AWWA ACE56362

Protected source water is key to the economic production of potable water that meets all local,state and federal drinking water requirements. As part of the California Department of HealthServices Drinking Water Source Assessment and Protection (DWSAP) Program, Black &Veatch completed a joint Sanitary Survey Update and Source Water Assessment for NevadaIrrigation District (NID) and Placer County Water Agency (PCWA) using tools includingArcView Geographic Information Systems (GIS) and the United States Environmental Protection Agency's (EPA's) BetterAssessment Science Integrating Point and Nonpoint Sources (BASINS) 3.0 computer program.The sixteen treatment plants NID and PCWA maintain are fed by watersheds located on thewestern slope of the Sierra Nevada mountains with an area totaling approximately 350 squaremiles. The complex relationship between topography, land use, pollution sources and otherwatershed-scale factors is extremely difficult to characterize with traditional tools such as tablescontaining data on pollution sources or charts of historic water quality data. EPA's most recentversion of BASINS uses tools to rapidly combine EPA-provided GIS data from various sources,including the U.S. Geological Survey, Bureau of Mines, U.S. Army Corps of Engineers and theFederal Emergency Management Agency, with external, project-specific data obtained by theuser. The resulting product allows the user to develop an appreciation for the watershed as awhole which is crucial for an accurate assessment. The output data was verified and used as aguide for more detailed aerial and foot surveys of high risk areas including freeways, railroads,grazing areas and other probable sources of contamination. The BASINS/GIS-based approachexpedited access to the nationwide databases maintained by the EPA resulting in the efficientlocation and identification of point and nonpoint sources throughout the watershed. Dataproducts derived from the system included land use maps, topographic maps, point sourcelocation maps as well as more traditional tabular data. When correlated with historic waterquality data, data from the GIS based assessment method resulted in the recognition of potentialwater supply contaminants and their relative risk. This innovative approach allowed the agenciesto develop management plans to ensure reliable delivery of clean source water to the sixteensystem treatment plants. Includes tables.

Product Details

Edition:

Vol. - No.

Published:

06/16/2002

Number of Pages:

4

File Size:

1 file , 540 KB