Water in North Dakota.
North Dakota's source water includes the Missouri River and shallow groundwater wells. Natural arsenic and agricultural runoff are the dominant concerns; oil-and-gas wastewater incidents add localized risk.
How North Dakota regulates drinking water.
Federal SDWA primacy. No state MCLs stricter than federal. Bakken oil-and-gas wastewater spills are a recurring contamination concern.
North Dakota Department of Environmental Quality — Division of Municipal Facilities
North Dakota's water history, in order.
The contamination events, regulatory shifts, and major settlements that define how this state thinks about drinking water today.
- 2015
Bakken oil-and-gas wastewater spills contaminate multiple Western ND surface water sources.
- 2023
Federal infrastructure funding directed to small-system arsenic-treatment upgrades.
The actual water you drink.
The physical rivers, aquifers, lakes, and reservoirs that feed North Dakota's public water systems. Source quality is the foundation of tap quality — and where the long-term protection fights happen.
- riverMissouri River
Bismarck supply.
- riverRed River of the North
Fargo / Grand Forks.
- riverGarrison Diversion Project
Federal water delivery.
Source-water mix
~70% surface water, ~30% groundwater
Major cities served
Fargo · Bismarck · Grand Forks · Minot
Who actually serves the water.
The largest public water systems in North Dakota by population served. Click your ZIP after to see the full live EWG report for your specific utility.
- Fargo Public WorksFargo130Kserved
- Bismarck Water Treatment PlantBismarck75Kserved
Where the contamination comes from.
Every state has a different industrial fingerprint. The industries below are the dominant historical and active contamination sources in North Dakota's drinking water systems.
Bakken oil-and-gas wastewater spills are the dominant industrial contamination concern. Coal-fired power plants in western ND (lignite mining) drive groundwater quality concerns. Agricultural runoff in eastern ND.
What state data flags most consistently.
Drawn from EPA SDWIS sampling records, EWG state summaries, and regional regulatory action over the past five years. Read the full deep dive on each.
Arsenic
A naturally occurring carcinogen. Highest in private wells and the rural Southwest.
Trihalomethanes (TTHMs)
Byproducts of chlorinating water. Linked to bladder cancer at chronic exposure.
Nitrate
Fertilizer and animal waste runoff. Acutely dangerous for infants under 6 months.
Risk isn't evenly distributed.
Bakken-region residents (Williston, Watford City, Tioga) face the highest oil-and-gas-wastewater exposure. Rural well users face arsenic.
~20% on private wells. Bakken-region wells have documented hydrocarbon and brine contamination.
What's coming for North Dakota's water.
Red River flooding intensity (2009, 2011) overwhelms Fargo / Grand Forks treatment infrastructure. Drought cycles in the western Bakken zone stress groundwater. Earlier spring runoff complicates Missouri River management.
Voluntary statewide
ND DEQ provides voluntary technical assistance.
Five questions for your next Consumer Confidence Report.
Your utility is required to send you a Consumer Confidence Report annually. Most are dense and procedural. These are the questions worth following up on for North Dakota specifically.
- 1
If I'm in the Bakken region, has my well been tested for hydrocarbons and brine?
- 2
Has my utility had any health-based violations in the past three years?
- 3
What is my system's arsenic running annual average?
Most state regulators allow public records requests for the underlying lab reports behind your CCR — your utility should be able to provide them on request.
NSF/ANSI 58 reverse osmosis covers arsenic, nitrate, and most VOCs from oil-and-gas contamination.
We don't recommend brands — the NSF/ANSI certification number matters more than the name on the box.
This is the state. Your address is the answer.
State-level patterns don't tell you about your specific tap. Run your ZIP for the live EWG contaminant report on your utility — or build a personalized Water File for your household.
Source-water mix, utility counts, lead-service-line estimates, and private-well shares are approximate, drawn from EPA SDWIS public data and state primacy-agency summaries. Contaminant rankings reflect EWG state-level monitoring data and regional regulatory action — they are not exhaustive. Timeline events are publicly documented. See methodology for the full sourcing. Search EPA SDWIS for North Dakota