Monitoring Contaminant Transport From a Stormwater Infiltration Facility to Ground Water

Background/Need: The State of Wisconsin has recently finalized administrative code NR 151 which will, in part, define performance standards for infiltration of stormwater from new developments. The stormwater infiltration standards are intended to preserve ground-water recharge and stream baseflow. However, depending on the landuse characteristics of a drainage area, stormwater may contain significant amounts of contaminants including hydrocarbons, metals, and chloride. In such cases, enforcement of infiltration performance standards has the potential to adversely affect ground-water quality.

Objectives: Monitoring contaminant transport to ground water resulting from infiltration at a site with specific physical characteristics (land use, contaminants, soil type, vadose zone characteristics) has been carried out in only a few settings around the country. This study was undertaken to quantify the relation between the quality of stormwater from the Stonefield neighborhood in Middleton, Wisconsin, and the transport of contaminants to the ground-water system.