Is Big Timber, 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 ↓
81.8/100
waterverge.com Big Timber, MT — Water Quality Report
Big Timber's drinking water received a grade of B+ (81.8 out of 100), indicating good water quality. The city's 3 water systems serve approximately 1,760 residents using 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 64 violations on record, including 6 health-based violations. 16 remain unresolved.
What to know about Big Timber's water
Big Timber ranks #32 out of 115 cities in Montana for water quality, placing it mid-range 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.
As a small community water system, Big Timber may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Big Timber, MT water safe to drink?
Big Timber's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (81.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 1,760 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Big Timber
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Big Timber's water quality assessment. Grade: B+ (81.8/100).
Federal disaster declaration (FEMA DR-4655). Flood event — may have impacted local water infrastructure.
Contaminants: E. COLI.
Contaminants: Lead and Copper Rule.
1 health-based. Contaminants: Surface Water Treatment Rule, Consumer Confidence 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 Big Timber'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
Big Timber's water system has 64 total violations on record, including 6 health-based violations. 16 remain unresolved.
Flood & environmental risk
Sweet Grass 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 Yellowstone River At Big Timber, Boulder River At Big Timber.
Where does Big Timber's water come from?
Big Timber's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 3 water systems serving approximately 1,760 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Yellowstone River At Big Timber (river), Boulder River At Big Timber (river).
What Big Timber residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Big Timber'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
Top industrial polluters within 10 miles of Big Timber
Industrial polluters nearby
Reported releases to surface water by facilities near Big Timber, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
STILLWATER MINING CO EAST BOULDER MINE BIG TIMBER, MT59011 | — | — | 0.6 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D2 — severe droughtSweet Grass County is currently in D2 (severe 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
Sweet Grass 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 Big Timber'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. | 1.49 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Big Timber compares by contaminant
Explore where Big Timber ranks among all Montana cities for specific contaminants.
Water source & infrastructure
Where Big Timber's water comes from
Big Timber'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 local government ownership and serves approximately 1,760 people through 3 water systems.
Water bodies near Big Timber
Big Timber 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 Big Timber
| System Name | PWSID | Population | Source |
|---|---|---|---|
| BIG TIMBER CITY OF | MT0000463 | 1,650 | SW |
| STROBEL TRAILER COURT | MT0000125 | 60 | GW |
| COTTONWOOD ESTATES | MT0004006 | 50 | GW |
How Big Timber compares
Full Montana rankings →Big Timber's score of 81.8/100 is above the average of 45/100 among major Montana cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Montana rankings →About Big Timber, MT
Wikipedia →Big Timber is a city in, and the county seat of, Sweet Grass County, Montana, United States. The population was 1,650 at the 2020 census.
Learn more about your water
Guides and resources related to Big Timber's water quality findings.
Explore water quality across Sweet Grass
Frequently asked questions
Is Big Timber, MT tap water safe to drink?
Big Timber's water quality earned a grade of B+ (81.8/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #32 out of 115 cities tested in Montana.
What contaminants are in Big Timber's water?
Lead was measured at 3.0 ppb (90th percentile). 64 violations are on record.
How is Big Timber'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 Big Timber?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Big Timber's water come from?
Big Timber's water is sourced from Surface water. The city has 3 water systems serving approximately 1,760 residents.
What health violations has Big Timber's water system had?
Big Timber has 6 health-based violations on record. The most recent violation was recorded in February 2020. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 16 violations remain unresolved.
How does Big Timber's water compare to other cities?
Big Timber ranks #32 out of 115 cities in Montana (better than 72% of state cities) and #7311 out of 15744 cities nationally (54th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.