Wisconsin Water Systems

Compiled by PlainEnviro · August 25, 2026

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

Water Systems

978

Health-Based Violation Records

2,317

Health Violations

422 systems

Population Served

4,261,844

Wisconsin 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? (236)

#	System Name	City	Source	Violations	Pop. Served	Health
1	WAUKESHA WATER UTILITY	-	Surface Water	779	70,718	Yes
2	SUSSEX VILLAGE HALL & WATER UTILITY	-	Groundwater	106	11,750	Yes
3	PEWAUKEE VILLAGE WATERWORKS Pewaukee	Pewaukee	Groundwater	61	8,166	Yes
4	PEWAUKEE CITY WATER AND SEWER UTILITY Pewaukee	Pewaukee	Groundwater	55	8,671	Yes
5	WINNECONNE WATERWORKS Winneconne	Winneconne	Groundwater	32	2,502	Yes
6	ASHLAND WATER UTILITY Ashland	Ashland	Surface Water	31	8,000	Yes
7	ELKHORN WATERWORKS Elkhorn	Elkhorn	Groundwater	26	10,317	Yes
8	JEFFERSON WATERWORKS Jefferson	Jefferson	Groundwater	23	7,926	Yes
9	RANDOLPH WATER DEPT Randolph	Randolph	Groundwater	20	1,800	Yes
10	WAUPUN CORRECTIONAL INST Madison	Madison	Groundwater	18	3,706	Yes
11	TOMAH WATERWORKS	-	Groundwater	17	9,192	Yes
12	EVANSVILLE WATERWORKS	-	Groundwater	12	5,703	Yes
13	PEPIN WATERWORKS Pepin	Pepin	Groundwater	12	816	Yes
14	JUNEAU WATERWORKS Juneau	Juneau	Groundwater	10	2,627	Yes
15	HILLSBORO WATERWORKS	-	Groundwater	10	1,325	Yes
16	CLARK COUNTY REHABILITATION & LIVING CENTER	-	Groundwater	10	510	Yes
17	GENOA CITY WATERWORKS	-	Groundwater	9	2,766	Yes
18	BELOIT CITY OF	-	Groundwater	8	36,677	Yes
19	ANTIGO WATERWORKS Antigo	Antigo	Groundwater	8	7,780	Yes
20	LAKE MILLS WATERWORKS Lake Mills	Lake Mills	Groundwater	8	6,211	Yes
21	BLOOMFIELD, VILLAGE OF Pell Lake	Pell Lake	Groundwater	8	4,071	Yes
22	HURLEY WATERWORKS Hurley	Hurley	Groundwater	8	1,515	Yes
23	CRYSTAL LAKE RV RESORT LLC	-	Groundwater	8	725	Yes
24	BROOKFIELD WATER UTILITY	-	Groundwater	7	29,070	Yes
25	NORTH FOND DU LAC WATERWORKS North Fond Du Lac	North Fond Du Lac	Groundwater	6	5,414	Yes
26	WATERLOO WATERWORKS Waterloo	Waterloo	Groundwater	6	3,520	Yes
27	SHARON WATERWORKS Sharon	Sharon	Groundwater	6	1,549	Yes
28	MONTFORT WATERWORKS Montfort	Montfort	Groundwater	6	718	Yes
29	RIDGEWAY WATERWORKS Ridgeway	Ridgeway	Groundwater	6	690	Yes
30	STETSONVILLE WATERWORKS Stetsonville	Stetsonville	Groundwater	6	563	Yes
31	OAK CREEK WATERWORKS Oak Creek	Oak Creek	Surface Water	5	32,104	Yes
32	DENMARK WATERWORKS	-	Surface Water	5	2,684	Yes
33	BARNEVELD WATERWORKS	-	Groundwater	5	1,258	Yes
34	ARLINGTON WATERWORKS Arlington	Arlington	Groundwater	5	946	Yes
35	REESEVILLE WATERWORKS Reeseville	Reeseville	Groundwater	5	718	Yes
