Characterization of stormwater runoff from the Naval Air Station and Naval Wepons Industrial Reserve Plant, Dallas, Texas, 1994-96

Abstract

The characterization of stormwater runoff from the Naval Air Station (NAS) and the Naval Weapons Industrial Reserve Plant (NWIRP), Dallas, Texas, is necessary to determine if runoff from the facilities is contributing to off-site contamination of surface waters, A network of five fixed sites and four grab sites was established to collect stormwater-runoff samples from a substantial part of the drainage area of each facility. Fixed sites were instrumented to measure and store precipitation, stage, discharge, and runoff-volume data and to collect flow-weighted composite samples during a storm. Grab and composite samples were collected for six storms at each of the five fixed sites from October 1994 to March 1996. The grab samples were analyzed for about 100 properties and constituents including specific conductance, pH, water temperature, bacteria, trace elements, oil and grease, total phenols, and volatile organic compounds. The composite samples were analyzed for about 220 properties and constituents including specific conductance, pH, chemical oxygen demand, biochemical oxygen demand, major ions, suspended and dissolved solids, nutrients, trace elements, total organic carbon, volatile organic compounds, semivolatile organic compounds, and organochlorine and organophosphorus pesticides. Grab samples were collected for two storms (September 18,1995, and October 2,1995) at each of the four grab sites. The grab samples were analyzed for about 80 constituents including specific conductance, pH, water temperature, trace elements, and volatile organic compounds. Composite samples were collected for two of the six storms sampled at the fixed sites and analyzed for aquatic toxicity. Fathead minnow growth and survival toxicity tests and water flea reproduction and survival toxicity tests were done. Median event-mean concentrations computed for 12 selected constituents in samples from NAS and NWIRP fixed sites were compared to median event-mean concentrations for residential, commercial, industrial, and highway land uses within the Dallas-Fort Worth area computed from data collected for the National Pollutant Discharge Elimination System program. NAS and NWIRP median event-mean concentrations also were compared to those for residential and commercial land uses from the Nationwide Urban Runoff Program.