On September 28, EPA’s independent Science Advisory Board (SAB) released its first draft review of EPA’s research into the water quality impacts of valley fills associated with mountaintop mining. In their draft review, the SAB supports EPA’s scientific research and agrees with EPA’s conclusion that valley fills are associated with increased levels of conductivity (a measure of water pollution for mining practices) in downstream waters, and that these increased levels of conductivity threaten stream life in surface waters, according to press release from EPA.

The SAB reviewed EPA’s draft report “A Field-Based Aquatic Life Benchmark for Conductivity in Central Appalachian Streams,” which uses field data to derive an aquatic life benchmark for conductivity. The benchmark is intended to protect 95 percent of aquatic species in streams in the Appalachian region influenced by mountaintop mining and valley fills. Based on that science, EPA released guidance in April designed to minimize irreversible water quality impacts caused by mountaintop mining.

Following the completion of the external peer review and review of public comments, the report will be revised and published as a final report.

A growing body of scientific literature, including previous and new studies performed by EPA, show significant damage to local streams that are polluted with the mining runoff from mountaintop removal, according to EPA. To protect water quality, EPA has identified a range of conductivity (a measure of the level of salt in the water) of 300 to 500 microSiemens per centimeter that is generally consistent with protecting life in Appalachian streams. The maximum benchmark conductivity of 500 microSiemens per centimeter is a measure of salinity that is roughly five times above normal levels.