PV Shelf is Operable Unit 5 of the Montrose Chemical Superfund site. At one
time, the Montrose Chemical Corporation of California, Inc. operated the nation's
largest DDT manufacturing plant. The former plant property is now the core of
the Montrose Chemical Superfund site in Torrance, California. Waste from the
manufacturing plant has contaminated soil and groundwater in the vicinity of the
former plant property as well as the waters and sediment within the Port of Los
Angeles and in the ocean, off the Palos Verdes Peninsula.
Since 1937, the main wastewater treatment plant of the Sanitation Districts of Los
Angeles County (LACSD) has sent treated industrial and municipal wastewater
(effluent) to ocean outfalls at White Point on the Palos Verdes Peninsula. From
the 1950s to 1971, the Montrose manufacturing plant in Torrance released tons of
DDT and associated waste into the sewer system to be treated then discharged from
the outfalls at White Point. Until polychlorinated biphenyls (PCBs) were banned
in 1976, PCBs from local industries also formed part of the waste stream dis-
charged to the sewer system and, after treatment, to PV Shelf. Peak mass emissions
of effluent solids (167,000 metric tons), DDT (21.1 metric tons) and PCBs (5.2
metric tons) occurred in 1971. Montrose stopped discharging DDT into the sewer
system in 1971. Since 1971, the heavily contaminated sediment has been gradually
buried by less contaminated effluent and natural sediment. This has created a layer
of cleaner sediment on top of the DDT- and PCB-contaminated sediment.
Site Characteristics
The California coast from Pt. Conception to the Mexican border curves inward,
forming a large bay called the "Southern California Bight." The Palos Verdes
' '"'
Figure 1: The Palos Verdes Shelf is a narrow, underwater shelf whose sediment is
contaminated with tons of DDT and PCBs
Peninsula is a small but prominent
land mass extending into the Southern
California Bight. It is bordered by Santa
Monica Bay to the north and the San
Pedro Shelf to the south. The Channel
Islands lie to the west and northwest.
The narrow underwater shelf off the
Palos Verdes Peninsula is called the Palos
Verdes Shelf. It is approximately 9 miles
long and 1 Vi miles wide. The seabed
over most of the shelf slopes at a gentle
1 to 3 degrees. The shelf breaks at a
depth of 250 to 300 feet, then drops
steeply over 2,500 feet to the ocean
floor. (See Figure 1.)
On the Palos Verdes Shelf, an estimated
5.7 million tons of sediment have been
affected by the effluent discharged from
the White Point outfalls. Mixed within
this effluent-affected sediment are an
estimated 110 tons of DDT and 10 tons
of PCBs. The effluent-affected (EA)
sediment forms an identifiable deposit
over a mile offshore at a depth of 150
feet to the shelf break. The deposit
ranges in thickness from 2 inches to
over 2 feet, with the area of greatest ac-
cumulation at the 200 feet depth.
The contaminant concentrations vary
with depth in the deposit. DDT con-
centrations in the buried deposit exceed
200 mg/kg, while PCBs in the buried
deposit reach 20 mg/kg. For most of
the deposit, these maximum concentra-
tions are found under about 1 foot of
cleaner sediment. The exception is the
area near the outfalls, where surface con-
centrations of DDT can be as high as
200 mg/kg. The deposit is thickest and
has the highest concentrations of DDTs
and PCBs at the 200 foot depth. The
slope has the second highest contami-
nant concentrations in surface sediment;
however, the deposit is thin.
The area of PV Shelf with surface con-
centrations exceeding 1 mg/kg DDT
is approximately 15 square miles. The
area with surface concentrations exceed-
ing 1 mg/kg PCBs is about 2.4 square
miles. Although contaminant concen-
trations have dropped from historical
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June 2009
highs, concentrations of DDT and
PCBs in fish continue to pose a threat
to human health and the natural envi-
ronment (see Risk Summary).
Early Investigations
Because of the DDT and PCB contami-
nation, the State of California issued an
interim health advisory in 1985 discour-
aging consumption of white croaker
caught in Santa Monica Bay, on the
PV Shelf, and in the Los Angeles/Long
Beach Harbor area. The advisory rec-
ommended limitations on the consump-
tion of sport fish. The CalEPA Office of
Environmental Health Hazard Assess-
ment (OEHHA) used a 1991 study
of seafood contamination to prepare a
final health advisory that recommends
recreational anglers not consume white
croaker caught in most areas offshore of
Los Angeles and Orange counties. The
advisory also recommends that anglers
greatly limit consumption of a number
of other fish species caught on or in the
vicinity of the PV Shelf due to the levels
of DDT and PCBs in fish tissue. These
warnings have been included in the
California sport fishing regulations since
March 1, 1992.