36	AVOCA WATERWORKS Avoca	Avoca	Groundwater	5	545	Yes
37	HOWARD WATERWORKS Green Bay	Green Bay	Surface Water	4	21,133	Yes
38	HUDSON WATERWORKS	-	Groundwater	4	18,558	Yes
39	COLUMBUS UTILITIES	-	Groundwater	4	5,173	Yes
40	WRIGHTSTOWN WATERWORKS	-	Surface Water	4	3,815	Yes
41	FOX LAKE CORRECTIONAL INSTITUTION Madison	Madison	Groundwater	4	1,850	Yes
42	MUSCODA WATERWORKS Muscoda	Muscoda	Groundwater	4	1,453	Yes
43	REEDSVILLE WATERWORKS Reedsville	Reedsville	Groundwater	4	1,200	Yes
44	LAONA SANITARY DIST Laona	Laona	Groundwater	4	950	Yes
45	RIB LAKE WATERWORKS	-	Groundwater	4	945	Yes
46	MONTREAL WATERWORKS	-	Groundwater	4	887	Yes
47	HILLCREST ESTATES MHP Altoona	Altoona	Groundwater	4	850	Yes
48	WAUSAUKEE WATERWORKS	-	Groundwater	4	585	Yes
49	MADISON WATER UTILITY	-	Groundwater	3	272,000	Yes
50	SUN PRAIRIE UTILITIES	-	Groundwater	3	39,300	Yes
51	SUPERIOR WATER LIGHT & POWER COMPANY Superior	Superior	Surface Water	3	26,084	Yes
52	ALLOUEZ WATERWORKS Green Bay	Green Bay	Surface Water	3	13,923	Yes
53	TWO RIVERS WATERWORKS Two Rivers	Two Rivers	Surface Water	3	11,270	Yes
54	LEDGEVIEW TN SANITARY DIST 2 De Pere	De Pere	Surface Water	3	7,602	Yes
55	CHILTON WATERWORKS Chilton	Chilton	Groundwater	3	4,191	Yes
56	KIEL WATERWORKS Kiel	Kiel	Groundwater	3	3,932	Yes
57	MARSHALL WATERWORKS Marshall	Marshall	Groundwater	3	3,862	Yes
58	COMBINED LOCKS WATERWORKS Combined Locks	Combined Locks	Groundwater	3	3,609	Yes
59	LODI WATERWORKS Lodi	Lodi	Groundwater	3	3,146	Yes
60	MINERAL POINT WATERWORKS Mineral Point	Mineral Point	Groundwater	3	2,487	Yes
61	WASHBURN WATERWORKS Washburn	Washburn	Groundwater	3	2,280	Yes
62	RED CLIFF NORTH Bayfield	Bayfield	Groundwater	3	2,080	Yes
63	EAGLE WATERWORKS Eagle	Eagle	Groundwater	3	1,950	Yes
64	MARATHON CITY WATERWORKS Marathon City	Marathon City	Groundwater	3	1,695	Yes
65	THORP WATERWORKS Thorp	Thorp	Groundwater	3	1,636	Yes
66	MONTELLO WATERWORKS Montello	Montello	Groundwater	3	1,329	Yes
67	HAZEL GREEN WATERWORKS Hazel Green	Hazel Green	Groundwater	3	1,193	Yes
68	GREEN LAKE WATERWORKS Green Lake	Green Lake	Groundwater	3	1,002	Yes
69	ARGYLE WATERWORKS Argyle	Argyle	Groundwater	3	823	Yes
70	STODDARD WATERWORKS Stoddard	Stoddard	Groundwater	3	793	Yes
71	POTOSI WATERWORKS Potosi	Potosi	Groundwater	3	718	Yes
72	RACINE WATERWORKS Racine	Racine	Surface Water	2	105,100	Yes
73	LA CROSSE WATERWORKS	-	Groundwater	2	53,000	Yes
74	NEENAH WATERWORKS Neenah	Neenah	Surface Water	2	27,506	Yes
75	MARSHFIELD UTILITIES Marshfield	Marshfield	Groundwater	2	18,815	Yes
76	DEFOREST WATERWORKS	-	Groundwater	2	10,500	Yes
77	HOLMEN WATERWORKS	-	Groundwater	2	10,147	Yes
