Water Quality in Maryland
461 water systems • 146 cities • EPA SDWIS Data
461
Water Systems
5,321
Total Violations
594
Health-Based Violations
5,523,173
Population Served
Overview
Maryland has 461 active community water systems serving 5,523,173 people. These systems have accumulated 5,321 EPA Safe Drinking Water Act violations on record, of which 594 are health-based violations (meaning a contaminant exceeded safe levels).
Common contaminants found in violations: Gross Alpha, Stage 2 DBP, Nitrate, Total Coliform (TCR), Fecal Coliform, Selenium, Disinfection Byproducts, E. coli, Total Haloacetic Acids (HAA5), Chromium.
Cities with Most Violations in Maryland
| # | City | Violations | Health-Based | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Port Deposit | 230 | 6 | 7 | 1,187 |
| 2 | Princess Anne | 217 | 1 | 2 | 4,050 |
| 3 | Frederick | 200 | 12 | 19 | 147,122 |
| 4 | Tylerton | 188 | 5 | 5 | 409 |
| 5 | La Plata | 179 | 2 | 19 | 106,661 |
| 6 | Waldorf | 160 | 6 | 18 | 3,332 |
| 7 | California | 158 | 0 | 28 | 59,957 |
| 8 | Elkton | 141 | 23 | 5 | 18,405 |
| 9 | Havre De Grace | 109 | 11 | 3 | 14,555 |
| 10 | Millersville | 94 | 7 | 14 | 387,543 |
Largest Cities in Maryland
| # | City | Population | Violations | Water Systems |
|---|---|---|---|---|
| 1 | Laurel | 1,900,000 | 0 | 1 |
| 2 | Baltimore | 1,601,584 | 87 | 7 |
| 3 | Millersville | 387,543 | 94 | 14 |
| 4 | Columbia | 286,458 | 31 | 2 |
| 5 | Frederick | 147,122 | 200 | 19 |
| 6 | La Plata | 106,661 | 179 | 19 |
| 7 | Abingdon | 104,567 | 9 | 1 |
| 8 | Hagerstown | 94,933 | 49 | 6 |
| 9 | Westminster | 62,913 | 64 | 6 |
| 10 | Fort Meade | 62,234 | 1 | 1 |
All Cities in Maryland
| City | Population | Violations | Health Violations | Contaminants |
|---|---|---|---|---|
| Laurel | 1,900,000 | 0 | 0 | |
| Baltimore | 1,601,584 | 87 | 7 | E. coli, Stage 2 DBP, Total Haloacetic Acids (HAA5) |
| Millersville | 387,543 | 94 | 7 | Chromium, Stage 2 DBP |
| Columbia | 286,458 | 31 | 8 | Barium |
| Frederick | 147,122 | 200 | 12 | Bromate, E. coli, Stage 2 DBP +2 more |
| La Plata | 106,661 | 179 | 2 | Disinfection Byproducts |
| Abingdon | 104,567 | 9 | 0 | |
| Hagerstown | 94,933 | 49 | 5 | Bromate, Chlorine Dioxide, Disinfection Byproducts +2 more |
| Westminster | 62,913 | 64 | 20 | Chlorine Dioxide, Disinfection Byproducts, Stage 2 DBP +2 more |
| Fort Meade | 62,234 | 1 | 1 | Disinfection Byproducts |
| California | 59,957 | 158 | 0 | |
| Annapolis | 43,780 | 10 | 2 | Disinfection Byproducts |
| Cumberland | 38,609 | 8 | 0 | |
| Aberdeen | 33,006 | 6 | 0 | |
| Salisbury | 31,338 | 52 | 10 | Disinfection Byproducts, Stage 2 DBP |
| Ocean City | 30,127 | 80 | 3 | Gross Alpha, Stage 2 DBP |
| Bowie | 25,000 | 3 | 1 | Stage 2 DBP |
| Berlin | 24,018 | 53 | 3 | Stage 2 DBP |
| Patuxent River | 22,000 | 40 | 0 | |
| Elkton | 18,405 | 141 | 23 | Disinfection Byproducts, Stage 2 DBP, Total Organic Carbon |
| Easton | 17,392 | 11 | 2 | Disinfection Byproducts |
| Cambridge | 15,690 | 16 | 3 | Disinfection Byproducts, Stage 2 DBP |
