privatewelldata / States / Michigan / Nitrate
Nitrate in well water in Michigan
2% of 1,970 sampled wells in Michigan had nitrate above the EPA limit of 10 mg/L (as nitrogen) (latest result per well, 45 counties, samples 1933–2026). The highest county share was Van Buren County: 12% of 42 wells. Data updated 2026-10-18.
of sampled wells above 10 mg/L (as nitrogen)
wells with a result
counties with data
counties where 1 in 4+ wells were above
Nitrate in wells most often comes from fertilizer, manure and septic systems, so shallow wells near fields or septic fields are more exposed, and levels can change with the seasons. Only a lab test shows it. Federal limits apply to public water systems; a private well is the owner's responsibility to test (EPA).
% of sampled wells above the EPA limit (latest result per well; counties with 10+ wells). Source: USGS/EPA Water Quality Portal, 2026-10-18 · privatewelldata.com
Nitrate by county in Michigan
| County | Above 10 mg/L (as nitrogen) | Median | 90th pct. | Years |
|---|---|---|---|---|
| Van Buren County | 12% of 42 | 0.03 mg/L as N | 7 | 1976–1991 |
| Kalamazoo County | 11% of 64 | 0.084 mg/L as N | 10 | 1965–2013 |
| Dickinson County | 10% of 41 | 0.65 mg/L as N | 7.54 | 1975–1996 |
| Gogebic County | 9% of 11 | 0.23 mg/L as N | 1.2 | 1966–2014 |
| Livingston County | 8% of 53 | 0.113 mg/L as N | 8.07 | 1965–2016 |
| Hillsdale County | 6% of 17 | 0 mg/L as N | 5.647 | 1976–2016 |
| Ionia County | 6% of 18 | 0.079 mg/L as N | 0.58 | 1965–1991 |
| Iosco County | 2% of 62 | 0.03 mg/L as N | 3.1 | 1978–1996 |
| Oakland County | 1% of 298 | 0 mg/L as N | 1.35 | 1938–2016 |
| Grand Traverse County | 1% of 217 | 0.3 mg/L as N | 5 | 1977–1987 |
| Marquette County | 1% of 124 | 0.045 mg/L as N | 0.66 | 1970–2015 |
| Washtenaw County | 1% of 178 | 0 mg/L as N | 0 | 1941–2016 |
| Ingham County | 0% of 115 | 0 mg/L as N | 0.124 | 1952–2017 |
| Monroe County | 0% of 69 | 0 mg/L as N | 0.023 | 1961–1992 |
| Clinton County | 0% of 54 | 0.011 mg/L as N | 0.452 | 1949–1986 |
| Huron County | 0% of 46 | 0 mg/L as N | 0 | 1980–2004 |
| St. Clair County | 0% of 41 | 0 mg/L as N | 0.113 | 1971–2016 |
| Saginaw County | 0% of 39 | 0 mg/L as N | 0.02 | 1978–1986 |
| Eaton County | 0% of 38 | 0 mg/L as N | 0.248 | 1953–2013 |
| Delta County | 0% of 35 | 0.01 mg/L as N | 0.384 | 1948–2015 |
| Genesee County | 0% of 26 | 0 mg/L as N | 0.23 | 1953–1997 |
| Alger County | 0% of 25 | 0.01 mg/L as N | 0.59 | 1960–2014 |
| Bay County | 0% of 22 | 0 mg/L as N | 0 | 1975–1984 |
| Barry County | 0% of 21 | 0.136 mg/L as N | 0.66 | 1965–1986 |
| Midland County | 0% of 21 | 0 mg/L as N | 0.63 | 1981–1986 |
| Gratiot County | 0% of 19 | 0 mg/L as N | 0.1 | 1965–1986 |
| Jackson County | 0% of 19 | 0 mg/L as N | 0.71 | 1965–2022 |
| Lapeer County | 0% of 19 | 0 mg/L as N | 0.05 | 1982–2016 |
| Baraga County | 0% of 18 | 0.05 mg/L as N | 0.28 | 1977–1997 |
| Roscommon County | 0% of 18 | 0 mg/L as N | 0.484 | 1975–2007 |
| Kent County | 0% of 17 | 0.068 mg/L as N | 0.429 | 1965–1991 |
| Leelanau County | 0% of 17 | 0.05 mg/L as N | 0.6 | 1979–1985 |
| Lenawee County | 0% of 17 | 0 mg/L as N | 0.15 | 1971–2016 |
| Antrim County | 0% of 15 | 0.159 mg/L as N | 0.651 | 1977–2026 |
| Gladwin County | 0% of 15 | 0 mg/L as N | 0.04 | 1977–2013 |
