Summary: In response to a congressional request, GAO described: (1) information in Environmental Protection Agency (EPA) documents about groundwater contaminants that is available to states for setting groundwater standards; and (2) existing drinking water standards.
GAO found that: (1) 41 of the 57 states and territories set their own numerical or narrative standards for groundwater contaminants, since there were no federal standards; (2) many states believed that a lack of information constrained their standard-setting efforts; (3) EPA is revising 20 of the 22 standards it issued before 1987 for individual contaminants and is reviewing 63 other contaminants for possible regulation; and (4) although there were 247 EPA documents that dealt fairly well with 83 contaminants, there was a substantial gap between what was available and what states needed to develop standards. GAO believes that, although Congress did not give EPA general authority to set groundwater standards, providing the information states need to establish their own standards would be consistent with current EPA goals and efforts.