The State - News from Nov. 1, 1987

High nitrate levels and “windows” of permeable sandy subsoils apparently allowed “plumes” of selenium-laden drainage water to escape the Kesterson Reservoir into groundwater supplies, according to a new U.S. Bureau of Reclamation report. In the report to the Central Valley Regional Water Quality Board, bureau scientists and consultants also estimated at least 16,000 acre-feet of drainage water (5.2 billion gallons) ponded at Kesterson in the early 1980s leaked into the aquifer below and is migrating toward the nearby San Joaquin River. The state Water Resources Control Board has rejected a bureau plan to pump local groundwater into the Kesterson ponds under the theory that anaerobic (oxygen free) conditions in the pond muds would lock up the selenium in a harmless, insoluble state. The usage of the leaky Kesterson ponds was halted in 1986 after discovery of mutations and deaths in birds blamed on selenium, a necessary micronutrient that is toxic at high doses.