Drinking Water Mapping Application (DWMA) Demonstration EPA GIS Workgroup Spring Meeting May 15-18, 2007 Boston, MA Authors: Roger Anzzolin, US EPA, Office of Ground Water and Drinking Water Bill Cooter, RTI International James Rineer, RTI International (presenter)

Presentation Outline Overview of the DWMA Data layers Georeferencing to the NHD Building Source Protection Areas (Wells and Intakes) Demo

DWMA Overview A secure, ArcIMS-based geospatial application for US EPA Office of Ground Water and Drinking Water Enables queries of the Safe Drinking Water Information System (SDWIS/Fed) Identifies potential risks and vulnerabilities to surface water and groundwater used for public drinking water

Web Interface SDWIS Points Source Protection Areas (SPA) System Type Population Served Violations Point Risks Nonpoint Risks Source Protection Areas (SPA) % Impervious Population in SPA Karst/DOD/SSA All the SDWIS Point Options

Driving the DWMA

Georeferencing to NHD Allows one to analyze upstream and downstream effects nationally >6,000 drinking water intakes >100,000 facility pipe discharges >9,000 combined sewer overflows

Source Protection Areas (SPAs) Land areas that can contribute water and pollutants Surface water and ground water protection areas State defined SPAs not available nationally

Building Analytical Source Protection Areas (SPAs) Analytical wellhead SPA defined as simple 2 mile buffers Analytical surface water SPAs Created 15 mile upstream drainage network for each intake Built a “convex hull” around each drainage network

Analytical Surface Water SPA vs. State Defined Surface Water SPA

NHDPlus derived SPAs Distance Time Detached Service based

Relating SPAs to Potential Point Contamination Risks Superfund sites Hazardous waste sites Class I Underground Injection Control (UIC) wells PCS CSO UST (MT,CO,AZ,TN,AL,SC)

Relating SPAs to Non-Point Concerns Atrazine use (USGS) Nitrogen fertilizer sales (USGS-EPA) Recoverable manure nitrogen from confined livestock (USDA)

Relating SPAs to Vulnerabilities Percent impervious cover Based on 1992 National Land Cover Dataset (NLCD) Weighted average impervious cover was calculated for SPAs using ArcGrid Update will be based on NHDPlus summaries

Relating SPAs to Vulnerabilities and Other Factors Presence of karst geology Population counts based on 2000 census data Disadvantaged communities based on median household income

Looking Below the Surface Well Visualization Tool generates a custom UIC well profile by clicking on a well Shows geology in area and all nearby wells Based on scalable vector graphics (SVG) WVT Tool Drinking Water Wells UIC

Looking Below the Surface Generalized geology UIC wells Drinking water wells in area of investigation Hyperlinked to scanned formation images

Drinking Water Mapping Application (DWMA) For more information contact: Roger Anzzolin, US EPA Anzzolin.Roger@epa.gov Bill Cooter, RTI International sid@rti.org James Rineer, RTI International jrin@rti.org