State Hub
Maryland Water Quality
184
Utilities in database
5.5M
Residents served
25%
On private wells
2
Key contaminants tracked
Drinking Water in Maryland
Maryland has 184 community water systems serving approximately 5.5 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, lead. 25% of Maryland residents rely on private wells. MDE holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in Maryland
1–25 of 184Washington Suburban Sanitary Commission
MD0150005 · 1,900,000 served
City of Baltimore
MD0300002 · 1,600,000 served
Glen Burnie-broadneck
MD0020017 · 290,606 served
Howard County D.p.w. Distribution
MD0130002 · 286,158 served
Harford County D.p.w.
MD0120016 · 104,567 served
City of Hagerstown
MD0210010 · 92,200 served
Waldorf - Charles County Dpw
MD0080049 · 84,296 served
New Design - Frederick County
MD0100030 · 74,911 served
Crofton-odenton
MD0020008 · 62,986 served
Fort George G. Meade
MD0020012 · 62,234 served
City of Frederick
MD0100015 · 54,000 served
City of Rockville
MD0150003 · 52,000 served
Lexington Park
MD0180007 · 43,030 served
City of Westminster
MD0060015 · 35,256 served
City of Annapolis
MD0020001 · 35,000 served
City of Salisbury
MD0220004 · 30,343 served
Town of Ocean City
MD0230003 · 30,000 served
City of Cumberland
MD0010008 · 27,039 served
Broad Creek
MD0020004 · 26,033 served
City of Bowie
MD0160002 · 25,000 served
Freedom District
MD0060002 · 24,867 served
Patuxent Naval Air Station (navfac-wash)
MD0180022 · 22,000 served
City of Aberdeen
MD0120001 · 18,006 served
Easton Utilities
MD0200003 · 17,357 served
Town of Elkton
MD0070011 · 15,625 served
Key Contaminant Concerns in Maryland
Lead
Lead is a naturally occurring heavy metal that was widely used in plumbing infrastructure until it was banned for new installations in 1986. An estimated 9.2 million lead service lines still connect homes to public water mains across the United States, along with millions of homes with lead solder in their internal plumbing.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
Maryland Water FAQs
Quick Links
Data source: Utility data from EPA SDWIS. 184 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-19