Is Plains, MT Tap Water Safe to Drink?
Graded B+ — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
84.8/100
waterverge.com Plains, MT — Water Quality Report
Plains's drinking water received a grade of B+ (84.8 out of 100), indicating good water quality. The city's 1 water system serves approximately 1,700 residents using groundwater.
Lead levels were measured at 2.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 126 violations on record, including 0 health-based violations. All violations have been resolved.
What to know about Plains's water
Plains ranks #20 out of 115 cities in Montana for water quality, placing it above average in the state.
Plains relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Plains may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Plains, MT water safe to drink?
Based on EPA testing data, Plains's tap water is generally safe to drink. The water system earned a grade of B+ (84.8/100), meeting federal drinking water standards across key contaminant categories. The city's 1 water system serves approximately 1,700 residents using groundwater (wells).
Recent water quality updates for Plains
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Plains's water quality assessment. Grade: B+ (84.8/100).
Federal disaster declaration (FEMA DR-3630). Flood event — may have impacted local water infrastructure.
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Federal disaster declaration (FEMA DR-4172). Flood event — may have impacted local water infrastructure.
Contaminants: Coliform (TCR).
Contaminants: Coliform (TCR).
Key contaminant findings
Based on the most recent EPA sampling data for Plains's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Plains's water system has 126 total violations on record, including 0 health-based violations. All violations have been resolved. 2 violations were issued in the last 5 years.
Flood & environmental risk
Sanders County has experienced 5 federally declared disasters since 1974. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Clark Fork Near Paradise, Clark Fork Near Plains.
Where does Plains's water come from?
Plains's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 1,700 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Clark Fork Near Paradise (river), Clark Fork Near Plains (river).
What Plains residents can do
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Plains's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Flood & disaster history
Sanders County has experienced 5 federally declared disasters since 1974. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Plains's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 2.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 1.49 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.490 mg/L (1994)
EPA action level: 1.3 mg/L
See how Plains compares by contaminant
Explore where Plains ranks among all Montana cities for specific contaminants.
Water source & infrastructure
Where Plains's water comes from
Plains's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by local government ownership and serves approximately 1,700 people through 1 water system.
Water bodies near Plains
Plains is located near 2 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Plains
| System Name | PWSID | Population | Source |
|---|---|---|---|
| PLAINS TOWN OF | MT0000305 | 1,700 | GW |
How Plains compares
Full Montana rankings →Plains's score of 84.8/100 is above the average of 45/100 among major Montana cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Montana rankings →About Plains, MT
Wikipedia →Plains is a town in Sanders County, Montana, United States. The population was 1,106 at the 2020 census. It was founded as Horse Plains and sometimes called Wild Horse Plains, as the local Native Americans would winter their horses here to feed on the grasses in the valley. The name was later shortened to Plains when the US Postal Service established a presence in 1905.
Learn more about your water
Guides and resources related to Plains's water quality findings.
Explore water quality across Sanders
Frequently asked questions
Is Plains, MT tap water safe to drink?
Plains's water quality earned a grade of B+ (84.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #20 out of 115 cities tested in Montana.
What contaminants are in Plains's water?
Lead was measured at 2.0 ppb (90th percentile). 126 violations are on record.
How is Plains's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Plains?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Plains's water come from?
Plains's water is sourced from Groundwater. The city has 1 water system serving approximately 1,700 residents.
Is Plains's groundwater at risk of contamination?
Plains uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 126 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Plains's water compare to other cities?
Plains ranks #20 out of 115 cities in Montana (better than 83% of state cities) and #5680 out of 15744 cities nationally (64th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Plains's small water system affect quality?
Plains's system serves approximately 1,700 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 126 violations on record.