Ohio Water Systems

Compiled by PlainEnviro · August 25, 2026

1,089 community water systems in Ohio, ranked by violation count. Data from EPA Safe Drinking Water Information System (SDWIS).

Water Systems

1,089

Health-Based Violation Records

1,500

Health Violations

308 systems

Population Served

10,444,506

Ohio community water systems are regulated by the EPA Safe Drinking Water Information System (SDWIS) under the Safe Drinking Water Act; each utility files compliance results with the state's primacy agency and, for federally listed contaminants, with the U.S. Environmental Protection Agency directly. PlainEnviro's health-based SDWIS extract above counts health-based exceedances only -- monitoring and reporting violations are not present in these figures.

Violation counts reflect both infrastructure realities and reporting diligence, a state with more small rural systems will accumulate more monitoring-type violations without necessarily delivering worse water. Health-based violations are the stronger safety signal. A past violation does not itself indicate current unsafe water; utilities must notify customers, remediate, and publish an annual Consumer Confidence Report. All numbers below draw directly from the federal SDWIS record.

Which water systems have violations? (146)

#	System Name	City	Source	Violations	Pop. Served	Health
1	MAYSVILLE REGIONAL WATER White Cottage	White Cottage	Groundwater	72	6,540	Yes
2	AYERSVILLE WATER AND SEWER DISTRICT Defiance	Defiance	Surface Water	47	2,372	Yes
3	WAUSEON CITY PWS Wauseon,	Wauseon,	Surface Water	34	7,568	Yes
4	NORTHWESTERN W AND SD - MCCOMB Bowling Green	Bowling Green	Surface Water	34	1,527	Yes
5	NELSONVILLE PWS Nelsonville	Nelsonville	Groundwater	33	6,656	Yes
6	VAN WERT CITY Van Wert	Van Wert	Surface Water	29	10,846	Yes
7	DEFIANCE CITY Defiance	Defiance	Surface Water	27	16,494	Yes
8	NEW LEXINGTON New Lexington	New Lexington	Surface Water	25	5,161	Yes
9	BYESVILLE Byesville	Byesville	Surface Water	22	5,104	Yes
10	DELTA VILLAGE Delta	Delta	Surface Water	18	3,518	Yes
11	GALION CITY Galion	Galion	Surface Water	17	10,453	Yes
12	ARCHBOLD VILLAGE Archbold	Archbold	Surface Water	16	5,586	Yes
13	GREEN SPRINGS VILLAGE PWS Green Springs	Green Springs	Surface Water	16	1,592	Yes
14	SEBRING VILLAGE PWS Sebring	Sebring	Surface Water	15	6,058	Yes
15	LAGRANGE VILLAGE PWS Lagrange	Lagrange	Surface Water	14	2,400	Yes
16	CADIZ VILLAGE PWS Cadiz	Cadiz	Surface Water	13	3,353	Yes
17	MANSFIELD CITY Mansfield	Mansfield	Surface Water	10	51,000	Yes
18	BLUFFTON VILLAGE Bluffton	Bluffton	Surface Water	10	4,125	Yes
19	ALLIANCE CITY PWS Alliance	Alliance	Surface Water	9	22,232	Yes
20	NORTHWESTERN W AND SD - OREGON WTLN 200 Bowling Green	Bowling Green	Surface Water	9	9,629	Yes
21	PUT-IN-BAY VILLAGE Put-in-bay	Put-in-bay	Surface Water	8	5,000	Yes
22	CHOCTAW UTILITIES, INC. London	London	Groundwater	8	2,200	Yes
