Severn Water Hardness & Quality Report (2026)

Severn Water Company, managed in association with the Maryland Environmental Service, provides drinking water to residents of Severn, Maryland, within Anne Arundel County. The utility operates two drilled wells drawing exclusively from the Patapsco aquifer. Water is pumped from these wells, undergoes pH adjustment, and receives a purifier to control microbial contaminants. No surface water treatment plants are involved, distinguishing it from broader Anne Arundel County facilities that treat water from Patapsco, Patuxent, and Aquia aquifers across 12 plants producing 12.6 billion gallons annually.

The supply originates in the Patapsco aquifer, part of the Potomac Group within the Atlantic Coastal Plain, encompassing the Severn River basin watershed. This geology features sandy-clayey Cretaceous marine sediments enriched with shell fragments and minor limestone lenses, which naturally leach alkaline earth metals into groundwater. The semi-confined nature of the aquifer limits rapid recharge, stabilizing water chemistry while exposing it to localized mineral dissolution — resulting in harder water compared to upland fractured rock aquifers.

As moderately hard water, Severn's supply promotes moderate scale buildup in pipes, water heaters, dishwashers, and boilers, reducing efficiency and lifespan. Soap scum and dry skin are common effects. Regular vinegar descaling, low-flow aerators, and magnetic anti-scale devices help; a water softener is recommended for households noticing spotting on fixtures. 2024 testing showed copper at 160 ppb (90th percentile), lead below 2.0–3 ppb, nitrate at 2.3–2.7 ppm, and barium at 24 ppb — all within EPA limits. PFAS concerns are noted with 7 contaminants over EPA thresholds in 2026 data. Treatment includes pH adjustment and disinfection.