| Havre De Grace | 14,555 | 109 | 11 | Contaminant 2920, E. coli, TTHM |
| Prince Frederick | 13,580 | 62 | 0 | |
| Hopewell | 13,200 | 0 | 0 | |
| Stevensville | 13,008 | 42 | 1 | Disinfection Byproducts |
| Mount Airy | 10,294 | 25 | 2 | Disinfection Byproducts, Stage 2 DBP |
| North East | 9,610 | 57 | 26 | Contaminant 2920, Disinfection Byproducts, Stage 2 DBP +2 more |
| Lusby | 9,565 | 16 | 1 | Stage 2 DBP |
| Indian Head | 9,339 | 66 | 1 | Stage 2 DBP |
| Dunkirk | 9,200 | 8 | 0 | |
| Newark | 8,636 | 35 | 3 | Disinfection Byproducts, E. coli, Total Organic Carbon |
| Chestertown | 8,496 | 19 | 2 | Stage 2 DBP |
| Walkersville | 8,440 | 2 | 0 | |
| Brunswick | 7,312 | 6 | 1 | Disinfection Byproducts |
| Taneytown | 6,750 | 0 | 0 | |
| Hampstead | 6,600 | 1 | 0 | |
| Fruitland | 6,572 | 29 | 8 | Disinfection Byproducts, Stage 2 DBP |
| Oakland | 6,474 | 17 | 5 | Disinfection Byproducts, Fecal Coliform |
| Thurmont | 6,200 | 4 | 1 | Disinfection Byproducts |
| Poolesville | 6,005 | 10 | 0 | |
| Mountain Lake Park | 5,935 | 2 | 0 | |
| Lavale | 5,500 | 12 | 3 | Disinfection Byproducts, Fecal Coliform |
| Bel Air | 5,447 | 5 | 0 | |
| Leonardtown | 5,100 | 41 | 7 | E. coli, Stage 2 DBP |
| Lonaconing | 5,045 | 30 | 6 | E. coli, Stage 2 DBP, Total Haloacetic Acids (HAA5) |
| Delmar | 5,038 | 4 | 3 | Disinfection Byproducts |
| Chesapeake Beach | 5,000 | 3 | 0 | |
| Manchester | 4,954 | 3 | 0 | |
| Denton | 4,690 | 30 | 1 | Stage 2 DBP |
| Boonsboro | 4,565 | 24 | 1 | Stage 2 DBP |
| Perryville | 4,472 | 82 | 16 | Bromate, Stage 2 DBP, TTHM +1 more |
| Middletown | 4,363 | 18 | 6 | Disinfection Byproducts, E. coli |
| Emmitsburg | 4,300 | 17 | 2 | Disinfection Byproducts |
| Williamsport | 4,260 | 42 | 4 | Disinfection Byproducts, Fecal Coliform, Stage 2 DBP |
| Pocomoke City | 4,100 | 16 | 9 | Stage 2 DBP, TTHM |
| Princess Anne | 4,050 | 217 | 1 | TTHM |
| Willards | 3,791 | 10 | 1 | Stage 2 DBP |
| Smithsburg | 3,641 | 9 | 0 | |
| Waldorf | 3,332 | 160 | 6 | Chlorine, Chlorine Dioxide, Disinfection Byproducts +1 more |
| Centreville | 3,322 | 23 | 2 | E. coli |
| North Beach | 3,000 | 10 | 1 | Stage 2 DBP |
| Chrisfield | 2,976 | 3 | 0 | |
| Lothian | 2,884 | 39 | 1 | Stage 2 DBP |
| St Michaels | 2,650 | 16 | 8 | Barium |
| Federalsburg | 2,535 | 39 | 8 | Disinfection Byproducts, Selenium, Stage 2 DBP |
| Severn | 2,426 | 13 | 2 | Disinfection Byproducts, Stage 2 DBP |
| Snow Hill | 2,409 | 16 | 8 | TTHM |
| Westernport | 2,200 | 11 | 3 | E. coli |
| Hurlock | 2,150 | 5 | 1 | Stage 2 DBP |
| St. Leonard | 2,000 | 2 | 0 | |
| Perry Point | 2,000 | 16 | 8 | TTHM, Total Haloacetic Acids (HAA5) |
| Sykesville | 1,950 | 33 | 21 | Stage 2 DBP, TTHM, Total Haloacetic Acids (HAA5) |
| Hancock | 1,921 | 5 | 0 | |
| Greensboro | 1,905 | 58 | 1 | Stage 2 DBP |
| Ridgely | 1,900 | 31 | 2 | Disinfection Byproducts |
| Rock Hall | 1,750 | 5 | 0 | |
| New Windsor | 1,732 | 1 | 0 | |
| Myersville | 1,516 | 0 | 0 | |