23	ST. CLAIRSVILLE, CITY OF PWS St. Clairsville	St. Clairsville	Surface Water	7	5,097	Yes
24	PAULDING VILLAGE PWS Paulding	Paulding	Surface Water	7	3,605	Yes
25	MONTGOMERY COUNTY WATER SERVICES 1 PWS Kettering	Kettering	Surface Water	6	150,207	Yes
26	MONTGOMERY COUNTY WATER SERVICES 2 PWS Kettering	Kettering	Surface Water	6	83,033	Yes
27	LIMA CITY Lima	Lima	Surface Water	6	65,619	Yes
28	STEUBENVILLE, CITY OF Steubenville	Steubenville	Surface Water	6	17,000	Yes
29	CAMBRIDGE, CITY OF Cambridge	Cambridge	Surface Water	6	10,520	Yes
30	GUERNSEY CO. WATER DEPT. Cambridge	Cambridge	Surface Water	6	8,891	Yes
31	BELLEVUE CITY Bellevue	Bellevue	Surface Water	6	8,236	Yes
32	MINGO JUNCTION PWS Mingo Junction	Mingo Junction	Groundwater	6	3,350	Yes
33	WOODSFIELD VILLAGE PWS Woodsfield	Woodsfield	Surface Water	6	2,598	Yes
34	WAYNOKA REGIONAL WATER AND SEWER DIST Sardinia	Sardinia	Surface Water	6	2,428	Yes
35	NORTHWESTERN W AND SD - TOLEDO SVC AREA Bowling Green	Bowling Green	Surface Water	5	19,758	Yes
36	PORTAGE COUNTY WATER RESOURCES Ravenna	Ravenna	Groundwater	5	8,606	Yes
37	NEW LONDON VILLAGE PWS	-	Surface Water	5	3,226	Yes
38	OLD STRAITSVILLE WATER ASSOCIATION Logan	Logan	Groundwater	5	2,950	Yes
39	COLUMBUS GROVE VILLAGE Columbus Grove	Columbus Grove	Groundwater	5	2,137	Yes
40	NORTHERN PERRY CO.WATER #1 New Lexington	New Lexington	Groundwater	5	1,706	Yes
41	TOLEDO CITY OF Toledo	Toledo	Surface Water	4	360,000	Yes
42	MID-OHIO WSD - CHRISMAN AVENUE WTP Columbus	Columbus	Groundwater	4	10,256	Yes
43	OBERLIN WATER DEPARTMENT Lagrange	Lagrange	Surface Water	4	8,600	Yes
44	NEWTON FALLS CITY Newton Falls	Newton Falls	Surface Water	4	6,109	Yes
45	WHITEHOUSE VILLAGE Whitehouse	Whitehouse	Surface Water	4	5,200	Yes
46	LEIPSIC VILLAGE Leipsic	Leipsic	Groundwater	4	2,348	Yes
47	EAST CANTON VILLAGE PWS Louisville	Louisville	Groundwater	4	1,606	Yes
48	COLUMBUS PUBLIC WATER SYSTEM Columbus	Columbus	Surface Water	3	1,305,946	Yes
49	WESTERVILLE CITY PWS Pataskala	Pataskala	Surface Water	3	39,000	Yes
50	SIDNEY CITY PWS Sidney	Sidney	Surface Water	3	20,614	Yes
51	BUCYRUS CITY Bucyrus	Bucyrus	Surface Water	3	12,570	Yes
52	AQUA OHIO - LAWRENCE COUNTY Westerville	Westerville	Surface Water	3	8,130	Yes
53	CORTLAND CITY PWS Cortland	Cortland	Groundwater	3	7,105	Yes
54	OTTAWA VILLAGE Ottawa	Ottawa	Surface Water	3	4,393	Yes
55	WAYNESVILLE VILLAGE PWS Waynesville	Waynesville	Groundwater	3	4,100	Yes
56	PUTNAM COMMUNITY WATER ASSOCIATION PWS Marietta	Marietta	Groundwater	3	2,744	Yes
57	CLERMONT PUBLIC WATER SYSTEM Batavia	Batavia	Surface Water	2	133,059	Yes
58	XENIA CITY PWS Xenia	Xenia	Groundwater	2	29,000	Yes
59	MUSKINGUM COUNTY WATER - SE	-	Groundwater	2	21,540	Yes
60	BEREA CITY PWS Berea	Berea	Surface Water	2	18,789	Yes
61	ASHTABULA COUNTY WATER SYSTEM Jefferson	Jefferson	Surface Water	2	14,757	Yes
62	CONNEAUT Conneaut	Conneaut	Surface Water	2	12,538	Yes
63	HUBBARD CITY PWS Hubbard	Hubbard	Surface Water	2	8,518	Yes
