Why does nitrate matter more in Aroostook than elsewhere?

Nitrate reaches groundwater from fertilizer and septic sources, and The County has more working farmland beside home wells than anywhere else in Maine. Maine CDC puts nitrate on the yearly test list for every well, with a 10 mg/L guideline, and a farm-adjacent well is the classic case for actually keeping that yearly schedule.

Is arsenic a County problem too?

It occurs here as it does across Maine bedrock, and the honest answer is that Aroostook is under-measured: only 32 percent of well households had tested for arsenic as of the Maine Tracking Network data, the lowest rate in the state. Statewide about one in 10 wells exceeds the standard. Your test fills in the local blank.

What is different about sand and gravel wells?

Parts of Aroostook draw from mapped sand and gravel aquifers rather than bedrock. These aquifers yield generously, but their coarse deposits also let surface contaminants like nitrate leach downward more easily, while bedrock wells carry more of the arsenic, uranium, and radon risk. Knowing which type you own shapes the test list.

Can I get testing and treatment done this far north?

Yes. The state lab in Augusta sells mail-order kits that work fine from Presque Isle or Houlton, certified labs serve the region, and independent treatment professionals cover The County. The quote is free, and the referral fee never raises the price you pay.

Well water in Aroostook County

Water in Aroostook County is spread out, like everything else. Town systems cover the centers of Presque Isle, Caribou, and Houlton, and past the last hydrant nearly every farmhouse, homestead, and camp runs on its own well. Two County facts should shape what owners do about that. First, this is Maine's farm belt, potato country above all, and nitrate, which moves into groundwater from fertilizer and septic sources, is on Maine CDC's yearly test list with a 10 mg/L guideline (Maine CDC testing guidance; guideline values at the Maine Tracking Network).

Second, The County tests least. As of Maine Tracking Network data reported in 2017, only 32 percent of Aroostook well households had ever tested for arsenic, the lowest rate of any Maine county, against 57 percent in Kennebec (Maine Tracking Network). Low testing does not mean low risk; it means the local picture is mostly blank, in a state where about one in 10 tested wells exceeds the federal arsenic standard.

Two kinds of County wells

Aroostook geology splits its wells. The Maine Geological Survey has mapped significant sand and gravel aquifers here, including in the Presque Isle quadrangle (MGS aquifer map): productive coarse deposits whose open structure also lets surface contaminants like nitrate leach toward the water table, a real consideration beside working fields. Drilled bedrock wells, the other type, carry more of the naturally occurring arsenic, uranium, and radon risk. The yearly bacteria-and-nitrate habit plus the three-to-five-year bedrock panel covers both cases; the testing checklist lays out the schedule.

Getting from sample to fix, at County distances

Mail-order kits from the state lab in Augusta work the same from Fort Fairfield as from Falmouth, and the testing page covers panels, certified labs, and costs. When a result needs equipment, a coliform hit points to UV and bacteria treatment, staining points to iron and manganese filtration, and high nitrate or arsenic results get their own designs. A free quote comes back from an independent professional who actually covers this territory. Every region is on the service areas page.

One more farm-country note: PFAS. Maine set an interim standard of 20 ng/L for the sum of six PFAS compounds in private wells, and Maine DEP offers free PFAS testing for wells near known sludge and septage spreading sites, reachable at (207) 287-7688, with funded filtration where contamination is linked to spreading (Maine CDC and DEP). If your land or a neighbor's has a spreading history, that call is free and worth making; background is on the PFAS treatment page.

Towns served in this region: Presque Isle, Caribou, Houlton, Fort Fairfield, Mars Hill, and Limestone.

Get a free quote for your Aroostook well

A first-ever arsenic test or a yearly nitrate check both start the same way: one form, no cost to you.

What it costs, and what happens after you send it

What does well water treatment cost in Aroostook County?: There is no single price, because the contaminant decides the system. Across the ranges this site publishes, point-of-use reverse osmosis starts around $150 plus install, the common whole-house systems run roughly $1,500 to $4,000, and radon aeration is the expensive end at $6,000 to $8,000 in this region. Those are installed figures with sources named, not quotes and not our prices, and annual media, filter or lamp costs sit on top. The Maine treatment cost guide prints the full table by system with every source.
How fast will someone get back to me?: Your request goes to an independent local water treatment contractor, usually within about an hour during the day. That contractor then contacts you to look at your water and price the work on their own schedule.
What work is covered?: Well water testing, arsenic treatment, iron and manganese treatment, radon in water, PFAS treatment, UV and bacteria treatment, and whole-house systems. See every service.

Only a contractor standing at your wellhead can price your actual water.

Aroostook County well questions

Why does nitrate matter more in Aroostook than elsewhere?: Nitrate reaches groundwater from fertilizer and septic sources, and The County has more working farmland beside home wells than anywhere else in Maine. Maine CDC puts nitrate on the yearly test list for every well, with a 10 mg/L guideline, and a farm-adjacent well is the classic case for actually keeping that yearly schedule.
Is arsenic a County problem too?: It occurs here as it does across Maine bedrock, and the honest answer is that Aroostook is under-measured: only 32 percent of well households had tested for arsenic as of the Maine Tracking Network data, the lowest rate in the state. Statewide about one in 10 wells exceeds the standard. Your test fills in the local blank.
What is different about sand and gravel wells?: Parts of Aroostook draw from mapped sand and gravel aquifers rather than bedrock. These aquifers yield generously, but their coarse deposits also let surface contaminants like nitrate leach downward more easily, while bedrock wells carry more of the arsenic, uranium, and radon risk. Knowing which type you own shapes the test list.
Can I get testing and treatment done this far north?: Yes. The state lab in Augusta sells mail-order kits that work fine from Presque Isle or Houlton, certified labs serve the region, and independent treatment professionals cover The County. The quote is free, and the referral fee never raises the price you pay.

Updated August 2026