Urban stormwater quality data collected over the past 20 years for several large government-sponsored sampling programs in the United States were assembled and analyzed to develop new nationwide estimators and statistics for urban storm water quality. We believe that this is the first attempt to assemble and analyze these major storm water quality data sets for this purpose. In this paper, the first public report of our work to-date, we present the results of the data acquisition, data base assembly, quality assurance, computation of new stormwater event mean concentrations and associated statistics, and comparisons with the original U.S. Environmental Protection Agency's Nationwide Urban Runoff Program (NURP) results. The differences between the pooled means and those estimated from our analysis of the NURP data range from a 79% lower estimate for Copper to a 36% higher estimate for Biochemical Oxygen Demand. It is concluded that the variations between the NURP results and those developed here from the pooling of the three national data bases are important and that future work may provide a basis for differentiating Event Mean Concentrations among urban land uses, geographic region and seasons.
A green approach to combined sewer overflow control promotes reduction of stormwater at the source through the application of low impact development and low impact redevelopment techniques. The approach is supported by innovations such as stormwater regulations and other progressive practices like street tree planting and riparian buffer creation and restoration. These practices are designed to improve conditions in both the combined and separate sewered areas and to better manage the water resources, to protect and ensure beneficial uses of water bodies, to restore stream habitat, and to meet the priorities of residents for cleaner and safer streams. The practices are intended to optimize the use of infrastructure planned and constructed in the past for larger populations than those realized today. This paper describes approaches to and benefits expected from low impact development and redevelopment in terms of projected reductions in sewage discharges from a highly urbanized area served by combined sewers.The portion of impervious surfaces in the study area subjected to stormwater control is related to the urban water balance and to combined sewer overflow volume, duration, and frequency. Runoff resulting from small, frequent storms is infiltrated into native soils to the maximum extent possible. Where soil conditions do not allow the full volume to be infiltrated, the volume can be detained and released at a prescribed rate, typically 24 hours or more.Relationships between impervious cover and stormwater management benefits are investigated numerically using the USEPA Storm Water Management Model (SWMM). Model representations such as depression storage, directly connected impervious area, soil properties, combined sewer regulator settings, head loss, and wastewater treatment plant capacity, are validated using observed sewer flow and stream discharge records. Model elements representing stormwater management facilities are added between the hydrologic model representing the precipitationrunoff processes from land surfaces, and the hydraulic model representing the pipes and related appurtenances of the combined sewer collection system. These additional model elements represent physical processes occurring in stormwater management facilities. Infiltration into native soil is represented using soil moisture accounting and a modified Green-Ampt model of infiltration processes. Evaporation of ponded water, storage, and controlled release are simulated as they would occur in facilities meeting the performance requirements of stormwater control regulations. Sustainability 2008714 Hydrologic and hydraulic model simulations indicate that significant reductions in annual combined sewer overflow volume will result from implementation of low impact development and low impact redevelopment on a watershed scale. Estimates are made of annual combined sewer overflow volumes for various levels of implementation of control practices.A detailed analysis of impervious surfaces by type and by ownership leads to conclusions regardi...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.