Wisconsin Tap Water Quality

EPA water quality data for 150 community water systems serving 772,024+ people in Wisconsin. Click any system to see violations, lead testing results, and a safety grade.

Wisconsin draws drinking water primarily from groundwater wells, with Lake Michigan serving Milwaukee and several other eastern cities. Naturally occurring radium in deep sandstone wells has caused widespread violations, particularly in Waukesha and other communities in the radium belt. Nitrate from dairy farming and manure spreading affects shallow wells in agricultural areas.

MADISON WATER UTILITY MADISON, WI · 272,000 people · Groundwater BELOIT CITY OF BELOIT, WI · 36,677 people · Groundwater SUN PRAIRIE UTILITIES SUN PRAIRIE, WI · 33,966 people · Groundwater FITCHBURG UTILITY DIST 1 FITCHBURG, WI · 24,500 people · Groundwater WATERTOWN WATERWORKS WATERTOWN, WI · 23,945 people · Groundwater MIDDLETON WATERWORKS MIDDLETON, WI · 23,868 people · Groundwater BEAVER DAM WATER UTILITY BEAVER DAM, WI · 16,200 people · Groundwater WAUNAKEE WATERWORKS WAUNAKEE, WI · 14,879 people · Groundwater VERONA WATERWORKS VERONA, WI · 14,030 people · Groundwater STOUGHTON WATERWORKS STOUGHTON, WI · 13,078 people · Groundwater FORT ATKINSON WATERWORKS FORT ATKINSON, WI · 12,390 people · Groundwater PLATTEVILLE WATERWORKS PLATTEVILLE, WI · 12,268 people · Groundwater OREGON WATERWORKS OREGON, WI · 11,200 people · Groundwater MONROE WATERWORKS MONROE, WI · 10,780 people · Groundwater DEFOREST WATERWORKS DEFOREST, WI · 10,500 people · Groundwater PORTAGE WATERWORKS PORTAGE, WI · 10,437 people · Groundwater MCFARLAND WATERWORKS MCFARLAND, WI · 9,676 people · Groundwater COTTAGE GROVE WATERWORKS COTTAGE GROVE, WI · 9,345 people · Groundwater MONONA WATERWORKS MONONA, WI · 8,624 people · Groundwater WAUPUN UTILITIES WAUPUN, WI · 8,056 people · Groundwater JEFFERSON WATERWORKS JEFFERSON, WI · 7,926 people · Groundwater MT HOREB WATERWORKS MOUNT HOREB, WI · 7,756 people · Groundwater LAKE MILLS WATERWORKS LAKE MILLS, WI · 6,211 people · Groundwater EVANSVILLE WATERWORKS EVANSVILLE, WI · 5,703 people · Groundwater EDGERTON WATERWORKS EDGERTON, WI · 5,512 people · Groundwater COLUMBUS UTILITIES COLUMBUS, WI · 5,173 people · Groundwater MAYVILLE WATERWORKS MAYVILLE, WI · 5,112 people · Groundwater RICHLAND CENTER WATERWORKS RICHLAND CENTER, WI · 5,100 people · Groundwater WINDSOR WATER UTILITY SOUTH WINDSOR, WI · 4,607 people · Groundwater DODGEVILLE WATERWORKS DODGEVILLE, WI · 4,583 people · Groundwater CROSS PLAINS WATERWORKS CROSS PLAINS, WI · 4,100 people · Groundwater LANCASTER WATERWORKS LANCASTER, WI · 3,907 people · Groundwater MARSHALL WATERWORKS MARSHALL, WI · 3,862 people · Groundwater WAUPUN CORRECTIONAL INST MADISON, WI · 3,706 people · Groundwater HORICON WATERWORKS HORICON, WI · 3,682 people · Groundwater WATERLOO WATERWORKS WATERLOO, WI · 3,520 people · Groundwater JOHNSON CREEK WATERWORKS JOHNSON CREEK, WI · 3,318 people · Groundwater BOSCOBEL WATERWORKS BOSCOBEL, WI · 3,237 people · Groundwater WISCONSIN DELLS WATERWORKS WISCONSIN DELLS, WI · 3,232 people · Groundwater BRODHEAD WATERWORKS BRODHEAD, WI · 3,216 people · Groundwater LODI WATERWORKS LODI, WI · 3,146 people · Groundwater MENDOTA MENTAL HEALTH INST MADISON, WI · 2,787 people · Groundwater BELLEVILLE WATERWORKS BELLEVILLE, WI · 2,712 people · Groundwater LOMIRA WATERWORKS