Well water in New Madrid County, Missouri

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Testing strongly recommended

private wells tested between 2010 and 2023 in New Madrid County had lead above the EPA limit (15 ug/L), according to Missouri DHSS.

112 private wells tested 2010 to 2023 in state summaries; 587 test results across 13 contaminants from at least 59 wells, 1931 to 2019; iron has the most at 108. Data refreshed September 15, 2026.

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

Missouri does not require private well testing, so these are samples homeowners chose to send to the state lab, often after a problem; shares above the limit run higher than a random survey would find.

An estimated 2,198 people in New Madrid County get their drinking water from a private well, per USGS 2015 county water use. That is about 12% of residents.

Separately, the USGS national arsenic model estimates that 5% of the 2,198 people on private wells in New Madrid County draw water above 10 ug/L (the model's range is 4% to 7%), from geology and well depth rather than local tests.

What homeowner tests found

Missouri DHSS private well sampling summaries: private wells tested and reported to the state, 2010 to 2023. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.

Contaminant	Above state level	Wells tested	State level
Iron	40%	25	300 ug/L
Lead	23%	112	15 ug/L
Nitrate	8%	26	10 mg/L
Chloride	0%	26	250 mg/L
Fluoride	0%	26	4 mg/L
Arsenic	0%	6	10 ug/L
Uranium	0%	2	30 ug/L

What individual samples found

Each row summarizes every public sample for that contaminant inside New Madrid 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 1932 to 2019	4%	83	80%	0.045	22	10 mg/L EPA limit
Arsenic 1970 to 2019	3%	31	35%	0	27	10 ug/L EPA limit
Fluoride 1936 to 2019	0%	52	96%	0.22	1.4	4 mg/L EPA limit
Lead 1970 to 2019	0%	31	23%	0	0.209	15 ug/L EPA limit
Copper 1970 to 2019	0%	12	25%	0	0	1.3 mg/L EPA limit
Iron 1931 to 2019	no limit	108	95%	265	19,100	300 ug/L nuisance level
Chloride 1931 to 2019	no limit	100	100%	18	1,300	250 mg/L nuisance level
Sodium 1931 to 2019	no limit	95	100%	16	620	20 mg/L health guideline
Manganese 1931 to 2019	no limit	63	100%	30	1,490	300 ug/L health guideline

Sampled fewer than 10 times, too few to summarize: Uranium (5), Radium (226 + 228) (3), E. coli (1), Radon (3).

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 homeowners in New Madrid County who sent a sample to the state lab, the health-based limits most often exceeded were lead (23% of 112 wells) and nitrate (8% of 26 wells). These are ordinary wells tested by their owners, so the shares are the best available picture of a typical well here, with one caveat: people test more often when they suspect a problem.

Iron exceeds the state's advisory level in a sizable share of wells; this is mostly a taste, staining or diet issue rather than a toxicity one.

What to test for in New Madrid County

1
Lead
23% of 112 local wells tested were above the EPA limit.
2
Nitrate
8% of 26 local wells tested were above the EPA limit.
3
Arsenic
3% of 31 local samples were above the limit.
4
Coliform bacteria
Recommended for every private well, every year.
5
Radon
Median local reading is 230 pCi/L.
6
Iron
40% of 25 local wells tested were above the EPA secondary standard.
7
Chloride
Detected in 100% of local samples.
8
Manganese
Detected in 100% of local samples.
9
Volatile organic compounds (VOCs)
1 leaking underground storage tank site on record locally.
10
Metals panel
3 hazardous waste sites on record locally.

Test your New Madrid County well for lead, nitrate and arsenic

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 Missouri: certified labs, state programs and prices.

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

Wells in New Madrid County

67 domestic wells in New Madrid County are on record with the state since 1986. the typical well is 90 feet deep (one in ten goes past 118 feet).

In a typical New Madrid County well, the median yield is 1,000 gallons per minute.

1980s

1990s

2000s

2010s

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 Missouri DNR WIMS and choose Water Well.
The certification record lists total depth, casing length, static water level, yield and the driller.

Missouri has required certification of new private wells since 1987, so a well drilled before then usually has no record.

The rock under New Madrid County

Mississippi River Valley alluvial 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.

Official help in Missouri

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 Drinking Water, Missouri DHSS
Certified Laboratories, Missouri DNR

Contamination sources on record in New Madrid County

Missouri DNR records 1 leaking underground storage tank site and 3 hazardous waste sites in New Madrid County, among 16 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.

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

Treatment that fits the local profile

Lead

Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching

Nitrate

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

Iron

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

Arsenic

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

Chloride

Point-of-use reverse osmosis; Distillation

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 lead

Under-sink reverse osmosis system

under-sink or countertop, about $300

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

For lead

Acid neutralizing filter

whole-house, at the point of entry, about $1,200

Raises pH so plumbing stops leaching lead and copper.

For lead

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.

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.

Free, no obligation

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

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

Common questions

How deep are wells in New Madrid County?

The typical domestic well in New Madrid County is 90 feet deep, based on 67 wells reported to the state since 1986. One in ten is deeper than 118 feet.

Is there arsenic in well water in New Madrid County?

Arsenic was detected in 35% of 31 public well samples in New Madrid County, and 3% 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 New Madrid 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 New Madrid 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 Missouri dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 587 samples in New Madrid 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.
Missouri DHSS private well sampling summaries: summaries for 7 contaminants in New Madrid County, up to 112 wells each. County summaries of private well samples analyzed by the Missouri State Public Health Laboratory, 2010 to 2023, published by the Missouri Department of Health and Senior Services. Counts are samples, not distinct wells. Shares are against the EPA maximum contaminant level, or the EPA secondary standard for chloride and iron. Counties with fewer than 20 samples are flagged unreliable by DHSS and are kept here with their counts so the threshold rule can judge them. Barium, sulfate and zinc layers exist but have no contaminant page yet. Retrieved September 15, 2026.
USGS national arsenic model (Ayotte 2017): estimated share of 2,198 people on private wells in New Madrid 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.
Missouri DNR certified well records: 4,125 well records in New Madrid County, 67 domestic. Well certification records from the Missouri Department of Natural Resources Wellhead Information Management System (WIMS), published through MSDIS. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 15, 2026.
Missouri DNR regulated sites: 16 regulated sites located in New Madrid County. Permitted solid waste facilities, and leaking tank, underground tank and hazardous waste sites from the historical CARES potential contaminant site inventory, Missouri Department of Natural Resources. Retrieved September 15, 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.