ABSTRACT
Irrigation drainage water from parts of the San Joaquin Valley in California contains levels of selenium and other trace contaminants that have been implicated in bird deformities at Kesterson Reservoir [1]. Depending on location and season, the drainage water contains 100-1400 ~g selenium (Se) per liter, predominantly as selenate [Se042-, Se(VI)], the most soluble form. The California State Water Resources Control Board [2] has recommended an interim maximum mean monthly selenium concentration of 2-5 ~g/L in receiving waters and wetlands. Drainage waters also contain 20-150 mg nitrate nitrogen (N03--N) and 2000-4000 mg sulfate (S042-) per liter, depending on season and location [3].
