Grand Forks County, North Dakota: drinking water report. Grand Forks County covers the Red River Valley in eastern North Dakota, with the city of Grand
Grand Forks County covers the Red River Valley in eastern North Dakota, with the city of Grand Forks serving as the primary population center alongside smaller communities like Northwood, Thompson, and Larimore. Most residents receive municipal water drawn from the Prairie Aquifer, a shallow groundwater source that runs beneath the Red River Valley, while rural households often rely on private wells tapping the same formation. The county's flat agricultural landscape and proximity to the Red River create specific water quality challenges tied to both natural geology and farming practices.
The Prairie Aquifer typically contains elevated levels of naturally occurring contaminants common to North Dakota groundwater. Hardness remains the most noticeable issue, with many municipal systems reporting levels above 300 parts per million due to dissolved calcium and magnesium in the sedimentary bedrock. Nitrate contamination presents ongoing concerns across agricultural areas, where fertilizer application and tile drainage systems can move nitrogen compounds into shallow groundwater. Rural well owners in Grand Forks County face particular vulnerability since private wells lack the monitoring requirements that apply to municipal utilities.
The EPA's UCMR5 monitoring program, which tracks emerging contaminants including PFAS compounds, has identified these substances in some North Dakota water systems serving populations over 3,300 people. Communities using surface water or groundwater near industrial sites, airports, or former military installations tend to show higher detection rates. Grand Forks Air Force Base sits just west of the city limits, and firefighting foam historically used at military installations nationwide has introduced PFAS into local groundwater in many cases. While specific detection levels vary by location and sampling period, the presence of these persistent chemicals in regional groundwater follows patterns documented across rural military communities.
Lead exposure risk in Grand Forks County depends largely on building age and plumbing materials. The city of Grand Forks maintains a lead and copper monitoring program under EPA requirements, with results generally showing compliance with action levels. However, homes built before 1986 may contain lead solder in copper pipes, and service lines connecting older properties to water mains can contribute lead even when source water leaves the treatment plant clean. Radium and uranium occur naturally in some North Dakota aquifers, though levels vary significantly based on specific geological conditions. Well water testing becomes particularly important for rural residents who lack the continuous monitoring that municipal customers receive through regulated utility programs.
Anyone concerned about their drinking water should start by reviewing available data for their specific system or testing private wells for common contaminants including nitrate, bacteria, hardness, and metals. Check your water to see current data for Grand Forks County, explore options in the water filter guide to address specific contaminants, and access the detailed report for complete testing information. Additional context on North Dakota water quality patterns appears on the state page.
Drinking water is one exposure route. These federal datasets also cover Grand Forks County, ND.
The EPA places Grand Forks County, ND in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
49% of homes in Grand Forks County, ND were built before 1980, and 16% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Grand Forks County, ND averages 6.3 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide