Facebook Twitter

No ‘smoking gun’ found in Utah Lake PCB study

SHARE No ‘smoking gun’ found in Utah Lake PCB study
Randy Smith from Salt Lake City spends some time fishing on Monday at Utah Lake State Park in Provo.

Randy Smith from Salt Lake City spends some time fishing on Monday at Utah Lake State Park in Provo.

Stuart Johnson, Deseret News

A study has found no definitive sign showing how PCBs are ending up in high enough levels in Utah Lake's carp and channel catfish to justify an ongoing consumption advisory for both fish species.

"There's no smoking gun as far as where the source is coming from," said Sandy Wingert, environmental scientist for the Utah Division of Water Quality.

Wingert plans to release the final report by the end of next week on a PCB study she conducted this past summer. She'll present the report to the Utah Water Quality Board in December.

Toxic chemicals known as polychlorinated biphenyls (PCBs) were once used as a coolant or to insulate equipment such as electrical transformers. PCBs are believed to be capable of causing cancer, and in the late 1970s, their use was banned. But PCBs still show up in the environment.

State and federal regulators last year sampled fish to check for PCB contamination, prompting a consumption advisory for channel catfish and reinforcing an existing 2006 advisory for carp. The mystery has been how PCBs are ending up in the fish.

This past June, Wingert sampled sediment at three depths in at least 21 sites around Utah Lake and found PCB levels below 50 parts per billion (ppb). The sediment is one food source for bottom feeders such as carp and catfish, which also feed on smaller carp. At a level higher than 59.8 ppb of PCBs, Wingert said, the state would consider doing more sediment samples toward determining if any cleanup efforts would be necessary.

For now, Wingert said, her research is done. She said any further study of possible PCB sources, such as algae or plankton, would probably be initiated by another state agency.

Meanwhile, the consumption advisory shouldn't necessarily be considered a total ban on eating carp and catfish taken from the lake, according to Reed Harris, director of the Utah Department of Natural Resources' June-sucker recovery program. "These are not high levels of PCBs," he said.

The 2006 advisory for carp recommended that adults limit their consumption of carp to one eight-ounce fillet per month. Children and pregnant women were advised to avoid eating any carp from the lake.

Harris said the U.S. Food and Drug Administration allows up to 2,000 ppb levels of PCBs in fish sold in stores. He said the average salmon fillet people buy at their grocer likely contains between 10 and 60 ppb of PCBs. The average fillet from a carp coming out of Utah Lake, he noted, might contain around 100 ppb of PCBs.

He's not sure where the PCBs originated, but Harris said the chemical's presence appears to be circulating within the food chain as fish feed on one another. The next sampling of fish for PCBs isn't planned until around 2012.

Harris has a theory, though, on how to reduce PCB levels in fish from Utah Lake. In his position with the division, Harris is in charge of reviving the June sucker population in Utah Lake. The June sucker is a native, endangered species.

The revival effort includes the Central Utah Water Conservancy District budgeting $500,000 to hire a commercial fisherman who will use nets to snare about 1 million carp a year for the next six years, reducing the non-native carp population by about 75 percent in that time. The carp eradication process, he added, may begin within the next week or so.

"If it (PCBs) is in the biomass, then we're hopeful through taking large numbers (of carp) out we'll start to see the levels of PCBs in fish start to drop," Harris said. The carp taken from the lake, he added, will probably end up as compost or sold to private farmers for use as fertilizer.


E-mail: sspeckman@desnews.com