Results from entry points (water leaving treatment, not household taps) of public water systems sampled under EPA's Fifth Unregulated Contaminant Monitoring Rule. Click a county to see every water system serving it, or turn on service areas and click a location to see the systems that serve that spot.
83 of the 1,014 public water systems listed for Maryland were sampled. Sorted by the highest single result relative to EPA's 2024 limits. Each name links to a page with all of that system's results. All 1,014 Maryland systems, including those not tested · Download all Maryland results (CSV, gzip)
| System | PWSID | City | Population | PFOA (ppt) | PFOS (ppt) | HI | Highest single result |
|---|---|---|---|---|---|---|---|
| Town Of Thurmont | MD0100023 | Thurmont | 6,200 | 15 | 48 | 0.532 | PFOS ≥ 3 × its limit |
| Town Of Elkton | MD0070011 | Elkton | 15,625 | 23.3 | 7.1 | 0.443 | PFOA ≥ 3 × its limit |
| City Of Salisbury | MD0220004 | Salisbury | 30,343 | 5.9 | 20 | 0.622 | PFOS ≥ 3 × its limit |
| New Life Christian School | MD1100052 | Frederick | 200 | 10.1 | 15.3 | 0.007 | PFOS ≥ 3 × its limit |
| Town Of Mount Airy | MD0060007 | Mount Airy | 9,890 | 12.7 | 6 | 0.003 | PFOA ≥ 3 × its limit |
| City Of Westminster | MD0060015 | Westminster | 35,256 | 12.4 | 6.9 | 0.422 | PFOA ≥ 3 × its limit |
| City Of Taneytown | MD0060012 | Taneytown | 6,750 | 4.6 | 10.7 | 0.433 | PFOS 1–3 × its limit |
| Glenelg Country School | MD1130003 | Ellicott City | 950 | 10 | <MRL | 0.653 | PFOA 1–3 × its limit |
| Maryland American Water Company | MD0120003 | Bel Air | 13,200 | 9.3 | 9.1 | 0.342 | PFOA 1–3 × its limit |
| Town Of Hampstead | MD0060003 | Hampstead | 6,600 | 9.1 | 5.7 | 0.343 | PFOA 1–3 × its limit |
| City Of Aberdeen | MD0120001 | Aberdeen | 18,006 | 7.6 | 8.6 | 0.582 | PFOS 1–3 × its limit |
| Boonsboro - Keedysville | MD0210002 | Boonsboro | 4,250 | 6.7 | <MRL | 0.314 | PFOA 1–3 × its limit |
| Town Of Middletown | MD0100018 | Middletown | 5,132 | 4.9 | 6.7 | 0.353 | PFOS 1–3 × its limit |
| Town Of Poolesville | MD0150002 | Poolesville | 6,005 | 5.4 | 6.5 | 0.69 | PFOS 1–3 × its limit |
| Town Of Manchester | MD0060006 | Manchester | 4,954 | 4.7 | <MRL | 0.315 | PFOA 1–3 × its limit |
| City Of Fruitland | MD0220008 | Fruitland | 5,907 | <MRL | 4.1 | 0.4 | PFOS 1–3 × its limit |
| Town Of Berlin | MD0230001 | Berlin | 4,500 | <MRL | <MRL | 0.49 | Hazard Index below its limit |
| City Of Rockville | MD0150003 | 52,000 | <MRL | <MRL | 0.002 | Hazard Index below its limit | |
| Ocean Pines | MD0230005 | Berlin | 11,890 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| Waldorf - Charles County Dpw | MD0080049 | La Plata | 84,296 | <MRL | <MRL | 0.002 | Hazard Index below its limit |
| City Of Baltimore | MD0300002 | Baltimore | 1,600,000 | <MRL | <MRL | 0 | Other PFAS detected |
| City Of Frederick | MD0100015 | Frederick | 54,000 | <MRL | <MRL | 0 | Other PFAS detected |
| Fort Detrick | MD0100011 | Frederick | 7,900 | <MRL | <MRL | 0 | Other PFAS detected |
| Freedom District | MD0060002 | Westminster | 24,867 | <MRL | <MRL | 0 | Other PFAS detected |
| Howard County D.P.W. Distribution | MD0130002 | Columbia | 286,158 | <MRL | <MRL | 0 | Other PFAS detected |
| Manor Shopping Center | MD1030054 | Phoenix | 2,921 | <MRL | <MRL | 0 | Other PFAS detected |
| Mgm National Harbor | MD1160049 | 24,000 | <MRL | <MRL | 0 | Other PFAS detected | |
| New Design - Frederick County | MD0100030 | Frederick | 74,911 | <MRL | <MRL | 0 | Other PFAS detected |
| Town Of North East | MD0070016 | North East | 8,600 | <MRL | <MRL | 0 | Other PFAS detected |
| Washington Suburban Sanitary Commission | MD0150005 | Laurel | 1,900,000 | <MRL | <MRL | 0 | Other PFAS detected |
| Broad Creek | MD0020004 | Millersville | 26,033 | <MRL | <MRL | 0 | No PFAS detected |
| Bryans Road | MD0080033 | La Plata | 6,260 | <MRL | <MRL | 0 | No PFAS detected |
| Chapel Hill - Aberdeen Proving Grounds | MD0120002 | Aberdeen | 15,000 | <MRL | <MRL | 0 | No PFAS detected |
| Charlotte Hall Va Home | MD0180217 | Millersville | 270 | <MRL | <MRL | 0 | No PFAS detected |
| Chesapeake Complex | MD1020003 | Pasadena | 4,785 | <MRL | <MRL | 0 | No PFAS detected |
