Published Wednesday, August 21, 2002—Stockton Record

High levels of PCBs found in Stockton fish

Study cites Yosemite Lake, Smith Canal

By Audrey Cooper

An outlawed chemical is found in such high concentrations in Stockton's Yosemite Lake and Smith Canal that people who eat fish caught there have much higher risks of developing cancer, according to a new study.

Largemouth bass and white catfish caught there show levels of PCBs five times higher than the federal government's cancer-risk limit, the study concluded.

The study, which was spearheaded by local environmental group DeltaKeeper and written by a Davis-based consultant, found that PCB soil concentrations were highest near Yosemite Lake and the far end of Smith Canal. PCB levels at the far end of the canal, where it meets the San Joaquin River, were lower.

DeltaKeeper chief Bill Jennings said Tuesday that people who fish regularly in the area should be warned about the contamination.

"Obviously, we should immediately post signs informing people of the potential health risks of consuming fish caught in Smith Canal. And we need to begin to evaluate potential remediation actions," Jennings said.

"No Swimming" signs are already posted at Yosemite Lake. Fishing health advisories are posted along the Stockton Deep Water Channel, not far from Smith Canal. The channel is dangerously polluted with carcinogenic dioxins and PCBs, among other pollutants.

Donna Heran, director of San Joaquin County's Environmental Health Services Department, said that fish warnings could be posted along the canal and Yosemite Lake pending a review of the study by state, county and city officials.

The manufacture of PCBs stopped in 1977 because of pollution risks. PCBs were commonly used as lubricants and coolants in electrical equipment because the chemical didn't easily burn and was a good insulator, according to the U.S. Agency for Toxic Substances and Disease Registry.

PCBs, or polychlorinated biphenyls, don't easily break down in the environment and can remain dangerous for several decades.

The new study indicates that PCBs in the canal's soil accumulated in animals such as worms.

The chemical worked its way up the food chain to fish and potentially to humans, said G. Fred Lee, the study's author.

The fish contained about 100 nanograms of the PCB brand-name Aroclor per gram of fish, according to lab tests.

Sediment near Yosemite Lake was up to 10 times more polluted than the fish.

Although it is unknown how the PCBs got into Smith Canal, the report suggests the likely source was central Stockton storm drains, which carry water directly from streets into Smith Canal. Before that area of Stockton became residential, it was home to many businesses, which may have dumped PCBs into storm drains.

Robert Murdoch, who runs the city's stormwater program, said the chemical could have come from many sources, including dumping accidents that happened 50 or 60 years ago.

"What we have to do now is sit down and figure out where it came from, if we can," he said. "We need to find out where it is, where it came from and what we can do about it."

That could include testing the storm system to see if any PCB residue remains, even though that is unlikely, Murdoch said.

DeltaKeeper's Jennings agreed that such tests are needed to ensure the chemical isn't continuing to flow into the canal in ever-increasing amounts.

He added that the problem likely has existed in the canal for several years or decades and lamented that no government agency has extensively studied the canal.

Jennings said he will request that water-quality regulators add PCBs to the list of pollutants in Smith Canal, the first step toward writing a pollution cleanup plan for the site. Cleanup could include removing contaminated soil, although other PCB sites have been buried with more dirt to contain the pollutant, Jennings said.

The news of the PCB contamination didn't surprise one Smith Canal resident.

Bill Maxwell, who heads the water-quality committee for the grass-roots group Friends of Smith Canal, said he occasionally sees people fishing in the area.

"Seeing a three-headed catfish there wouldn't surprise me," Maxwell said.

"It's unfortunate, but it adds fuel to our argument that (Smith Canal) needs to be taken care of."

Smith Canal already is considered by the Regional Water Quality Control Board to be seriously burdened with pesticides, pathogens and low oxygen levels.

The new study was paid for by DeltaKeeper in part through a federal grant. The Regional Water Quality Control Board and State Water Resources Control Board also contributed funds. Additional support came from G. Fred Lee & Associates and Pacific EcoRisk.

* To reach reporter Audrey Cooper, phone 546-8298 or e-mail acooper@recordnet.com