Federal officials propose scraping out more than a half-mile stretch of sewer line in Harbor Gateway to remove an estimated 30,000 to 40,000 pounds of toxic DDT pesticide lodged inside.
The contaminated section extends south along Normandie Avenue from the former Montrose Chemical Corp. property, once the home of a major DDT plant and now on the federal "Superfund" list of the most toxic waste sites in the nation.
Under a plan proposed by the U.S. Environmental Protection Agency, the nearly five-foot-diameter sewer pipe would be stripped of a total of 243,000 pounds of sediment that contains the DDT. The estimated $1.3-million cost would be charged to Montrose.
The DDT dates back at least 20 years and has remained in one place because it is ensconced in sticky, tar-like sediment. Although the contamination is not thought to pose an immediate threat, officials fear a planned overhaul of the line--which is corroding--could dislodge the chemical, allowing it to pass through the sewer system and into the ocean.
"The way these overhauls work is that a new pipeline is inserted in the original pipeline, and that would cause this sediment to move," said Johanna Miller, the EPA official overseeing the project. "We don't want this DDT to get out into the ocean and into the sediment that fish use as a food source."
Frank Bachman, Montrose's general manager, questions whether all the DDT lodged in the pipe came from the former pesticide plant. But he says the Connecticut-based company still plans to cooperate with the EPA sewer cleanup.
"We won't have a big hassle on this one," Bachman said. "We acknowledge we made DDT there for many years, and since (the sewer contamination) is that close to our plant, we have to step forward and help solve the problem. Even though it's not moving, we understand the EPA's concern."
The DDT removal is being proposed as part of a massive federal cleanup of the former Montrose site, where the pesticide was manufactured from 1947 to 1982. So far, the project has centered on soil and ground-water testing. Among other findings, the agency has traced ground-water contamination extending 2.5 miles southeast of the 13-acre property.
The EPA expects to unveil a comprehensive soil and ground-water cleanup plan this fall. In the meantime, the agency is conducting a one-month public comment period on its sewer cleanup proposal and on four other responses to the pipe contamination, ranging from no action to abandonment of the sewer line. The comment period closes July 10, and EPA officials expect to choose a final plan by the end of August.
Officials attribute the sewer line contamination to Montrose's practice of pumping DDT-tainted waste water directly into the sewage system from about 1953 to 1971.
Hundreds of tons of DDT disposed of in this manner are believed to have flowed through the Los Angeles County Sanitation Districts sewer outfalls off the Palos Verdes Peninsula, polluting the ocean bottom and damaging marine life. A federal ocean pollution lawsuit filed last year by the state and federal governments names Montrose and its four parent companies among the eight defendants.
In order to prevent more DDT pollution, the EPA is proposing to decontaminate the 3,500-foot section of sewer line running along Normandie Avenue from Francisco Street to just south of Torrance Boulevard.
DDT concentrations in the pipe range from 364 parts per million to 207,000 parts per million, according to the EPA. Under state law enacted since 1970, waste containing DDT at levels of one part per million or more is considered hazardous.
The EPA's preferred plan, which would be set in motion next year or in 1993, involves pulling a dredge bucket through the sewer line with a cable and then scouring the pipe with water jets. The contaminated sediment would be dried on the Montrose site and trucked away--probably to Texas--for incineration.
Beforehand, sewage in the line would be diverted to an existing sewer line along Normandie Avenue and a new one that the sanitation agency plans to build near Western Avenue next year. Once the contaminated line is cleaned, it would be overhauled and returned to service.
EPA officials say the work would probably take just two months, but sanitation officials warn that it won't be easy.
"The stuff on the bottom of that pipe is very sticky," said Robert Horvath, an engineer with the sanitation districts. "It has resisted at least 20 years of sewage flowing over it. It's not going to be easy to remove."
Montrose DDT Cleanup Federal officials are proposing to decontaminate more than a half-mile stretch of sewer line running along Normandie Avenue from Francisco Street to just south of Torrance Boulevard. An estimated 30,000 to 40,000 pounds of toxic DDT pesticide are lodged inside. Map shows route of sewer line past the former Montrose site to outfalls off the Palos Verdes Peninsula.