Spurred by a Sierra Club lawsuit, Texaco has agreed to prevent further contamination of the North Platte River by its defunct oil refinery near Casper, Wyo. If the EPA and Justice Department approve the consent decree next month, Texaco must clean up the river, report monthly to the Sierra Club, and step up efforts to keep pollution from reaching the river in the first place. According to the Sierra Club, at least 55 tons of petroleum products reach the river yearly, and an EPA test revealed adverse effects for larvae and other invertebrates, the base of the river's food chain. In a precedent-setting case, Sierra Club lawyers successfully argued that groundwater contamination flowing into a river constituted a "point source" and therefore was subject to the Clean Water Act, rather than the Resource Conservation and Recovery Act governing groundwater (HCN, 11/29/93). "The section of the Clean Water Act that allows citizens to sue polluters is a godsend," says Earline Hittel, a North Platte Sierra Club member. Tom Davis, another Sierra Club member, says the state and the EPA were lax with Texaco. The Sierra Club took on the case after Davis and his wife found oil globs bubbling up to the river's surface while canoeing.