Frederick Water Hardness & Quality Report (2026)

The Frederick County Division of Water and Sewer Utilities serves the City of Frederick, Maryland, operating multiple treatment plants including the New Design Road Water Treatment Plant, which draws primarily from the Potomac River and supplies 93% of the county's 2.47 billion gallons produced annually in 2022. The utility also draws from three additional surface sources: the Monocacy River, Linganore Creek, and Fishing Creek Reservoir, with water distributed through the City of Frederick's distribution system to serve the local community.

The Monocacy River watershed encompasses approximately 974 square miles across Frederick County, Carroll County, Maryland, and Adams County, Pennsylvania, making it the largest Maryland tributary to the Potomac River. The region's geology is characterized by carbonate and silicate rock formations typical of the Piedmont and Valley & Ridge physiographic provinces, which naturally dissolve calcium and magnesium carbonates into groundwater and surface water. This results in a moderately hard water supply of approximately 101 mg/L as CaCO₃, with watershed contamination sources including agricultural runoff, on-site septic systems, and stormwater.

Frederick's moderately hard water causes noticeable scale buildup in kettles, coffee makers, and dishwashers over time, and may reduce soap and detergent efficiency in laundry and bathing. Water heaters and boilers are particularly susceptible to mineral accumulation, increasing energy costs. Most residents do not require a water softener at this hardness level, though those with older plumbing or high water usage may benefit from point-of-use softening. Regular descaling and use of chelating agents in cleaning products help manage mineral deposits. The city's water met all EPA standards; detected contaminants include bromodichloromethane, a disinfection byproduct, with corrosion control in place to manage lead and copper from aging plumbing infrastructure.