M2 PM Non-Point Source Pollution and TMDLs
Monday, 14 November 2005: 1:50 PM - 5:30 PM in Ballroom 2

(WEB-1117-848783) Investigative Urban Surface Water Quality Monitoring Program Integrating Land Use and Watershed Topography.

Weber, G^{1, 2, 3}, Uwins, J^{2, 3}, Lancy, T^{2, 3}, Aguinaga, G^{2, 3}, Phillips, J^{2, 3}, Williams, D^{2, 3}, ¹ Blasland Bouck & Lee Inc, Carpinteria, CA, USA² University of California, Santa Barbara, Santa Barbara, CA, USA³ The City of Santa Barbara, Santa Barbara, CA

ABSTRACT- The last 15 years have shown a heightened awareness to general water quality impacts of urban runoff as a non-point pollution source; particularly since the release of NPDES Phase II MS4 designations, and the beginning of CWA 303(d) TMDL enforcement. In order to improve water quality and reduce the potential risk of ecological or human exposure to hazardous constituents, communities frequently utilize Best Management Practices (BMPs) in conjunction with monitoring. Commonly, monitoring is used for reporting compliance, and in gauging the effectiveness of BMPs. Less common is the use of monitoring as an investigative tool to help identify source(s) contributing to non-point source pollution. A monitoring program was developed to investigate both sub-watershed drainages and land use classifications as potential non-point sources, thus providing both a qualitative and geographic dimension of analysis. Analytes were selected using historical city monitoring data, peer review literature investigating land use - contaminant relationships, and grey literature performed by other municipalities with similar climates and cityscapes. Sample collection sites were selected by integrating Geographic Information Systems (GIS) analysis and historical sampling locations. Drawing from the U.S. Geological Survey National Ambient Water Quality Assessment (NAWQA) program, sampling sites were divided into integrator sites and indicator sites. Integrator sites were selected to characterize overall watershed conditions. Indicator sites were chosen to examine inputs from individual drainage basins that consisted of a homogeneous land use. Results from indicator sites were intended to provide insight into the impacts from specific land uses on the receiving waters in the area. If successful, the city could better identify land use types and sub-watersheds as targets for future BMPs and policy actions. This investigative monitoring methodology could potentially serve as a template for developing other watershed management programs aimed at improving urban surface water quality and/or mitigating exposure to non-point, anthropogenic contaminants.

Key words: Land-use, Non-point, GIS, water quality