Water quality for ZIP code 20620
ZIP 20620 covers Callaway in St. Mary's County, Maryland, one of 26 ZIP codes in the county. 202 active public water systems serve the county; 46 had an EPA violation in the past three years.
Most likely your provider
Your location is within the outer bounds of this system's EPA service area.
Other community water systems in St. Mary's County
37 systems, nearest first| System | Serves | Status | Rules violated, 3 yr | Distance |
|---|---|---|---|---|
| Hunting Quarters |
715 | 1 | 0.7 mi | |
| Lord Calvert Trailer Park |
892 | 1 | 2.1 mi | |
| Langley Mobile Home Park |
175 | 2 | 2.2 mi | |
| Leonardtown Farm |
193 | 1 | 3.4 mi | |
| Christmas Tree Farm Trailer Park |
100 | 3 | 4.2 mi | |
| Fox Meadow |
128 | 1 | 4.4 mi | |
| Wilderness Run |
511 | 2 | 4.6 mi | |
| Greenbrier |
1,161 | 1 | 4.7 mi | |
| Cook's Trailer Court (aka Garrett Tp) |
120 | 1 | 4.8 mi | |
| Piney Point Landings |
239 | 1 | 5.3 mi | |
| Southgate |
188 | 1 | 5.8 mi | |
| Forrest Farm Subdivision |
577 | 1 | 6.0 mi | |
| Saint Marys College |
2,200 | 1 | 6.3 mi | |
| Piney Point |
672 | 1 | 6.4 mi | |
| Lexington Estates |
300 | 0 | 6.6 mi | |
| Cedar Cove |
2,728 | 1 | 6.7 mi | |
| Patuxent Naval Air Station (navfac-Wash) |
22,000 | 1 | 6.7 mi | |
| Mulberry South |
65 | 1 | 6.8 mi | |
| Town of Leonardtown |
5,000 | 1 | 7.6 mi | |
| Breton Bay |
1,012 | 2 | 7.8 mi | |
| Holland Forest |
139 | 1 | 8.1 mi | |
| Fenwick Manor |
234 | 1 | 8.6 mi | |
| Villages at Leonardtown |
239 | 1 | 9.7 mi | |
| St. Clements Shores |
620 | 1 | 10.0 mi | |
| Mount Pleasant Water Co., Inc. |
150 | 2 | 12.5 mi |
Non-community systems in St. Mary's County (164: schools, campgrounds, workplaces, restaurants)
These systems serve places you visit rather than homes.
About this data
Water systems are matched to St. Mary's County, the county this ZIP code lies in, nearest to the ZIP code's centre first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system.
ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.
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.