83 public water systems in Maryland were sampled in EPA's UCMR 5 programme (2023–2025); we show six PFAS and lithium. Read 2026-10-31.
16 of 83 systems had at least one sample above a 2024 federal limit; 40 had at least one PFAS found above the reporting level; 43 had none found above the reporting level.
A single sample above a 2024 limit is a measurement, not a violation. Compliance is judged on running yearly averages, and water systems have until 2029 to meet the limits. On 20 May 2026 EPA proposed giving qualifying systems until 2031 for PFOA and PFOS and removing the limits for PFHxS, PFNA and HFPO-DA; those proposals were not final when we last checked (5 Nov 2026). Counts are per system, not per person; population figures are available only for systems serving more than 25,000 people (about 4,890,659 people across those systems here). UCMR 5 was a one-time national monitoring programme (2023–2025). The results are a snapshot at the system's entry points or taps on the sample dates, not a continuous measurement and not a compliance record.
| System | People served | UCMR 5 result |
|---|---|---|
| Washington Suburban Sanitary Commission Washington Suburban Sanitary Commission | 1,900,000 | None detected (below the reporting level) |
| Baltimore City of Baltimore | 1,600,000 | None detected (below the reporting level) |
Pages for these are being added in stages. The data for all 83 systems is in the public dataset.
| System | People served | UCMR 5 result |
|---|---|---|
| Glen Burnie-Broadneck Glen Burnie-Broadneck | 290,606 | None detected (below the reporting level) |
| Howard County D.P.W. Distribution Howard County D.P.W. Distribution | 286,158 | None detected (below the reporting level) |
| Harford County D.P.W. Harford County D.P.W. | 104,567 | None detected (below the reporting level) |
| City of Hagerstown City of Hagerstown | 92,200 | None detected (below the reporting level) |
| Waldorf - Charles County Dpw Waldorf - Charles County Dpw | 84,296 | Detected, below the 2024 limit |
| New Design - Frederick County New Design - Frederick County | 74,911 | None detected (below the reporting level) |
| Crofton-Odenton Crofton-Odenton | 62,986 | None detected (below the reporting level) |
| Fort George G. Meade Fort George G. Meade | 62,234 | None detected (below the reporting level) |
| City of Frederick City of Frederick | 54,000 | None detected (below the reporting level) |
| City of Rockville City of Rockville | 52,000 | Detected, below the 2024 limit |
| Lexington Park Lexington Park | 43,030 | None detected (below the reporting level) |
| City of Westminster, Md City of Westminster, Md | 35,256 | Above the 2024 limit in at least one sample |
| City of Annapolis City of Annapolis | 35,000 | None detected (below the reporting level) |
| City of Salisbury City of Salisbury | 30,343 | Above the 2024 limit in at least one sample |
| Town of Ocean City Town of Ocean City | 30,000 | None detected (below the reporting level) |
| City of Cumberland City of Cumberland | 27,039 | None detected (below the reporting level) |
| Broad Creek Broad Creek | 26,033 | None detected (below the reporting level) |
| Eastern Region Allegany Distrib. System Eastern Region Allegany Distrib. System | — | None detected (below the reporting level) |
| Western Region Allegany Distrib. System Western Region Allegany Distrib. System | — | None detected (below the reporting level) |
| City of Frostburg City of Frostburg | — | None detected (below the reporting level) |
| Lavale Sanitary Commission Lavale Sanitary Commission | — | None detected (below the reporting level) |
| Midland-Lonaconing Midland-Lonaconing | — | None detected (below the reporting level) |
| Severn Water Company Severn Water Company | — | None detected (below the reporting level) |
| The Provinces The Provinces | — | None detected (below the reporting level) |
| U.S. Naval Academy U.S. Naval Academy | — | None detected (below the reporting level) |