ORIGINAL ARTICLE Potential for localized groundwater contamination in a porous pavement parking lot setting in Rhode Island Thomas B. Boving Æ Mark H. Stolt Æ Janelle Augenstern Æ Brian Brosnan Received: 22 September 2006 / Accepted: 16 July 2007 / Published online: 2 September 2007 Ó Springer-Verlag 2007 Abstract The control of polluted surface runoff and the assessment of possible impacts on groundwater is a con- cern at the local and regional scale. On this background, a study investigates possible impacts of organic and inor- ganic pollutants (including bacteria) originating from a permeable asphalt parking lot on the water quality imme- diately beneath it. The functioning of the permeable pavement, including clogging and restricted vertical per- colation, was also evaluated. Four nested sample ports (shallow and deep) were installed below low- and high- traffic areas, including one port outside the parking lot. At least initially there was a good hydraulic connection between the parking surface and the shallow sample ports. The presence of a geotextile layer at the base of the parking lot structure, however, was identified in lab tests as one factor restricting vertical percolation to the deeper ports. Clogging of the permeable surface was most pronounced in heavy traffic areas and below snow pile storage areas. Corroborated by high electric conductivity and chloride measurements, sand brought in by cars during winter was the principal cause for clogging. No bacteria or BOD were found in percolating water. Polycyclic aromatic hydrocar- bons (PAH) were present at concentrations near minimum detection limit. Nutrients (nitrate and phosphate) were being leached into the ground via the permeable parking lot surface at annual flux rates of 0.45–0.84 g/m 2 /year. A multi-species tracer test demonstrated a retention capacity of the permeable parking lot structure of [ 90% for metals and 27% for nutrients, respectively. Keywords Permeable pavement  Non-point source pollution  Ground water quality  Treatment  Runoff Introduction Development and urbanization has resulted in an increase in impervious land cover, such as pavement and parking lots. Since the volume of urban stormwater is a direct function of the extent of impervious surfaces (USEPA 1983), increases in development result in greater incidents of storm water runoff occurrences and volume. Infiltration of stormwater runoff to groundwater and direct discharge to surface waters can be a widespread nonpoint-source pollution problem. The control of polluted runoff at the local as well as the regional scale is therefore a challenge for many federal and state agencies and there are now calls for better-contained pavement drainage to control pollution from stormwater runoff. Stormwater runoff may contain elevated concentrations of heavy metals originating from corrosion or ordinary wear of brakes, tires, and other vehicle parts (Pitt et al. 1994; Sansalone and Buchberger 1997; Davis et al. 2001; Sorme and Lagerkvist 2002; Dempsey and Swisher 2003). Runoff may also contain elevated levels of organic compounds, including petroleum hydrocarbons (Boving 2002; Dempsey and Swisher 2003; Mahler et al. 2005). Additional sources of stormwater contamination include T. B. Boving (&)  J. Augenstern Department of Geosciences, University of Rhode Island, Woodward Hall, Rm. 315, Kingston, RI 02881, USA e-mail: boving@uri.edu M. H. Stolt Department of Natural Resources, University of Rhode Island, Kingston, RI 02881, USA B. Brosnan Beta Group, Inc., Lincoln, RI 02865, USA 123 Environ Geol (2008) 55:571–582 DOI 10.1007/s00254-007-1008-z