Silver Spring Water Hardness & Quality Report (2026)

Silver Spring, Maryland receives its public water from the Washington Suburban Sanitary Commission (WSSC Water), serving Montgomery County and surrounding areas across a 1,300-square-mile service area. The primary source is surface water from the Potomac River, treated at the Potomac Water Filtration Plant in Potomac, Maryland, with supplemental supply from the Patuxent Water Filtration Plant in Laurel, Maryland, drawing from the Patuxent River. These facilities serve over 1.8 million customers; most Silver Spring residents rely on WSSC's river-based supply. Treatment involves coagulation, sedimentation, filtration, and disinfection using chloramine, with pH adjustment to 7.5–8.5 for stability.

The Potomac River watershed spans 11,600 square miles across four states and the District of Columbia. The Maryland portion is influenced by the Coastal Plain's unconsolidated sediments and the underlying crystalline bedrock of the Piedmont, which limit mineral dissolution and yield a naturally soft supply with low dissolved solids. Cretaceous and Tertiary unconsolidated gravels, sands, and clays predominate over limestone bedrock at the primary intake. The Patuxent River similarly traverses sedimentary formations with minimal carbonate exposure, contributing to the consistently soft character of the treated product.

As soft water, Silver Spring's supply produces minimal scale buildup on fixtures, pipes, or appliances, reducing risks to water heaters, dishwashers, and washing machines. Soap lathers easily without excess detergent, though corrosion may be more noticeable on metal pipes due to lower mineral buffering. Routine maintenance involves checking for pinhole leaks in older plumbing rather than descaling; a water softener is not recommended and could introduce unnecessary sodium. WSSC Water maintains EPA compliance via corrosion control and pipe replacement programs; recent CCRs note no PFAS exceedances, with chromium-6 detected but below MCLs, and over 500,000 annual tests confirm high quality.