Well water in Mason County, Michigan

No public well test results have been compiled for Mason County yet. The USGS national arsenic model estimates that 7% of the 17,676 people on private wells there draw water with arsenic above 10 ug/L, the EPA limit, based on geology, well depth and land use rather than local tests.

The strongest signal is coliform bacteria: Recommended for every private well, every year, too few samples to carry the headline but first on the test list below.

29 test results across 9 contaminants from at least 4 wells, 1977 to 1987; arsenic has the most at 4. Data refreshed September 15, 2026.

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

Data confidence: estimate. No state program or federal monitoring data for Mason County has been compiled here yet, so the arsenic figure is the USGS national model, not a measurement. Treat a high estimate as a reason to test, not as your well's number. Measured results are added as states publish them.

An estimated 17,676 people in Mason County get their drinking water from a private well, per USGS 2015 county water use. That is about 61% of residents.

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

Among contaminants with a federal limit, no tested sample in Mason County came back above it. That is reassuring, but sampling is uneven: wells that were never tested are not in this data.

Manganese, Iron, and Chloride 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 Mason County

1
Coliform bacteria
Recommended for every private well, every year.
2
Nitrate
Recommended for every private well, especially near farms or septic systems.
3
Fluoride
Detected in 100% of local samples.
4
Copper
Detected in 100% of local samples.
5
Manganese
Detected in 100% of local samples.
6
Chloride
Detected in 100% of local samples.
7
Iron
Detected in 75% of local samples.
8
Volatile organic compounds (VOCs)
44 leaking underground storage tank sites on record locally.
9
Metals panel
107 hazardous waste sites on record locally.

Test your Mason County well for coliform bacteria, 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 Mason County numbers, $29. Every line explained, ranked by what matters, with the fix for each.

Wells in Mason County

7,922 domestic wells in Mason County are on record with the state since 1955. <1% are drilled into bedrock, and the typical well is 70 feet deep (one in ten goes past 147 feet).

In a typical Mason County well, the median yield is 20 gallons per minute, <1% of wells yield under 3 gallons per minute and usually need a storage tank.

169

1960s

592

1970s

924

1980s

1,751

1990s

2,266

2000s

1,219

2010s

991

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 Mason 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 Mason County

Michigan EGLE records 44 leaking underground storage tank sites and 107 hazardous waste sites in Mason County, among 298 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.

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

Treatment that fits the local profile

Manganese

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

Iron

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

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 manganese

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 Mason County

No water treatment company serves Mason 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 Mason County, and you get an email naming it first.

Common questions

How deep are wells in Mason County?

The typical domestic well in Mason County is 70 feet deep, based on 7,922 wells reported to the state since 1955. One in ten is deeper than 147 feet. <1% are drilled into bedrock.

How often should I test a private well in Mason 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 Mason County

17 towns have fewer than 30 public samples and are included in the Mason County totals above rather than shown separately: Amber township, Branch township, Custer township, Eden township, Free Soil township, Grant township, Hamlin township, Logan township, Ludington, Meade township, Pere Marquette charter township, Riverton township, Scottville, Sheridan township, Sherman township, Summit township, Victory township.

Counties near Mason 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: 29 samples in Mason 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 17,676 people on private wells in Mason 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: 7,922 well records in Mason County, 7,922 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: 298 regulated sites located in Mason 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.