Water Service Outages in Maryland by City
84% of Maryland's 464 community water systems serve 3,300 people or fewer, so many outages and boil water notices affect a single small town or subdivision.
Maryland drinking water record
Busiest year: 2024 (130 violations). Counted by the year the violation period began. Source: EPA SDWIS.
- Community water systems: 464 active systems serve about 5,529,590 people. 391 of them (84%) serve 3,300 people or fewer; 386 draw mainly on groundwater and 66 on surface water.
- Health-based violations since 2015: 298, at 161 systems (35% of all systems). That share is 29th of 50 states (1 = lowest).
- Most common problems: contaminant averages over the limit (112); lead and copper corrosion-control studies (10); uncorrected Ground Water Rule deficiencies (9). Source: EPA SDWIS
- Largest system: Washington Suburban Sanitary Commission, about 1,900,000 people, with 0 health-based violations since 2015. Source: EPA SDWIS
- Housing age: the median Maryland home was built in 1979 (US 1980). Source: US Census Bureau, ACS 2020–2024 (table B25035)
- Storm damage to water service: NOAA storm narratives mention water mains, boil water notices or lost water service in 9 episodes in Maryland since 2015. Source: NOAA Storm Events Database
- May 14, 2025, Frederick (flood): “Water approaches the water treatment plant in Brunswick.” Source: NOAA Storm Events Database
- May 7, 2022, Frederick (flood): “Waters are also approaching the Frederick city wastewater treatment plant and the Ballenger Creek wastewater treatment plant.” Source: NOAA Storm Events Database
| System | People served | Main source | Health violations since 2015 |
|---|---|---|---|
| Washington Suburban Sanitary Commission | 1,900,000 | Surface water | 0 |
| City of Baltimore | 1,600,000 | Surface water | 3 |
| Glen Burnie-Broadneck | 290,606 | Groundwater | 0 |
| Howard County D.P.W. Distribution | 286,158 | Bought surface water | 0 |
| Harford County D.P.W. | 104,567 | Surface water | 0 |
| City of Hagerstown | 92,200 | Surface water | 1 |
Source: EPA SDWIS.
Maryland is 3rd of 5 (1 = lowest share). Source: EPA SDWIS.
Checked September 2026.
Who to call in Maryland, city by city
5 Maryland cities on this site and the water utility for each. What to do while you wait is in our water service outage guide.
- Baltimore Baltimore City Department of Public Works
- Frederick City of Frederick Department of Public Works
- Gaithersburg WSSC Water
- Rockville City of Rockville Water
- Bowie WSSC Water
Frequently asked questions
Is there a water service outage in Maryland right now?
Not on this site: no reports from Maryland in the last 24 hours.
How many public water systems are in Maryland?
EPA records list 464 active community water systems in Maryland, serving about 5,529,590 people. 84% serve 3,300 people or fewer.
How common are drinking water violations in Maryland?
Since 2015, 161 of 464 community water systems in Maryland (35%) have had at least one health-based violation, 298 in total.
What is the largest water system in Maryland?
Washington Suburban Sanitary Commission, which EPA records list as serving about 1,900,000 people.
Report counts are user-submitted; other figures name their official source. How our data works
Cities in Maryland with Water Service Outages Information
Baltimore
no reports in the last 24 hours · pop. 575,584
Baltimore City Department of Public Works
Frederick
no reports in the last 24 hours · pop. 78,780
City of Frederick Department of Public Works
Rockville
no reports in the last 24 hours · pop. 67,979
City of Rockville Water