78	PLYMOUTH UTILITIES Plymouth	Plymouth	Groundwater	2	8,964	Yes
79	EDGERTON WATERWORKS Edgerton	Edgerton	Groundwater	2	5,512	Yes
80	SUAMICO WATERWORKS Suamico	Suamico	Groundwater	2	4,697	Yes
81	CLINTONVILLE UTILITIES	-	Groundwater	2	4,635	Yes
82	OCONTO WATERWORKS Oconto	Oconto	Groundwater	2	4,583	Yes
83	PRESCOTT WATERWORKS Prescott	Prescott	Groundwater	2	4,258	Yes
84	PRAIRIE DU SAC WATERWORKS	-	Groundwater	2	4,006	Yes
85	HORICON WATERWORKS Horicon	Horicon	Groundwater	2	3,682	Yes
86	BLACK RIVER FALLS WATERWORKS Black River Falls	Black River Falls	Groundwater	2	3,608	Yes
87	SOMERSET WATERWORKS Somerset	Somerset	Groundwater	2	3,334	Yes
88	BRILLION WATERWORKS	-	Groundwater	2	3,262	Yes
89	WISCONSIN DELLS WATERWORKS Wisconsin Dells	Wisconsin Dells	Groundwater	2	3,232	Yes
90	NEW HOLSTEIN WATERWORKS New Holstein	New Holstein	Groundwater	2	3,012	Yes
91	KEWAUNEE WATERWORKS Kewaunee	Kewaunee	Groundwater	2	2,848	Yes
92	LOMIRA WATERWORKS Lomira	Lomira	Groundwater	2	2,701	Yes
93	MONDOVI WATERWORKS Mondovi	Mondovi	Groundwater	2	2,667	Yes
94	NEW LISBON WATERWORKS	-	Groundwater	2	2,526	Yes
95	POYNETTE WATERWORKS Poynette	Poynette	Groundwater	2	2,520	Yes
96	ABBOTSFORD WATERWORKS Abbotsford	Abbotsford	Groundwater	2	2,502	Yes
97	DOUSMAN WATER UTILITY Dousman	Dousman	Groundwater	2	2,350	Yes
98	DARLINGTON WATERWORKS Darlington	Darlington	Groundwater	2	2,235	Yes
99	CRANDON WATERWORKS Crandon	Crandon	Groundwater	2	1,958	Yes
100	FONTANA WATER UTILITY	-	Groundwater	2	1,839	Yes
101	FALL RIVER WATERWORKS	-	Groundwater	2	1,793	Yes
102	GALESVILLE WATERWORKS Galesville	Galesville	Groundwater	2	1,679	Yes
103	CAMBRIDGE WATER & SEWER UTILITY Cambridge	Cambridge	Groundwater	2	1,638	Yes
104	EAGLE RIVER WATERWORKS	-	Groundwater	2	1,530	Yes
105	PHILLIPS WATERWORKS	-	Groundwater	2	1,473	Yes
106	AUGUSTA WATERWORKS	-	Groundwater	2	1,450	Yes
107	CORNELL WATERWORKS Cornell	Cornell	Groundwater	2	1,390	Yes
108	MANAWA WATERWORKS Manawa	Manawa	Groundwater	2	1,300	Yes
109	BLAIR WATERWORKS Blair	Blair	Groundwater	2	1,280	Yes
110	THERESA WATERWORKS Theresa	Theresa	Groundwater	2	1,262	Yes
111	AMHERST WATERWORKS	-	Groundwater	2	1,119	Yes
112	OAKHILL CORRECTIONAL INST Oregon	Oregon	Groundwater	2	1,096	Yes
113	BELMONT WATERWORKS Belmont	Belmont	Groundwater	2	991	Yes
114	SOUTHERN WISCONSIN CENTER Union Grove	Union Grove	Groundwater	2	950	Yes
115	LONE ROCK WATERWORKS Lone Rock	Lone Rock	Groundwater	2	895	Yes
116	FOOTVILLE WATERWORKS Footville	Footville	Groundwater	2	816	Yes
117	CASSVILLE WATERWORKS Cassville	Cassville	Groundwater	2	777	Yes
118	CAMBRIA WATERWORKS	-	Groundwater	2	767	Yes
