Washington County, Maryland: drinking water report. Washington County sits in western Maryland, stretching from Hagerstown (the county seat and largest
Washington County sits in western Maryland, stretching from Hagerstown (the county seat and largest city) through smaller communities like Boonsboro, Williamsport, and Hancock along the Potomac River. The county's water supply comes primarily from surface sources including the Potomac River and Antietam Creek, with rural areas relying on private wells that draw from the region's limestone and carbonate aquifer system. This geographic position between the Blue Ridge and Appalachian mountains creates a patchwork of municipal systems serving urban centers and thousands of private wells serving farmland and mountain communities.
Maryland's statewide PFAS testing under EPA's UCMR5 program has identified these forever chemicals in multiple public water systems, and Washington County's agricultural and industrial history suggests potential exposure pathways. The county's manufacturing sector, including aerospace and defense contractors around Hagertown Regional Airport, combined with decades of farming operations using biosolids and pesticides, creates multiple potential contamination sources. Municipal systems serving Hagerstown and surrounding areas test for PFAS and regulated contaminants, but the thousands of private wells scattered across rural Washington County receive no mandatory testing or oversight.
The Potomac River watershed faces upstream contamination from agricultural runoff, stormwater discharge, and legacy industrial sites. Washington County's position on this major waterway means treatment plants must address seasonal variations in source water quality, including elevated nitrate levels during spring runoff and potential pesticide residues from farmland. Lead service lines remain present in older neighborhoods of Hagerstown and historic towns, particularly in homes built before 1950. The county's karst geology (limestone bedrock with underground channels) makes groundwater especially vulnerable to surface contamination, as pollutants can move quickly through fractures and sinkholes into the aquifer system that feeds private wells.
Rural well owners face particular challenges in Washington County. The carbonate bedrock that provides abundant groundwater also dissolves easily, creating hard water with elevated calcium and magnesium. More concerning, this geology allows agricultural chemicals, road salt, and septic system discharge to reach groundwater rapidly. Wells near farmland may show elevated nitrate from fertilizer application or manure spreading. The county's position along Interstate 81, a major trucking corridor, adds road salt and petroleum product risks to groundwater. Without regular testing, private well users remain unaware of contamination until health problems emerge or water becomes visibly or taste-problematically affected.
Municipal water customers should request recent test results from their utility and ask specifically about PFAS, lead service line inventory, and disinfection byproducts. Private well owners must take responsibility for annual testing covering bacteria, nitrate, and baseline metals at minimum. Check your water to see what contaminants have been detected in your area, review our water filter guide to find treatment options appropriate for your specific concerns, and access your detailed report for comprehensive data on Washington County's water quality. For additional context on Maryland's water challenges and regulatory environment, visit our state page.