EPA proposes stricter selenium standards for San Francisco Bay

The Environmental Protection Agency (EPA) recently proposed heightening the water quality criteria for selenium in the San Francisco Bay and Delta, which would protect aquatic species and reduce exposure to the contaminant.

The current levels for selenium were set in 1992, but newer research suggests that the aquatic and aquatic-dependent species living in the waters need more stringent standards. Selenium, which mostly enters the bay due to agricultural runoff and oil refinery discharges, can negatively impact threatened and endangered species like the green sturgeon, Chinook salmon, steelhead trout, delta smelt and the California Ridgeways rail, as well as migratory birds that travel to the estuary for winter.

“Reducing selenium in the San Francisco Bay and Delta will benefit the wildlife that are part of this critical ecosystem,” Alexis Strauss, EPA’s Acting Regional Administrator for the Pacific Southwest, said. “This proposal is based on years of scientific study, and will accelerate the restoration of the Bay and Delta.”

The EPA’s proposal would reduce the selenium criteria from 5 parts per billion to 0.2 parts per billion. The EPA has scheduled a virtual public hearing for Aug. 22 and a public hearing at its San Francisco office for Aug. 23.