Wisconsin Drinking Water Compliance Records
1,022 water systems serving 4,236,576 people. 7,058 historical EPA violation records in the Q2 2026 snapshot.
TapScore Compliance-History Grades
A
824
81%
B
105
10%
C
73
7%
D
18
2%
F
2
0%
1,022
Water Systems
4,236,576
Population Served
7,058
Historical Records
749
Health-Based (All Years)
Systems With the Most Recent EPA Records
NORRIS INC
141 served76 historical records55 recent
D
WEST BEND WATERWORKS
31,752 served47 historical records45 recent
C
OAKS THE
135 served43 historical records43 recent
C
52ND AVE WATER GROUP
35 served169 historical records36 recent
D
WAUKESHA WATER UTILITY
70,718 served267 historical records35 recent
F
LUDWELL ESTATES
100 served36 historical records35 recent
C
GLEN FLORA WATERWORKS
93 served37 historical records32 recent
D
BIT O GREEN LLC MHP
49 served31 historical records30 recent
C
COLONIAL GARDENS HOMES
48 served33 historical records30 recent
C
NORTHLAND MISSION
75 served27 historical records27 recent
C
Large Systems With No Recent Records
MILWAUKEE WATERWORKS
626,000 served1 historical record
A
MADISON WATER UTILITY
272,000 served5 historical records
A
GREEN BAY WATERWORKS
107,369 served0 historical records
A
RACINE WATERWORKS
105,100 served9 historical records
A
KENOSHA WATER UTILITY
99,218 served1 historical record
A
APPLETON WATERWORKS
74,511 served1 historical record
A
EAU CLAIRE WATERWORKS
70,587 served0 historical records
A
JANESVILLE WATER UTILITY
64,415 served1 historical record
A
WEST ALLIS WATERWORKS
63,240 served1 historical record
A
OSHKOSH WATERWORKS
63,000 served0 historical records
A
Largest Water Systems in Wisconsin
| Water System | Grade | Population | Historical Records |
|---|---|---|---|
| MILWAUKEE WATERWORKS | A | 626,000 | 1 |
| MADISON WATER UTILITY | A | 272,000 | 5 |
| GREEN BAY WATERWORKS | A | 107,369 | 0 |
| RACINE WATERWORKS | A | 105,100 | 9 |
| KENOSHA WATER UTILITY | A | 99,218 | 1 |
| APPLETON WATERWORKS | A | 74,511 | 1 |
| WAUKESHA WATER UTILITY | F | 70,718 | 267 |
| EAU CLAIRE WATERWORKS | A | 70,587 | 0 |
| JANESVILLE WATER UTILITY | A | 64,415 | 1 |
| WEST ALLIS WATERWORKS | A | 63,240 | 1 |
| OSHKOSH WATERWORKS | A | 63,000 | 0 |
| LA CROSSE WATERWORKS | A | 53,000 | 2 |
| SHEBOYGAN WATER UTILITIES | A | 49,931 | 3 |
| WAUWATOSA WATERWORKS | A | 49,064 | 1 |
| FOND DU LAC WATERWORKS | C | 44,678 | 31 |
| WAUSAU WATERWORKS | A | 39,994 | 1 |
| SUN PRAIRIE UTILITIES | C | 39,300 | 12 |
| BELOIT CITY OF | A | 36,677 | 1 |
| NORTH SHORE WATER COMMISSION | A | 35,598 | 1 |
| MANITOWOC WATERWORKS | A | 34,500 | 1 |
Contaminants in Wisconsin
Lead in WisconsinArsenic in WisconsinNitrate in WisconsinFluoride in WisconsinPFOS in WisconsinPFOA in WisconsinTHMs in WisconsinHAA5 in Wisconsin
Cities in Wisconsin
MILWAUKEE(19)MADISON(20)GREEN BAY(7)RACINE(3)KENOSHA(10)MENASHA(3)APPLETON(4)WAUKESHA(7)EAU CLAIRE(10)OSHKOSH(4)JANESVILLE(3)WEST ALLIS(2)LA CROSSE(15)SHEBOYGAN(3)NEENAH(3)Wauwatosa(1)WAUWATOSA(1)GLENDALE(2)FOND DU LAC(6)WAUSAU(6)SUN PRAIRIE(2)DE PERE(4)BELOIT(1)BROOKFIELD(5)MANITOWOC(3)WEST BEND(5)OAK CREEK(4)Oak Creek(1)STEVENS POINT(19)NEW BERLIN(2)SUPERIOR(2)MENOMONEE FALLS(2)FITCHBURG(4)MIDDLETON(3)WATERTOWN(3)FRANKLIN(3)CALEDONIA(1)GRAND CHUTE(2)SOUTH MILWAUKEE(1)WISCONSIN RAPIDS(4)GERMANTOWN(3)CHIPPEWA FALLS(4)MARSHFIELD(6)HUDSON(2)CUDAHY(1)KAUKAUNA(3)Onalaska(1)ONALASKA(1)PEWAUKEE(11)ASHWAUBENON(1)OCONOMOWOC(8)MENOMONIE(7)BEAVER DAM(4)MEQUON(27)RIVER FALLS(3)River Falls(1)WESTON(1)WAUNAKEE(4)HARTFORD(2)SHAWANO(3)BARABOO(5)Greendale(1)GREENDALE(1)WHITEWATER(3)WHITEFISH BAY(1)VERONA(1)PLOVER(2)SHOREWOOD(1)STOUGHTON(2)LAKE GENEVA(6)PORT WASHINGTON(2)BROWN DEER(1)FORT ATKINSON(5)GRAFTON(6)CEDARBURG(1)PLATTEVILLE(3)OREGON(4)PLYMOUTH(5)SUSSEX(2)LITTLE CHUTE(1)BURLINGTON(6)WAUPUN(3)GREENVILLE(2)TWO RIVERS(2)PORTAGE(4)NEW RICHMOND(4)MONROE(3)PLEASANT PRAIRIE(2)MARINETTE(1)ALTOONA(3)MUSKEGO(9)ELKHORN(3)DEFOREST(1)DELAVAN(8)HOLMEN(2)FORT MCCOY(2)SPARTA(3)REEDSBURG(3)MERRILL(3)STURGEON BAY(2)