Southern California Ocean Disposal Site #2 Investigation
- What is the challenge?
- What is being done about it?
- Frequently Asked Questions
- Recreational Activities
- Fishing and Wildlife
From the 1930s until the early 1970s, multiple government agencies (the California Regional Water Quality Control Board and the U.S. Army Corps of Engineers) approved ocean disposal of domestic, industrial, and military waste at 14 deep-water locations (See Figure 1) off the coast of Southern California. Waste disposed included: refinery wastes, filter cakes and oil drilling wastes, chemical wastes, refuse and garbage, military explosives and radioactive wastes. Very little is known about the history of this deep-ocean disposal, the nature of the wastes, or waste sources.
While EPA and our federal, state and local agency partners have been aware of (or even approved) these disposal practices over the years, the significant depth (up to 1000 meters or 3200 feet) and distance from shore of these disposal sites have historically posed significant challenges to assessing the sites for potential threats to human health or the environment. EPA’s efforts to-date have focused on the shallower, near-shore environment of the Palos Verdes Shelf Operable Unit of the Montrose Chemical Corp. Superfund Site (PV Shelf), where we have evaluated the nature and extent of contamination and cleanup options and implemented significant outreach, education and enforcement measures to reduce the public’s consumption of contaminated seafood.
With the recent public interest in this challenge, spurred by an October 25, 2020 Los Angeles Times article about recent exploration of historic deep-water ocean disposal of DDT waste, EPA and several federal, state and local agencies (the Collaborating Agencies, see sidebar) began working together to see if advances in technology enable a new look at this issue. In 2021, the Collaborating Agencies began developing plans to (1) further understand the site, including potential waste volumes and composition (Note: although the LA Times article attributed the DDT waste to Montrose Chemical Corp. of California (Montrose), multiple other industrial companies also disposed of other wastes in the area (Disposal Site #2) described in the article), (2) investigate potential risk to human health and the environment, and (3) identify strategies that may be available to reduce adverse impacts.
The Collaborating Agencies decided to focus on Disposal Site #2 (Figure 2), the location where Scripps Institution of Oceanography conducted a preliminary survey in early 2021 which mapped the debris field, and which was also the subject of recent scientific research. Disposal Site #2 is located in the San Pedro Channel, about halfway (12 miles or 19 km) between the Palos Verdes Peninsula and Santa Catalina Island, and approximately 8 miles or 13 km beyond PV Shelf.
The Collaborating Agencies jointly developed four tasks to better understand the extent and impacts of the ocean waste disposal. These tasks are:
- Document the operational and regulatory history of Disposal Site #2;
- Determine the nature of contamination of Disposal Site #2 and identify areas of significant drum disposal;
- Evaluate Southern California Bight environmental conditions and trends; and
- If conditions at Disposal Site #2 are determined to threaten human health or the environment, conduct technology screening of potential options for addressing risk for Disposal Site #2.
The Collaborating Agencies have focused primarily on the first two tasks; the third and fourth will follow after the first two are complete.
Task 1: Document the Operational and Regulatory History of Disposal Site #2
The goal of this work is to assess historical records that may shed light on the volume and composition of the wastes disposed of at Disposal Site #2, as well as the methods of disposal.
Task 1 - Work Completed to Date
EPA’s research indicates that Montrose did not use drums for ocean disposal of its acid waste. Although the disposal records from the company that transported the waste used the term “bbls” (short for barrels), EPA’s document review concluded that the unit ‘barrels’ was used as a term of volume, which was common at the time rather than as a reference to actual drums. Instead, acid waste containing DDT was stored in large above-ground storage tanks, transported to the Port of Los Angeles in tanker trucks, pumped to Cal Salvage’s barges that were later towed to Disposal Site #2, and dumped into the ocean. This conclusion is supported by depositions and interviews of former Montrose employees and officials, as well as sampling data which shows there is DDT in the seafloor sediment. The evidence collected to date also shows that the barrels referenced in the LA Times article likely contain other chemical substances. EPA’s investigation and conclusions are documented in the Initial Findings Regarding Ocean Disposal of Montrose Chemical’s Acid Waste (pdf) (378.79 KB, April 20, 2021) and the Findings Regarding Montrose Chemical Aerial Photograph Review (1947-1972) (pdf) (810.77 KB, June 7, 2021) .
