Authors: James Rineer, RTI International (presenter) William Cooter, RTI International Brandon Bergenroth, RTI International Roger Anzzolin, US EPA, Office of Ground Water and Drinking Water ESRI International User Conference Session: Regional Water Information Systems Thursday, July 16, 2009 San Diego, CA Drinking Water Mapping Application: Core Features and Cross-program Approaches

The work described in this presentation was funded by the U.S. Environmental Protection Agency under Contract EP-C with Research Triangle Institute (RTI). RTI gratefully acknowledges this support. Disclaimer: Although the research described has been funded wholly or in part by the U.S. Environmental Protection Agency Contract EP- C to Research Triangle Institute, it has not been subject to the Agency's review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. Disclaimer: In the interest of protecting certain types of information, and in accordance with EPA protocol, the GIS data displayed in the following images were rendered for display purposes only and do not accurately represent actual data from EPA’s spatial databases. Acknowledgements

DWMA Overview Data Sources Web Interface Query Functionality Version 3 Enhancements Cross-program Approaches Presentation Outline

A secure Web-based geospatial application for US EPA Office of Ground Water and Drinking Water Enables queries of the Safe Drinking Water Information System (SDWIS/FED) with other federal and state data Identifies potential risks to surface water and groundwater used for public drinking water Generates query driven maps and reports at a variety of spatial scales DWMA Overview

 Provides query and mapping for both surface water and ground water for issues related to source water protection  Uses ArcIMS for visualization and Oracle for query What is the DWMA?

 Uses information (e.g., intakes) georeferenced to the National Hydrography Dataset Plus (NHDPlus)  Performs NHDPlus-based upstream/downstream and proximity analyses What is the DWMA? continued

Drinking water sources (intakes and wells) from SDWIS/FED Analytical Source Protection Areas (SPAs) for intakes and wells Point sources of contamination including dischargers, hazardous waste sites, Superfund sites, and others Non-point sources of contamination including USGS nitrogen fertilizer use, herbicide use, and USDA animal waste Surface waters represented by the NHDPlus in the RAD A variety of other layers from EPA IGD and RAD and USGS Data Sources

Web Interface Side-by-side queries and maps via frames

Driving the DWMA

Drill-Down Tool Drill-down Functionality Show states matching query definition at national scale Click on state, show matching counties served at state scale Click on county, show matching water sources at local scale National Scale State Scale Local Scale

SDWIS/FED Query Functionality Locate public water sources by location, type, size, and violations Identify potential upstream point sources of contamination Identify potential nearby point sources of contamination Identify sources drawing from areas with elevated non-point source impacts Find interactions between any of the above

SPA Query Functionality All of the SDWIS/FED query options SPA % impervious (NLCD 2001) Area intersections with: Karst Sole Source Aquifers DOD lands (military bases)

Query, Reports, and Maps Looking for potential contaminant risks within protection areas Example: Locate States with at least one system serving less than 1000 people with permitted dischargers within their SPAs, with reported violations for lead, and where the SPA intersects karst topography

Query, Reports, and Maps Drill down to system and link to SDWIS Violation Report

DWMA Source Protection Areas: DWMA Version 2 Approach  Polygon Areas of Investigation (AOIs) constructed around the reaches that fall within 15 miles of a drinking water intake  Convex hulls created in Oracle Spatial  Not a watershed, but a reasonable approximation Surface water analytical Source Protection Areas (SPAs)

NHDPlus: Provides Enhancements to the Standard National Hydrography Dataset  Improves the utility of the NHD in applications  Includes facilities to model water flow and time of travel through the NHD network  Provides a set of catchments polygons for each NHD flowpath  Can tie datasets or GIS layers related to landscape features (e.g., the National Land Cover Dataset) to the NHD stream network

DWMA Source Protection Areas: DWMA Version 3 Approach  Navigate upstream 24 hours time of travel vs. fixed distance  Select corresponding NHDPlus simplified catchments  Dissolve selected catchments

Increasing Stream Gradient

Analytical Groundwater Source Protection Areas  Wells handled differently, since they extend vertically  Source protection Area defined as simply a 1 mile radius buffer around each of approximately 200,000 wellheads

SPAs provide Area of Investigation frameworks for analyzing patterns for vector data (e.g., point risks form dischargers or waste sites) and raster data (e.g., land cover information from the NLCD)  Percent Impervious Cover indicators can be estimated for each SPA  Indicators determined for around 200,000 SPAs related to both surface intakes and wellheads

Cross-program applications of DWMA Much of the content of the DWMA, including drinking water facilities and SPAs fall under EPA’s policy on sensitive drinking water information (U.S. GAO, 2006) There are restrictions that apply to displaying the precise locations of drinking water entities or SPAs to a wide public audience One acceptable approach is to adopt a cross-program perspective where it is possible to display the locations of entities from other programs that are in proximity to drinking water facilities or that are located within SPAs

Cross-program applications of DWMA Examples Source water protection and TMDLs Underground Storage Tanks

Source Water Protection and 303(d)/TMDL Crosswalk

Underground Storage Tanks & Source Water Protection Crosswalk

DWMA/TANKS Application

Drinking Water Mapping Application: Core Features and Cross-program Approaches ESRI International User Conference Session: Regional Water Information Systems Thursday, July 16, 2009 San Diego, CA  Roger Anzzolin US EPA, OGWDW, Washington, DC  James Rineer RTI International, RTP, NC Contact Information