Well water in Oakland County, Michigan

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Testing strongly recommended

tested well samples in Oakland County exceeded the EPA limit for arsenic (10 ug/L), based on public data from USGS Water Quality Portal.

3,239 test results across 13 contaminants from at least 335 wells, 1901 to 2026; nitrate has the most at 554. Data refreshed September 15, 2026.

Compiled by Nick at Well Water Nerd from public records. How these pages are built

An estimated 217,662 people in Oakland County get their drinking water from a private well, per USGS 2015 county water use. That is about 18% of residents.

Separately, the USGS national arsenic model estimates that 3% of the 217,662 people on private wells in Oakland County draw water above 10 ug/L (the model's range is 3% to 4%), from geology and well depth rather than local tests.

What individual samples found

Each row summarizes every public sample for that contaminant inside Oakland County. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.

Contaminant	Above limit	Samples	Detected	Median	Highest	Limit
Arsenic 1975 to 2023	52%	233	89%	11	194	10 ug/L EPA limit
Nitrate 1938 to 2026	5%	554	64%	0	90.3	10 mg/L EPA limit
Fluoride 1901 to 2023	<1%	374	93%	0.2	8.2	4 mg/L EPA limit
Copper 1956 to 2023	0%	97	51%	0	0.036	1.3 mg/L EPA limit
Uranium 1929 to 2023	0%	94	88%	0.555	9.21	30 ug/L EPA limit
Lead 1975 to 2023	0%	93	42%	0	2	15 ug/L EPA limit
E. coli 1997 to 2016	0%	80	0%	0	0	0 MPN/100mL EPA limit
Radium (226 + 228) 2007 to 2016	0%	60	87%	0.365	2.5	5 pCi/L EPA limit
Iron 1901 to 2023	no limit	477	95%	941	6,430	300 ug/L nuisance level
Chloride 1901 to 2023	no limit	445	100%	22	57,500	250 mg/L nuisance level
Manganese 1956 to 2023	no limit	355	93%	20	1,000	300 ug/L health guideline
Sodium 1901 to 2023	no limit	348	100%	15	2,650	20 mg/L health guideline
Radon 1996 to 2013	no limit	29	100%	180	690	2,000 pCi/L health guideline

Over time

Share of samples above the limit by period. A cell needs ten samples to show; a comparison needs twenty in each period. Later periods sample fewer wells, and often the ones already known to have a problem.

Contaminant	before 2000	2000s	2010s	2020s
Nitrate	3%376 samples	6%110 samples	9%64 samples	n/a
Fluoride	<1%287 samples	0%54 samples	0%32 samples	n/a
Arsenic	70%162 samples	11%38 samples	9%32 samples	n/a
Copper	0%26 samples	0%38 samples	0%32 samples	n/a
Uranium	0%23 samples	0%38 samples	0%32 samples	n/a
Lead	0%22 samples	0%38 samples	0%32 samples	n/a

Nitrate, fluoride, arsenic, copper, uranium, lead have held within a few points between the two most recent periods with enough samples.

Closer than the county

See the sampled wells near your address

The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.

Check my address

What this means

The contaminants most often above their limit here are arsenic (52% of 233 samples), nitrate (5% of 554 samples), and fluoride (<1% of 374 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.

Iron, Chloride, and Manganese are widespread in local groundwater. They are mainly a staining and taste problem, but high manganese also carries a health advisory for infants.

What to test for in Oakland County

1
Arsenic
52% of 233 local samples were above the limit.
2
Nitrate
5% of 554 local samples were above the limit.
3
Fluoride
<1% of 374 local samples were above the limit.
4
Coliform bacteria
Recommended for every private well, every year.
5
Radon
Median local reading is 180 pCi/L.
6
Chloride
Detected in 100% of local samples.
7
Iron
Detected in 95% of local samples.
8
Volatile organic compounds (VOCs)
520 leaking underground storage tank sites on record locally.
9
Metals panel
1,958 hazardous waste sites on record locally.

Test your Oakland County well for arsenic, nitrate and fluoride

Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.

Order the Tap Score well water test kit, from $209 Already tested? Upload the report

Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.

Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.

Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.

Where to get a well tested in Michigan: certified labs, state programs and prices.

Already have results back? Get your lab report read against the Oakland County numbers, $29. Every line explained, ranked by what matters, with the fix for each.

Wells in Oakland County

64,030 domestic wells in Oakland County are on record with the state since 1917. 3% are drilled into bedrock, and the typical well is 88 feet deep (one in ten goes past 170 feet).

In a typical Oakland County well, bedrock starts about 177 feet down, the median yield is 28 gallons per minute, <1% of wells yield under 3 gallons per minute and usually need a storage tank.