| Pittsville | 1,500 | 8 | 1 | Disinfection Byproducts |
| Port Republic | 1,425 | 5 | 0 | |
| Timonium | 1,373 | 10 | 2 | Disinfection Byproducts |
| Funkstown | 1,300 | 1 | 0 | |
| Silver Spring | 1,248 | 0 | 0 | |
| Sherwood Forest | 1,200 | 0 | 0 | |
| Port Deposit | 1,187 | 230 | 6 | Disinfection Byproducts, Stage 2 DBP |
| Jessup | 1,070 | 17 | 1 | Stage 2 DBP |
| Hebron | 1,022 | 3 | 0 | |
| Union Bridge | 997 | 3 | 1 | Fecal Coliform |
| Farmington Hills | 990 | 9 | 0 | |
| Lexington Park | 892 | 15 | 1 | Stage 2 DBP |
| Grantsville | 885 | 4 | 0 | |
| Woodsboro | 846 | 22 | 0 | |
| Tysons | 828 | 1 | 0 | |
| Glen Arm | 818 | 55 | 9 | Disinfection Byproducts, Fecal Coliform, Stage 2 DBP |
| Oxford | 813 | 12 | 1 | Stage 2 DBP |
| Brandywine | 780 | 4 | 0 | |
| Preston | 750 | 19 | 2 | Stage 2 DBP |
| Queenstown | 705 | 29 | 0 | |
| St. Michaels | 675 | 1 | 0 | |
| Chesapeake City | 673 | 4 | 0 | |
| Ellicott City | 649 | 41 | 9 | Disinfection Byproducts, Selenium, Stage 2 DBP |
| Street | 643 | 89 | 1 | Stage 2 DBP |
| Millington | 625 | 11 | 0 | |
| Sharptown | 625 | 7 | 2 | E. coli, Stage 2 DBP |
| Leesport | 569 | 79 | 4 | Disinfection Byproducts, Stage 2 DBP |
| Grasonville | 556 | 10 | 2 | Stage 2 DBP |
| Secretary | 535 | 5 | 0 | |
| Huntingtown | 526 | 32 | 3 | Stage 2 DBP |
| Sudlersville | 497 | 5 | 0 | |
| Betterton | 481 | 16 | 6 | Disinfection Byproducts |
| East New Market | 480 | 9 | 0 | |
| Cecilton | 477 | 19 | 4 | Disinfection Byproducts |
| Vienna | 460 | 3 | 0 | |
| Reading | 430 | 43 | 1 | Stage 2 DBP |
| Tylerton | 409 | 188 | 5 | Stage 2 DBP |
| Newburg | 406 | 69 | 1 | Stage 2 DBP |
| Durham | 400 | 23 | 2 | E. coli |
| Seaford | 384 | 7 | 1 | Stage 2 DBP |
| Freeland | 336 | 17 | 4 | Disinfection Byproducts, Stage 2 DBP |
| New Castle | 325 | 13 | 4 | Disinfection Byproducts |
| Springfield | 320 | 2 | 1 | Stage 2 DBP |
| Crofton | 320 | 5 | 0 | |
| Midlothian | 300 | 5 | 1 | Stage 2 DBP |
| Lancaster | 300 | 19 | 2 | Stage 2 DBP |
| Accident | 300 | 4 | 0 | |
| Accokeek | 300 | 4 | 0 | |
| Rising Sun | 290 | 3 | 1 | Stage 2 DBP |
| Sacramento | 275 | 10 | 1 | Stage 2 DBP |
| Finksburg | 259 | 9 | 1 | Selenium |
| Alexandria | 256 | 0 | 0 | |
| Colora | 250 | 19 | 3 | Disinfection Byproducts |
| Potomac | 220 | 15 | 3 | Disinfection Byproducts |
| Belle Mead | 220 | 7 | 1 | Stage 2 DBP |
| Sharpsburg | 220 | 4 | 0 | |
| Linthicum Heights | 175 | 6 | 1 | Stage 2 DBP |
| Darlington | 173 | 20 | 3 | Stage 2 DBP |
| Reistertown | 170 | 4 | 2 | Disinfection Byproducts, Stage 2 DBP |
| Berwyn | 159 | 13 | 0 | |
| Marbury | 150 | 12 | 1 | Stage 2 DBP |
| Bishopville | 150 | 9 | 0 | |
| Mt. Savage | 130 | 33 | 2 | Gross Alpha, Stage 2 DBP |
| Herndon | 126 | 4 | 1 | Stage 2 DBP |
| Randalstown | 125 | 20 | 2 | Selenium |
| Hollywood | 120 | 13 | 0 | |
| Cascade | 100 | 4 | 1 | Stage 2 DBP |
Data Sources
Drinking water data from the EPA Safe Drinking Water Information System (SDWIS). Only active community water systems (CWS) serving 100+ people are included.