20 Years of Stormwater Samples
Nest Environmental Services has accumulated 20 years of samples and analysis at the rate of about 50 to 60 samples per year, over 1000+ storm water samples. We thought it would be interesting and instructive to look at the results of that monitoring to see if there was any long term trend in the levels of contamination and secondly, if there were any correlations between the various contaminants required for testing: pH, Conductivity, Total Suspended Solids, Total Organic Carbon / Oil & Grease, Aluminum, Iron, Copper, Lead and Zinc. Such a study could suggest strategies for reducing the contamination of storm water runoff.
Nest Environmental Services began consulting for small businesses such as automotive salvage yards, scrap metal recyclers, cement manufacturers, and other businesses in 1994 in regards to their management of hazardous materials and storm water runoff. In 1994 California’s State Water Resources Control Board (SWRCB) issued regulations (Industrial Storm Water Permit) for storm water management. This required those businesses that had outdoor facilities and activities that could contaminate storm water to monitor storm water run-off and to implement Best Management Practices to prevent the contamination of storm water run-off.
Since different types of businesses would have different mixes of contaminants we choose a particular SIC code and analyzed the data for that group.
This study will presents the following descriptions: 1) an overview of the data and its properties; 2) a description of 18 year trends in median and arithmetic mean values for the contaminants; 3) correlations among the contaminants; 4) discussion of potential management strategies, in particular trapping the Total Suspended Solids (TSS) from the storm water runoff.