Is Culbertson, 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 ↓
84.2/100
waterverge.com Culbertson, MT — Water Quality Report
Culbertson's drinking water received a grade of B+ (84.2 out of 100), indicating good water quality. The city's 2 water systems serve approximately 3,719 residents using purchased surface water.
Lead levels were measured at 3.0 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 34 violations on record, including 6 health-based violations. 6 remain unresolved.
What to know about Culbertson's water
Culbertson ranks #22 out of 115 cities in Montana for water quality, placing it above average in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
Water quality score
See methodology →Is Culbertson, MT water safe to drink?
Culbertson's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (84.2/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 3,719 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Culbertson
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Culbertson's water quality assessment. Grade: B+ (84.2/100).
Contaminants: Lead and Copper Rule.
Contaminants: TTHM, Total Haloacetic Acids (HAA5).
Federal disaster declaration (FEMA DR-4726). Flood event — may have impacted local water infrastructure.
Contaminants: Lead and Copper Rule.
Federal disaster declaration (FEMA DR-3253). Hurricane event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Culbertson'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
Culbertson's water system has 34 total violations on record, including 6 health-based violations. 6 remain unresolved. 3 violations were issued in the last 5 years.
Flood & environmental risk
Roosevelt County has experienced 2 federally declared disasters since 2005. 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 Big Muddy Creek Nr Mouth Nr Culbertson, Missouri River Near Culbertson.
Where does Culbertson's water come from?
Culbertson's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 2 water systems serving approximately 3,719 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Big Muddy Creek Nr Mouth Nr Culbertson (river), Missouri River Near Culbertson (river).
What Culbertson residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Culbertson's water.
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.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Drought conditions
D1 — moderate droughtRoosevelt County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Roosevelt County has experienced 2 federally declared disasters since 2005. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Culbertson'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. | 3.0 | 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. | 1.35 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 1.350 mg/L (2016)
EPA action level: 1.3 mg/L
See how Culbertson compares by contaminant
Explore where Culbertson ranks among all Montana cities for specific contaminants.
Water source & infrastructure
Where Culbertson's water comes from
Culbertson's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by public/private ownership and serves approximately 3,719 people through 2 water systems.
Water bodies near Culbertson
Culbertson is located near 2 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Culbertson
| System Name | PWSID | Population | Source |
|---|---|---|---|
| DRY PRAIRIE RURAL WATER AUTHORITY | MT0004348 | 3,005 | SWP |
| CULBERTSON TOWN OF | MT0000192 | 714 | SWP |
How Culbertson compares
Full Montana rankings →Culbertson's score of 84.2/100 is above the average of 45/100 among major Montana cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Montana rankings →About Culbertson, MT
Learn more about your water
Guides and resources related to Culbertson's water quality findings.
Explore water quality across Roosevelt
Frequently asked questions
Is Culbertson, MT tap water safe to drink?
Culbertson's water quality earned a grade of B+ (84.2/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #22 out of 115 cities tested in Montana.
What contaminants are in Culbertson's water?
Lead was measured at 3.0 ppb (90th percentile). 34 violations are on record.
How is Culbertson'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 Culbertson?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Culbertson's water come from?
Culbertson's water is sourced from Purchased surface water. The city has 2 water systems serving approximately 3,719 residents.
What health violations has Culbertson's water system had?
Culbertson has 6 health-based violations on record. The most recent violation was recorded in October 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 6 violations remain unresolved.
How does Culbertson's water compare to other cities?
Culbertson ranks #22 out of 115 cities in Montana (better than 81% of state cities) and #6038 out of 15744 cities nationally (62th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.