It bears a striking resemblance to several pieces of "model legislation" recently leaked from The American Legislative Exchange Council (ALEC), and might be the newest testament to the organization's potency.
The mission of the Clean Water Cooperative Federalism Act of 2011 (H.R. 2018) is self-evident in its title. It would eliminate, wholesale, the EPA's power to supersede individual states' water pollution rules. States would no longer be held to federal water quality standards they disagree with, and the EPA would be unable to make changes to Clean Water Act quality standards without states' approval.
It would prohibit the federal government from "specification of any defined area as a disposal site for the discharge of dredged or fill material into navigable waters," so if the state does not believe the dumped material would harm drinking water or fisheries, then chemical dumping and manufacturing runoff would not be prevented.