64	WEST CARROLLTON CITY PWS Camden	Camden	Groundwater	2	8,361	Yes
65	KENTON CITY Kenton	Kenton	Groundwater	2	8,360	Yes
66	LEADING CREEK CONSERVANCY DISTRICT Rutland	Rutland	Groundwater	2	6,663	Yes
67	BELPRE CITY PWS Belpre	Belpre	Groundwater	2	6,441	Yes
68	WELLSTON CITY PWS Wellston	Wellston	Surface Water	2	5,846	Yes
69	MONTPELIER VILLAGE Montpelier	Montpelier	Groundwater	2	4,280	Yes
70	AQUA OHIO - MASURY	-	Surface Water	2	4,019	Yes
71	JACKSON/MILTON METRO WATER DISTRICT PWS Youngstown	Youngstown	Surface Water	2	3,728	Yes
72	LOCKLAND VILLAGE PWS Lockland	Lockland	Groundwater	2	3,486	Yes
73	ODRC-PICKAWAY CORRECTION PWS Fredricktown	Fredricktown	Groundwater	2	3,376	Yes
74	FAIRPORT HARBOR VILLAGE PWS Fairport Harbor	Fairport Harbor	Surface Water	2	3,180	Yes
75	OBETZ VILLAGE PWS Obetz	Obetz	Groundwater	2	3,167	Yes
76	DOYLESTOWN VILLAGE PWS Doylestown	Doylestown	Groundwater	2	3,051	Yes
77	LOUDONVILLE VILLAGE Loudonville	Loudonville	Groundwater	2	2,641	Yes
78	SABINA VILLAGE PWS Sabina	Sabina	Groundwater	2	2,564	Yes
79	SEVILLE VILLAGE PWS Seville	Seville	Groundwater	2	2,296	Yes
80	RICHWOOD VILLAGE PWS Richwood	Richwood	Groundwater	2	2,200	Yes
81	AQUA OHIO - MIDVALE Massillon	Massillon	Groundwater	2	2,147	Yes
82	ARCANUM VILLAGE PWS Arcanum	Arcanum	Groundwater	2	2,100	Yes
83	BRILLIANT WATER AND SEWER Brilliant	Brilliant	Groundwater	2	2,000	Yes
84	PURE WATER CORPORATION Caldwell	Caldwell	Surface Water	2	1,989	Yes
85	LITHOPOLIS VILLAGE PWS Lithopolis	Lithopolis	Groundwater	2	1,573	Yes
86	OTTERBEIN-LEBANON RETREAT CENTER Lebanon	Lebanon	Groundwater	2	1,541	Yes
87	TIMBERBROOK MOBILE HOME PARK Cincinnati	Cincinnati	Groundwater	2	1,418	Yes
88	WEST ALEXANDRIA, VILLAGE OF West Alexandria	West Alexandria	Groundwater	2	1,385	Yes
89	BETHESDA PUBLIC WATER SYSTEM Bethesda	Bethesda	Groundwater	2	1,382	Yes
90	MILAN VILLAGE PWS Milan	Milan	Surface Water	2	1,371	Yes
91	JEFFERSONVILLE VILLAGE PWS Jeffersonville	Jeffersonville	Groundwater	2	1,356	Yes
92	FOREST VILLAGE Forest	Forest	Groundwater	2	1,354	Yes
93	PEMBERVILLE VILLAGE PWS Pemberville	Pemberville	Groundwater	2	1,326	Yes
94	AKRON CITY PWS Kent	Kent	Surface Water	1	280,000	Yes
95	ELYRIA WATER DEPARTMENT Lorain	Lorain	Surface Water	1	68,000	Yes
96	CUYAHOGA FALLS CITY PWS Cuyahoga Falls	Cuyahoga Falls	Groundwater	1	51,114	Yes
97	WARREN CITY PWS Warren	Warren	Surface Water	1	49,130	Yes
98	STOW PUBLIC WATER SYSTEM Stow	Stow	Surface Water	1	35,437	Yes
99	BELMONT CO. SANITARY DISTRICT 3 PWS Barnesville	Barnesville	Groundwater	1	26,822	Yes
100	GREENVILLE CITY PWS Greenville	Greenville	Surface Water	1	13,227	Yes
101	URBANA CITY PWS Urbana	Urbana	Groundwater	1	11,428	Yes
102	IRONTON Ironton	Ironton	Surface Water	1	11,129	Yes
103	BUCKEYE WATER DISTRICT - OHIO RIVER Wellsville	Wellsville	Surface Water	1	10,300	Yes
104	JACKSON, CITY OF Jackson	Jackson	Surface Water	1	9,691	Yes
105	BELLBROOK WATER WORKS Bellbrook	Bellbrook	Groundwater	1	9,475	Yes
