Private Well Water Testing in Michigan
County-by-county USGS area-risk estimates for private wells across Michigan — arsenic exceedance probability and private-well population — plus how to test your own well at a Michigan-certified laboratory.
Michigan private-well risk summary
Counties covered
83
Michigan counties with modeled risk data.
People on private wells
area estimate2,448,389
estimated across covered Michigan counties.
Average arsenic risk
area estimate9%
average modeled chance a well exceeds 10 µg/L arsenic across covered counties.
Michigan counties
- Oakland County6% arsenic exceedance (area estimate)163,638 people on private wells
- Genesee County27% arsenic exceedance (area estimate)127,706 people on private wells
- Kent County8% arsenic exceedance (area estimate)87,868 people on private wells
- Jackson County5% arsenic exceedance (area estimate)74,775 people on private wells
- Livingston County7% arsenic exceedance (area estimate)73,494 people on private wells
- Allegan County5% arsenic exceedance (area estimate)65,719 people on private wells
- Berrien County6% arsenic exceedance (area estimate)60,039 people on private wells
- Kalamazoo County2% arsenic exceedance (area estimate)55,380 people on private wells
- Calhoun County7% arsenic exceedance (area estimate)54,172 people on private wells
- Washtenaw County13% arsenic exceedance (area estimate)54,159 people on private wells
- Muskegon County7% arsenic exceedance (area estimate)53,547 people on private wells
- Lapeer County55% arsenic exceedance (area estimate)53,205 people on private wells
- Ottawa County5% arsenic exceedance (area estimate)52,021 people on private wells
- St. Clair County14% arsenic exceedance (area estimate)48,931 people on private wells
- Van Buren County4% arsenic exceedance (area estimate)44,167 people on private wells
- Monroe County7% arsenic exceedance (area estimate)42,000 people on private wells
- Montcalm County5% arsenic exceedance (area estimate)41,823 people on private wells
- Lenawee County9% arsenic exceedance (area estimate)41,088 people on private wells
- Barry County13% arsenic exceedance (area estimate)39,546 people on private wells
- Ingham County7% arsenic exceedance (area estimate)39,374 people on private wells
- Eaton County26% arsenic exceedance (area estimate)38,806 people on private wells
- Clinton County31% arsenic exceedance (area estimate)38,461 people on private wells
- Tuscola County32% arsenic exceedance (area estimate)38,147 people on private wells
- Saginaw County46% arsenic exceedance (area estimate)38,057 people on private wells
- Grand Traverse County4% arsenic exceedance (area estimate)37,945 people on private wells
- Shiawassee County39% arsenic exceedance (area estimate)37,811 people on private wells
- Cass County3% arsenic exceedance (area estimate)37,738 people on private wells
- Newaygo County2% arsenic exceedance (area estimate)37,601 people on private wells
- Ionia County7% arsenic exceedance (area estimate)34,968 people on private wells
- Macomb County11% arsenic exceedance (area estimate)34,633 people on private wells
- St. Joseph County2% arsenic exceedance (area estimate)31,446 people on private wells
- Midland County21% arsenic exceedance (area estimate)31,206 people on private wells
- Sanilac County20% arsenic exceedance (area estimate)30,207 people on private wells
- Hillsdale County7% arsenic exceedance (area estimate)29,225 people on private wells
- Mecosta County2% arsenic exceedance (area estimate)27,830 people on private wells
- Isabella County22% arsenic exceedance (area estimate)27,760 people on private wells
- Branch County4% arsenic exceedance (area estimate)27,005 people on private wells
- Clare County2% arsenic exceedance (area estimate)23,103 people on private wells
- Gratiot County51% arsenic exceedance (area estimate)22,877 people on private wells
- Huron County12% arsenic exceedance (area estimate)20,456 people on private wells
- Cheboygan County2% arsenic exceedance (area estimate)20,231 people on private wells
- Gladwin County6% arsenic exceedance (area estimate)19,973 people on private wells
- Oceana County5% arsenic exceedance (area estimate)19,924 people on private wells
- Marquette County4% arsenic exceedance (area estimate)19,508 people on private wells
- Emmet County4% arsenic exceedance (area estimate)19,482 people on private wells
- Wexford County2% arsenic exceedance (area estimate)18,958 people on private wells
- Roscommon County2% arsenic exceedance (area estimate)17,860 people on private wells
- Bay County13% arsenic exceedance (area estimate)17,784 people on private wells
- Osceola County2% arsenic exceedance (area estimate)17,754 people on private wells
- Ogemaw County2% arsenic exceedance (area estimate)16,869 people on private wells
- Otsego County1% arsenic exceedance (area estimate)16,839 people on private wells
- Delta County4% arsenic exceedance (area estimate)16,560 people on private wells
- Manistee County5% arsenic exceedance (area estimate)16,506 people on private wells
- Leelanau County6% arsenic exceedance (area estimate)16,433 people on private wells
- Mason County5% arsenic exceedance (area estimate)16,128 people on private wells
- Antrim County4% arsenic exceedance (area estimate)15,969 people on private wells
- Iosco County5% arsenic exceedance (area estimate)15,292 people on private wells
- Charlevoix County5% arsenic exceedance (area estimate)15,240 people on private wells
- Chippewa County4% arsenic exceedance (area estimate)15,110 people on private wells
- Kalkaska County1% arsenic exceedance (area estimate)14,630 people on private wells
- Alpena County5% arsenic exceedance (area estimate)14,341 people on private wells
- Menominee County3% arsenic exceedance (area estimate)13,269 people on private wells
- Benzie County6% arsenic exceedance (area estimate)13,056 people on private wells
- Missaukee County2% arsenic exceedance (area estimate)12,465 people on private wells
- Arenac County11% arsenic exceedance (area estimate)12,219 people on private wells
- Crawford County2% arsenic exceedance (area estimate)12,141 people on private wells
- Lake County2% arsenic exceedance (area estimate)10,743 people on private wells
- Presque Isle County5% arsenic exceedance (area estimate)9,951 people on private wells
- Alcona County4% arsenic exceedance (area estimate)9,938 people on private wells
- Houghton County3% arsenic exceedance (area estimate)9,272 people on private wells
- Montmorency County2% arsenic exceedance (area estimate)8,960 people on private wells
- Oscoda County2% arsenic exceedance (area estimate)8,015 people on private wells
- Wayne County4% arsenic exceedance (area estimate)7,245 people on private wells
- Mackinac County4% arsenic exceedance (area estimate)7,185 people on private wells
- Dickinson County2% arsenic exceedance (area estimate)6,533 people on private wells
- Alger County5% arsenic exceedance (area estimate)6,531 people on private wells
- Schoolcraft County3% arsenic exceedance (area estimate)5,054 people on private wells
- Gogebic County4% arsenic exceedance (area estimate)4,076 people on private wells
- Ontonagon County6% arsenic exceedance (area estimate)3,678 people on private wells
- Baraga County3% arsenic exceedance (area estimate)3,374 people on private wells
- Luce County4% arsenic exceedance (area estimate)3,236 people on private wells
- Iron County2% arsenic exceedance (area estimate)1,563 people on private wells
- Keweenaw County6% arsenic exceedance (area estimate)560 people on private wells
Find a Michigan-certified testing lab
Get your well tested at a Michigan-certified laboratory. We list certification programs by state.
These figures are USGS area estimates: statistical groundwater models describing how likely elevated contaminant levels are across a county. They are not designed to predict the concentration in any single well. Only testing your own well reveals its water quality.
By TapWaterData Editorial
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