Water Resources Research Act Program

Details for Project ID 2008PA89B

Impact of infiltrating runoff on groundwater recharge quality

Institute: Pennsylvania
Year Established: 2008 Start Date: 2008-03-01 End Date: 2009-02-28
Total Federal Funds: $19,923 Total Non-Federal Funds: $39,936

Principal Investigators: Mira Olson

Project Summary: The Valley Creek Watershed is rapidly urbanizing, resulting in harmful levels of pollutants in stormwater runoff. Much of the runoff collected in detention basins infil-trates the subsurface within a relatively short distance of its release, indicating that storm-water runoff represents a significant contribution to ground-water recharge. In this study we will measure the pollutant load to ground water in the Valley Creek Water-shed, an urbanizing Pennsylvania watershed. The overall objective of this project is to analyze the impact of infiltrating storm-water runoff on the quality of ground-water re-charge. The specific aims are as follows: 1) To estimate ground-water recharge rates from stormwater detention basins in the Valley Creek Watershed; 2) To observe ground-water recharge quality versus depth in the Valley Creek Watershed; and 3) To correlate peak stream flow with peak turbidity in Valley Creek. Briefly, we will measure infiltration rates at several selected detention basins within the watershed and perform a detailed analysis of heterogeneities in local infiltra-tion rates and preferential flow at a single site. We will also measure ground-water quality versus depth at two select basins to analyze pollutant removal as a function of depth beneath the surface. Last, we will examine the correlation between peak dis-charge and peak turbidity in Valley Creek to identify sources of contamination from con-tributing detention basins. Results from this study will help stormwater management workers make in-formed decisions about how and where to place infiltration zones and basins in order to minimize the impact of infiltrating runoff on the quality of ground-water supplies. Be-cause of the karst geography underlying many of Pennsylvanias urbanizing watersheds, including the Valley Creek Watershed, small-scale analyses of the heterogeneities of in-filtration and pollutant loading are critical in protecting ground-water resources from contamination.