In 1990, the California Department of
Fish and Game (CDFG) closed the PV
Shelf to commercial fishing of white
croaker. The closure extends from Pt.
Vicente to Pt. Fermin, covering an area
from the shoreline to the edge of Cali-
fornia's "coastal zone," three miles from
the shoreline. In March 1998, CDFG
revised the white croaker recreational
catch limit from unlimited to a limit of
10 fish per day.
In 1994, five state and federal agen-
cies that are responsible for managing
natural resources (Natural Resource
Trustees, or "Trustees") and now com-
prise the Montrose Settlement Restora-
tion Program (MSRP), issued a study
of the ecological impacts caused by
sediment contamination in the area on
and around Palos Verdes Shelf. After re-
viewing these reports and other available
Sjanta Monica Bay
Los Angeles
702
Redondo Beach
701
KEY
ggi Palos Verdes Shelf
719 CDFG catch blocks
Commercial no-take zone
for while croaker
-
721
Palos Verdes
Peninsula
Long Beach
20
719
718
San Pedro Bay
Figure 2: The PV Shelf is closed to commercial fishing of white croaker
information, EPA began its Superfund investigation of the contaminated area and
joined a lawsuit initiated by the Trustees against Montrose and other companies
responsible for the pollution. The lawsuit resulted in four Consent Decrees wherein
the responsible parties deposited over $100 million dollars into special accounts to
pay for site remediation and restoration of the environmental resources damaged by
the pollution.
EPA completed an abbreviated evaluation of potential cleanup alternatives, called
an Engineering Evaluation/Cost Analysis (EE/CA), in 2000. In the EE/CA, EPA
recommended instituting a program to curtail consumption offish from the PV
Shelf area. After modifying the program in response to public comments, EPA is-
sued an Action Memorandum in 2001 that established the Institutional Controls
(ICs) program that is fully in place today (see description of ICs on page 7).
Pilot Capping Project and Remedial Investigations
In 2000, EPA conducted a pilot capping study to assess the feasibility of using this
technique to clean up the site. Three 45-acre cells at different depths were capped
with sand from two different sources, using different capping methods. Post-cap
monitoring in 2002 showed that contaminant levels over the capped areas were
comparable to uncapped areas. Additionally, the LACSD collected sediment cores
across the PV Shelf in 2001 and noted that the peak concentration of contaminated
sediment in one core collected from a capped cell was closer to the surface than it
had been historically. The surface recontamination and possible sediment scouring
prompted EPA to conduct four field studies in 2004 to evaluate sediment geotech-
nical properties, impacts of large, deep-burrowing worms and shrimp, resuspension
of sediment from capping, and oceanographic conditions during winter storms. The
study reports were completed in 2005 and posted on EPA's website (www.epa.gov/
Region09/Superfund/pvshelf) under "Site Documents and Reports." The results of
these and other studies were used to develop the Feasibility Study and the Preferred
Alternative.
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Palos Verdes Shelf Superfund Site
Coastal Marine Fish
Contaminants Survey
From 2002 to 2004, EPA and MSRP collected 23 species of
fish from 30 locations along the Southern California coast
and analyzed them for DDT, PCBs and other contaminants.
White croaker from the PV Shelf vicinity was generally the
most highly contaminated species. In most cases, DDT
concentrations were higher than PCBs, particularly in the
PV Shelf area. OEHHA is using the multi-species survey
to update Southern California fish advisories. EPA used the
survey to recalculate the health hazards from consumption of
certain species of fish and will use the new advisory in the ICs
program.
Natural Recovery Studies
During the early 1990s, modeling of natural recovery pro-
cesses occurring on PV Shelf predicted that the majority of
the buried effluent-affected (EA) deposit north of the outfalls
would stay buried. The area around the outfalls, however,
would experience an increase in surface concentrations before
reaching equilibrium. For the Remedial Investigation (RI)
Report, EPA reevaluated natural recovery processes occurring
on PV Shelf to assess the longterm fate of the EA sediment,
which is now buried under cleaner sediment. EPA funded the
Figure 3: USGS placed tripods on the PV Shelf floor to collect
data on winter storms
U.S. Geological Survey (USGS) to perform oceanographic
studies from December 2007 to April 2008. Six instrument-
laden tripods were deployed across PV Shelf to measure
waves, currents, bed stresses, and suspended-sediment concen-
trations. These measurements will allow USGS to model the
stability of the contaminated sediment deposit.
