Evaluation of the environmental effects of stormwater pollutants for Oak Ridge National Laboratory

Abstract

Despite Best Management Practices (BMP), total suspended solids (TSS) and oil and grease (O and G) concentrations in stormwater runoff frequently have been above the National Pollutant Discharge Elimination System (NPDES) Permit effluent limits at ORNL. Although the effects of stormwater pollutants to aquatic ecosystems are of concern regionally and nationally, NPDES permit violations at ORNL are best addressed on a site-specific basis. This document explores several key questions to determine whether the TSS and O and G noncompliances at ORNL are primarily a regulatory problem (i.e., Category 1 and 2 effluent limits are neither reasonably achievable nor effective in achieving environmental protection), or a legitimate ecological concern that will require effective remediation. The three tasks outlined in the study plan were to (1) clarify the degree of TSS and O and G noncompliances at ORNL, (2) provide guidance as to appropriate limits for TSS and O and G in Category 1 and 2 discharges, and (3) provide information about the effectiveness of possible mitigation or remediation measures for TSS and O and G in stormwater releases, assuming that such measures are needed for one or more ORNL Category 1 or 2 outfalls.