In addition to compiling records from Collaborating Agencies, document requests have been sent to:
- City of LA Sanitation Department
- County of LA Department of Public Works
- Los Angeles County Sanitation Districts
In addition, EPA reviewed its own records, including the national records on ocean dumping, and is also seeking information about other wastes that may have been disposed by Montrose Chemical and other companies at Disposal Site #2. Very little is known about the history of this deep-ocean disposal, the nature of the wastes, or waste sources.
Task 1: Next Steps
- Continue document requests to relevant agencies and parties
- Complete a report
Task 2: Determine the Nature of Contamination of Disposal Site #2 and Identify Areas of Significant Drum Disposal
The goal of Task 2 is to develop our scientific understanding, through data acquisition and analysis, of the contamination present at Disposal Site #2 and whether (and how) that contamination is creating risks to the environment or to human health. As compared to the near-shore area of the Southern California Bight, there is relatively little information about the deep-ocean environment at or in the vicinity of Disposal Site #2 or the other disposal sites.
Task 2: Work Completed to Date
- Developed a conceptual plan to conduct further sonar surveys to identify areas of significant drum disposal at Disposal Site #2
- Developed a working Conceptual Site Model for Disposal Site #2 that will help us understand the characteristics of sediment contamination and the risks to human health and the environment
Task 2: Ongoing Work
- The Collaborating Agencies are developing a sampling plan to characterize the contamination
- The Collaborating Agencies will continue to modify the Conceptual Site Model, as needed
Task 3: Evaluate Southern California Bight Environmental Conditions and Trends
The goal for this task is to evaluate available data to establish historical baseline concentrations and conduct trend analysis for contaminants of concern in sediment, water, and biota – in the Southern California Bight.
Task 4: If Conditions at Disposal Site #2 are Determined to Threaten Human Health or the Environment, Conduct Technology Screening of Potential Options for Addressing Risk for Disposal Site #2
The Collaborating Agencies are currently working together to identify a strategy to investigate this area and the potential risk to human health and the marine environment. The Collaborating Agencies will update this section as new information becomes available.
From the 1930s until the early 1970s, ocean disposal of domestic, industrial, and military waste was allowed at multiple deep-water locations off the coast of Southern California.
The wastes disposed in the waters included oil refinery waste, chemical waste, oil drilling waste, and garbage (Ocean Dumping Under Los Angeles Regional Water Quality Control Board, March 1985).
How did this occur?
This disposal was possible prior to the 1970’s because environmental science, awareness, and regulations were not what they are today. As has been the case with many issues, knowledge increased with time as science and technology improved and informed the understanding of environmental processes. Laws to better protect the ocean and people were also enacted over the years.
The ocean dumping of industrial chemicals and other wastes near Santa Catalina Island was allowed as a disposal practice in previous decades and was regulated at various times by different governmental agencies.
Contaminated waste disposal in the ocean in the San Pedro Channel ended in 1975. Uncontaminated dredge materials continued to be disposed of at an approved EPA site in the San Pedro Channel.
The presence of Disposal Site #2 waste thousands of feet below the surface has the potential to impact human health and the environment. Given the limitations historically associated with conducting work at this depth, there is very little data about the contamination at the site, and the risks and threats to human health and the environment.
As indicated in Task 2 above, the Collaborating Agencies are currently working together to identify a strategy to investigate this area and assess potential risk to human health and the marine environment. An initial Conceptual Site Model has been developed that lays out the path by which contaminants on the seafloor could migrate and even concentrate as they work their way through the food web -- from smaller organisms to fish, birds, marine mammals, and humans who might consume contaminated seafood. Understanding the food web model helps pinpoint the types of sediment, water, and/or organisms we need to analyze in order to start understanding the potential impacts from the waste.
EPA understands the importance of preserving natural resources and protecting human health and takes seriously our commitment to science and transparency. As demonstrated at the nearby underwater PV Shelf site, where we have determined that there is a risk from consuming contaminated seafood, EPA -- with assistance from local agency and non-profit organization partners --, has reduced exposure through a variety of measures, including multi-lingual signage, pier angler outreach, community outreach, and fish market inspection programs.
