Maryland Tap Water Quality
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Overview
Baltimore's reservoir system and the Washington suburbs' Potomac/Patuxent supply (WSSC Water) serve most Marylanders, and both large systems meet all federal standards. WSSC has never recorded a health-based violation in over a century of operation, a record it advertises.
Baltimore's aging distribution has produced high-profile incidents: the 2022 E. coli detection in West Baltimore triggered a boil-water advisory, and main breaks are chronic. On the Eastern Shore, poultry-belt groundwater carries nitrate, and scattered PFAS detections track bases and industry.
Common Contaminants in Maryland
Baltimore's older rowhouse stock contributes lead from private-side plumbing; the city offers testing and filter programs
Eastern Shore shallow groundwater near intensive poultry operations shows elevated levels, mainly affecting private wells
Managed within limits in the big surface-water systems; occasional small-system exceedances
Violations & Compliance
The two dominant utilities are strongly compliant; Baltimore's issues are distribution-side (breaks, pressure, aging valves) rather than treatment failures. Small Eastern Shore and western Maryland systems account for most formal violations.
City Water Reports in Maryland
Frequently Asked Questions
Sources & References
The safety rating and guidance on this page draw on the following sources. See our full methodology.
- •US EPA Safe Drinking Water Act regulations
- •EWG Tap Water Database
- •The utility's most recent Consumer Confidence Report (CCR)
- •WHO Guidelines for Drinking-water Quality