Well water in North Slope County, Alaska
In North Slope County, none of 68 tested well samples exceeded the EPA limit for nitrate, based on public data from USGS Water Quality Portal.
The strongest signal is coliform bacteria: Recommended for every private well, every year, too few samples to carry the headline but first on the test list below.
149 test results across 9 contaminants from at least 21 wells, 1959 to 2003; nitrate has the most at 68. Data refreshed September 3, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
An estimated 1,921 people in North Slope County get their drinking water from a private well, per USGS 2015 county water use. That is about 20% of residents.
What individual samples found
Each row summarizes every public sample for that contaminant inside North Slope 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 1959 to 2003 | 68 | 50% | 0.01 | 9.2 | 10 mg/L EPA limit | |
| Fluoride 1959 to 2003 | 15 | 73% | 0 | 0.25 | 4 mg/L EPA limit | |
| Sodium 1959 to 2003 | no limit | 15 | 100% | 5.6 | 33 | 20 mg/L health guideline |
| Manganese 1959 to 2003 | no limit | 15 | 87% | 0.69 | 50 | 300 ug/L health guideline |
| Iron 1959 to 2003 | no limit | 15 | 87% | 25.2 | 1,100 | 300 ug/L nuisance level |
| Chloride 1959 to 2003 | no limit | 15 | 93% | 7.4 | 53 | 250 mg/L nuisance level |
Sampled fewer than 10 times, too few to summarize: Copper (3), Lead (2), Arsenic (1).
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
Among contaminants with a federal limit, no tested sample in North Slope County came back above it. That is reassuring, but sampling is uneven: wells that were never tested are not in this data.
Manganese, Iron, and Chloride 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 North Slope County
- 1Coliform bacteriaRecommended for every private well, every year.
- 2NitrateRecommended for every private well, especially near farms or septic systems.
- 3CopperDetected in 100% of local samples.
- 4ChlorideDetected in 93% of local samples.
- 5ManganeseDetected in 87% of local samples.
- 6IronDetected in 87% of local samples.
- 7FluorideDetected in 73% of local samples.
- 8Volatile organic compounds (VOCs)4 leaking underground storage tank sites on record locally.
- 9Metals panel531 hazardous waste sites on record locally.
Test your North Slope County well for coliform bacteria, nitrate and copper
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 Alaska: certified labs, state programs and prices.
Already have results back? Get your lab report read against the North Slope County numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Contamination sources on record in North Slope County
Alaska DEC contaminated sites records 4 leaking underground storage tank sites and 531 hazardous waste sites in North Slope County, among 535 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.
- 4
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 531
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
Treatment that fits the local profile
Iron
Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Systems we would look at first
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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 North Slope County
No water treatment company serves North Slope 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 North Slope County, and you get an email naming it first.
Common questions
How often should I test a private well in North Slope 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 North Slope 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 Alaska dataset as CSV, every county and town, with the sources named.
Sources
- USGS Water Quality Portal: 149 samples in North Slope 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.
- Alaska DEC contaminated sites: 535 regulated sites located in North Slope County. Contaminated sites, including leaking tank sites, from the Alaska Department of Environmental Conservation. 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.