STATE REPORT
MD
1 ALERT
12 HEALTH VIOLATIONS
Maryland Water Quality & Safety Report
20 ZIP codes · 66 water systems · IPC plumbing code · Updated 2026-03-16
Data: EPA SDWIS, NWS, State plumbing boards, Rewiring America Last verified: 2026-03-16
20
ZIP Codes
66
Water Systems
14
ZIPs with Violations
1
Active Alerts
IPC
Plumbing Code
Overview
We track water quality, weather alerts, plumbing regulations, and energy rebates for 20 ZIP codes across Maryland, covering 66 community water systems that serve approximately 4,168,071 people.
14 of 20 ZIP codes (70%) have recorded EPA violations. 12 health-based violations have been documented.
Active Weather Alerts
1 active alert in Maryland. Severe weather can directly affect tap water quality — flooding, power outages, and infrastructure damage may lead to boil-water advisories.
| Alert | Severity | Areas |
|---|---|---|
| Coastal Flood Watch | Moderate | Anne Arundel |
Plumbing Regulations
Maryland follows the International Plumbing Code (2018 edition).
- Plumbing code: IPC (2018)
- Homeowner DIY: Licensed plumber required
- Water heater permit: Required
- Annual backflow test: Required
Areas with Most Violations
| ZIP Code | City | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|---|
| 21201 | Baltimore | — | 33 | 2 | CITY OF BALTIMORE |
| 21842 | Ocean City | — | 29 | 2 | TOWN OF OCEAN CITY |
| 21701 | Frederick | — | 19 | 3 | NEW DESIGN - FREDERICK COUNTY |
| 21041 | Ellicott City | — | 11 | 1 | LUTHERAN VILLAGE AT MILLER’S GRANT |
| 21157 | Westminster | — | 8 | 1 | CITY OF WESTMINSTER |
| 21660 | Ridgely | — | 7 | 0 | TOWN OF RIDGELY |
| 21740 | Hagerstown | — | 6 | 0 | CITY OF HAGERSTOWN |
| 21014 | Bel Air | — | 4 | 0 | MARYLAND AMERICAN WATER–SEVERN SYSTEM |
| 21801 | Salisbury | — | 4 | 1 | CITY OF SALISBURY |
| 20601 | Waldorf | — | 3 | 0 | CHARLES COUNTY GARDENS WATER |
Areas with No Violations
| ZIP Code | City | Safety Score | System | Population |
|---|---|---|---|---|
| 20707 | Laurel | — | WASHINGTON SUBURBAN SANITARY COMMISSION | 1,900,000 |
| 20810 | Bethesda | — | GRANITE MOBILE HOME PARK | 96 |
| 20854 | Potomac | — | WOODBINE VILLAGE MOBILE HOME PARK | 150 |
| 20901 | Silver Spring | — | FAIRLAND CROSSING APARTMENTS | 1,248 |
| 21501 | Cumberland | — | CITY OF CUMBERLAND | 27,039 |
| 21601 | Easton | — | EASTON UTILITIES | 17,357 |
Lead & Copper
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
- High risk (Zone 1): 0 ZIP codes (0%)
- Moderate risk (Zone 2): 0 ZIP codes
- Low risk (Zone 3): 0 ZIP codes
All 20 ZIP Codes in Maryland
- 21401 (Annapolis) — 3 violations
- 21201 (Baltimore) — 33 violations ⚠
- 21014 (Bel Air) — 4 violations
- 20810 (Bethesda)
- 20715 (Bowie) — 2 violations ⚠
- 21620 (Chestertown) — 2 violations ⚠
- 21044 (Columbia) — 2 violations
- 21501 (Cumberland)
- 21601 (Easton)
- 21041 (Ellicott City) — 11 violations ⚠
- 21701 (Frederick) — 19 violations ⚠
- 21740 (Hagerstown) — 6 violations
- 20707 (Laurel)
- 21842 (Ocean City) — 29 violations ⚠
- 20854 (Potomac)
- 21660 (Ridgely) — 7 violations
- 21801 (Salisbury) — 4 violations ⚠
- 20901 (Silver Spring)
- 20601 (Waldorf) — 3 violations
- 21157 (Westminster) — 8 violations ⚠
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Weather alerts: National Weather Service (NWS)
- Regulations: State plumbing boards, ICC, IAPMO
- Rebates: Rewiring America
Updated daily.