Well Water Nerd

Well water in Cherokee County, Iowa

1in13

Testing recommended

tested well samples in Cherokee County exceeded the EPA limit for radium (226 + 228) (5 pCi/L), based on public data from USGS Water Quality Portal.

1,462 test results across 12 contaminants from at least 75 wells, 1910 to 2016; chloride has the most at 199. Data refreshed September 15, 2026.

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

An estimated 1,940 people in Cherokee County get their drinking water from a private well, per USGS 2015 county water use. That is about 17% of residents.

Separately, the USGS national arsenic model estimates that 4% of the 1,940 people on private wells in Cherokee County draw water above 10 ug/L (the model's range is 3% to 5%), from geology and well depth rather than local tests.

What individual samples found

Each row summarizes every public sample for that contaminant inside Cherokee 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.

ContaminantAbove limitSamplesDetectedMedianHighestLimit
Radium (226 + 228)
1974 to 2012
12177%295 pCi/L
EPA limit
Nitrate
1934 to 2006
17358%0.0252.710 mg/L
EPA limit
Fluoride
1934 to 2013
184100%0.72.24 mg/L
EPA limit
Lead
1973 to 2013
805%0115 ug/L
EPA limit
Copper
1973 to 2013
8013%00.031.3 mg/L
EPA limit
Arsenic
1973 to 2013
8031%01010 ug/L
EPA limit
Chloride
1910 to 2016
no limit19991%343250 mg/L
nuisance level
Iron
1910 to 2013
no limit18295%1,10035,000300 ug/L
nuisance level
Manganese
1934 to 2013
no limit17988%1801,600300 ug/L
health guideline
Sodium
1952 to 2013
no limit168100%4328020 mg/L
health guideline
Radon
1982 to 2005
no limit1331%04152,000 pCi/L
health guideline

Sampled fewer than 10 times, too few to summarize: Uranium (3).

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.

Contaminantbefore 20002000s2010s2020s
Fluoride0%147 samples0%33 samplesn/an/a
Nitrate3%154 samples0%19 samplesn/an/a
Radium (226 + 228)26%31 samples1%86 samplesn/an/a
Lead0%49 samples0%27 samplesn/an/a
Copper0%49 samples0%27 samplesn/an/a
Arsenic0%49 samples0%27 samplesn/an/a

Radium (226 + 228) above the limit in Cherokee County fell from 26% of 31 samples before 2000 to 1% of 86 in the 2000s.

Fluoride, lead, copper, arsenic 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 radium (226 + 228) (7% of 121 samples) and nitrate (2% of 173 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.

Chloride, Iron, 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 Cherokee County

  1. 1
    Radium (226 + 228)
    7% of 121 local samples were above the limit.
  2. 2
    Nitrate
    2% of 173 local samples were above the limit.
  3. 3
    Coliform bacteria
    Recommended for every private well, every year.
  4. 4
    Fluoride
    Detected in 100% of local samples.
  5. 5
    Iron
    Detected in 95% of local samples.
  6. 6
    Chloride
    Detected in 91% of local samples.
  7. 7
    Manganese
    Detected in 88% of local samples.
  8. 8
    Volatile organic compounds (VOCs)
    33 leaking underground storage tank sites on record locally.
  9. 9
    Metals panel
    4 hazardous waste sites on record locally.

Test your Cherokee County well for radium (226 + 228), nitrate and coliform bacteria

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 $209Already 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 Iowa: certified labs, state programs and prices.

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

The rock under Cherokee 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 Iowa

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.

Contamination sources on record in Cherokee County

Iowa DNR records 33 leaking underground storage tank sites and 4 hazardous waste sites in Cherokee County, among 49 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.

33
leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
4
hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
2
lined landfills and transfer facilities
2
other remediation projects
8
other solid waste facilities

Treatment that fits the local profile

Radium (226 + 228)

Water softener (cation exchange); Point-of-use reverse osmosis

Nitrate

Point-of-use reverse osmosis; Anion exchange; 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 radium (226 + 228)

Under-sink reverse osmosis system

under-sink or countertop, about $300

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

For nitrate

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 Cherokee County

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Common questions

Is there arsenic in well water in Cherokee County?

Arsenic was detected in 31% of 80 public well samples in Cherokee County, and 0% 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 Cherokee County?

The median radon level across 13 public samples in Cherokee County was 0 pCi/L, with a high of 415 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Cherokee 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.

Counties near Cherokee 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 Iowa dataset as CSV, every county and town, with the sources named.

Sources

  • USGS Water Quality Portal: 1,462 samples in Cherokee 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 1,940 people on private wells in Cherokee 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.
  • Iowa DNR regulated sites: 49 regulated sites located in Cherokee County. Contaminated sites, solid waste facilities and leaking underground storage tank sites from the Iowa Department of Natural Resources. Retrieved September 18, 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.