San Diego Regional Storm Water Monitoring Program: Contaminant Inputs to Coastal Wetlands and Bays

Abstract

A watershed-based, Regional Monitoring Program was established by <br /><br />the City of San Diego, the County of San Diego, the San Diego Unified Port <br /><br />District, and 1 7 other incorporated cities within the county to evaluate the water <br /><br />quality of their wet weather runoff. Seventeen different locations were sampled <br /><br />between 1993 and 1995, and samples were analyzed for priority pollutants and <br /><br />toxicity. In general, measurable quantities of some metals and fecal indicator <br /><br />bacteria were found consistently while nearly all organic contaminants were below <br /><br />method detection limits. Results indicated that residential areas had similar event <br /><br />mean concentrations (EMC) of suspended solids, oil and grease, cadmium, chro- <br /><br />mium, nickel, and zinc compared to industrial or commercial areas. The EMC <br /><br />of copper and lead from residential areas were higher relative to commercial or <br /><br />industrial areas. However, even EMC from residential areas of San Diego were <br /><br />lower than the EMC from other urbanized watersheds measured from around the <br /><br />country as part of the Nationwide Urban Runoff Program. Potential receiving <br /><br />water effects included 7-day chronic toxicity of storm water effluents to Cerio- <br /><br />daphnia. Storm water was responsible for increased contamination of Mission <br /><br />Bay receiving waters by fecal indicator bacteria and exceedences in water quality <br /><br />objectives resulted in post-storm beach closures.