106	ST MARYS CITY St Marys	St Marys	Groundwater	1	9,356	Yes
107	CHILLICOTHE CORRECTIONAL INSTITUTION Oak Hill	Oak Hill	Groundwater	1	9,000	Yes
108	SANITARY DISTRICT #4 Columbus	Columbus	Surface Water	1	8,575	Yes
109	HUDSON CITY PWS Hudson	Hudson	Groundwater	1	8,385	Yes
110	WILLARD CITY Willard	Willard	Surface Water	1	7,099	Yes
111	GRANVILLE, VILLAGE OF Granville	Granville	Groundwater	1	5,946	Yes
112	TORONTO PWS Toronto	Toronto	Surface Water	1	5,676	Yes
113	LEXINGTON VILLAGE Lexington	Lexington	Groundwater	1	4,825	Yes
114	WELLINGTON VILLAGE PWS Wellington	Wellington	Surface Water	1	4,802	Yes
115	WEST JEFFERSON VILLAGE PWS West Jefferson	West Jefferson	Groundwater	1	4,488	Yes
116	MONROE WATER SYSTEMS Laings	Laings	Groundwater	1	4,334	Yes
117	MCDONALD VILLAGE PWS Mcdonald	Mcdonald	Surface Water	1	4,236	Yes
118	CEDARVILLE UNIVERSITY Cedarville	Cedarville	Groundwater	1	4,000	Yes
119	MORROW VILLAGE PWS Morrow	Morrow	Groundwater	1	3,360	Yes
120	WEST UNION PUBLIC WATER SYSTEM West Union	West Union	Groundwater	1	3,170	Yes
121	KELLEYS ISLAND VILLAGE Kelleys Island	Kelleys Island	Surface Water	1	3,125	Yes
122	GENOA VILLAGE Genoa	Genoa	Surface Water	1	3,110	Yes
123	CARROLLTON VILLAGE Carrollton	Carrollton	Groundwater	1	3,055	Yes
124	GRAFTON VILLAGE PWS Grafton	Grafton	Surface Water	1	2,769	Yes
125	BUCKEYE LAKE, VILLAGE OF PWS Buckeye Lake	Buckeye Lake	Groundwater	1	2,746	Yes
126	BETHEL VILLAGE PWS Bethel	Bethel	Groundwater	1	2,620	Yes
127	CROOKSVILLE Crooksville	Crooksville	Groundwater	1	2,534	Yes
128	WILLIAMSBURG VILLAGE PWS Williamsburg	Williamsburg	Surface Water	1	2,490	Yes
129	MIDDLEPORT VILLAGE PWS Middleport	Middleport	Groundwater	1	2,446	Yes
130	AQUA OHIO - MOHAWK PWS Massillon	Massillon	Groundwater	1	2,376	Yes
131	UTICA VILLAGE PWS Utica	Utica	Groundwater	1	2,235	Yes
132	SUGARCREEK VILLAGE PWS Sugarcreek	Sugarcreek	Groundwater	1	2,220	Yes
133	CRESTON VILLAGE Creston	Creston	Groundwater	1	2,171	Yes
134	MANCHESTER VILLAGE Manchester	Manchester	Groundwater	1	2,043	Yes
135	SOUTH BLOOMFIELD VILLAGE PWS South Bloomfield	South Bloomfield	Groundwater	1	1,999	Yes
136	NORTH LEWISBURG VILLAGE PWS North Lewisburg	North Lewisburg	Groundwater	1	1,850	Yes
137	NORTHERN PERRY CO.WATER #2 New Lexington	New Lexington	Groundwater	1	1,802	Yes
138	WEST LIBERTY VILLAGE PWS West Liberty	West Liberty	Groundwater	1	1,800	Yes
139	POMEROY VILLAGE PWS Pomeroy	Pomeroy	Groundwater	1	1,800	Yes
140	SOUTH AMHERST VILLAGE PWS South Amherst	South Amherst	Surface Water	1	1,688	Yes
141	NEW PARIS VILLAGE PWS New Paris	New Paris	Groundwater	1	1,681	Yes
142	GLOUSTER PUBLIC WATER SYSTEM Glouster	Glouster	Groundwater	1	1,659	Yes
143	TIMBERLAKE WATER SYSTEM Columbus	Columbus	Groundwater	1	1,600	Yes
144	NEWPORT WATER/SEWER DISTRICT PWS Newport	Newport	Groundwater	1	1,582	Yes
145	GREENWICH VILLAGE PWS Grafton	Grafton	Groundwater	1	1,476	Yes
146	HIRAM VILLAGE PWS Hiram	Hiram	Groundwater	1	1,406	Yes