This is a distinct matter from the EPA Superfund work at the Montrose Palos Verdes Shelf site, which involves the near-shore, underwater (130-490 feet or 40-150 meters deep) area that became contaminated through chemical runoff from the Montrose plant into the Pacific Ocean via sewage outfalls. The deep-water ocean disposal site is about 8 miles (13 kilometers) from Palos Verdes Shelf and is at a depth of around 3,200 feet (1,000 meters).
Can I still surf, dive, snorkel, or take part in other water activities in the area, and am I at any increased risk if I do?
As part of Task 2 (above), the Collaborating Agencies are developing our scientific understanding, through data acquisition and analysis, of the contamination present at Disposal Site #2. We are looking into whether (and how) that contamination is creating risks to the environment or to human health.
Disposal Site #2 is located more than 10 miles offshore and approximately 3,200 feet (1,000 meters) below water surface. Water recreation activities occur near-shore and in shallower water (less than 130 feet or 40 meters under the water surface). It is unlikely that recreational diving, snorkeling, or other water contact activities are conducted near this disposal site.
Water recreation activities are more likely to occur near the Palos Verdes (PV) Peninsula as compared to Disposal Site #2. EPA collected water samples one mile offshore from the PV Peninsula as part of the Palos Verdes Shelf Site’s First Monitored Natural Recovery Study (PDF). The results of the study show that the DDT sediment contamination does not affect those engaging in water contact recreation activities in the area.
Can I consume fish in this area?
Based on recent monitoring, if appropriate Fish Advisories are followed, eating fish caught in the Southern California Bight is safe. In 2018 the Southern California Coastal Water Research Project collected various sports fish that are popular for human consumption in the area where these disposal sites are located (Bight 18 Sport Fish Study). The fish were tested for mercury, selenium, arsenic, DDT, and PCBs. The results showed that consuming sports fish collected from this area does not pose a significant health risk as long as appropriate California Office of Environmental Health Hazard Assessment (OEHHA) fish advisories are followed.
OEHHA established fish advisories covering the region between Ventura Harbor and San Mateo Point that recommend how often you can safely eat fish caught in these areas. You can find more information on the applicable fish advisories below:
- From Ventura Harbor to Santa Monica Pier
- From Santa Monica Beach south of Santa Monica Pier to Seal Beach Pier
- From South of Seal Beach Pier to San Mateo Point
- California Coastal Advisory (from Ventura Harbor to San Mateo Point and includes Santa Catalina Island)
- Fish in these areas have DDT and PCB contamination primarily related to the Palos Verdes Shelf Superfund Site
As part of Task 2 (above), the Collaborating Agencies are developing our scientific understanding, through data acquisition and analysis, of the contamination present at Disposal Site #2 and whether (and how) that contamination is creating risks to human health. This website will be updated as more information becomes available.
What about the health of sea lions, dolphins, and other marine mammals and birds like bald eagles and brown pelicans?
In a December 2020 Marine Mammal Center Study, scientists found that pollutants such as PCBs and DDT play a significant role both as primary carcinogens (or cancer-causing substances) and as co-factors in the development of a specific type of cancer in sea lions. As a part of the Task 2 described above, the Collaborating Agencies will evaluate whether contaminants from Disposal Site #2 are impacting the health of wildlife such as marine mammals and birds.
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Department of Commerce to Senator Dianne Feinstein (pdf)
(124.8 KB, April 7, 2021)
April 7, 2021, Department of Commerce response letter to Senator Dianne Feinstein regarding prioritization of urgent and meaningful actions to remediate DDT contamination off the coast of California.
EPA Letter to Senator Dianne Feinstein (pdf)
(251.31 KB, March 24, 2021)
March 24, 2021, EPA response letter to Senator Dianne Feinstein regarding the human health impacts associated with the historical DDT Ocean Disposal practice and the cleanup progress at the Palos Verdes Shelf.
Senator Dianne Feinstein to EPA (pdf)
(770.93 KB, March 8, 2021)
March 8, 2021, Letter to EPA, Acting Administrator Nishida, requesting NOAA to prioritize urgent and meaningful actions to remediate DDT contamination off the coast of California.
Senator Dianne Feinstein to Secretary of Commerce Raimondo (pdf)
(959.75 KB, March 8, 2021)
March 8, 2021, Letter to Secretary of Commerce Raimondo requests NOAA to prioritize urgent and meaningful actions to remediate DDT contamination off the coast of California.
