Well water in Clark County, Nevada

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Testing recommended

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

3,665 test results across 13 contaminants from at least 209 wells, 1973 to 2019; nitrate has the most at 734. Data refreshed September 15, 2026.

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

An estimated 98,399 people in Clark County get their drinking water from a private well, per USGS 2015 county water use. That is about 5% of residents.

Separately, the USGS national arsenic model estimates that 6% of the 98,399 people on private wells in Clark County draw water above 10 ug/L (the model's range is 5% 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 Clark 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
Arsenic 1976 to 2019	14%	248	81%	2	230	10 ug/L EPA limit
Nitrate 1973 to 2015	12%	734	89%	1	230	10 mg/L EPA limit
E. coli 2003 to 2015	10%	10	10%	0	10	0 MPN/100mL EPA limit
Uranium 1980 to 2015	5%	78	100%	3.08	56	30 ug/L EPA limit
Lead 1980 to 2015	1%	197	29%	0	250	15 ug/L EPA limit
Fluoride 1975 to 2015	<1%	429	100%	0.31	8.72	4 mg/L EPA limit
Copper 1980 to 2015	0%	199	41%	0	0.22	1.3 mg/L EPA limit
Radium (226 + 228) 2013 to 2015	0%	12	75%	0.24	0.82	5 pCi/L EPA limit
Chloride 1973 to 2015	no limit	513	100%	84	23,000	250 mg/L nuisance level
Sodium 1973 to 2015	no limit	459	100%	98	13,000	20 mg/L health guideline
Iron 1975 to 2015	no limit	387	80%	21.1	49,800	300 ug/L nuisance level
Manganese 1975 to 2015	no limit	339	68%	1	2,900	300 ug/L health guideline
Radon 1993 to 2015	no limit	60	100%	325	950	2,000 pCi/L health guideline

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	13%653 samples	6%54 samples	7%27 samples	n/a
Fluoride	0%395 samples	10%20 samples	0%14 samples	n/a
Arsenic	11%212 samples	45%20 samples	13%16 samples	n/a
Copper	0%166 samples	0%20 samples	0%13 samples	n/a
Lead	1%163 samples	0%20 samples	0%14 samples	n/a
Uranium	10%39 samples	0%20 samples	0%19 samples	n/a

Fluoride above the limit in Clark County rose from 0% of 395 samples before 2000 to 10% of 20 in the 2000s.

Arsenic above the limit in Clark County rose from 11% of 212 samples before 2000 to 45% of 20 in the 2000s.

Uranium above the limit in Clark County fell from 10% of 39 samples before 2000 to 0% of 20 in the 2000s.

Nitrate, copper, lead 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 arsenic (14% of 248 samples), nitrate (12% of 734 samples), and e. coli (10% of 10 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 Clark County

1
Arsenic
14% of 248 local samples were above the limit.
2
Nitrate
12% of 734 local samples were above the limit.
3
E. coli
10% of 10 local samples were above the limit.
4
Uranium
5% of 78 local samples were above the limit.
5
Lead
1% of 197 local samples were above the limit.
6
Fluoride
<1% of 429 local samples were above the limit.
7
Radon
Median local reading is 325 pCi/L.
8
Volatile organic compounds (VOCs)
1,801 leaking underground storage tank sites on record locally.

Test your Clark County well for arsenic, nitrate and E. coli

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 Nevada: certified labs, state programs and prices.

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

Wells in Clark County

10,639 domestic wells in Clark County are on record with the state since 1970. the typical well is 230 feet deep (one in ten goes past 505 feet).

In a typical Clark County well, the median yield is 35 gallons per minute, <1% of wells yield under 3 gallons per minute and usually need a storage tank.

1,793

1970s

1,303

1980s

1,645

1990s

1,425

2000s

502

2010s

283

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 NDWR well driller reports and choose Water Well.
The report lists depth, casing, static water level and the yield test.

Nevada has required driller reports since the 1940s, so most wells have one.

The rock under Clark 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 Nevada

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 wells, NDEP
Get Your Drinking Water Tested, NDEP

Contamination sources on record in Clark County

NDEP corrective action release events records 1,801 leaking underground storage tank sites in Clark County, among 1,805 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.

1,801: leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
4: other remediation projects

Treatment that fits the local profile

Arsenic

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

Nitrate

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

E. coli

Shock chlorination and fix the well cap or casing; UV disinfection whole-house; Chlorination system

Uranium

Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange

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 arsenic

Under-sink reverse osmosis system

under-sink or countertop, about $300

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

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 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 E. coli

UV disinfection system

whole-house, at the point of entry, about $900

Fix the well cap and casing first; UV keeps bacteria from returning.

For E. coli

Aquasana Rhino Well Water with UV

whole-house, at the point of entry, about $2,871

Whole-house system built for wells: sediment pre-filter, KDF and carbon, and a UV lamp rated to kill 99.99% of bacteria and viruses. It does not remove arsenic, nitrate, uranium or radon.

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 Clark County

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

Common questions

How deep are wells in Clark County?

The typical domestic well in Clark County is 230 feet deep, based on 10,639 wells reported to the state since 1970. One in ten is deeper than 505 feet.

Is there arsenic in well water in Clark County?

Arsenic was detected in 81% of 248 public well samples in Clark County, and 14% 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 Clark County?

The median radon level across 60 public samples in Clark County was 325 pCi/L, with a high of 950 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Clark 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 Clark 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 Nevada dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 3,665 samples in Clark 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 98,399 people on private wells in Clark 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.
Nevada NDWR well driller reports: 46,873 well records in Clark County, 10,639 domestic. Well driller reports filed with the Nevada Division of Water Resources. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 18, 2026.
NDEP corrective action release events: 1,805 regulated sites located in Clark County. Leaking tank and other release events under corrective action at the Nevada Division of Environmental Protection. 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.