| Chippewa County | 0% of 14 | 0.01 mg/L as N | 0.22 | 1975–1995 |
| Menominee County | 0% of 14 | 0 mg/L as N | 0 | 1976–2015 |
| Tuscola County | 0% of 13 | 0 mg/L as N | 0 | 1980–1986 |
| Isabella County | 0% of 12 | 0 mg/L as N | 0 | 1981–2004 |
| Schoolcraft County | 0% of 12 | 0 mg/L as N | 0.023 | 1933–2014 |
| Shiawassee County | 0% of 12 | 0 mg/L as N | 0 | 1958–1986 |
| Iron County | 0% of 11 | 0.113 mg/L as N | 4.111 | 1965–2014 |
| Muskegon County | 0% of 11 | 0 mg/L as N | 0.03 | 1976–2015 |
| Calhoun County | 0% of 10 | 0 mg/L as N | 0 | 1975–1986 |
| Ottawa County | 0% of 10 | 0.192 mg/L as N | 0.587 | 1965–1991 |
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Download this table (CSV) · public-domain source data: Water Quality Portal (USGS, EPA, NWQMC). How we calculate these numbers.
How Michigan compares
Share of sampled wells above the EPA nitrate limit in each state we cover (states with 100+ wells).
| # | State | Above 10 mg/L (as nitrogen) |
|---|---|---|
| 1 | California | 10% of 16,344 |
| 2 | Pennsylvania | 8% of 6,478 |
| 3 | Minnesota | 6% of 7,259 |
| 4 | North Carolina | 5% of 1,964 |
| 5 | New York | 5% of 6,236 |
| 6 | Massachusetts | 4% of 2,556 |
| 7 | New Jersey | 4% of 3,915 |
| 8 | Wisconsin | 4% of 3,666 |
| 9 | Virginia | 3% of 1,394 |
| 10 | Maine | 2% of 726 |
| 11 | Michigan | 2% of 1,970 |
| 12 | Ohio | 1% of 1,239 |
| 13 | New Hampshire | 0% of 1,685 |
Where to test: official lab list for Michigan
About this data
- Each well counts once, using its latest nitrate result in the Water Quality Portal (siteType = Well), downloaded 2026-10-18.
- Results reported as "not detected" count as below the limit. Results far outside the plausible range are withheld for review, not shown.
- Sampled wells include monitoring and research wells, not only household wells, and are not a random sample, so the share is a guide to local risk, not a rate for all homes.
- The limit is the EPA maximum contaminant level for public water systems (EPA).
Questions
Is nitrate common in Michigan well water?
In our data, 32 of 1,970 sampled wells in Michigan (2%) had a latest nitrate result above the EPA limit of 10 mg/L (as nitrogen), across 45 counties. That ranks Michigan 11 of 13 states we cover for this share.
Which Michigan counties have the most wells above the nitrate limit?
Among counties with at least 10 sampled wells: Van Buren County (12%, 5 of 42 wells); Kalamazoo County (11%, 7 of 64 wells); Dickinson County (10%, 4 of 41 wells).
Does this tell me whether my well is safe?
No. These are past results from wells sampled by USGS, EPA and state programs, including monitoring wells, and levels differ from well to well. The only way to know your water is to test your own well at a certified lab.
How do I test my well for nitrate in Michigan?
Order a nitrate test from a lab on Michigan's official certified-lab list (linked on this page) and ask for its bottles and sampling instructions. Our test helper suggests what else to test for at the same time.
What should I do if my nitrate result is above 10 mg/L (as nitrogen)?
Retest to confirm, use another water source for drinking and cooking while you sort it out, and look at certified treatment options. Our guide walks through each step with sources.