119	GLIDDEN SANITARY DISTRICT Glidden	Glidden	Groundwater	2	750	Yes
120	TIGERTON WATERWORKS Tigerton	Tigerton	Groundwater	2	705	Yes
121	SADDLE RIDGE ESTATES Portage	Portage	Groundwater	2	700	Yes
122	ROCKLAND WATERWORKS Rockland	Rockland	Groundwater	2	642	Yes
123	ELEVA WATERWORKS	-	Groundwater	2	635	Yes
124	BROWNSVILLE WATERWORKS Browsville	Browsville	Groundwater	2	630	Yes
125	NORTH FREEDOM WATERWORKS North Freedom	North Freedom	Groundwater	2	589	Yes
126	LENA WATERWORKS Lena	Lena	Groundwater	2	585	Yes
127	ROCKY KNOLL HEALTH CARE FAC Sheboygan	Sheboygan	Groundwater	2	564	Yes
128	ONTARIO WATERWORKS Ontario	Ontario	Groundwater	2	554	Yes
129	SURING WATERWORKS	-	Groundwater	2	517	Yes
130	ADELL WATERWORKS Adell	Adell	Groundwater	2	510	Yes
131	FOND DU LAC WATERWORKS	-	Groundwater	1	44,678	Yes
132	WEST BEND WATERWORKS	-	Groundwater	1	31,752	Yes
133	MIDDLETON WATERWORKS	-	Groundwater	1	23,868	Yes
134	MENOMONEE FALLS WW - SURFACE WATER Menomonee Falls	Menomonee Falls	Surface Water	1	23,867	Yes
135	CALEDONIA WATER UTILITY - VILLAGE OF Caledonia	Caledonia	Surface Water	1	21,819	Yes
136	GERMANTOWN WATER UTILITY Germantown	Germantown	Groundwater	1	20,027	Yes
137	RIVER FALLS WATERWORKS River Falls	River Falls	Groundwater	1	16,000	Yes
138	VERONA WATERWORKS Verona	Verona	Groundwater	1	14,030	Yes
139	FOX CROSSING UTILITIES WEST Neenah	Neenah	Groundwater	1	14,000	Yes
140	SHOREWOOD WATERWORKS Shorewood	Shorewood	Surface Water	1	13,535	Yes
141	PLOVER WATERWORKS Plover	Plover	Groundwater	1	13,486	Yes
142	LITTLE CHUTE WATERWORKS	-	Groundwater	1	12,168	Yes
143	GREENVILLE UTILITIES VIL OF Greenville	Greenville	Groundwater	1	11,340	Yes
144	FOX CROSSING UTILITIES EAST Neenah	Neenah	Surface Water	1	10,927	Yes
145	NEW RICHMOND WATERWORKS New Richmond	New Richmond	Groundwater	1	10,824	Yes
146	PLEASANT PRAIRIE WATER UTILITY Pleasant Prairie	Pleasant Prairie	Surface Water	1	10,754	Yes
147	SPARTA WATERWORKS	-	Groundwater	1	10,025	Yes
148	FORT MCCOY NORTH POST	-	Groundwater	1	10,000	Yes
149	MERRILL WATERWORKS Merrill	Merrill	Groundwater	1	9,661	Yes
150	ALTOONA WATERWORKS Altoona	Altoona	Groundwater	1	9,627	Yes
151	COTTAGE GROVE WATERWORKS Cottage Grove	Cottage Grove	Groundwater	1	9,345	Yes
152	SHEBOYGAN FALLS UTILITIES Sheboygan Falls	Sheboygan Falls	Surface Water	1	8,687	Yes
153	RHINELANDER WATER & WASTEWATER Rhinelander	Rhinelander	Groundwater	1	8,234	Yes
154	MUSKEGO WATER UTILITY	-	Groundwater	1	8,150	Yes
155	JACKSON WATERWORKS Jackson	Jackson	Groundwater	1	7,844	Yes
156	MT HOREB WATERWORKS Mount Horeb	Mount Horeb	Groundwater	1	7,756	Yes
157	RIPON WATER UTILITY	-	Groundwater	1	7,716	Yes
