Loading water data...
Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Compare water quality across 12 counties in Maryland
12 counties ranked by average water quality score
| Rank | County | Avg Score | Grade | Cities | Population | Score Range |
|---|---|---|---|---|---|---|
| 1 | Washington County | 100 | A | 1 | 92,200 | 100 - 100 |
| 2 | Allegany County | 100 | A | 1 | 27,039 | 100 - 100 |
| 3 | Talbot County | 100 | A | 1 | 17,357 | 100 - 100 |
| 4 | Frederick County | 98 | A | 1 | 54,000 | 98 - 98 |
| 5 | Howard County | 96 | A | 1 | 286,158 | 96 - 96 |
| 6 | Anne Arundel County | 93 | A | 3 | 388,592 | 85 - 98 |
| 7 | Prince George's County | 93 | A | 2 | 1,925,000 | 89 - 96 |
| 8 | Montgomery County | 84 | B | 1 | 52,000 | 84 - 84 |
| 9 | Carroll County | 74 | C | 1 | 35,256 | 74 - 74 |
| 10 | Wicomico County | 74 | C | 1 | 30,343 | 74 - 74 |
| 11 | Baltimore County | 72 | C | 1 | 1,600,000 | 72 - 72 |
| 12 | Harford County | 64 | D | 1 | 13,200 | 64 - 64 |
Our county-level water quality analysis aggregates data from municipal water systems across Maryland. Each county's score represents the average water quality across all analyzed cities within that county, weighted by population served.
With 12 counties and 15 cities analyzed, this data helps residents understand regional water quality patterns in Maryland. County scores range from 64/100 to 100/100, reflecting the diversity of water sources and treatment infrastructure across the state.
Currently, 1 counties in Maryland have average scores below 70, indicating potential water quality concerns. Residents in these areas should review their city's specific report and consider water filtration options.