Potomac Drinking Water Source Protection
MULTI-STATE CASE STUDY: POTOMAC RIVER BASIN: Potomac Drinking Water Source Protection Partnership
Location: The Potomac River basin is a 14,670 square mile drainage area which includes the District of Columbia and portions of the states of Virginia, Maryland, West Virginia, and Pennsylvania.
Water Supply: The Potomac River is the primary water supply source for the city of Washington, DC, and surrounding communities, providing water to over 4 million people in the DC metropolitan area. The river and its tributaries also supply water to cities and towns throughout the basin.
Source Water Assessments: EPA Region 3 has compiled and summarized source water assessments (SWAs) for 68 communities that rely on water from the Potomac River and/or its tributaries. The Interstate Commission on the Potomac River Basin (ICPRB) completed the SWA for the District of Columbia, which relies solely for its water supply on intakes in the Potomac River which are operated by the Washington Aqueduct. This SWA identified potential contaminants and their sources throughout the over 11,000 square mile Potomac River drainage area upstream of Washington, DC. Assessments for smaller communities in the basin have identified local threats to drinking water supplies. After the SWAs were completed, the three major water utilities of the DC metropolitan area, along with a number of other water providers in the basin, expressed interest pursuing a coordinated approach to source water protection through a partnership with state and federal agencies.
Priority Contamination Threats
Major threats to Potomac basin water supplies include fecal coliform and other microbial pathogens from municipal waste water treatment plants, combined sewer overflows, storm sewers, and agricultural sources. Additionally, there is potential for an accidental spill of petroleum products or other chemical contaminants because of the many transportation corridors that cross waterways in the source water areas.
Local Team and Developing the Protection Plan
The Potomac Drinking Water Source Protection Partnership (DWSPP) was formed to develop a coordinated approach to source water protection in the Potomac River basin. The Partnership was officially launched at a signing ceremony on September 24, 2004, and the Partnership’s Strategic Plan for source water protection was adopted August 9, 2005. The Potomac Partnership is currently comprised of nearly 20 drinking water utilities and government agencies from 4 states providing a unique opportunity for collaboration in support of Goal 2 of EPA’s Strategic Plan: Clean and Safe Water. Members include:
- Washington Aqueduct
- Washington Suburban Sanitary Commission
- Fairfax Water, Loudoun Water
- City of Frederick and Frederick County, MD
- City of Hagerstown, MD
- City of Rockville, MD
- Washington County, MD
- Town of Leesburg, VA
- District of Columbia Department of Environment
- Virginia Department of Environmental Quality
- Virginia Department of Health
- Maryland Department of Environment
- West Virginia Department of Health and Human Resources
- West Virginia Department of Environmental Protection
- Pennsylvania Department of Environmental Protection
- US Environmental Protection Agency
- U.S. Geological Survey
- Interstate Commission on the Potomac River Basin
The Partnership has identified issues of importance and has formed workgroups focused on pathogens, emerging contaminants, disinfection byproduct precursors, urban issues, agricultural issues, and early warning/emergency response. In order to keep members up-to-date, workshops have been conducted periodically on topics of interest, including Cryptosporidium and other pathogens, emerging contaminants, agricultural practices related to livestock, urban storm water, and the role of land conservation in source water protection. The Partnership has identified several research needs and pursues funding opportunities as they arise. It recently completed a joint project with the Center for Disease Control on Cryptosporidium source tracking in the Potomac basin, with funding from an EPA Regional Applied Research Efforts (RARE) grant. The Partnership also conducts periodic exercises of emergency response procedures. Future anticipated activities include implementation of specific measures, regulatory and nonregulatory efforts, and inter-agency coordination to focus environmental programs on drinking water protection. Partnership members are also involved in a water quality early warning monitoring network and an emergency response notification system for water suppliers.
The Partnership’s workgroup on early warning and emergency response helps water utilities prepare for spills or other events that may affect their source water, and helps them keep abreast of regional efforts to safeguard against accidental or intentional releases of contaminants. It conducts periodic exercises of emergency response procedures that would be used in the event of an accidental spill or intentional release of a contaminant into the Potomac River. If a spill occurs, ICPRB uses the RiverSpill computer simulation model to provide water utilities with quick information on when the contamination is likely to arrive at their intakes. Partnership members also participate in an early warning monitoring network and in the Regional Incident Communication and Coordination System (RICCS), coordinated by the Metropolitan Washington Council of Governments. In 2008, at a two-day pipeline spill exercise sponsored by DWSPP and EPA, contingency plans for potential disruptions in DC metropolitan area water supply were reviewed and evaluated.
Measuring Program Results
Partnership objectives are given in the Strategic Plan, along with a list of anticipated workgroup activities and measures of workgroup success. At annual Partnership meetings, goals for the coming year are adopted and the past year’s progress is evaluated. Partnership activities and successes are summarized yearly in an Annual Report. Information on Partnership activities and achievements are available at the organization website, www.potomacdwspp.org.
Contacts for Further Information
Interstate Commission on the Potomac River Basin (ICPRB)
Phone: (301) 984-1908 ext. 120