Well water in Hamilton County, Kansas

Name: Private well water quality in Hamilton County, Kansas
Creator: Well Water Nerd
License: Public domain (US federal government data)

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Testing recommended

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

738 test results across 13 contaminants from at least 89 wells, 1940 to 2018; chloride has the most at 148. Data refreshed September 15, 2026.

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

An estimated 659 people in Hamilton County get their drinking water from a private well, per USGS 2015 county water use. That is about 27% of residents.

Separately, the USGS national arsenic model estimates that 4% of the 659 people on private wells in Hamilton 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 Hamilton 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
Nitrate 1940 to 2018	16%	95	100%	2.58	62	10 mg/L EPA limit
Arsenic 1977 to 2018	12%	17	59%	0	39	10 ug/L EPA limit
Fluoride 1940 to 2018	0%	143	100%	1	3.5	4 mg/L EPA limit
Lead 1977 to 2018	0%	16	63%	0	0.104	15 ug/L EPA limit
Copper 1977 to 2018	0%	16	50%	0	0.04	1.3 mg/L EPA limit
Chloride 1940 to 2018	no limit	148	100%	29	2,800	250 mg/L nuisance level
Sodium 1940 to 2018	no limit	148	100%	98	4,900	20 mg/L health guideline
Iron 1940 to 2018	no limit	97	96%	120	7,000	300 ug/L nuisance level
Manganese 1959 to 2018	no limit	45	71%	20	400	300 ug/L health guideline

Sampled fewer than 10 times, too few to summarize: Radium (226 + 228) (7), Uranium (3), E. coli (1), Radon (2).

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 nitrate (16% of 95 samples) and arsenic (12% of 17 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 Hamilton County

1
Nitrate
16% of 95 local samples were above the limit.
2
Arsenic
12% of 17 local samples were above the limit.
3
Coliform bacteria
Recommended for every private well, every year.
4
Radon
Median local reading is 660 pCi/L.
5
Radium (226 + 228)
Above the limit in 1 of 7 local samples; too few to quote a rate.
6
Fluoride
Detected in 100% of local samples.
7
Chloride
Detected in 100% of local samples.
8
Volatile organic compounds (VOCs)
32 leaking underground storage tank sites on record locally.

Test your Hamilton County well for nitrate, arsenic 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 $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 Kansas: certified labs, state programs and prices.

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

The rock under Hamilton County

High Plains aquifer

Unconsolidated sand and gravel. Wells in sand and gravel are usually shallow and productive, and they recharge quickly from the surface. That makes them the most exposed to nitrate, bacteria and anything spilled nearby, and the least likely to carry arsenic or radon from the rock.

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.

Contamination sources on record in Hamilton County

KDHE records 32 leaking underground storage tank sites in Hamilton County, among 43 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.

32: leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
9: other remediation projects
2: other solid waste facilities

Treatment that fits the local profile

Nitrate

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

Arsenic

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

Fluoride

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

Chloride

Point-of-use reverse osmosis; Distillation

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 nitrate

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 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 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 Hamilton County

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

Common questions

Is there arsenic in well water in Hamilton County?

Arsenic was detected in 59% of 17 public well samples in Hamilton County, and 12% 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 often should I test a private well in Hamilton 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 Hamilton 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 Kansas dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 738 samples in Hamilton 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 659 people on private wells in Hamilton 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.
KDHE regulated sites: 43 regulated sites located in Hamilton County. Identified contaminated sites, leaking underground storage tank facilities and solid waste facilities from the Kansas Department of Health and Environment. Retrieved September 9, 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.