DDT has been breaking down into less chlorinated com-
pounds throughout the sediment deposit. A 2006 study by
USGS confirmed that this process, called reductive dechlori-
nation, was occurring at least in one area at a relatively rapid
rate. Additional studies are underway to assess the reductive
dechlorination rates for other areas of the deposit, and to
identify the environmental conditions and microbial organ-
isms responsible for the transformation.
Scope and Role of the
Proposed Action
The Feasibility Study (FS) evaluated the three principal rem-
edies used at sediment sites: dredging, capping, and natural
recovery. The depth and size of the deposit make dredging
infeasible, cost-prohibitive, and technically impracticable.
Appendix F of the Feasibility Study presents the dredging
alternative in detail. The study determined that only capping
and natural recovery are applicable to the PV Shelf site.
EPA plans to take a phased approach to cleaning up the PV
Shelf. The Preferred Alternative is the first phase. During re-
medial design, low-impact capping techniques that minimize
disturbance of effluent-affected sediment will be tested. Also
as part of remedial design, EPA will assess the viability and
desirability of accelerating the DDT reductive dechlorina-
tion that is occurring. Simultaneously, EPA will fund a white
croaker fish tracking study to learn where white croaker feed.
This will enable EPA to determine whether there are priority
areas for additional capping. Based on the success of the in-
terim remedy and what we learn from additional studies, EPA
will determine what additional cleanup actions are needed.
All alternatives (except no action) will continue the ICs
program. Data from the ocean fish survey (see page 4) indi-
cate that contaminant concentrations, particularly of PCBs,
continue to pose a health risk to individuals who eat fish from
the PV Shelf area. The ICs program addresses the continuing
need to limit fish consumption and will remain an integral
part of site cleanup.
Risk Summary
The DDTs and PCBs found in the sediment of PV Shelf enter
the food chain, affecting the health of marine wildlife as well
as people who regularly consume fish from the area. Elevated
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June 2009
levels of DDTs and PCBs are found in fish that reside on PV
Shelf, especially fish like white croaker that feed on organisms
that live in the sediment.
Human Health Risk
Health risk from fish consumption varies depending on the
contaminant burden in the fish, how much fish is consumed,
and over how long a period. For example, white croaker
typically are more contaminated than other fish at PV Shelf,
and the more white croaker a person eats, the higher the risk
of adverse health effects. Additionally, DDTs and PCBs are
stored primarily in the fatty part of the fish; therefore, if a
person eats the whole fish instead of only the fillets, s/he will
be exposed to more contamination. EPA calculated increased
cancer risk from white croaker and other fish for different eat-
ing habits: 1) recreational angler or "average" consumer who
may eat white croaker once a week (called "central tendency
exposure"), or 2) someone who consumes white croaker on
a subsistence basis, often daily (called "reasonable maximum
exposure"). EPA found that both groups suffered increased
health risks. Table 1 lists the estimated cancer and non-cancer
risks for species commonly found on PV Shelf.
Ecological Risk
The concentration of DDT, but not PCBs, in PV Shelf ocean
water exceeds the ambient water quality criteria (AWQC)
for aquatic life. Based on EPA's Ecological Risk Assessment,
DDT in fish continues to pose potential risks to piscivorous
(fish eating) birds and marine mammals. The concentrations
of PCBs in fish are of less concern to ecological receptors than
DDTs.
Based on the human health and ecological risk assessments,
it is EPA's current judgment that the Preferred Alternative
or other remedial action identified in this Proposed Plan, is
necessary to protect public health and the environment from
actual or threatened releases of pollutants or contaminants
into the environment which may present an imminent and
substantial endangerment to public health or welfare.
Remedial Action Objectives
EPA's Preferred Alternative is an interim action including
institutional controls, monitored natural recovery, and a clean
sand cap to address potential erosion that could expose and
release sediment with high concentrations of DDT and PCBs.
After completing additional studies (see sidebar Remedy
Selection Studies), EPA may determine that additional actions
are necessary to protect human health and the environment.
