Revision of Certain Federal Water Quality Criteria Applicable to Washington

The Environmental Protection Agency (EPA) proposes to revise the current federal Clean Water Act (CWA) human health criteria applicable to waters under the state of Washington's jurisdiction to ensure that the criteria are set at levels that will adequately protect Washington residents, including tribes with treaty-protected rights, from exposure to toxic pollutants. EPA promulgated Washington's existing criteria for the protection of human health in 1992 as part of the National Toxics Rule (NTR), (amended in 1999 for Polychlorinated Biphenyls (PCBs)) using the Agency's recommended criteria values at the time. EPA derived those criteria using a fish consumption rate (FCR) of 6.5 grams per day (g/day) based on national surveys. However, the best available data now demonstrate that fish consumers in Washington, including tribes with treaty-protected rights, consume much more fish than 6.5 g/day. There are also new data and scientific information available to update the toxicity and exposure parameters used to calculate human health criteria. Therefore, EPA proposes to revise the federal human health criteria applicable to waters under Washington's jurisdiction to take into account the best available science, including local and regional information, as well as applicable EPA policies, guidance, and legal requirements, to protect human health.