1950s

2,801

1960s

9,542

1970s

9,411

1980s

17,002

1990s

13,393

2000s

7,522

2010s

3,822

2020s

Find your own well's report

The state keeps the driller's report for most wells drilled since 1984. It tells you how deep your well is, where bedrock starts, and how much water it makes, which decides what treatment can work.

Open Wellogic (EGLE) and choose Water Well.
The record lists depth, casing, static water level, the pump test and the geologic log.

Michigan has required well records since 1966, so most drilled wells are on file.

The rock under Oakland County

Not a principal aquifer

The USGS map places this area outside any principal aquifer, which usually means wells here draw from fractured bedrock or thin local deposits rather than a large regional aquifer. Bedrock wells of that kind are where arsenic, radon and uranium turn up, and yields vary from well to well.

Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the county centroid. A single well can sit in a different unit, especially near a boundary.

Official help in Michigan

Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.

Private Residential Water Well Testing, Michigan EGLE
Laboratory certification program, Michigan EGLE

Contamination sources on record in Oakland County

Michigan EGLE records 520 leaking underground storage tank sites and 1,958 hazardous waste sites in Oakland County, among 4,559 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.

520: leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
1,958: hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
2,080: registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
1: lined landfill or transfer facility

Treatment that fits the local profile

Arsenic

Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange

Nitrate

Point-of-use reverse osmosis; Anion exchange; Distillation

Fluoride

Point-of-use reverse osmosis; Activated alumina; Distillation

Iron

Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration

Manganese

Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis

Systems we would look at first

Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.

For arsenic

Under-sink reverse osmosis system

under-sink or countertop, about $300

Look for NSF/ANSI 58 certification listing the contaminant you need removed.

For arsenic

Whole-house arsenic and uranium filter

whole-house, at the point of entry, about $2,500

Adsorptive iron-based media; sized to your well yield.

For arsenic

Aquasana SmartFlow reverse osmosis

under-sink or countertop, about $225

Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.

For iron

Iron and manganese oxidizing filter

whole-house, at the point of entry, about $1,800

Air-injection or greensand media; fixes staining at the source.

Free, no obligation

Get on the list for a free in-home water test in Oakland County

No water treatment company serves Oakland County through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Oakland County, and you get an email naming it first.

Common questions

How deep are wells in Oakland County?

The typical domestic well in Oakland County is 88 feet deep, based on 64,030 wells reported to the state since 1917. One in ten is deeper than 170 feet. 3% are drilled into bedrock.

Is there arsenic in well water in Oakland County?

Arsenic was detected in 89% of 233 public well samples in Oakland County, and 52% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.

How high is radon in well water in Oakland County?

The median radon level across 29 public samples in Oakland County was 180 pCi/L, with a high of 690 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Oakland County?

Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.

Towns in Oakland County

44 towns have fewer than 30 public samples and are included in the Oakland County totals above rather than shown separately: Addison township, Auburn Hills, Berkley, Birmingham, Bloomfield charter township, Bloomfield Hills, Clawson, Farmington, Farmington Hills, Fenton, Ferndale, Groveland township, Hazel Park, Highland charter township, Huntington Woods, Keego Harbor, Lake Angelus, Lathrup Village, Lyon charter township, Madison Heights, Milford charter township, Northville, Novi, Novi township, Oak Park, Orchard Lake Village, Oxford charter township, Pleasant Ridge, Rochester, Rochester Hills, Rose township, Royal Oak, Royal Oak charter township, Southfield, Southfield township, South Lyon, Sylvan Lake, Troy, Village of Clarkston, Walled Lake, Waterford charter township, West Bloomfield charter township, White Lake charter township, Wixom.

Counties near Oakland County

Closest first. Groundwater does not stop at a line on a map, so the next county over is a fair second opinion.

Want the numbers themselves? Download the Michigan dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 3,239 samples in Oakland County. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
USGS national arsenic model (Ayotte 2017): estimated share of 217,662 people on private wells in Oakland County above 10 ug/L of arsenic, from geology, well depth and land use. County estimates of domestic well users with arsenic above 10 ug/L from the USGS national logistic regression model (Ayotte, Medalie and Qi, 2017), with private well population from the USGS 2015 county water-use compilation (Dieter and others, 2018). Retrieved September 15, 2026.
Michigan Wellogic well records: 64,030 well records in Oakland County, 64,030 domestic. Water well records from Wellogic, the Michigan Department of Environment, Great Lakes, and Energy statewide well database. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 16, 2026.
Michigan EGLE regulated sites: 4,559 regulated sites located in Oakland County. Part 201 environmental contamination sites, underground storage tank facilities and Part 115 landfills from the Michigan Department of Environment, Great Lakes, and Energy. Retrieved September 16, 2026.

Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.