The interim action recommended in this proposed plan will
support the following remedial action objectives (RAOs):
• Reduce to acceptable levels the risk to human health from
ingestion offish contaminated with DDTs and PCBs;
• Reduce to acceptable levels the risks from DDTs to the
ecological community (i.e., benthic invertebrates, fish and
piscivorous birds) at the PV Shelf;
Fish species
White croaker
Kelp Bass
Rockfish
Surfperch
CA Scorpionfish
Barred Sandbass
(Subsistence consumption
R9m5
(Reasonable Maximum Exposure) (Central Te
Cancer Risk
6x103
1 x104
1 x104
7x105
3x104
3x104
Noncancer Risk
( >1 exceeds reference dose)
183
5
5
2
8
10
Cancer Risk
6x104
1 x105
1 x105
6x106
3x105
3x105
nal consumption
ndency Exposure)
Noncancer Risk
( >1 exceeds reference dose)
37
0.9
0.9
0.5
2
2
Table 1: Many fish found on PV Shelf pose a health risk. Reasonable maximum exposure assumed a consumption rate of
116 g/day. Central tendency exposure assumes a consumption rate of 21.4 g/day. Excess lifetime cancer risks of 1X104 (1
person in 10,000) to 1X106 (1 person in 1,000,000) are within EPA's risk management range. Noncancer risks are expressed as
a hazard quotient (HQ). When the HQ is >1, there is concern for potential noncancer health effects.
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Palos Verdes Shelf Superfund Site
Remedy
Selection Studies
Reductive
Dechlorination
EPA learned in 2007 that the DDT
in the sediment off Long Point is
transforming into less chlorinated
compounds. Studies to identify the
processes driving the transforma-
tion, and to learn whether this phe-
nomenon is occurring throughout
the contaminated sediment, will be
completed in 2010. The potential
to accelerate the process through-
out the sediment deposit will also be
assessed. These studies will be per-
formed after the Interim Record of
Decision (ROD) is signed.
White Croaker Tracking
Study
In 2002, EPA and the National Oce-
anic and Atmospheric Administra-
tion (NOAA) conducted a coastal
marine fish contaminants survey.
One finding was that concentrations
of DDT and PCBs in white croaker
on the PV Shelf vary greatly over a
small area. EPA and NOAA are
planning a tracking study of feeding
patterns of PV Shelf white croaker.
The study will indicate where the fish
are getting their contaminant body
burdens. This information will be
useful for ICs ocean monitoring, and
for determining in the final ROD
how much additional risk reduction
is possible.
7
• Reduce concentrations of DDTs and PCBs in the surface waters over the PV
Shelf to acceptable levels that meet ambient water quality criteria for protection
of human health and ecological receptors; and
• Minimize potential adverse impacts to sensitive habitats and biological commu-
nities on the PV Shelf during remedy implementation.
Over time, the proposed action will reduce the excess cancer risk from DDT
associated with consumption of white croaker from PV Shelf to one in one hun-
dred thousand for recreational anglers and to one in ten thousand for subsistence
fishermen.
The RAOs aim to reduce contaminant concentrations in fish by reducing the
concentrations in their environment, i.e., sediment and water. The remedial action
objectives described above are expected to be achieved when: 1) DDT in sediment
averages 230 ug/kg at 1% total organic carbon (i.e., 23 mg/kg OC), and DDT in
water averages 0.22 ng/L; and 2) PCBs in sediment average 70 ug/kg at 1% total
organic carbon (i.e., 7 mg/kg OC), and PCBs in water average 0.064 ng/L.
The preferred interim action waives the PCB AWQC for human health. EPA will
forecast when the PCB cleanup levels will be achieved after further investigation
of PCBs flux and transport. Since the area with highest surface concentrations
of PCBs largely overlaps the area of highest DDTs, the Preferred Alternative will
reduce PCBs concentrations as well as DDTs.
Summary Of Remedial Alternatives
The Feasibility Study (FS) identified and screened possible response actions and re-
medial technologies for the EA sediment on Palos Verdes Shelf. The initial screen-
ing considered institutional controls, monitored natural recovery, containment (i.e.,
capping), removal, in-situ treatment and ex-situ treatment.
In accordance with the NCP, EPA evaluated each remedial option against imple-
mentability, effectiveness, and cost criteria. Based on this evaluation, the FS devel-
oped four alternatives:
• Alternative 1: the "no action" alternative
• Alternative 2: institutional controls and monitored natural recovery;
• Alternative 3: institutional controls, monitored natural recovery, and small cap
(containment), and
• Alternative 4: institutional controls, monitored natural recovery, and large cap
(containment).
EPA's Preferred Alternative is Alternative 3: institutional controls, monitored natu-
ral recovery, and small cap.
