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Ocean-Bound Effluent From Carson Plant Found to Be Southland’s Most Toxic

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TIMES STAFF WRITER

Ocean-bound effluent from the Los Angeles County Sanitation Districts’ giant sewage plant in Carson is significantly more toxic than waste from other Southern California treatment facilities with ocean outfalls, a new study found.

The study, part of an annual report by the Southern California Coastal Water Research Project, shows that concentrations of key pollutants from the Carson plant do not exceed state limits.

But one test indicates the facility’s waste is significantly more toxic than that of seven other ocean disposal plants studied in Southern California. The waste was found to be eight times more toxic, for instance, than effluent from the city of Los Angeles’ Hyperion facility near Los Angeles International Airport.

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The results, obtained by comparing the effects of different effluents on sea urchins, are likely to add fuel to the current debate about whether the Carson plant should be subject to tighter federal treatment standards.

However, they also suggest that even if the so-called secondary treatment standards are imposed, the toxicity of the plant’s effluent might still remain higher than that of other treatment facilities in the region.

The reason, experts say, is that such large quantities of industrial waste pass through the plant, which serves sanitation districts from Torrance to Pomona, sending 382 million gallons of effluent a day into the ocean south of the Palos Verdes Peninsula.

“The treatment level is not the whole picture. What is going into that waste stream is also important,” Jack Anderson, the director of the research project, said Wednesday. “Industrial effluent contains a higher proportion of chemicals that we know, at least in the soluble form, are toxic to marine organisms.”

Sanitation officials say 15% to 18% of the Carson plant’s waste--about 70 million gallons a day--comes from industrial sources, including 16 petroleum refineries, 30 chemical companies, and 600 metal finishing facilities.

Officials from the sanitation districts said Wednesday they had not yet thoroughly reviewed the report by the research group, a public agency formed in 1969 to conduct marine research in Southern California.

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But Margaret Nellor, head of the districts’ industrial waste division, questioned the significance of the toxicity comparisons, saying the test involving sea urchins has not been perfected.

“I don’t think they’ve come far enough along with the sea urchin test to begin drawing conclusions,” Nellor said Wednesday. “I don’t know how much credence should be put in the results.”

The annual report summarized several studies. One, for instance, found that polluted storm runoff is less toxic to marine animals than effluent from sewage treatment plants.

The comparison of effluent toxicity, however, is likely to attract the most attention. In that test, sperm from sea urchins was subjected to mixtures of seawater and effluent from seven ocean disposal plants, including Southern California’s four largest--the Carson plant, Hyperion, Orange County’s facility at Huntington Beach and San Diego’s Point Loma plant.

The sperm’s ability to fertilize eggs was then measured. In the case of the Carson plant, major reductions in fertilization rates were noted with sperm subject to effluent concentrations of 0.5%--much lower than the results of tests on effluent from other plants.

With Hyperion effluent, for instance, fertilization rates did not show major declines until sperm was used that had been subjected to effluent concentrations of 4% or higher.

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“Comparing it across the board one plant to the next, indeed the L.A. County (sanitation districts’) plant effluent was more toxic,” Anderson said.

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