Expansion of the National Stormwater Quality Database

An expansion of the National Stormwater Quality Database (NSQD) was conducted by the University of Alabama, Department of Civil, Construction, and Environmental Engineering, with the Center for Watershed Protection, as part of an EPA-funded 104(b)3 project. The main emphasis of this expansion effort was to obtain additional data from communities in the Northeastern region of the United States. New data obtained from seven MS4 (Municipal separate storm sewer system) communities. Most of the new data were in this region, but with some additional data representing other areas. The new data was obtained from Indianapolis, IN, Madison, WI, Minneapolis, MN, St. Paul, MN, Worchester, MA, New Castle County, DE, and Broward County, FL. In addition, updated information for 17 other municipalities was also obtained. The updated information was obtained from cities located in Massachusetts, Maryland, Virginia, and Wisconsin. Data also reviewed for possible inclusion in the NSQD were the International BMP Database (http://www.bmpdatabase.org/), as well as older information from the Nationwide Urban Runoff Program (NURP) (EPA 1983). Additional data were selected from MS4 NPDES (National Pollution Discharge Elimination System) Phase I monitoring, the BMP database, NURP data, as well as USGS data for Madison, WI. These additional data selected for inclusion in the NSQD, after extensive QA/QC review, represented more than 4,800 separate storm events. The NSQD 1.1 along with these additions completes the NSQD ver. 3. The NSQD ver. 3 contains 8,602 rain events from 104 cities throughout the continental United States. The NSQD includes sampling information such as city, state, land use, drainage area, EPA rain zone, date, season, and rain depth, as well as concentrations of many constituents. Supplemental information available on sampling location includes the exact sampling locations (street intersections or longitude/latitude), breakdown of land use by percentage, aerial photographs, topographic maps, and information on sampling procedures, and quality control. Supplemental material can vary based on availability, but can provide a model of necessary information for new permit holders to collect. Example statistical evaluations are included with the completion of this project, including ANOVA analyses comparing different constituent concentrations with land use and geographical location. This information is useful in characterizing stormwater on a national basis, and will provide assistance for the many municipalities that are affected by the NPDES stormwater permit program. An examination of the effects of land use and geographical region on stormwater constituent concentrations can be a valuable reference tool for stormwater managers, researchers, environmental scientists, and engineers. This information can provide reasonable concentrations for given stormwater constituents for specific land use and EPA Rain Zone combinations.