Common Elements
All of the alternatives have an interim action waiver of the ARAR for PCBs ambient
water quality criteria (AWQC) for human health. Until EPA completes an analysis
of PCB loss rates, we cannot predict when the AWQC of 0.064 ng/L PCB may be
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June 2009
reached. Additionally, all of the alternatives (except no action) continue the ICs
program, collect additional data, and monitor natural recovery.
Alternatives 2, 3, and 4 continue the ICs program of public outreach and educa-
tion, enforcement, and monitoring. The ICs program limits human exposure to
contaminated fish through an aggressive outreach program that uses a variety of
channels to educate the public on safe fish consumption practices. Public outreach
and education is carried out by the Fish Contamination Education Collaborative
(FCEC), and entails angler outreach, outreach to at-risk ethnic communities, and
outreach to commercial fish operations. The ICs monitoring component consists
of monitoring contaminant levels in fish (particularly white croaker) at selected
locations in the ocean, markets, landing areas and piers. Enforcement consists of
enforcing existing white croaker regulations for commercial and recreational an-
glers, along with inspections of retail food facilities and enforcement of market pro-
tocol under the California Health & Safety Code. Efforts include monitoring and
enforcing the daily catch limit and the commercial no-take zone for white croaker.
The ICs program relies on partnerships with other federal, state, and local agencies
as well as community-based organizations to prevent PV Shelf fish from reaching
consumers. Please visit the www.pvsfish.org website for more information.
Another element shared by alternatives 2, 3 and 4 is some reliance on natural recov-
ery. Data analyzed for the PV Shelf RI Report indicate contaminant loss is occur-
ring across the site through transport, sediment burial, and, in the case of DDTs,
chemical transformation. Contaminant levels in sediment and fish have dropped
over the last decade. The alternatives include monitoring the levels of DDTs and
PCBs in sediment, water, and fish to confirm that recovery is progressing. The
alternatives would monitor chemical transformation of DDT throughout the site.
Also, alternatives 2, 3, and 4 include certain data gap studies: 1) a white croaker
tracking study; 2) a DDT reductive dechlorination study; 3) toxicity tests on DDT
breakdown products; and 4) analysis of PCBs in sediment and water.
PCBs on PV Shelf
Because the quantity of PCBs in the
effluent-affected sediment is much
less than DDTs (about 1 to 10),
most of the investigation of PV Shelf
has focused on DDT. However, the
2002 fish survey found that although
the volume of PCBs is less, their
threat to human health is greater.
No data on PCBs within the sedi-
ment deposit were collected from the
1990s until 2006, when the study on
DDT chemical transformation with-
in the deposit incidentally found that
PCBs are not degrading. More data
on the extent of PCBs throughout
PV Shelf will be obtained as part of
this interim remedial action in order
to calculate their long-term fate and
the probable timeline to meet water
and sediment goals under the select-
ed alternative.
Capping Techniques
The combination of depth and soft
sediment make PV Shelf a challenge
to cap. EPA has been investigating
possible low-impact capping tech-
niques such as using a tremie tube to
lay the sediment down gently. Mod-
eling and treatability studies will be
implemented as part of the remedial
design for either Alternative 3 or 4.
Figure 4: The FCEC performs education and outreach to increase the public's
awareness of the risk from consuming PV Shelf fish
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Palos Verdes Shelf Superfund Site
No Action Alternative
Estimated Capital Cost: $0
Estimated Annual O&M Cost: $0
Estimated Present Worth Cost: $0
Estimated Construction Timeframe: None
Superfund regulations require that the "no action" alterna-
tive be evaluated to establish a baseline for comparison to the
other alternatives and to establish the baseline risk. Under
this alternative, EPA would take no action to reduce contami-
nant concentrations or limit consumption offish with unac-
ceptable levels of DDTs and PCBs.
Alternative 2: Institutional Controls and
Monitored Natural Recovery
Estimated Capital Cost: $3,650,000
Estimated Annual O&M Cost: $1,700,000 (ICs)
Estimated Five-Year Monitoring & Review: $2,360,000
Estimated Present Worth Cost: $15,500,000 (7% discount rate)
Estimated Construction Timeframe: None
Figure 6: All alternatives would monitor sediment and biota
Figure 5: All alternatives would monitor water quality
This alternative monitors the naturally occurring reduction
in contaminants in the PV Shelf Study Area while controlling
risks to human health through the ICs program.
