Valley Voices

Selenium still poisons Valley, Delta, nation

The Kesterson National Wildlife Refuge sits quiet and empty of birds on Dec. 14, 1983.
The Kesterson National Wildlife Refuge sits quiet and empty of birds on Dec. 14, 1983. The Fresno Bee file

Thirty-three years ago the obscure word “selenium” flashed across the national consciousness when it was learned that bird embryos were suffering grotesque deformities and death as a result of selenium poisoning of the food chain at Kesterson National Wildlife Refuge in western Fresno County.

Selenium is a trace element and a necessary micronutrient for humans and other creatures. It is widely touted as a nutritional aid and may help battle cancer. But it was selenium that killed the fish and birds at Kesterson, triggering deformities and death. Scientists soon learned that even very small amounts of selenium – less than two parts per billion in water – could quickly move up the food chain and impair fish reproduction and harm birds.

Elsewhere in the U.S., it was learned selenium pollution in agricultural wastewater from farms on high-selenium shale soils was often funneled to the nearest creek or river and harming fisheries, despite a 1949 U.S. Geological Survey warning to keep shale soils from being farmed.

Moreover, farm wastewater was not the only source of selenium pollution. Coal-ash disposal, coal-mining debris washing into creeks, and fertilizer were also damaging aquatic ecosystems. Fish everywhere were dying.

Foot-dragging industrial polluters fought back, filing lawsuits and pressuring state and local governments to delay imposing wildlife-protection selenium standards for lakes and rivers.

Now, a third of a century later, the Environmental Protection Agency is finally proposing new aquatic life and aquatic-dependent wildlife criteria for selenium in the San Francisco Bay-Delta Estuary. Simultaneously, the EPA is proposing revised and strengthened national selenium safety standards. The proposed standards were immediately attacked as insufficient.

In June, a Duke University study of coal-ash ponds near 21 power plants in five southeastern U.S. states found evidence that nearby surface waters and groundwater were consistently and lastingly contaminated by the unlined ponds.

“High levels of toxic heavy metals including arsenic and selenium were found in surface waters or groundwater at all of the sites tested. Concentrations of trace elements in 29 percent of the surface water samples exceeded EPA standards for drinking water and aquatic life,” said the Duke report.

The study did not test drinking water wells, but that will be the next phase of the research, a Duke scientist said.

The EPA promulgated the Bay-Delta’s current selenium criteria in 1992 but now acknowledges “the latest science on selenium fate and bioaccumulation indicates that the existing criteria are not protective of aquatic life and aquatic-dependent wildlife in the salt and estuarine waters of the San Francisco Bay and Delta.”

EPA officials said an introduced species of clam commonly known as Corbula has triggered “a rapid acceleration of selenium accumulation in the food chain of fish and bird species in the San Francisco Bay and Delta ecosystem.” Clam-eating fish and birds are most at risk.

The proposed new national selenium standards for coal states drew a quick rebuke from the Sierra Club. A July 16 Sierra Club news release said enforcement of the new selenium standards would be placed in the hands of individual state agencies “who have already established that they will not miss an opportunity to aid their polluter friends in the mining business.”

The Center For Biological Diversity said the new proposed nationwide water-quality criteria for selenium are substantially weaker than proposed standards issued nearly six years ago.

“The EPA ignored the recommendations and concerns of the U.S. Fish and Wildlife Service and National Marine Fisheries Service regarding what levels of selenium pollution would be harmful to endangered species. Although selenium is beneficial to human health in very small doses, this metal becomes toxic as it accumulates in larger and larger amounts through the food chain. Selenium pollution, which causes grotesque spinal deformities in fish, is a common byproduct of mountaintop-removal coal mining, coal-fired power plants and many industrial processes.”

“These selenium standards are a step backward for water quality and little more than a green light for industry to keep polluting our rivers and streams,” said Brett Hartl, endangered species policy director at the CBD. “Endangered freshwater fish, amphibians and mussels are some of the fastest-declining species in the United States — in large part because toxic pollutants like selenium continue to be poorly regulated by the EPA.”

Lloyd G. Carter of Clovis is president of the California Save Our Streams Council. His website is

Selenium hearings

The Bay-Delta proposed standards for selenium will be the subject of hearings this month.

Date: Aug. 22 on internet and Aug. 23 in public hearings in San Francisco

Feedback: Written comments can be submitted

Details: Diane Fleck, EPA, 415-972–3527 or