Tap & Air

Private wells

Alaska well water: who's on a well and what to test for

An estimated 205,800 people in 107,000 homes, about 33.4% of Alaska homes, above the national 14.6%. Estimates are from EPA's Water Source 2020 model.

People on private wells

205,800

Homes on wells

33.4%

Est. above arsenic limit

Not modeled

Wrangell: about 34% of homes on private wellsKusilvak: about 51% of homes on private wellsBristol Bay Borough: about 92% of homes on private wellsHoonah-Angoon: about 69% of homes on private wellsPetersburg: about 26% of homes on private wellsNorthwest Arctic Borough: about 30% of homes on private wellsHaines Borough: about 59% of homes on private wellsAleutians East Borough: about 39% of homes on private wellsKodiak Island Borough: about 19% of homes on private wellsLake and Peninsula Borough: about 87% of homes on private wellsValdez-Cordova Census Area: no estimateYukon-Koyukuk Census Area: about 58% of homes on private wellsSoutheast Fairbanks Census Area: about 84% of homes on private wellsPrince of Wales-Hyder: about 39% of homes on private wellsSitka City and Borough: about 5% of homes on private wellsNorth Slope Borough: about 13% of homes on private wellsBethel Census Area: about 47% of homes on private wellsFairbanks North Star Borough: about 34% of homes on private wellsDillingham Census Area: about 71% of homes on private wellsKetchikan Gateway Borough: about 30% of homes on private wellsYakutat City and Borough: about 31% of homes on private wellsJuneau City and Borough: about 18% of homes on private wellsDenali Borough: about 74% of homes on private wellsMatanuska-Susitna Borough: about 66% of homes on private wellsAnchorage Municipality: about 9% of homes on private wellsAleutians West Census Area: about 41% of homes on private wellsKenai Peninsula Borough: about 63% of homes on private wellsNome Census Area: about 41% of homes on private wellsSkagway Municipality: about 16% of homes on private wells
Homes on private wellsUnder 5%5-15%15-30%30-50%50% or more

Every Alaska county

Sorted by people on private wells. Arsenic and nitrate are modeled for typical wells in the county, not measured at yours; depth is the median of domestic well records.

Matanuska-Susitna Borough62,40066%n/an/an/a
Kenai Peninsula Borough34,20063%n/an/an/a
Fairbanks North Star Borough28,60034%n/an/an/a
Anchorage Municipality26,1009%n/an/an/a
Bethel Census Area8,40047%n/an/an/a
Juneau City and Borough6,00018%n/an/an/a
Southeast Fairbanks Census Area5,80084%n/an/an/a
Kusilvak3,90051%n/an/an/a
Ketchikan Gateway Borough3,80030%n/an/an/a
Nome Census Area3,50041%n/an/an/a
Dillingham Census Area3,20071%n/an/an/a
Yukon-Koyukuk Census Area2,50058%n/an/an/a
Aleutians West Census Area2,40041%n/an/an/a
Aleutians East Borough2,30039%n/an/an/a
Prince of Wales-Hyder1,70039%n/an/an/a
Northwest Arctic Borough1,40030%n/an/an/a
North Slope Borough1,30013%n/an/an/a
Kodiak Island Borough1,30019%n/an/an/a
Hoonah-Angoon1,20069%n/an/an/a
Denali Borough1,20074%n/an/an/a
Lake and Peninsula Borough1,20087%n/an/an/a
Haines Borough1,10059%n/an/an/a
Bristol Bay Borough76092%n/an/an/a
Petersburg60026%n/an/an/a
Wrangell52034%n/an/an/a
Skagway Municipality21016%n/an/an/a
Sitka City and Borough2005%n/an/an/a
Yakutat City and Borough13031%n/an/an/a

Shading: red is among the highest counties nationally, amber the middle, green the lower range. Click a column to sort.

Test first, then treat what the test finds

We may earn a commission from links below, at no cost to you. Picks follow the testing order, not who pays. How we make money.

1. Certified lab well test

Start here, every year

A mail-in kit analyzed by a certified lab measures bacteria, nitrate, arsenic, metals and more. Test strips cannot measure arsenic or uranium reliably.

Mail-in certified lab well water test$$

2. Sediment pre-filter

Sand, silt or cloudy water

A 5-micron cartridge after the pressure tank catches sand, silt and rust before they reach fixtures or other filters. Cartridges are cheap and swap every few months.

5-micron whole-house sediment filter$

3. Iron and sulfur filter

Orange stains or rotten-egg smell

Air-injection or oxidizing-media filters remove orange staining and rotten-egg smell. Size one from a lab result for iron, manganese and hydrogen sulfide.

Air-injection iron and sulfur filter$$$

4. UV disinfection system

Coliform bacteria in a test

Inactivates bacteria and viruses; usually for private wells or after boil notices.

12 GPM whole-house UV purifier$$$

5. Under-sink reverse osmosis

Arsenic, nitrate or uranium in a test

The most thorough option for drinking water: PFAS, lead, nitrate, arsenic and more. Look for NSF/ANSI 58.

Waterdrop G3P600 tankless RO$$$ iSpring RCC7AK reverse osmosis$$

6. Whole-house well filter

Several problems at once

Multi-stage sediment and carbon for every tap. Add UV if bacteria shows up, and choose stages from your lab results, not a guess.

Waterdrop WHF21 2-stage whole-house filter$$
Get free well water treatment quotes

Questions

Which Alaska counties rely most on wells?+

By share of homes: Bristol Bay Borough (92%), Lake and Peninsula Borough (87%), Southeast Fairbanks Census Area (84%), Denali Borough (74%), Dillingham Census Area (71%). By number of people: Matanuska-Susitna Borough (62,400), Kenai Peninsula Borough (34,200), Fairbanks North Star Borough (28,600).

Is arsenic a problem in Alaska wells?+

The USGS county arsenic estimate does not cover Alaska. Arsenic has no taste or smell, so test for it at least once.

Do I have to test my well when I sell a house in Alaska?+

We could not confirm a statewide rule for Alaska. Check with your county health department. Buyers can still make a lab test a condition of the offer.

How often should I test my well?+

No federal law covers private wells. EPA's drinking water limits apply to public water systems, so testing and treating a private well is up to the owner. EPA and CDC recommend testing at least once a year for coliform bacteria, nitrate, pH and total dissolved solids, and testing for arsenic, uranium, radon and other local concerns based on where you live.

Well-user counts, arsenic and nitrate figures are each a modeled estimate built from national datasets, not a count of tested wells, and well depths summarize drilling records rather than every well. Your own well can be very different from the county average, which is why the only answer for your home is a lab test. Sources: EPA Office of Research and Development, Water Source 2020 (private well estimates by census block); CDC Environmental Public Health Tracking, Well Water Index (from USGS nitrate and arsenic models); USGS, county-level domestic well population with arsenic above 10 micrograms per liter (Ayotte and others, 2017); USGS Synthesized Domestic Well Database for the Conterminous United States (SynDWell-US), McCarthy and others, 2025 (depth, where a county has 30+ usable records).