In response to a congressional request, GAO reviewed the status of cleanup activities at the Kesterson National Wildlife Refuge to determine whether the federal government: (1) assessed the extent of contamination at refuges nationwide; (2) developed water quality criteria to protect wildlife and refuge habitats from contamination; and (3) dealt with actual or potential contamination from agricultural drainage water or other sources.

GAO found that the: (1) Bureau of Reclamation stopped the flow of contaminated water to the Kesterson Refuge and prepared a phased cleanup plan to initially treat contamination in place, rather than dispose of it; (2) board responsible for protecting California's water resources rejected the phased plan and approved the concept of on-site disposal; and (3) cleanup will cost an estimated $27 billion. GAO also found that the Department of the Interior: (1) intensified efforts to identify contaminated refuges, since an Interior survey indicated that 85 of 430 refuges were or could be contaminated by agricultural drainwater or by municipal, industrial, or military activities; and (2) did not use survey techniques that would identify all contaminated refuges. GAO concluded that obstacles to identifying and cleaning up sites include the: (1) lack of water quality criteria to determine when contamination threatens wildlife and refuge habitats; (2) lack of federal regulatory authority over agricultural drainage water; and (3) lengthy process of identifying the party responsible for cleanup, deciding on a cleanup plan, and obtaining cleanup funds.