Systems with No Violations (354)

354 water systems in Ohio have zero recorded violations. Showing the 50 largest by population served.

CLEVELAND PUBLIC WATER SYSTEM (1,308,955) CINCINNATI PUBLIC WATER SYSTEM (750,200) DEL-CO WATER COMPANY, INC. (150,000) DAYTON PUBLIC WATER SYSTEM (141,407) YOUNGSTOWN CITY PWS (130,530) BUTLER CO. WATER DISTRICT 2 PWS (116,572) CANTON PUBLIC WATER SYSTEM (107,113) AQUA OHIO - MASSILLON PWS (95,636) WARREN COUNTY (81,975) LAKE COUNTY WEST WATER SUBDISTRICT (78,379) AQUA OHIO - MENTOR (74,500) RURAL LORAIN CO. WATER A (73,125) LORAIN CITY PWS (64,152) HAMILTON PUBLIC WATER SYSTEM (62,447) SPRINGFIELD CITY PWS (60,680) AQUA OHIO - STRUTHERS (58,551) FINDLAY CITY PWS (54,040) MIDDLETOWN CITY PWS (51,229) LAKEWOOD CITY PWS (50,942) NEWARK CITY PWS (49,934) AQUA OHIO - MARION (47,102) MEDINA CO/NORTHWEST PWS (46,324) FAIRFIELD CITY PWS (44,907) DELAWARE CITY PWS (43,895) HUBER HEIGHTS PUBLIC WATER SYSTEM (43,439) SOUTHWEST REGIONAL WATER DISTRICT (42,856) GREENE CO.-NORTHWEST REG WATER (41,895) LAKE COUNTY EAST WATER SUBDISTRICT (40,656) PORTSMOUTH CITY (40,475) LANCASTER CITY PWS (40,400) WESTERN WATER COMPANY (39,508) REYNOLDSBURG CITY PWS (37,847) ROSS COUNTY WATER CO INC (35,345) HECLA WATER ASSOCIATION (34,942) FAIRBORN PUBLIC WATER SYSTEM (34,620) GAHANNA CITY PWS (33,258) ATHENS PWS (32,725) AQUA OHIO - ASHTABULA (32,342) BROWN COUNTY RURAL WATER (32,090) PAINESVILLE CITY PWS (31,728) BOWLING GREEN CITY (31,578) BARBERTON CITY (31,298) NAWA (29,974) KENT CITY PWS (29,662) NORTH RIDGEVILLE CITY PWS (29,465) ZANESVILLE PWS (29,381) HIGHLAND COUNTY WATER COMPANY, INC. (28,421) PERRYSBURG CITY PWS (27,000) WOOSTER CITY PWS (26,618) TROY CITY PWS (26,305) +304 more

All Water Systems in Ohio (1,089)

Page 18 of 22, ordered by population served.