158	KIMBERLY WATERWORKS Kimberly	Kimberly	Groundwater	1	7,608	Yes
159	LAKE GENEVA UTILITY COMMISSION	-	Groundwater	1	7,107	Yes
160	KRONENWETTER WATER & SEWER UTILITY Kronenwetter	Kronenwetter	Groundwater	1	6,931	Yes
161	LAKE HALLIE WATERWORKS VILLAGE OF Chippewa Falls	Chippewa Falls	Groundwater	1	6,701	Yes
162	WAUPACA WATERWORKS	-	Groundwater	1	6,062	Yes
163	PRAIRIE DU CHIEN WATERWORKS	-	Groundwater	1	6,005	Yes
164	SLINGER WATER UTILITY Slinger	Slinger	Groundwater	1	5,659	Yes
165	MILTON WATERWORKS Milton	Milton	Groundwater	1	5,588	Yes
166	WATERFORD WATERWORKS	-	Groundwater	1	5,368	Yes
167	RICHLAND CENTER WATERWORKS Richland Center	Richland Center	Groundwater	1	5,100	Yes
168	SHAWANO LK SAN DIST 1 Shawano	Shawano	Groundwater	1	4,950	Yes
169	UNION GROVE WATERWORKS Union Grove	Union Grove	Groundwater	1	4,900	Yes
170	MAUSTON WATERWORKS Mauston	Mauston	Groundwater	1	4,456	Yes
171	BLOOMER WATERWORKS Bloomer	Bloomer	Groundwater	1	3,680	Yes
172	STANLEY WATERWORKS Stanley	Stanley	Groundwater	1	3,500	Yes
173	JOHNSON CREEK WATERWORKS Johnson Creek	Johnson Creek	Groundwater	1	3,318	Yes
174	ELLSWORTH WATERWORKS Ellsworth	Ellsworth	Groundwater	1	3,304	Yes
175	ROTHSCHILD WATERWORKS	-	Groundwater	1	3,190	Yes
176	LADYSMITH WATERWORKS	-	Groundwater	1	3,184	Yes
177	TOMAHAWK WATERWORKS Tomahawk	Tomahawk	Groundwater	1	3,180	Yes
178	SHERWOOD WATERWORKS Sherwood	Sherwood	Surface Water	1	3,114	Yes
179	HORTONVILLE WATER UTILITY Hortonville	Hortonville	Groundwater	1	3,028	Yes
180	PARK FALLS WATERWORKS Park Falls	Park Falls	Groundwater	1	2,993	Yes
181	AMERY WATERWORKS Amery	Amery	Groundwater	1	2,962	Yes
182	OCONTO FALLS WATERWORKS Oconto Falls	Oconto Falls	Groundwater	1	2,892	Yes
183	MENDOTA MENTAL HEALTH INST Madison	Madison	Groundwater	1	2,787	Yes
184	BELLEVILLE WATERWORKS Belleville	Belleville	Groundwater	1	2,712	Yes
185	OSCEOLA WATERWORKS Osceola	Osceola	Groundwater	1	2,680	Yes
186	WILLIAMS BAY WATERWORKS Williams Bay	Williams Bay	Groundwater	1	2,601	Yes
187	HAYWARD WATER UTILITY Hayward	Hayward	Groundwater	1	2,552	Yes
188	BELGIUM WATERWORKS Belgium	Belgium	Groundwater	1	2,493	Yes
189	WESTBY WATERWORKS Westby	Westby	Groundwater	1	2,400	Yes
190	LAKELAND SANITARY DIST 1	-	Groundwater	1	2,381	Yes
191	NEW GLARUS WATERWORKS New Glarus	New Glarus	Groundwater	1	2,348	Yes
192	WALWORTH WATERWORKS Walworth	Walworth	Groundwater	1	2,304	Yes
193	SCHOFIELD WATERWORKS Schofield	Schofield	Groundwater	1	2,205	Yes
194	CUBA CITY WATERWORKS Cuba City	Cuba City	Groundwater	1	2,141	Yes
195	PRAIRIE VILLAGE WATER TRUST North Prairie	North Prairie	Groundwater	1	2,100	Yes