EPA Letter to County of Los Angeles Board of Supervisors (pdf)
(233.45 KB, July 2, 2021)
EPA response letter to Los Angeles County Board of Supervisors regarding the human health impacts associated with the historical DDT Ocean Disposal practice and the progress being made by the Collaborating Agencies to address Ocean Disposal Site #2.
County of Los Angeles Board of Supervisors Letter to EPA (pdf)
(736.85 KB, May 7, 2021)
Los Angeles County Board of Supervisors letter to EPA regarding the human health impacts associated with the historical DDT Ocean Disposal practice.
EPA Response Letter to CalEPA (pdf)
(228.39 KB, April 26, 2021)
EPA Response Letter to California Environmental Protection Agency’s April 13, 2021, letter.
CalEPA Letter to Deborah Jordan (pdf)
(193.49 KB, April 13, 2021)
California Environmental Protection Agency (CalEPA) letter to the EPA requesting a meeting on Ocean Disposal Site #2.
EPA Letter to Mayor Eric Alegria, City of Rancho Palos Verdes (pdf)
(195.56 KB, March 30, 2021)
EPA letter to Mayor Eric Alegria of the City of Rancho Palos Verdes, on ocean disposal and cleanup progress on the Palos Verdes Shelf.
City of Rancho Palos Verdes to EPA (pdf)
(239.4 KB, March 10, 2021)
Letter to EPA Region 9, Deputy Regional Administrator Jordan requesting an assessment of the extent and impacts of offshore DDT disposal.
California Coastal Chloro-Contamination Conference Presentation (pdf)
(5.05 MB, May 17, 2022)
EPA Presentation at the California Coastal Chloro-Contamination Conference concerning the Ocean DDT Disposal Site.
SMBRC EPA Deep Ocean Disposal Presentation (pdf)
(3.11 MB, October 21, 2021)
EPA Presentation to the Santa Monica Bay Restoration Commission (SMBRC) Governing Board concerning the Ocean DDT Disposal Site.
Findings Regarding Montrose Chemical Aerial Photograph Review (1947-1972) (pdf)
(810.77 KB, June 7, 2021)
EPA memorandum documents the results of historical aerial photograph review.
Initial Findings Regarding Ocean Disposal of Montrose Chemical’s Acid Waste (pdf)
(378.79 KB, April 20, 2021)
EPA memorandum documents the results of historical document review into Montrose Chemical Corp. of California’s ocean disposal of acid waste.
- Contaminant Bioaccumulation in Edible Sport Fish Tissue (PDF)
December 2020 technical report issued by the Southern California Coastal Water Research Project (SCCWRP) about The Ecology of the Southern California Bight and Implications for Water Quality Management.
- Ocean Dumping of Containerized DDT Waste Was a Sloppy Process (PDF)
March 4, 2019, Environmental Science & Technology Journal Article Ocean Dumping of Container Waste by multiple authors, including Professor David Valentine. (Environ. Sci. Technol. 2019, 53, 2971−2980) (Valentines Study).
- First Monitored Natural Recovery Report (PDF)
May 2018 EPA Palos Verdes Shelf First Monitored Natural Recovery Report.
- ToxGuideTM for DDT/DDD/DDE (PDF)
September 2002 Agency Toxic Substances and Disease Registry ToxGuidetm for DDT/DDD/DDE.
- Ocean Dumping Under Los Angeles Regional Water Quality Control Board Permit: A Review of Past Practices, Potential Adverse Impacts and Recommendations for Future Action
March 1985 Los Angeles Regional Water Quality Control Board report on Ocean Disposal past practices and potential adverse impacts and recommendations for future action.
- Interstate Electronics Corporation Ocean Waste Disposal in Selected Geographic Areas (PDF)
July 1973 EPA Technical Report on Nationwide Ocean Disposal Practices, including Southern California Bight.
- The Ecology of the Southern California Bight: Implications for Water Quality Management (PDF)
March 1973 Southern California Coastal Water Research Project (SCCWRP) technical report on the ecology of the Southern California Bight.
The agencies listed below are working together to address Ocean Disposal Site #2:
- U.S Environmental Protection Agency (EPA)
- National Oceanic and Atmospheric Administration (NOAA)
- U.S. Department of the Interior
- California Natural Resources Agency (CNRA)
- California Environmental Protection Agency (CALEPA)