System	Population Served	Violations
FAYETTE CO-LAKEWOOD HILLS SUBDIVISION	200	0
BIG PRAIRIE COMMUNITY WATER COMPANY	200	4
OAKWOOD CROSSING MHP	200	0
WILLOW PARK WATER ASSOCIATION	200	0
KETTLERSVILLE WELL ASSOCIATION PWS	200	0
ALTERCARE OF HARTVILLE	198	0
NASHVILLE VILLAGE PWS	197	2
PM ESTATES PWS	197	2
HCWSD - EAST CADIZ	191	0
AURORA CITY - PORTAGE PWS	191	0
COUNTRY LANE GARDENS HC	190	0
SPRING LAKES MOBILE HOME PARK	185	0
COLONIAL HILLS MHP	185	0
GREENE COUNTY - KITRIDGE	184	0
MCCARTYVILLE WELL ASSOCIATION PWS	184	0
GREEN MEADOWS HEALTH AND WELLNESS CENTER	182	4
MAURERS MOBILE HOME PARK	181	0
RUSTIC PINES MHC	180	0
BLACKBROOK VALLEY ESTATES	180	2
SOUTH LEBANON PWS NO 2	180	0
OAKWOOD MHP	180	0
HCWSD-PIEDMONT PWS	178	0
HOMESTEAD MANOR MHP	178	2
JUST CRICKET CONDO ASSOCIATION	178	0
SCIOTO WATER INC - STONY RUN	178	0
PINE MILL RIDGE 2 PWS	178	0
HEATHERWOOD COMMUNITY WATER ASSOC PWS	177	0
ROSEDALE BIBLE INSTITUTE	175	0
SOUTHERN PERRY CO-MAINESVILLE	175	0
ARBORS AT MIFFLIN	172	0
LOUISVILLE CENTER FOR REHABILITATION	172	0
AQUA OHIO - MANSFIELD SYSTEM #08	170	6
HCWSD - GERMANO WATER AND SEWER	169	0
WOOSTER ROLLING WHEELS ESTATES MHP	169	0
WOODLAND HILLS MOBILE HOME PARK #2	168	0
FRANKS MOBILE HOME PARK	164	0
SPRING VALLEY MOBILE HOME PARK	160	6
HILLSDALE COMMUNITY WATER ASSOCIATION PW	160	0
BEDFORD MEADOWS	156	0
WILLOW REST TRAILER PARK	155	0
OBETZ SATELLITE 1 PWS	151	0
ORANGE BLOSSOM FELLOWSHIP	150	0
COUNTRY ACRES MOBILE HOME PARK	150	2
MOHICAN YOUNG STAR ACADEMY	150	3
MAYWOOD COMMUNITY INC.	150	0
SOUTHERN ESTATES WATER ASSOC PWS	150	0
CORNELL ABRAXAS OHIO	150	0
PEYTON COMMUNITY WELL	149	0
SOUTHERN PERRY CO-MILLERTOWN	146	0
BROOKWOOD MHP PWS	145	0

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Frequently Asked Questions

How many water systems are in Ohio?

Ohio has 1,089 community water systems tracked by the EPA, serving a combined population of 10,444,506 people.

How many water systems in Ohio have health violations?

308 water systems in Ohio have health-based violations, which include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations. These represent 28% of all systems in the state.

How many health-based violation records are in this extract for Ohio?

PlainEnviro's health-based EPA SDWIS extract contains 1,500 records joined to 1,089 active community water systems in Ohio. Monitoring and reporting records are not included.

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About This Data

Water system data is from the EPA Safe Drinking Water Information System (SDWIS). Health-based violations include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations that may pose a direct risk to public health. Only community water systems (CWS) are included.

Source: U.S. Environmental Protection Agency, SDWIS Federal Reporting Services

Read our methodology - how this data is sourced, computed, and verified.

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