Selenium Contamination Found Near Kern County Wildlife Refuge

High levels of selenium contamination have been found in two widely separated sites in Kern County, one of them just 12 miles from the Kern National Wildlife Refuge, state officials said Thursday.

The announcement by the state Department of Water Resources marked the first time that the naturally occurring chemical, which has killed and maimed waterfowl at Kesterson National Wildlife Refuge more than 150 miles to the north, had been found in such high concentrations in Kern County.

State officials said the findings came as a shock. “We’ve never found anything other than extremely low levels. This is why we were so shocked to find samples ranging from 362 to 827 parts per billion,” said Louis Beck, chief of the San Joaquin district of the Department of Water Resources.

Drinking Water Standard

The drinking water standard is 10 parts per billion. Officials say selenium has an adverse effect on waterfowl in concentrations as low as 5 to 10 parts per billion.

Authorities said they do not know what caused the high readings but noted that in both cases the selenium was found in agricultural waste water. Such runoff is responsible for the high levels of selenium found at Kesterson.

At the Wheeler Ridge-Maricopa Water Storage District site southwest of Bakersfield and 180 miles from Kesterson, selenium concentrations ranged from 411 parts per billion to 827 parts per billion. The sump is part of an on-farm recirculation system that blends the drainage with fresh water to irrigate 160 acres of land used to grow watermelons.

Concentrations at the northern sump in the Lost Hills Water District ranged from 362 parts per billion to 528 parts per billion and drains 600 acres of land planted in cotton into evaporation ponds 12 miles from the Kern National Wildlife Refuge. Samples from both locations were drawn in May and June.

20 Locations Tested

The two Kern County sumps are among 20 locations being tested. Another 45 samples were taken on Tuesday, and additional results are expected today.

By comparison, selenium levels in drain water flowing from 42,000 acres of Fresno County farmland down the San Luis Drain to Kesterson average around 400 parts per billion.

Waterfowl are affected at lower initial concentrations because the selenium accumulates in the food chain. By the time it reaches the waterfowl, it is more highly concentrated.

Despite the findings announced Thursday, there were no immediate indications that waterfowl at the Kern National Wildlife Refuge are endangered.

Bob Bruggeman, a state Fish and Game Department biologist in Fresno, said, “We have checked those areas from the wildlife standpoint, and we don’t see a problem at this time.”

Lies Beneath Flyway

However, Bruggeman said there could be a problem this fall when waterfowl fly south. The Lost Hills Water District, like most of the San Joaquin Valley, lies beneath the Pacific Flyway. While Bruggeman said it would be premature to say what actions may be required come fall, it is possible that a hazing program similar to one at Kesterson will be considered.

The U.S. Bureau of Reclamation has served notice to Fresno County farmers that it will close Kesterson to agricultural waste water next year. By then, farmers must find other ways to dispose of their waste water.

The Westlands Water District has embarked upon a program to construct a series of evaporation ponds into which the waste water would be discharged until a long-term solution can be found. The ponds will be chemically treated to kill algae and other growth so that they do not become habitats for waterfowl.