Under this alternative, the surface water quality goal for
DDT of 0.22 ng/L is estimated to be reached in 2037- The
sediment cleanup level for DDT of 230 ug/kg is estimated to
be reached in 2053- Until contaminant concentrations drop
to RAO levels, this alternative would keep in place the ICs
program.
Alternative 3: Institutional Controls,
Monitored Natural Recovery with a
Small Cap
Estimated Capital Cost: $36,600,000
Estimated Annual O&M Cost: $1,700,000 (ICs)
Estimated Five-Year Monitoring & Review: $3,136,000
Estimated Present Worth Cost: $49,000,000 (7% discount rate)
Estimated Construction Timeframe: 3 years
Alternative 3 is the preferred alternative. It includes the ICs
and MNR program elements of Alternative 2. Additionally,
it would accelerate natural recovery by placing clean sand/
coarse silt over the area of PV Shelf that has the highest
surficial contaminant concentrations and appears to be erod-
ing. Without a cap, continued erosion will cause more EA
sediment to be released into the environment. Alternative 3
would use low-impact techniques to place an 18-inch layer
of clean sand/coarse silt over approximately 320 acres of the
shelf. This alternative would require 864,000 cubic yards
of clean silty sand. Cap material would come from harbor
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June 2009
or maintenance dredging projects or
from clean areas of the shelf. The clean
sediment cap would accelerate recovery
through:
• Physical armoring of 320 acres
of the shelf to prevent erosion of
contaminated sediment by winter
storms;
• Preventing flux of dissolved con-
taminants from the sediment into
the water column;
• Reducing exposure and uptake of
contaminants by benthic organ-
isms by replacing effluent-affected
sediment with a clean layer for
recolonization.
The alternative includes studies to verify
effectiveness of low-impact engineering
techniques and to characterize further
the geotechnical and chemical prop-
erties of the area to be capped. This
alternative would cover an estimated
36.5 metric tons of DDT, accelerating
attainment of water quality and sedi-
ment cleanup levels.
Under Alternative 3, the surface water
quality goal for DDT of 0.22 ng/L is
estimated to be reached in 2023- The
sediment level for DDT of 230 ug/kg is
estimated to be reached in 2039- The
ICs program would continue to protect
human health until remediation goals
for fish are met.
Alternative 4: Institutional
Controls, Monitored
Natural Recovery With A
Large Cap
Estimated Capital Cost: $64,100,000
Estimated Annual O&M Cost:
$1,700,000 (ICs)
Estimated Five-Year Monitoring & Re-
view: $3,420,000
Estimated Present Worth Cost: $76,700,000 (7% discount rate)
Estimated Construction Timeframe: 4years
Alternative 4 shares the ICs and MNR program elements of Alternatives 2 and 3-
Additionally, this alternative would cap approximately 640 acres under an 18-inch
cap of clean sand/coarse silt. The cap would cover an estimated 54.4 metric tons
of DDT. It would include areas of potential erosion as well as areas that have the
highest DDT and PCB concentrations. Alternative 4 would require 1,776,000
cubic yards of clean silty sand. Cap material would come from harbor or mainte-
nance dredging projects or from clean areas of the shelf. The clean sediment cap
would accelerate recovery through:
• Physical armoring of 640 acres of the shelf bottom to prevent erosion of con-
taminated sediment by winter storms;
• Preventing dissolved contaminant flux from the sediment into the water col-
umn; and
^
Palos Verdes Peninsula
Study Area
Boundary
(-200-Ml3ofcattij
Pacific Ocean
-600-
LACD-SjrtQUoci DBiKli
Figure 7: Alternative 3 would cap grid cell 8C. Alternative 4 would cap grid cells
8C, 7C, and 6C.
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10
Palos Verdes Shelf Superfund Site
• Reducing exposure and uptake of contaminants by
benthic organisms by replacing effluent-affected sediment
with a clean layer for recolonization.
Alternative 4 would use low-impact techniques to prevent
resuspension of the soft, silty contaminated sediment that
covers the PV Shelf at the 150 to 220 ft. depth. Studies to
verify effectiveness of low-impact engineering techniques and
to characterize accurately the geotechnical properties of the
proposed capping area would precede construction.
Under this alternative, the surface water quality criteria for
DDT of 0.22 ng/L is estimated to be reached in 2019- The
sediment cleanup level of 230 ug/kg DDT is estimated to be
reached in 2031. This alternative would achieve immediately
the PCB sediment cleanup level of 7 mg/kg PCBs OC for the
shelf, but not the slope, of PV Shelf. The ICs program would
continue to protect human health until fish reach remediation
levels.
