Well water in Grand Forks County, North Dakota

Name: Private well water quality in Grand Forks County, North Dakota
Creator: Well Water Nerd
License: Public domain (US federal government data)

1in5

Testing strongly recommended

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

The strongest signal is arsenic: 42% of 12 local samples were above the limit, too few samples to carry the headline but first on the test list below.

616 test results across 11 contaminants from at least 103 wells, 1956 to 2018; iron has the most at 114. Data refreshed September 15, 2026.

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

An estimated 2,051 people in Grand Forks County get their drinking water from a private well, per USGS 2015 county water use. That is about 3% of residents.

Separately, the USGS national arsenic model estimates that 3% of the 2,051 people on private wells in Grand Forks County draw water above 10 ug/L (the model's range is 3% to 4%), from geology and well depth rather than local tests.

What individual samples found

Each row summarizes every public sample for that contaminant inside Grand Forks 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 1984 to 2018	42%	12	75%	5.5	22	10 ug/L EPA limit
Nitrate 1956 to 1995	19%	110	93%	1	547	10 mg/L EPA limit
Fluoride 1956 to 2018	2%	110	100%	0.3	8	4 mg/L EPA limit
Lead 1984 to 2018	0%	11	64%	0	10	15 ug/L EPA limit
Iron 1956 to 2018	no limit	114	100%	0	3,300	300 ug/L nuisance level
Chloride 1956 to 2018	no limit	114	100%	74	5,640	250 mg/L nuisance level
Sodium 1956 to 2018	no limit	111	100%	69	3,390	20 mg/L health guideline
Manganese 1973 to 2018	no limit	19	100%	770	1,500	300 ug/L health guideline

Sampled fewer than 10 times, too few to summarize: Uranium (5), Copper (5), Radon (5).

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 (42% of 12 samples), nitrate (19% of 110 samples), and fluoride (2% of 110 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.

Iron, Chloride, 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 Grand Forks County

1
Arsenic
42% of 12 local samples were above the limit.
2
Nitrate
19% of 110 local samples were above the limit.
3
Fluoride
2% of 110 local samples were above the limit.
4
Coliform bacteria
Recommended for every private well, every year.
5
Radon
Median local reading is 170 pCi/L.
6
Iron
Detected in 100% of local samples.
7
Chloride
Detected in 100% of local samples.

Test your Grand Forks County well for arsenic, nitrate and fluoride

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 North Dakota: certified labs, state programs and prices.

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

The rock under Grand Forks County

Paleozoic aquifers

Sandstone and carbonate-rock. Layered sandstone and limestone means a well may draw from either. Hardness and iron are routine, and the limestone layers can carry bacteria and nitrate from the surface quickly, so test for both yearly.

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 North Dakota

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.

Groundwater Protection Program, North Dakota DEQ

Contamination sources on record in Grand Forks County

North Dakota solid waste facilities records 10 regulated sites in Grand Forks County, among 10 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.

10: lined landfills and transfer facilities

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

Fluoride

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

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 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 manganese

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 Grand Forks County

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

Common questions

Is there arsenic in well water in Grand Forks County?

Arsenic was detected in 75% of 12 public well samples in Grand Forks County, and 42% 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 Grand Forks 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 Grand Forks 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 North Dakota dataset as CSV, every county and town, with the sources named.

Sources

USGS Water Quality Portal: 616 samples in Grand Forks 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 2,051 people on private wells in Grand Forks 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.
North Dakota solid waste facilities: 10 regulated sites located in Grand Forks County. Permitted solid waste facilities from the North Dakota Department of Environmental Quality. 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.