Well water in Converse County, Wyoming
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Testing strongly recommended
tested well samples in Converse County exceeded the EPA limit for uranium (30 ug/L), based on public data from USGS Water Quality Portal.
1,036 test results across 13 contaminants from at least 130 wells, 1923 to 2024; nitrate has the most at 190. Data refreshed September 15, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
An estimated 4,741 people in Converse County get their drinking water from a private well, per USGS 2015 county water use. That is about 33% of residents.
Separately, the USGS national arsenic model estimates that 5% of the 4,741 people on private wells in Converse 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 individual samples found
Each row summarizes every public sample for that contaminant inside Converse 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 |
|---|---|---|---|---|---|---|
| Uranium 1980 to 2013 | 50 | 78% | 8.6 | 340 | 30 ug/L EPA limit | |
| Arsenic 1975 to 2013 | 41 | 29% | 0 | 150 | 10 ug/L EPA limit | |
| Radium (226 + 228) 1975 to 1983 | 42 | 100% | 0.655 | 220 | 5 pCi/L EPA limit | |
| Nitrate 1950 to 2024 | 190 | 79% | 0.354 | 49.8 | 10 mg/L EPA limit | |
| Lead 1974 to 2013 | 41 | 27% | 0 | 100 | 15 ug/L EPA limit | |
| Fluoride 1950 to 2013 | 138 | 96% | 0.5 | 5.7 | 4 mg/L EPA limit | |
| Copper 1974 to 2013 | 38 | 29% | 0 | 0.79 | 1.3 mg/L EPA limit | |
| E. coli 2013 | 29 | 0% | 0 | 0 | 0 MPN/100mL EPA limit | |
| Chloride 1923 to 2013 | no limit | 148 | 100% | 12.5 | 25,700 | 250 mg/L nuisance level |
| Sodium 1923 to 2013 | no limit | 148 | 100% | 120 | 15,100 | 20 mg/L health guideline |
| Iron 1950 to 2013 | no limit | 103 | 80% | 80 | 110,000 | 300 ug/L nuisance level |
| Manganese 1974 to 2013 | no limit | 61 | 85% | 20 | 3,000 | 300 ug/L health guideline |
Sampled fewer than 10 times, too few to summarize: Radon (7).
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 | 8%110 samples | 14%44 samples | 6%32 samples | n/a |
| Fluoride | 6%108 samples | n/a | 0%30 samples | n/a |
| Uranium | 15%20 samples | n/a | 40%30 samples | n/a |
| Arsenic | 18%11 samples | n/a | 13%30 samples | n/a |
| Lead | 18%11 samples | n/a | 3%30 samples | n/a |
Nitrate above the limit in Converse County fell from 14% of 44 samples in the 2000s to 6% of 32 in the 2010s.
Fluoride above the limit in Converse County fell from 6% of 108 samples before 2000 to 0% of 30 in the 2010s.
Uranium above the limit in Converse County rose from 15% of 20 samples before 2000 to 40% of 30 in the 2010s.
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 addressWhat this means
The contaminants most often above their limit here are uranium (30% of 50 samples), arsenic (15% of 41 samples), and radium (226 + 228) (14% of 42 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 Converse County
- 1Uranium30% of 50 local samples were above the limit.
- 2Arsenic15% of 41 local samples were above the limit.
- 3Radium (226 + 228)14% of 42 local samples were above the limit.
- 4Nitrate11% of 190 local samples were above the limit.
- 5Lead7% of 41 local samples were above the limit.
- 6Fluoride4% of 138 local samples were above the limit.
- 7Coliform bacteriaRecommended for every private well, every year.
Test your Converse County well for uranium, arsenic and radium (226 + 228)
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 Wyoming: certified labs, state programs and prices.
Already have results back? Get your lab report read against the Converse County numbers, $29. Every line explained, ranked by what matters, with the fix for each.
The rock under Converse County
Lower Tertiary aquifers
Sandstone. Sandstone wells draw from pore space in the rock and tend to be dependable. Iron, manganese and hardness are common, and some sandstones carry arsenic or radium, so a first test should include both.
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 Wyoming
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.
- Know Your Well, Wyoming DEQ
- Certified Drinking Water Laboratories for Systems in Wyoming (EPA Region 8), EPA Region 8
Treatment that fits the local profile
Uranium
Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange
Arsenic
Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
Radium (226 + 228)
Water softener (cation exchange); Point-of-use reverse osmosis
Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation
Lead
Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching
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 uranium
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For uranium
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 lead
Aquasana Claryum 3-Stage under-sink filter
under-sink or countertop, about $175
Certified to NSF/ANSI 53 to reduce 99% of lead and 99.7% of PFOA and PFOS at the tap. Not a fix for arsenic, nitrate or bacteria.
For lead
Acid neutralizing filter
whole-house, at the point of entry, about $1,200
Raises pH so plumbing stops leaching lead and copper.
Free, no obligation
Get on the list for a free in-home water test in Converse County
No water treatment company serves Converse 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 Converse County, and you get an email naming it first.
Common questions
Is there arsenic in well water in Converse County?
Arsenic was detected in 29% of 41 public well samples in Converse County, and 15% 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 Converse 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 Converse 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 Wyoming dataset as CSV, every county and town, with the sources named.
Sources
- USGS Water Quality Portal: 1,036 samples in Converse 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 4,741 people on private wells in Converse 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.
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.