2010 Contaminants in municipal water

Summary Information

Range in Wisconsin (Min-Max): 0%-99%
Overall in Wisconsin: 57%
Target Value: 0% (90th percentile)

Ranking Methodology

Summary Measure: Health Factors - Physical Environment (Water Quality)
Weight in Health Factors: 0%
Years of Data Used: 2006-2008
Map ↓
The counties are shaded with lighter counties having a better rank. Gray counties are not reported (NR).
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Contaminants in municipal water represent the percent of the population on municipal water exposed to any maximum contaminant limit (MCL) violation in a calendar year.

The measure is based on data from the Wisconsin Department of Natural Resources (WDNR) Drinking Water System: Contaminants in Public Water Supplies Query. We estimate the population on municipal water supplies that was exposed to at least one maximum contaminant limit (MCL) violation between January 1 and December 31, 2008.

The U.S. Environmental Protection Agency has established maximum contaminant limits (MCLs) for approximately 90 contaminants considered harmful to human health at excess levels. MCLs are established for several classes of contaminants including microorganisms, disinfectants and their byproducts, inorganic and organic chemicals, and radionuclides. Though MCL violations often do not pose immediate health risks, they indicate that interventions are required to limit adverse health effects in the future.

Table ↓
# On Munical Water County population on municipal water supply in 2009
# Exposed County population exposed to any violation of maximum contaminant leves in 2008
% Exposed Percent of county population exposed to any violation of maximum contaminant leves in 2008
Z-Score (Measure - Average of WI counties)/(Standard Deviation)
Place# On Munical Water# Exposed % ExposedZ-Score
Adams7,25678111%-0.85
Ashland11,2859,11581%1.28
Barron20,3429,73048%0.28
Bayfield4,20200%-1.18
Brown210,177167,65780%1.25
Buffalo5,5724358%-0.94
Burnett3,16400%-1.18
Calumet19,3067,43939%-0.00
Chippewa28,2397,98628%-0.32
Clark10,2981,46414%-0.75
Columbia33,90113,31839%0.02
Crawford9,4535065%-1.02
Dane388,73858,68815%-0.72
Dodge53,40021,13740%0.03
Door10,7329,50089%1.52
Douglas29,98629,66699%1.84
Dunn21,1341551%-1.16
Eau Claire74,0085641%-1.16
Florence1,80900%-1.18
Fond du Lac61,04654,02789%1.52
Forest3,99875019%-0.61
Grant32,43110,39232%-0.20
Green20,35910,99054%0.47
Green Lake9,7356,47166%0.85
Iowa13,0853,45126%-0.38
Iron3,79395125%-0.42
Jackson8,95100%-1.18
Jefferson57,59353,82493%1.67
Juneau12,2588,22867%0.87
Kenosha107,66293,62887%1.47
Kewaunee8,69600%-1.18
La Crosse87,00813,15415%-0.72
Lafayette7,80200%-1.18
Langlade9,36400%-1.18
Lincoln14,92010,87373%1.04
Manitowoc59,18554,10691%1.61
Marathon85,71564,34275%1.11
Marinette22,52713,49960%0.65
Marquette1,4651,32991%1.59
Menominee0.00
Milwaukee983,314846,06286%1.44
Monroe28,3831,2754%-1.04
Oconto10,5186016%-1.01
Oneida11,1677,42767%0.85
Outagamie157,02575,53548%0.29
Ozaukee56,49630,04653%0.44
Pepin2,96800%-1.18
Pierce22,5844,04618%-0.63
Polk15,9035,48634%-0.13
Portage40,5113241%-1.16
Price5,67900%-1.18
Racine150,123120,85681%1.27
Richland6,98489513%-0.79
Rock121,86339,34232%-0.20
Rusk5,5663,61865%0.80
Sauk37,31317,44147%0.25
Sawyer3,5412,57373%1.04
Shawano19,2912,82515%-0.73
Sheboygan85,0591,2221%-1.14
St. Croix35,17213,84139%0.02
Taylor5,58900%-1.18
Trempealeau14,8054,15828%-0.32
Vernon12,4226675%-1.02
Vilas3,1161,37444%0.16
Walworth64,25749,56277%1.17
Washburn5,4371,36825%-0.41
Washington77,12066,35486%1.44
Waukesha229,37090,70940%0.03
Waupaca25,27513,61054%0.46
Waushara6,14100%-1.18
Winnebago123,257121,03798%1.81
Wood46,37121,73047%0.25