Performance Evaluation of Cold Weather Flow Control and Runoff Treatment BMPs

Abstract

The effectiveness of stormwater best management practices (BMPs) in warm climates has been extensively researched. However, little research has been conducted to determine the effectiveness of these BMPs for flow control and pollutant removal during cold weather conditions. Freezing conditions and short growing seasons can adversely affect the pollutant removal efficiency of BMPs by decreasing infiltration through frozen soils, inhibiting biological uptake, and decreasing residence times. In addition, deicers may compete for positively charged soil binding sites, thus increasing metal mobility. The objectives of this study were to determine how well BMPs in cold climates such as eastern Washington control runoff volumes and flow rates, and how efficiently they remove heavy metals (Cu, Cd, Pb, and Zn). This will be determined by integrating the following three subcomponents (1) soil metal concentrations within various BMPs, (2) sampling and monitoring of runoff during storm events, and (3) quantifying metal transport as affected by deicing/anti icing agents in soil cores in a laboratory setting. Soil metals distributions within five eastern Washington stormwater treatment BMPs have been quantified by sampling at increasing distances and depths from culvert inlets. Results show a significant decrease in soil metals concentrations with depth in the upper