Largest Water Systems With Unaddressed Health-Based Violations

The biggest community water systems that currently carry at least one unaddressed health-based Safe Drinking Water Act violation.

How this is measured

Active community water systems (CWS) that currently have one or more unaddressed health-based violations — a health-based Safe Drinking Water Act violation whose EPA status is "Unaddressed" (the system has not yet returned to compliance and no enforcement action is recorded as resolving it) — ranked by the population each serves, largest first.

"Unaddressed" is EPA’s own compliance status for the violation, not a judgment of the operator. Population served is the system’s reported figure.

#	Water system	People served	Unaddressed
1	PORTLAND WATER BUREAU Portland, OR	666,200	1
2	MCWA Rochester, NY	525,262	1
3	ROCHESTER CITY Rochester, NY	210,000	1
4	SYRACUSE CITY Syracuse, NY	192,000	1
5	CITY OF GEORGETOWN Georgetown, TX	191,639	1
6	CITY OF JACKSON Jackson, MS	189,673	1
7	SCWA - LAGUNA/VINEYARD Sacramento, CA	184,896	1
8	EPCOR - AGUA FRIA El Mirage, AZ	127,718	1
9	CITY OF FAIRFIELD Fairfield, CA	120,377	1
10	RIO RANCHO WATER & WW SERVICES Rio Rancho, NM	107,350	1
11	PORTERVILLE, CITY OF Porterville, CA	63,487	1
12	MONTEREY PARK-CITY, WATER DEPT. Monterey Park, CA	62,183	1
13	DEARBORN HEIGHTS Dearborn Heights, MI	57,774	1
14	CERES, CITY OF Ceres, CA	54,513	1
15	ROSWELL MUNICIPAL WATER SYSTEM Roswell, NM	54,025	2
16	CITY OF WEST SACRAMENTO West Sacramento, CA	53,355	1
17	YUCAIPA VALLEY WATER DISTRICT Yucaipa, CA	52,010	1
18	CALEXICO, CITY OF Calexico, CA	40,357	1
19	CITY OF WESLACO Weslaco, TX	40,033	1
20	HALLANDALE BEACH, CITY OF Hallandale Beach, FL	40,000	1
21	SAN LUIS CITY OF San Luis, AZ	39,705	1
22	CALUMET CITY Calumet City, IL	37,000	1
23	MEADE COUNTY WATER DISTRICT Bradenburg, KY	33,313	1
24	EAST NILES CSD Bakersfield, CA	32,517	1
25	SCWA MATHER-SUNRISE Sacramento, CA	30,825	1
26	FKAA - FLORIDA KEYS R.O. PLANTS Key West, FL	30,000	1
27	DANIA BEACH, CITY OF Dania Beach, FL	30,000	1
28	WHEELING Wheeling, WV	29,899	2
29	CALIF STATE POLYTECHNICAL UNIV - POMONA Pomona, CA	29,854	1
30	SUISUN-SOLANO WATER AUTHORITY Vacaville, CA	29,105	1
31	CITY OF BIG SPRING Big Spring, TX	27,282	1
32	DINUBA, CITY OF Dinuba, CA	27,281	1
33	MAYWOOD Maywood, IL	24,090	1
34	GRIC DPW Wild Horse Pass Sacaton, AZ	22,795	1
35	NICEVILLE, CITY OF Niceville, FL	22,243	1
36	SAN LORENZO VALLEY WATER DIST Boulder Creek, CA	21,145	1
37	GALLUP WATER SYSTEM Gallup, NM	20,880	8
38	SAFFORD CITY OF Safford, AZ	20,600	1
39	CALLAWAY, CITY OF WATER SYSTEM Callaway, FL	20,520	1
40	CITY OF PINEVILLE WATER SYSTEM Pineville, LA	20,358	7
41	ARVIN COMMUNITY SERVICES DIST Arvin, CA	19,669	1
42	CAMINO REAL REGIONAL UTILITY AUTHORITY Sunland Park, NM	19,466	2
43	CITY OF WHITE SETTLEMENT White Settlement, TX	18,522	1
44	BRADFORD CITY WATER AUTHORITY Bradford, PA	18,500	1
45	VERSAILLES WATER SYSTEM Versailles, KY	17,822	1
46	SPARTA TWP WATER UTILITY - LAKE MOHAWK Sparta, NJ	17,625	1
47	BAKMAN WATER COMPANY Fresno, CA	17,393	1
48	CITY OF GROVES Groves, TX	17,335	1
49	MEDFORD TWP DEPT OF MUNI Medford, NJ	17,272	1
50	CITY OF COVINGTON WATER SUPPLY Covington, LA	16,185	1

See how the Tap Grade is calculated on the methodology page, or where the underlying data comes from on data sources. Spotted something that looks wrong? Email contact@tapgraded.com.

Source: EPA SDWIS/ECHO + UCMR5 (see Methodology) · Data as of 2026Q2 — EPA SDWA/ECHO quarterly bulk data (2026 Q2) downloaded 2026-07-16; EPA UCMR5 occurrence data downloaded 2026-07-16