Evaluation Of Alternatives
The NCP requires the use of nine criteria to evaluate the dif-
ferent remediation alternatives individually and in compari-
son to each other. These criteria are threshold criteria, which
are requirements that each alternative must meet in order to
be eligible for selection. Primary balancing criteria are used
to weigh major trade-offs among alternatives, and modifying
criteria are state and community acceptance.
The two threshold criteria are 1) overall protection of human
health and the environment and 2) compliance with ap-
plicable or relevant and appropriate requirements. The five
primary balancing criteria are 3) long-term effectiveness and
permanence; 4) reduction of toxicity, mobility or volume
through treatment; 5) short-term effectiveness; 6) implement-
ability; and 7) cost. The two modifying criteria are 8) state
acceptance, and 9) community acceptance. EPA assesses
public comment on the Proposed Plan to gauge community
acceptance.
This section of the Proposed Plan discusses the relative per-
formance of each alternative against the nine criteria and the
rationale for selecting the Preferred Alternative. The Feasibili-
ty Study contains a detailed analysis of each alternative against
the criteria and a comparative analysis of how the alternatives
compare to each other.
Threshold Criteria:
1. Overall Protection of Human Health and the
Environment
Alternatives 2, 3, and 4 protect human health through reduc-
tion of contaminants in surface sediment combined with a
robust institutional controls (ICs) program. They fund angler
and community outreach and a comprehensive enforcement
program to prevent consumption offish that may contain
unsafe levels of DDT and PCBs. Alternatives 3 and 4 acceler-
ate reduction of surface sediment concentrations of DDT and
PCBs by capping areas of the shelf with the highest contami-
nant concentrations and the greatest potential to erode. The
preferred alternative would cap half the area capped under
Alternative 4, which would cause less resuspension of sedi-
ment and fewer loss of worms and crustaceans living in the
sediment.
2. Compliance with ARARs
The preferred alternative is an interim measure and will
become part of a total remedial action that will attain the
applicable or relevant and appropriate federal requirements
(ARARs). All alternatives would waive the PCB ambient
water quality criteria (AWQC) for human health. EPA will
determine if the PCB AWQC can be achieved after further
investigation of PCBs flux and background concentrations.
Under the Preferred Alternative, the DDT AWQC for human
health, 0.22 ng/L, and ecological receptors, 1 ng/L, would be
achieved 14 years sooner than under Alternative 2. Alterna-
tive 4 would achieve the DDT AWQC four years sooner than
the Preferred Alternative. The PCB AWQC for ecological
receptors has been met.
Primary Balancing Criteria:
3. Long-term Effectiveness and Permanence
This Proposed Plan is for an interim action that includes stud-
ies to determine what further remedial actions can provide
additional, permanent risk reduction. Alternative 3 and 4
(capping), would limit contaminant migration and uptake by
invertebrates. Monitoring would be necessary to ensure the
long-term effectiveness and permanence of the cap(s). Alter-
native 3 caps only the part of the buried contaminated sedi-
ment deposit that appears to be eroding. This is less disruptive
to the environment since it caps only about 1.6 percent of the
PV Shelf, but covers an estimated 44 percent of the total mass
of DDTs. The timeframe for PCB in sediment and water to
attain RAOs would be calculated after gathering and analyz-
ing additional data on PCB loss.
4. Reduction of Toxicity, Mobility, or Volume of
Contaminants through Treatment
None of the alternatives reduces contaminants through treat-
ment. Capping does have the potential to reduce mobility
of the contaminated sediment. Natural recovery has the
potential to reduce the toxicity and volume of contaminants.
Studies of enhanced reductive dechlorination may lead to
treatment as part of the final remedy.
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June 2009
11
5. Short-term Effectiveness
Alternatives 2, 3 and 4 rely on the ICs program to protect
human health in the short-term. Placement of capping mate-
rials will have an adverse short-term effect on the existing
benthic organisms present in the surface sediments, but less
so under the Preferred Alternative than under Alternative 4.
Cap placement could resuspend the surficial soft sediment,
exposing the deeper, more contaminated sediment. Alterna-
tive 2 would reach surface sediment levels of 230 ug/kg by
2053- The Preferred Alternative would reach target sedi-
ment levels by 2039- Although Alternative 4 would achieve
sediment levels sooner than Alternative 3, by 2031 vs. 2039;
however, less disturbance of sediment and destruction of
benthic organisms makes Alternative 3 preferable. Although
PCB loss rates have not been modeled, PCBs are co-located
with the DDT; therefore, reductions of PCBs in water and
sediment would be similar under each active alternative.
