State Well Water Guide
Michigan Private Well Water Guide
Michigan has one of the highest rates of private well use in the Great Lakes region — about 42% of residents, or roughly 4 million people, rely on private wells. Michigan's diverse geology creates varied contamination risks: arsenic in specific glacial outwash deposits (particularly in the Kent County and nearby areas), PFAS contamination from numerous industrial and military sites (including the Plainfield Township PFAS crisis and Wurtsmith AFB), naturally elevated radon in some areas, and agricultural nitrate and bacterial contamination in rural counties. The Michigan PFAS Action Response Team (MPART) has been nationally recognized for its aggressive monitoring program. EGLE regulates well construction under Part 127 of the Michigan Public Health Code.
Testing Guidance
Michigan recommends annual testing for coliform bacteria and nitrates. Kent County and adjacent area well owners should test for arsenic — Michigan's highest-risk area for natural arsenic. All well owners should test for PFAS given Michigan's extensive PFAS contamination map. Well owners near Wurtsmith AFB, Kalamazoo, and the West Michigan industrial corridor should be especially diligent about PFAS testing.
What to Test For in Michigan
Total coliform bacteria and E. coli — annual minimum
Arsenic — Kent, Ottawa, Allegan, Barry, and adjacent counties (glacial outwash deposits)
PFAS — Michigan has one of the most extensive PFAS contamination maps in the nation; testing recommended statewide
Nitrates — agricultural areas in the Lower Peninsula
Iron and manganese — glacial sediment aquifer wells throughout Michigan
Radon — northern Michigan crystalline basement areas
Volatile organic compounds — near industrial sites in the Kalamazoo, Grand Rapids, and Detroit metro areas
Common Contamination Risks in Michigan
Arsenic from glacial outwash — Kent County and surrounding areas have some of the highest rates of naturally elevated arsenic in Michigan private wells; a significant public health concern
PFAS from industrial and military sources — Michigan has hundreds of identified PFAS contamination sites; Plainfield Township's contamination from Wolverine Worldwide was a national story
Iron and manganese from glacial sediments — extremely common throughout Michigan's glaciated landscape
Bacterial contamination from agricultural and septic sources — Michigan's many farms and rural communities create contamination risk
Trichloroethylene from industrial sites — legacy manufacturing contamination in multiple Michigan communities
Contaminant Guides Relevant to MI Wells
PFAS
Synthetic Chemicals
EPA limit: 4 ppt
Lead
Heavy Metals
EPA limit: 15 ppb (action level)
Nitrates
Agricultural Chemicals
EPA limit: 10 mg/L
DBPs
Disinfection Byproducts
EPA limit: 80 µg/L (TTHMs) / 60 µg/L (HAA5)
Arsenic
Heavy Metals
EPA limit: 10 ppb
Hard Water
Minerals
EPA limit: No federal limit
Chlorine
Disinfection Chemicals
EPA limit: 4 mg/L (MRDL)
Microplastics
Emerging Contaminants
EPA limit: No federal limit
Bacteria
Microbial Contamination
EPA limit: Zero E. coli / < 1 coliform per 100 mL
Fluoride
Minerals
EPA limit: 4 mg/L (MCL) / 2 mg/L (Secondary MCL)
Chromium-6
Heavy Metals
EPA limit: 100 ppb (total chromium)
Copper
Heavy Metals
EPA limit: 1.3 mg/L (action level)
Radon
Radioactive Contaminants
EPA limit: No finalized MCL
Iron & Manganese
Minerals
EPA limit: 0.3 mg/L iron / 0.05 mg/L manganese (aesthetic SMCLs)
Atrazine
Agricultural Chemicals
EPA limit: 3 ppb (0.003 mg/L)
Uranium
Radioactive Contaminants
EPA limit: 30 µg/L (30 ppb)
Perchlorate
Industrial Chemicals
EPA limit: 0.056 mg/L (56 ppb)
VOCs
Industrial Chemicals
EPA limit: Varies by compound: benzene 5 ppb; TCE 5 ppb; PCE 5 ppb; vinyl chloride 2 ppb
Radium
Radioactive Contaminants
EPA limit: 5 pCi/L (combined Ra-226 + Ra-228)
Crypto & Giardia
Microbial Contamination
EPA limit: Zero (treatment technique standard)
Hydrogen Sulfide
Naturally Occurring Compounds
EPA limit: No MCL; Secondary MCL (aesthetic) of 0.05 mg/L
Selenium
Minerals
EPA limit: 50 ppb (0.05 mg/L)
Cadmium
Heavy Metals
EPA limit: 5 ppb (0.005 mg/L)
Mercury
Heavy Metals
EPA limit: 2 ppb (0.002 mg/L)
Barium
Heavy Metals
EPA limit: 2 mg/L
Find a Certified Lab in Michigan
Use the Michigan state-certified laboratory program to find accredited labs for private well testing. Always verify current certification before submitting samples.
MI Certified Lab Directory ↗Michigan Well Water FAQs
Related Pages
Data Sources & Provenance
All data on this page is sourced from official U.S. government or public datasets.
Quick Reference
State program
MI Certified Labs ↗EPA guidance
EPA Private Wells Program ↗State lab directory
MI Certified Labs ↗Minimum Annual Tests
Plus state-specific contaminants listed above
Other State Guides