LOMIRA, WI · 2,701 people · Groundwater JUNEAU WATERWORKS JUNEAU, WI · 2,627 people · Groundwater POYNETTE WATERWORKS POYNETTE, WI · 2,520 people · Groundwater DEERFIELD WATERWORKS DEERFIELD, WI · 2,510 people · Groundwater FENNIMORE WATERWORKS FENNIMORE, WI · 2,507 people · Groundwater MINERAL POINT WATERWORKS MINERAL POINT, WI · 2,487 people · Groundwater NEW GLARUS WATERWORKS NEW GLARUS, WI · 2,348 people · Groundwater DARLINGTON WATERWORKS DARLINGTON, WI · 2,235 people · Groundwater PARDEEVILLE WATERWORKS PARDEEVILLE, WI · 2,151 people · Groundwater CUBA CITY WATERWORKS CUBA CITY, WI · 2,141 people · Groundwater CLINTON WATERWORKS CLINTON, WI · 2,119 people · Groundwater HARMONY GROVE SAN DIST LODI, WI · 1,950 people · Groundwater FOX LAKE CORRECTIONAL INSTITUTION MADISON, WI · 1,850 people · Groundwater RANDOLPH WATER DEPT RANDOLPH, WI · 1,800 people · Groundwater FALL RIVER WATERWORKS FALL RIVER, WI · 1,793 people · Groundwater PALMYRA WATERWORKS PALMYRA, WI · 1,756 people · Groundwater MAZOMANIE WATERWORKS MAZOMANIE, WI · 1,744 people · Groundwater SHOREWOOD HILLS WATERWORKS MADISON, WI · 1,670 people · Groundwater Purchased CAMBRIDGE WATER & SEWER UTILITY CAMBRIDGE, WI · 1,638 people · Groundwater FOX LAKE WATERWORKS FOX LAKE, WI · 1,610 people · Groundwater BROOKLYN WATERWORKS BROOKLYN, WI · 1,524 people · Groundwater BLACK EARTH WATERWORKS BLACK EARTH, WI · 1,493 people · Groundwater MUSCODA WATERWORKS MUSCODA, WI · 1,453 people · Groundwater MAPLE BLUFF WATERWORKS MADISON, WI · 1,342 people · Groundwater Purchased THERESA WATERWORKS THERESA, WI · 1,262 people · Groundwater BARNEVELD WATERWORKS BARNEVELD, WI · 1,258 people · Groundwater SHULLSBURG WATERWORKS SHULLSBURG, WI · 1,222 people · Groundwater MONTICELLO WATERWORKS MONTICELLO, WI · 1,217 people · Groundwater HAZEL GREEN WATERWORKS HAZEL GREEN, WI · 1,193 people · Groundwater DANE WATERWORKS DANE, WI · 1,117 people · Groundwater OAKHILL CORRECTIONAL INST OREGON, WI · 1,096 people · Groundwater RIO WATERWORKS RIO, WI · 1,095 people · Groundwater DICKEYVILLE WATERWORKS DICKEYVILLE, WI · 1,069 people · Groundwater HUSTISFORD WATERWORKS HUSTISFORD, WI · 1,063 people · Groundwater ALBANY WATERWORKS ALBANY, WI · 1,018 people · Groundwater BELMONT WATERWORKS BELMONT, WI · 991 people · Groundwater BENTON WATERWORKS BENTON, WI · 976 people · Groundwater BLUE MOUNDS WATERWORKS BLUE MOUNDS, WI · 950 people · Groundwater IRON RIDGE WATERWORKS IRON RIDGE, WI · 937 people · Groundwater LONE ROCK WATERWORKS LONE ROCK, WI · 895 people · Groundwater ARENA WATERWORKS ARENA, WI · 877 people · Groundwater HIGHLAND WATERWORKS HIGHLAND, WI · 842 people · Groundwater ARLINGTON WATERWORKS ARLINGTON, WI · 823 people · Groundwater ARGYLE WATERWORKS ARGYLE, WI · 823 people · Groundwater BLANCHARDVILLE WATERWORKS BLANCHARDVILLE, WI · 810 people · Groundwater WESTPORT WATER UTILITY WAUNAKEE, WI · 800 people · Groundwater CASSVILLE WATERWORKS CASSVILLE, WI · 777 people · Groundwater WYOCENA WATERWORKS WYOCENA, WI · 768 people · Groundwater CAMBRIA WATERWORKS Cambria, WI · 767 people · Groundwater CRYSTAL LAKE RV RESORT LLC LODI, WI · 725 people · Groundwater REESEVILLE WATERWORKS REESEVILLE, WI · 718 people · Groundwater MONTFORT WATERWORKS MONTFORT, WI · 718 people · Groundwater POTOSI WATERWORKS POTOSI, WI · 718 people · Groundwater SADDLE RIDGE ESTATES PORTAGE, WI · 700 people · Groundwater