To establish a minimum requirement for the water quality criteria for dioxin published pursuant to section 304(a) of the Federal Water Pollution Control Act, to require each State to adopt a water quality standard for dioxin which is at least as stringent as that criteria, and to direct the United States Fish and Wildlife Service, in consultation with National Oceanic and Atmospheric Administration, to conduct a study on the effects of dioxin on wildlife, aquatic life, and the entire aquatic environment.

Requires water quality criteria for dioxin published pursuant to the Federal Water Pollution Control Act to ensure that the application of such criteria to a State's waters will limit the probability to not more than 1 in 1,000,000 that an individual with high exposure to dioxins in such waters will be diagnosed with cancer as a result of lifetime exposure. Directs the Administrator of the Environmental Protection Agency to revise such criteria if they do not meet such requirement.

Requires States to submit to the Administrator for approval a chemical-specific numeric water quality standard for dioxin that is at least as stringent as the criteria established by this Act. Sets forth standard approval and modification procedures. Provides that the criteria established for dioxin by this Act shall take effect for any State without an approved standard.

Requires the Director of the Fish and Wildlife Service to conduct a study to: (1) assess the impact of discharges of dioxin on wildlife and the aquatic environment; (2) evaluate the potential effects of uptake and accumulation of dioxin in wildlife and aquatic life on the food chain and public health; and (3) evaluate the effectiveness of public health-oriented criteria to protect wildlife and aquatic life from the effects of dioxin discharges.