All water systems in Maryland
3,216 systems
| System | Serves | Status | Rules violated, 3 yr | Unresolved |
|---|---|---|---|---|
|
Washington Suburban Sanitary Commission Montgomery County |
1,900,000 | 0 | 0 | |
|
City of Baltimore Baltimore city County |
1,600,000 | 3 | 0 | |
|
Glen Burnie-Broadneck Anne Arundel County |
290,606 | 0 | 0 | |
|
Howard County D.p.w. Distribution Howard County |
286,158 | 0 | 0 | |
|
Harford County D.p.w. Harford County |
104,567 | 1 | 0 | |
|
City of Hagerstown Washington County |
92,200 | 0 | 0 | |
|
Waldorf Charles County Dpw Charles County |
84,296 | 2 | 0 | |
|
New Design Frederick County Frederick County |
74,911 | 1 | 0 | |
|
Crofton-Odenton Anne Arundel County |
62,986 | 1 | 0 | |
|
Fort George G. Meade Anne Arundel County |
62,234 | 0 | 0 | |
|
City of Frederick Frederick County |
54,000 | 0 | 0 | |
|
City of Rockville Montgomery County |
52,000 | 2 | 0 | |
|
Lexington Park St. Mary's County |
43,030 | 3 | 0 | |
|
City of Westminster Carroll County |
35,256 | 1 | 0 | |
|
City of Annapolis Anne Arundel County |
35,000 | 1 | 0 | |
|
City of Salisbury Wicomico County |
30,343 | 0 | 0 | |
|
Town of Ocean City Worcester County |
30,000 | 2 | 0 | |
|
City of Cumberland Allegany County |
27,039 | 0 | 0 | |
|
Broad Creek Anne Arundel County |
26,033 | 1 | 0 | |
|
City of Bowie Prince George's County |
25,000 | 1 | 0 | |
|
Freedom District Carroll County |
24,867 | 2 | 0 | |
|
Mgm National Harbor Prince George's County |
24,000 | 1 | 0 | |
|
Patuxent Naval Air Station (navfac-Wash) St. Mary's County |
22,000 | 1 | 0 | |
|
City of Aberdeen Harford County |
18,006 | 0 | 0 | |
|
Easton Utilities Talbot County |
17,357 | 0 | 0 | |
|
Town of Elkton Cecil County |
15,625 | 2 | 0 | |
|
Chapel Hill Aberdeen Proving Grounds Harford County |
15,000 | 0 | 0 | |
|
City of Cambridge Water Dorchester County |
15,000 | 0 | 0 | |
|
City of Havre de Grace Harford County |
14,000 | 3 | 0 | |
|
Maryland American Water Company Harford County |
13,200 | 0 | 0 | |
|
Ocean Pines Worcester County |
11,890 | 1 | 0 | |
|
Town of la Plata Charles County |
11,535 | 0 | 0 | |
|
City of Frostburg Allegany County |
11,000 | 0 | 0 | |
|
Assateague National Park North Beach Worcester County |
10,020 | 0 | 0 | |
|
Town of Mount Airy Carroll County |
9,890 | 2 | 0 | |
|
Chesapeake Ranch Estates Calvert County |
9,500 | 0 | 0 | |
|
Stevensville Queen Anne's County |
9,155 | 0 | 0 | |
|
U.s. Naval Academy Anne Arundel County |
8,700 | 0 | 0 | |
|
Town of North East Cecil County |
8,600 | 3 | 0 | |
|
Town of Walkersville Frederick County |
8,440 | 1 | 0 | |
|
Fort Detrick Frederick County |
7,900 | 1 | 0 | |
|
City of Brunswick Frederick County |
7,312 | 0 | 0 | |
|
City of Taneytown Carroll County |
6,750 | 0 | 0 | |
|
Town of Hampstead Carroll County |
6,600 | 0 | 0 | |
|
Bryans Road Charles County |
6,260 | 1 | 0 | |
|
Town of Thurmont Frederick County |
6,200 | 0 | 0 | |
|
Town of Poolesville Montgomery County |
6,005 | 1 | 0 | |
|
Mystic Harbour Worcester County |
5,945 | 0 | 0 | |
|
City of Fruitland Wicomico County |
5,907 | 1 | 0 | |
|
Eastern Region Allegany Distrib. System Allegany County |
5,703 | 0 | 0 |
About this data
Rules violated counts the rules a system was in violation of in the past three years, including monitoring and reporting lapses; one rule can carry several violations. Unresolved is the number of those rules still in violation at EPA's latest data refresh.
Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Maryland records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.