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Montrose Chemical Corporation of California

After World War II, Montrose Chemical Corporation of California, 20201 S. Normandie Ave., Unincorporated LA County, California began producing Dichloro-Diphenyl-Trichloroethane (DDT), the new "wonder pesticide". Its waste disposal system funneled the plant’s processed waste into the county sewer system and ultimately into the ocean. Montrose continued producing DDT even in the face of increasing scientific concerns about DDT in the 1960s. Production did not stop until 1982.[1] The site discharged an estimated 1,700 tons of DDT between the late 1950s and early 1970s alone, which contaminated ocean sediments on the floor of the Palos Verdes Shelf (PVS) near Los Angeles, California.[2]

By designating Montrose Chemical as a Superfund site, the federal government put it on the National Priorities List as a hazardous waste site. The United States Environmental Protection Agency (EPA) was then committed to cleaning up the PVS and making the public aware of all health risks.[3]


Environmental impacts and health risks of DDTEdit

DDT and polychlorinated biphenyls (PCBs) move from contaminated sediments into the water, so although the dumping of DDT stopped in 1983, the PVS remains contaminated [2] DDT and PCBs enter the food chain through worms and micro-organisms living in the sediment. One fish may eat many of these organisms, causing the DDT and PCBs to accumulate in fish tissue. Fish-eating birds, marine mammals and birds of prey that feed on both, accumulate more of the toxins.[2] Since 1985, fish consumption advisories and health warnings have been posted in southern California because of elevated DDT and PCB levels. Bottom-feeding fish are particularly at risk for high contamination levels. Consumption of white croaker, which has the highest contamination levels, should be avoided. Other bottom-feeding fish, including kelp bass, rockfish, queenfish, black croaker, sheepshead, surfperches and sculpin, are also highly contaminated.[2]

The effects of DDT differ depending on the organism it infects. Until as recently as 2007, bald eagles on Santa Catalina Island were unable to reproduce because the DDT caused their eggshells to become too thin and to break open before the eagle was fully developed.[4] For people, DDT and PCBs can increase cancer risks,[dubious ] harm the liver and affect the central nervous system.[citation needed] Nursing infants whose mothers regularly consume the fish are at especially high risk.[2] As a part of the Superfund project, the EPA is looking to reinforce the commercial and recreational fishing ban on white croaker.[5]

In October 1989, the former Montrose Chemical site was added to the Superfund National Priorities List (NPL).

In 1990, the United States and the State of California filed lawsuits against Montrose Chemical and nine other facilities near the Palos Verdes peninsula, citing damages to the nearby marine environment.


1994 – The Federal and State Natural Resources Trustees[6] determined that the ocean floor was contaminated with 100 metric tons of DDT and 10 tons of PCB over an area of 27 square miles (70 km2).

July 1996 - The EPA began investigating options for cleaning up the DDT- and PCB-polluted ocean sediments.

Policy changes and cleanupEdit

In 1990, the federal and state natural resource trustees began a natural resource damage assessment for the Southern California Bight, which includes the Palos Verdes Shelf. Following a review of the Trustees' 1994 expert reports, EPA in July 1996 initiated a Superfund non-time critical removal action to evaluate the need for and feasibility of actions to address human health and ecological risks. In July 1997, EPA completed the Screening Evaluation of Response Actions for Contaminated Sediment on the Palos Verdes Shelf.

March 2000 – The EPA increased enforcement of the commercial fishing ban and recreational catch limit for white croaker along the Palos Verdes coast, began educating people about fish consumption advisories, monitored contaminant levels in commercially sold fish, and announced a plan to cap the polluted ocean sediment with clean sediment.

December 2000 – Montrose Chemical Corporation of California and three other corporations settled their lawsuits for a collective $73 million. When combined with prior lawsuits, this brought the total up to $140 million to fund the restoration of the PVS marine environment.

Since 1997, the EPA has implemented a control program with three major elements: public outreach and education, fish monitoring, and enforcement. The fish monitoring program involves sampling both fish in the ocean and fish in retail markets. The MSRP and EPA completed the ocean fish sampling program in July 2007. EPA utilized the data to update the risk assessments for the site. EPA and the public are currently awaiting the State of California to update the existing fish advisory based on the recent data. EPA continues to sample white croakers at local markets. The first phase effort started in 2004. Finally, EPA is working with the local county health departments on marketplace inspection. EPA will be working with the California Department of Fish and Game to enhance enforcement of the white croaker commercial fishing ban off Palos Verdes peninsula and the daily catch limit on white croaker for non-commercial anglers.

Currently, the EPA is its 5th year of full implementation of the public outreach and education program. The EPA created the Fish Contamination Education Collaborative (FCEC) as a mechanism for drawing interested agencies, groups and community-based organizations together to design and implement a community-based outreach program to address the health risks from eating contaminated fish related to the Palos Verdes Shelf site. The current program focus is to measure risk reduction through the IC's program implementation. EPA, with assistance from all stakeholders, put together a draft road map for the Institutional Controls Program which outlines the numeric objectives and associated strategies and tactics for the program.

Four investigation studies were done during 2004. EPA prepared a Proposed Plan that presents the remedial alternatives and identifies EPA’s preferred alternative for the PV Shelf site. The Proposed Plan has been mailed to the site mailing list and posted on the website. EPA has met informally with interested community groups. The EPA sought public comment on the Proposed Plan from June 15 thru July 15, 2009, and a response to comments (Responsiveness Summary) will be included with the Record of Decision.

EPA initiated its work on the Palos Verdes Shelf as a non-time-critical removal action and is implementing the institutional controls program under that authority. EPA continued with the evaluation of ecological risks and sediment cleanup activities such as capping under its remedial program authority. The cleanup decision will be documented in a Record of Decision, supported by the remedial investigation/feasibility study (RI/FS).


  1. ^ Kehoe, Terence and Jacobsen, Charles "Environmental Decision Making and DDT Production at the Montrose Chemical Corporation of California", Enterprise and Society, (2003) 4(4), pp. 640-675.
  2. ^ a b c d e Cleaning Up the Palos Verdes Shelf | Region 9: Superfund | US EPA last updated July 26, 2007.
  3. ^ Superfund | EPA last updated April 30, 2008.
  4. ^ Cone, Marla (March 13, 2013). "The Mystery of the Vanishing DDT in the Ocean Near Los Angeles". Scientific American.
  5. ^ Palos Verdes Ecology 2002.
  6. ^ Natural Resources Trustees | Superfund | US EPA last updated September 17, 200.