6. Implementability
Capping is a proven technique for remediation of contami-
nated sediment; however, capping in the open ocean over soft
sediments at the depth of PV Shelf is unique. Fine-grained
sediment, with high water content and low shear strength
can be easily displaced or resuspended during cap placement.
Cap stability after placement is also critical to assure contami-
nants in the pore water stay within the cap. For these reasons,
Alternatives 3 and 4 would be more difficult to implement
than the non-capping Alternative 2. To ensure proper cap
installation, modeling and treatability studies to perfect an ef-
fective capping technique will be part of the remedial design
for both Alternatives. Since the Preferred Alternative covers
a smaller area and begins at the edge of the contaminated
sediment deposit, it will be easier to implement than Alter-
native 4. Alternative 3 requires less than half the amount of
capping material that Alternative 4 requires.
7. Cost
The cost of the alternatives was calculated for a 10-year pe-
riod, under the assumption that a final ROD will be in place
within 10 years. The estimated net present value of Alterna-
tive 3 is $49 million. For Alternative 2, the net present value
is $15-5 million over 10 years, and Alternative 4 has a net
present value of $76.7 million.
Modifying Criteria
8. State Agency Acceptance
In preparing this Proposed Plan, EPA has consulted with the
CalEPA, Department of Toxic Substances Control (DTSC)
as well as state, local and federal agencies that form the
Montrose Settlement Restoration Program and the PV Shelf
Technical Information Exchange Group. These agencies
support a phased approach to remediation and agree with the
need for additional studies.
DTSC supports the Preferred Alternative 3, with the under-
standing that this is an interim action. DTSC raised ques-
tions about the physical characteristics of the sediments, and
the seismic impact on sediment transport and will continue to
work with EPA through the remedial design process.
9. Community Acceptance
Community acceptance of the preferred alternative will
be evaluated after the public comment period and will be
described in the Interim ROD, as well as documented in the
Responsiveness Summary. EPA has been meeting regularly
with community and environmental organizations to discuss
the FS and the alternatives presented in the Proposed Plan.
This has helped EPA become aware of the issues and concerns
held by the public.
Summary Of Preferred
Alternative
The Preferred Alternative for cleaning up the Palos Verdes
Shelf Superfund Site is continuation of the existing ICs pro-
gram, monitored natural recovery and placement of a 320-
acre cap over the most contaminated sediments that are in
an area that appears to be eroding. As part of the monitored
natural recovery component of the remedy, EPA will under-
take additional studies, discussed on pages 6 and 7- After
these studies are completed, but no later than five years after
completion of the Interim Remedial Action, EPA will decide
whether additional capping or other measures are warranted
in a Final Record of Decision.
Based on information currently available, EPA believes the
Preferred Alternative meets the threshold criteria and provides
the best balance of tradeoffs among the other alternatives
with respect to the balancing and modifying criteria. EPA
expects the Preferred Alternative to satisfy the following statu-
tory requirements of CERCLA §121 (b): (1) be protective
of human health and the environment; (2) comply with all
ARARs except the PCB AWQC for human health, which will
be waived until PCB flux data can be collected and analyzed
to determine if the AWQC can be met; (3) be cost-effective;
and (4) utilize permanent solutions and alternative treatment
technologies to the extent practicable. This interim action
does not meet the preference for treatment because the size,
depth, and complexity of the EA deposit render the identified
treatment options infeasible.
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Palos Verdes Shelf Superfund Site
EPA Announces Proposed Plan
Request Comments
Contacts
Carmen White, SFD-8-2
Remedial Project Manager
(Remedial Investigation and Cleanup)
(415) 972-3010
white. carmen@epa. gov
U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
Toll Free Hotline: (800) 231-3075
Sharon Lin, SFD-8-2
Remedial Project Manager
(Institutional Controls)
(415) 972-3446
lin.sharon@epa.gov
Jackie Lane, SFD-3
Community Involvement Coordinator
(415) 972-3236
lane.jackie@epa.gov
Websites:
http://www.epa.gov/region09/features/pvshelf/
http ://www.pvsfish. org
Para obtener una copia en espanol de esta hpja informativa, visite la pagina Web al:
www.pvsfish.org o llame a la linea gratuita al 1 800 231-3075.
, HiltS www.pvsflsh.org ,
1 800231-3075o
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