| Chesapeake Ranch Estates | MD0040004 | Lusby | 9,500 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Annapolis | MD0020001 | Annapolis | 35,000 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Bowie | MD0160002 | Bowie | 25,000 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Brunswick | MD0100005 | Brunswick | 7,312 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Cambridge Water | MD0090002 | Cambridge | 15,000 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Cumberland | MD0010008 | Cumberland | 27,039 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Frostburg | MD0010011 | Frostburg | 11,000 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Hagerstown | MD0210010 | Hagerstown | 92,200 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Havre De Grace | MD0120012 | Havre De Grace | 14,000 | <MRL | <MRL | 0 | No PFAS detected |
| City Of Pocomoke City | MD0230006 | 4,100 | <MRL | <MRL | 0 | No PFAS detected | |
| Crofton-Odenton | MD0020008 | Millersville | 62,986 | <MRL | <MRL | 0 | No PFAS detected |
| Eastern Correctional Institute | MD0190013 | Millersville | 3,500 | <MRL | <MRL | 0 | No PFAS detected |
| Eastern Region Allegany Distrib. System | MD0010005 | Cumberland | 5,703 | <MRL | <MRL | 0 | No PFAS detected |
| Easton Utilities | MD0200003 | Easton | 17,357 | <MRL | <MRL | 0 | No PFAS detected |
| Elkton West | MD0070015 | Newark | 3,500 | <MRL | <MRL | 0 | No PFAS detected |
| Fort George G. Meade | MD0020012 | Fort Meade | 62,234 | <MRL | <MRL | 0 | No PFAS detected |
| Glen Burnie-Broadneck | MD0020017 | Millersville | 290,606 | <MRL | <MRL | 0 | No PFAS detected |
| Harford County D.P.W. | MD0120016 | Abingdon | 104,567 | <MRL | <MRL | 0 | No PFAS detected |
| Lavale Sanitary Commission | MD0010016 | Lavale | 5,500 | <MRL | <MRL | 0 | No PFAS detected |
| Lexington Park | MD0180007 | California | 43,030 | <MRL | <MRL | 0 | No PFAS detected |
| Maryland American Water--Severn System | MD0020027 | Bel Air | 5,447 | <MRL | <MRL | 0 | No PFAS detected |
| Md American Water Provinces | MD0020029 | Belair | 3,886 | <MRL | <MRL | 0 | No PFAS detected |
| Midland-Lonaconing | MD0010018 | Lonaconing | 5,000 | <MRL | <MRL | 0 | No PFAS detected |
| Mystic Harbour | MD0230011 | Berlin | 5,945 | <MRL | <MRL | 0 | No PFAS detected |
| Naval Support Facility, Indian Head | MD0080058 | Indian Head | 3,321 | <MRL | <MRL | 0 | No PFAS detected |
| Oakville Elementary School | MD1180037 | Loveville | 475 | <MRL | <MRL | 0 | No PFAS detected |
| Patuxent Naval Air Station (Navfac-Wash) | MD0180022 | Patuxent River | 22,000 | <MRL | <MRL | 0 | No PFAS detected |
| Penn-Mar Organization, Inc. | MD1030058 | Freeland | 122 | <MRL | <MRL | 0 | No PFAS detected |
| Piney Point | MD0180034 | California | 672 | <MRL | <MRL | 0 | No PFAS detected |
| Prince Frederick | MD0040011 | Prince Frederick | 4,371 | <MRL | <MRL | 0 | No PFAS detected |
| Solomons | MD0040027 | Prince Frederick | 3,811 | <MRL | <MRL | 0 | No PFAS detected |
| Stevensville | MD0170019 | Stevensville | 9,155 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Centreville | MD0170001 | Centreville | 3,322 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Chesapeake Beach | MD0040003 | Chesapeake Beach | 5,000 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Chestertown | MD0140002 | Chestertown | 5,400 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Delmar | MD0220001 | Delmar | 4,500 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Denton | MD0050001 | Denton | 4,848 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Hancock | MD0210012 | Hancock | 1,921 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Indian Head | MD0080020 | Indian Head | 4,100 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of La Plata | MD0080025 | La Plata | 11,535 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Millington | MD0140010 | Millington | 630 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Ocean City | MD0230003 | Ocean City | 30,000 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Perryville | MD0070018 | Perryville | 4,413 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Princess Anne | MD0190002 | Princess Anne | 3,300 | <MRL | <MRL | 0 | No PFAS detected |
| Town Of Walkersville | MD0100025 | Walkersville | 8,440 | <MRL | <MRL | 0 | No PFAS detected |
| U.S. Naval Academy | MD0020042 | Annapolis | 8,700 | <MRL | <MRL | 0 | No PFAS detected |
| Western Region Allegany Distrib. System | MD0010009 | Cumberland | 4,955 | <MRL | <MRL | 0 | No PFAS detected |
| White Plains 2 Mhp/Jack Blair | MD0080208 | Jessup | 70 | <MRL | <MRL | 0 | No PFAS detected |
Highest single result for each system; PFOA and PFOS in ppt (ng/L). Entry-point samples, not tap water; screening comparisons, not compliance determinations.