Selenium Peril Spreads Beyond Wildlife Refuge
A Central Valley wetlands system more than 50 times the size of the contaminated Kesterson Wildlife Refuge is threatened by high enough levels of the element selenium to cause death and birth defects in birds, federal studies show.
Deformed bird embryos and dead wildfowl could begin turning up this year or next in parts of the 66,000-acre Grasslands Resource Conservation District, following the same pattern that beset Kesterson, according to two internal U.S. Fish and Wildlife Service memoranda obtained by The Times.
“It’s sort of like seeing history repeated at a couple of years’ lag,” said Fish and Wildlife Service spokesman Bill Meyer. “We’re seeing the Kesterson situation about a year or two years behind.”
More Studies Called For
Harry Ohlendorf, a Fish and Wildlife Service scientist involved in testing for selenium, said more extensive studies are needed before anyone can determine just how serious a threat selenium poses to wildlife in the Grasslands area, which surrounds the 1,200-acre Kesterson refuge.
However, an April 16 memo written by a Fish and Wildlife Service environmental specialist to the agency’s regional director in Portland said: “The entire Grasslands could become another Kesterson-type situation.”
The report further warned: “The birth deformities and little or no successful reproduction of selected migratory birds, which occurred at Kesterson in 1984, could be expected and may be occurring in other parts of the Grasslands. All the circumstantial evidence is there. The only thing missing is dead and/or deformed birds. . . .”
Earlier this year, the U.S. Department of the Interior ordered the closure of Kesterson, a receptacle for farm runoff water, by July 1, 1986, because selenium had caused death and birth defects in birds that inhabit the refuge.
Selenium is a trace element necessary to animal and human health in small amounts, but harmful in heavy concentrations. It is found naturally in the soil of the western San Joaquin Valley and has been flushed out in large quantities by irrigation of farmlands.
Over the years, agricultural runoff water containing selenium has been used to flood the 1,200-acre Kesterson refuge, as well as the surrounding Grasslands.
Located near the town of Los Banos, the Grasslands encompasses Kesterson, five other state and federal wildlife refuges and 160 duck hunting clubs. It is one of the few remaining wetlands in California and is a key part of the Pacific Flyway, providing a winter habitat for millions of migratory birds.
No solution has yet emerged for the problem of where to deposit the contaminated water once it leaves farms in the western San Joaquin Valley.
Now, as a result of the high selenium findings in the Grasslands, contaminated runoff water is being diverted past nearly all of the duck clubs and directly into the San Joaquin River, according to Don Marciochi, manager of the Grasslands Water District.
Recent tests have shown that the selenium content of the river is increasing but does not pose a health hazard, said Dennis Westcot, a spokesman for the state Water Resources Control Board.
However, other preliminary tests along the southern end of San Francisco Bay, where the river empties, have found high levels of selenium in some wild birds, Meyer said.
Because of the findings in the Grasslands and the bay, the Fish and Wildlife Service has embarked on an extensive yearlong program of testing birds, fish, mammals, vegetation and other wildlife in 10 different zones of the marsh system.
Concern over the fate of wildfowl in the Grasslands is based on tests of 37 birds taken from seven locations last year, Meyer said.
In some cases, the selenium level in those birds was even higher than those tested at Kesterson, he said. The highest selenium levels were measured at the southern end of the Grasslands--the area where the selenium-laden water first enters the wetlands system.
Within the agency, there is some difference of opinion on how to interpret the data.
“We’re not sure what it means yet because the samples are relatively small,” Ohlendorf said. “I think it’s premature to assess how severe it is until we complete the study.”
However, the internal memos, based on the data Ohlendorf helped collect, suggest that the problem has already reached serious levels.
“Based on the 1983 and 1984 observations of bird mortality and low reproduction at Kesterson and the high levels of selenium found in the birds taken throughout the Grasslands in the spring of 1984, it should not be a surprise if growth abnormalities, mortalities of young birds and poor reproductive success or even complete failure would occur in the Grasslands, particularly the south Grasslands, during the spring and summer of 1985 or 1986,” according to a March 14 memo.
The amount of selenium reaching the Grasslands has increased over the last two decades as farmers have installed tile drains below ground to carry runoff water that has a high content of salt and other minerals.
Originally, the water was to be sent directly to San Francisco Bay through a system known as the San Luis Drain. But that plan was abandoned in the 1970s and Kesterson became the terminus of the drain.
Beginning in 1978, subsurface drain water was dumped directly into twelve 100-acre ponds at Kesterson. The effects of selenium contamination first became apparent in late 1983 when dead birds and deformed embryos were discovered at Kesterson.
The Grasslands has received selenium-laden water for a much longer time than Kesterson. However, the selenium buildup has been slower in the Grasslands because, unlike Kesterson, it receives fresh and surface drainage water as well as the more toxic subsurface runoff water.
Last week, the Grasslands Water District submitted a required timetable to the state water board that calls for providing a detailed cleanup plan by October. The water district is responsible for the drain water over 51,000 acres of the Grasslands.
But Marciochi, manager of the water district, said the problem of selenium in the Grasslands goes beyond the responsibility of his district and is shared by federal agencies.
The Fish and Wildlife Service may have some obligation to help end the contamination because of its duty to protect migratory birds and because it has obtained easements from private owners to maintain 22,000 acres of the Grasslands as wetlands.
Furthermore, the Bureau of Reclamation, which operates Kesterson, may also be partially responsible because it supplies the irrigation water.
“The Bureau of Reclamation is as concerned with Grasslands as it is with Kesterson and is doing everything it can to make sure that the same kinds of kills do not take place at Grasslands that took place at Kesterson,” said bureau spokesman Larry Hancock.