RIDGEWAY WATERWORKS RIDGEWAY, WI · 690 people · Groundwater BLOOMINGTON WATERWORKS BLOOMINGTON, WI · 682 people · Groundwater LIVINGSTON WATERWORKS LIVINGSTON, WI · 664 people · Groundwater BROWNSVILLE WATERWORKS BROWSVILLE, WI · 630 people · Groundwater AUTUMN RIDGE WATER SYSTEM LLC IXONIA, WI · 575 people · Groundwater KIELER SD NO 1 KIELER, WI · 560 people · Groundwater LINDEN WATERWORKS LINDEN, WI · 547 people · Groundwater AVOCA WATERWORKS AVOCA, WI · 545 people · Groundwater SPACIOUS ACRES MOBILE HOME COMMUNITY MENOMONIE FALLS, WI · 525 people · Groundwater SOUTH WAYNE WATERWORKS SOUTH WAYNE, WI · 478 people · Groundwater TREMAIN MOBILE HOME PARK STEVENS POINT, WI · 475 people · Groundwater HOUSE ON THE ROCK RESORT SPRING GREEN, WI · 470 people · Groundwater COBB WATERWORKS COBB, WI · 458 people · Groundwater BAY VIEW HEIGHTS INC OREM, UT · 450 people · Groundwater SEXTONVILLE WATERWORKS SEXTONVILLE, WI · 425 people · Groundwater BLUE RIVER WATERWORKS BLUE RIVER, WI · 424 people · Groundwater CLYMAN WATERWORKS CLYMAN, WI · 422 people · Groundwater NORTH HILLS MHP BARRINGTON, IL · 420 people · Groundwater LAKE FOREST WATER COOP MADISON, WI · 400 people · Groundwater WINDSOR WATER UTILITY NORTH WINDSOR, WI · 400 people · Groundwater TENNYSON WATERWORKS POTOSI, WI · 367 people · Groundwater BAGLEY WATERWORKS BAGLEY, WI · 353 people · Groundwater CAZENOVIA WATERWORKS CAZENOVIA, WI · 351 people · Groundwater FITCHBURG UTILITY DIST 1 SOUTH FITCHBURG, WI · 350 people · Groundwater FRIESLAND WATERWORKS FRIESLAND, WI · 345 people · Groundwater LOWELL WATERWORKS LOWELL, WI · 337 people · Groundwater LEROY SANITARY DISTRICT 1 MAYVILLE, WI · 320 people · Groundwater CARAVILLA EDUCATION AND REHAB CENTER JANESVILLE, WI · 298 people · Groundwater REWEY WATERWORKS REWEY, WI · 290 people · Groundwater HOLLANDALE WATERWORKS HOLLANDALE, WI · 283 people · Groundwater PLEASANT VIEW NURSING HOME MONROE, WI · 260 people · Groundwater BROWNTOWN WATERWORKS BROWNTOWN, WI · 256 people · Groundwater PINE VALLEY COMMUNITY VILLAGE RICHLAND CENTER, WI · 225 people · Groundwater GRATIOT WATERWORKS GRATIOT, WI · 224 people · Groundwater SINSINAWA DOMINICANS INC SINSINAWA, WI · 213 people · Groundwater MOUNT HOPE WATERWORKS MOUNT HOPE, WI · 181 people · Groundwater HIDDEN MEADOWS WATERTOWN, WI · 166 people · Groundwater DONS MOBILE MANOR WAUNAKEE, WI · 160 people · Groundwater PATCH GROVE WATERWORKS PATCH GROVE, WI · 160 people · Groundwater LAKEWOOD VILLAGE BAYSIDE, WI · 160 people · Groundwater MIDWAY VILLAGE MOBILE HOME PARK CEDAREDGE, CO · 160 people · Groundwater POYNETTE MOBILE ESTATES CHICAGO, IL · 150 people · Groundwater DANVILLE DRIVE SERVICE AREA FITCHBURG, WI · 150 people · Groundwater Purchased STITZER SANITARY DIST 1 STITZER, WI · 150 people · Groundwater SHADY HILL MOBILE HOME PARK STEVENS POINT, WI · 140 people · Groundwater RIMROCK ROAD NEIGHBORHOOD FITCHBURG, WI · 135 people · Groundwater Purchased SUNNYSIDE ESTATES BARABOO, WI · 135 people · Groundwater OAK RIDGE MOBILE COM 1 & 2 FARMINGTON HILLS, MI · 133 people · Groundwater OAKHILL WATERWORKS EDGERTON, WI · 130 people · Groundwater APPLEWOOD HILL MADISON, WI · 125 people · Groundwater MAPLE GROVE MHP BEAVER DAM, WI · 125 people · Groundwater BREEZY KNOLL COMMUNITY CEDAREDGE, CO · 116 people · Groundwater WISCONSIN ACADEMY MAIN CAMPUS FALL RIVER, WI · 115 people · Groundwater