IT IS not often that Whiting, Indiana, makes the national news. But Indiana's plan to let bp, a British energy company, expand an oil refinery there, possibly increasing pollution in Lake Michigan, has raised hackles not just in neighbouring Illinois but all the way to Capitol Hill. Barack Obama, a senator from Illinois, wrote a stern letter. Illinois's governor and Chicago's mayor threatened to sue. Faced with such protests (and a petition signed by more than 100,000 people), on August 23rd bp agreed to limit discharges to the lake. But the scuffle goes on. Not only does bp now face scrutiny over its atmospheric emissions, but Indiana's permit allowing the company to increase pollution to the lake also remains valid. In October a judge will consider a lawsuit that seeks to revoke it. The brawl has made two things clear. First, there is widespread hostility to polluting any of the five Great Lakes, which supply drinking water to some 30m Americans, not to mention many Canadians, each year. Second, despite the common desire to keep the lakes clean, there is confusion over who is in charge of doing so. Of the many rules that limit pollution to the lakes, the most important is the Clean Water Act. But implementing it remains as tricky as ever. The act, which was passed in 1972, aims "to restore and maintain the chemical, physical and biological integrity of the nation's waters." It does this, in part, by regulating so-called "point source" polluters, such as factories or refineries. Each state creates its own standards for water quality