196	SPENCER WATERWORKS Spencer	Spencer	Groundwater	1	1,848	Yes
197	CAMPBELLSPORT WATERWORKS	-	Groundwater	1	1,825	Yes
198	WEYAUWEGA WATERWORKS Weyauwega	Weyauwega	Groundwater	1	1,820	Yes
199	WHITEHALL WATERWORKS Whitehall	Whitehall	Groundwater	1	1,820	Yes
200	STRATFORD WATERWORKS	-	Groundwater	1	1,643	Yes
201	FOX LAKE WATERWORKS	-	Groundwater	1	1,610	Yes
202	ELKHART LAKE WATERWORKS Elkhart Lake	Elkhart Lake	Groundwater	1	1,567	Yes
203	FEDERAL CORRECTIONAL INSTITUTION Oxford	Oxford	Groundwater	1	1,550	Yes
204	CLEVELAND WATERWORKS Cleveland	Cleveland	Groundwater	1	1,524	Yes
205	BANGOR WATERWORKS Bangor	Bangor	Groundwater	1	1,520	Yes
206	BLACK EARTH WATERWORKS Black Earth	Black Earth	Groundwater	1	1,493	Yes
207	EDGAR WATERWORKS	-	Groundwater	1	1,491	Yes
208	FALL CREEK WATERWORKS	-	Groundwater	1	1,269	Yes
209	MONTICELLO WATERWORKS Monticello	Monticello	Groundwater	1	1,217	Yes
210	HILBERT WATERWORKS Hilbert	Hilbert	Groundwater	1	1,176	Yes
211	PRINCETON WATERWORKS Princeton	Princeton	Groundwater	1	1,166	Yes
212	STRUM WATERWORKS Strum	Strum	Groundwater	1	1,100	Yes
213	RIO WATERWORKS Rio	Rio	Groundwater	1	1,095	Yes
214	BOYCEVILLE WATERWORKS Boyceville	Boyceville	Groundwater	1	1,043	Yes
215	CRIVITZ WATERWORKS Crivitz	Crivitz	Groundwater	1	1,026	Yes
216	ATHENS WATERWORKS Athens	Athens	Groundwater	1	1,025	Yes
217	FOND DU LAC TN WATER UTILITY Fond Du Lac	Fond Du Lac	Groundwater	1	980	Yes
218	SHELL LAKE WATERWORKS	-	Groundwater	1	950	Yes
219	NECEDAH WATERWORKS	-	Groundwater	1	844	Yes
220	DORCHESTER WATERWORKS Dorchester	Dorchester	Groundwater	1	834	Yes
221	PLAIN WATERWORKS Plain	Plain	Groundwater	1	792	Yes
222	CLAYTON WATERWORKS Claytoon	Claytoon	Groundwater	1	765	Yes
223	COON VALLEY WATERWORKS Coon Valley	Coon Valley	Groundwater	1	765	Yes
224	WHITELAW WATERWORKS Whitelaw	Whitelaw	Groundwater	1	757	Yes
225	CASCADE WATERWORKS Cascade	Cascade	Groundwater	1	719	Yes
226	STOCKBRIDGE WATERWORKS Stockbridge	Stockbridge	Groundwater	1	650	Yes
227	MEQUON TRAIL TOWNHOMES Mequon	Mequon	Groundwater	1	615	Yes
228	IRON RIVER SANITARY DISTRICT Iron River	Iron River	Groundwater	1	600	Yes
229	BRISTOL WATERWORKS VILLAGE OF Bristol	Bristol	Groundwater	1	598	Yes
230	AUTUMN RIDGE WATER SYSTEM LLC Ixonia	Ixonia	Groundwater	1	575	Yes
231	KIELER SD NO 1 Kieler	Kieler	Groundwater	1	560	Yes
232	PHELPS SANITARY DISTRICT Phelps	Phelps	Groundwater	1	550	Yes
233	NEW AUBURN WATERWORKS New Auburn	New Auburn	Groundwater	1	549	Yes
234	GRESHAM WATERWORKS Gresham	Gresham	Groundwater	1	534	Yes
235	MERRILLAN WATERWORKS Merrillan	Merrillan	Groundwater	1	531	Yes
236	MELROSE WATERWORKS Melrose	Melrose	Groundwater	1	524	Yes

Systems with No Violations (264)

264 water systems in Wisconsin have zero recorded violations. Showing the 50 largest by population served.

MILWAUKEE WATERWORKS (626,000) GREEN BAY WATERWORKS (107,369) KENOSHA WATER UTILITY (99,218) APPLETON WATERWORKS (74,511) EAU CLAIRE WATERWORKS (70,587) JANESVILLE WATER UTILITY (64,415) WEST ALLIS WATERWORKS (63,240) OSHKOSH WATERWORKS (63,000) SHEBOYGAN WATER UTILITIES (49,931) WAUWATOSA WATERWORKS (49,064) WAUSAU WATERWORKS (39,994) NORTH SHORE WATER COMMISSION (35,598) MANITOWOC WATERWORKS (34,500) NEW BERLIN WATER UTILITY (27,899) STEVENS POINT WATERWORKS (26,717) DE PERE WATERWORKS SA 1 (25,660) FITCHBURG UTILITY DIST 1 (24,500) WATERTOWN WATERWORKS (23,945) FRANKLIN WATER UTILITY (22,500) GRAND CHUTE TN SAN DIST 1 (21,583) SOUTH MILWAUKEE WATERWORKS (21,340) WIS RAPIDS WATER WORKS & LIGHTING COMM (20,000) CUDAHY WATERWORKS (18,659) ONALASKA WATERWORKS (18,000) ASHWAUBENON WATERWORKS (17,730) KAUKAUNA UTILITIES (17,493) BELLEVUE WATERWORKS (16,715) BEAVER DAM WATER UTILITY (16,200) WESTON MUNICIPAL UTILITIES (16,000) MENOMONIE WATERWORKS (15,950) HARTFORD WATERWORKS (15,805) OCONOMOWOC WATERWORKS (15,805) MENASHA ELEC & WATER UTIL (15,144) WAUNAKEE WATERWORKS (14,879) GREENDALE WATERWORKS (14,393) WHITEFISH BAY WATERWORKS (14,272) WHITEWATER WATERWORKS (14,000) CHIPPEWA FALLS WATERWORKS (13,375) STOUGHTON WATERWORKS (13,078) DARBOY SANITARY DIST 1 (13,024) GLENDALE WATERWORKS (12,883) PORT WASHINGTON WATERWORKS (12,853) BROWN DEER WATERWORKS (12,741) BARABOO WATERWORKS (12,703) CEDARBURG L & W COMMISSION (12,500) FORT ATKINSON WATERWORKS (12,390) GRAFTON WATERWORKS (12,269) PLATTEVILLE WATERWORKS (12,268) OREGON WATERWORKS (11,200) MEQUON WATER UTILITY (11,152) +214 more

All Water Systems in Wisconsin (978)

Page 1 of 20, ordered by population served.

System	Population Served	Violations
MILWAUKEE WATERWORKS	626,000	0
MADISON WATER UTILITY	272,000	3
GREEN BAY WATERWORKS	107,369	0
RACINE WATERWORKS	105,100	2
KENOSHA WATER UTILITY	99,218	0
APPLETON WATERWORKS	74,511	0
WAUKESHA WATER UTILITY	70,718	779
EAU CLAIRE WATERWORKS	70,587	0
JANESVILLE WATER UTILITY	64,415	0
WEST ALLIS WATERWORKS	63,240	0
OSHKOSH WATERWORKS	63,000	0
LA CROSSE WATERWORKS	53,000	2
SHEBOYGAN WATER UTILITIES	49,931	0
WAUWATOSA WATERWORKS	49,064	0
FOND DU LAC WATERWORKS	44,678	1
WAUSAU WATERWORKS	39,994	0
SUN PRAIRIE UTILITIES	39,300	3
BELOIT CITY OF	36,677	8
NORTH SHORE WATER COMMISSION	35,598	0
MANITOWOC WATERWORKS	34,500	0
OAK CREEK WATERWORKS	32,104	5
WEST BEND WATERWORKS	31,752	1
BROOKFIELD WATER UTILITY	29,070	7
NEW BERLIN WATER UTILITY	27,899	0
NEENAH WATERWORKS	27,506	2
STEVENS POINT WATERWORKS	26,717	0
SUPERIOR WATER LIGHT & POWER COMPANY	26,084	3
DE PERE WATERWORKS SA 1	25,660	0
FITCHBURG UTILITY DIST 1	24,500	0
WATERTOWN WATERWORKS	23,945	0
MIDDLETON WATERWORKS	23,868	1
MENOMONEE FALLS WW - SURFACE WATER	23,867	1
FRANKLIN WATER UTILITY	22,500	0
CALEDONIA WATER UTILITY - VILLAGE OF	21,819	1
GRAND CHUTE TN SAN DIST 1	21,583	0
SOUTH MILWAUKEE WATERWORKS	21,340	0
HOWARD WATERWORKS	21,133	4
GERMANTOWN WATER UTILITY	20,027	1
WIS RAPIDS WATER WORKS & LIGHTING COMM	20,000	0
MARSHFIELD UTILITIES	18,815	2
CUDAHY WATERWORKS	18,659	0
HUDSON WATERWORKS	18,558	4
ONALASKA WATERWORKS	18,000	0
ASHWAUBENON WATERWORKS	17,730	0
KAUKAUNA UTILITIES	17,493	0
BELLEVUE WATERWORKS	16,715	0
BEAVER DAM WATER UTILITY	16,200	0
RIVER FALLS WATERWORKS	16,000	1
WESTON MUNICIPAL UTILITIES	16,000	0
MENOMONIE WATERWORKS	15,950	0

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Frequently Asked Questions

How many water systems are in Wisconsin?

Wisconsin has 978 community water systems tracked by the EPA, serving a combined population of 4,261,844 people.

How many water systems in Wisconsin have health violations?

422 water systems in Wisconsin have health-based violations, which include Maximum Contaminant Level (MCL) and Treatment Technique (TT) violations. These represent 43% of all systems in the state.

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

PlainEnviro's health-based EPA SDWIS extract contains 2,317 records joined to 978 active community water systems in Wisconsin. 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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