01The verdict: is Big Timber water safe?
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 1,710 residents using surface water (rivers, lakes, or reservoirs).
Copper is over its legal limit
Measured at 1.49 mg/L against the EPA Action Level of 1.3 mg/L. The ledger below shows how far over — and which filter removes it.
See the measurement ↓Lead is well under the limit
90th-percentile lead is 3.0 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓Check back after the next refresh
EPA data updates on a rolling basis; we fold in new samples and violations every month.
Get alerts ↓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 1,710 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.
Big Timber ranks #30 out of 110 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.
02What's in Big Timber's water
Every contaminant flagged in Big Timber, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Over Limit — EPA Action Level: 1.3 mg/L
Exceeds the EPA action level. Copper leaches from household plumbing — flush taps for 30 seconds before drinking, and consider a certified filter.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 |
Cities ranked by 90th-percentile lead PF PFAS in Montana
Cities ranked by compounds detected Cu Copper in Montana
Cities ranked by 90th-percentile copper
03Big Timber's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 64 violations on record, including 6 health-based violations. 16 remain unresolved.
9 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 2 ppb since 1993. Latest reading: 3 ppb (2024) — 20% of the action level. Sampled at higher-risk homes (90th percentile).
▼ Down 0.01 mg/L since 2010. The latest reading (1.5 mg/L, 2018) is over the action level. Sampled at higher-risk homes (90th percentile).
04Where 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
Rivers, lakes, or reservoirs — more exposed to runoff, agriculture, and seasonal swings than groundwater.
Local treatment
Multi-barrier treatment: coagulation, sedimentation, filtration, and disinfection to meet EPA standards.
3 systems
3 water systems, operated under local government ownership.
1,710 people
Residents served across Big Timber's service area.
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 1,710 people through 3 water systems.
| System name | PWSID | Population | Source |
|---|---|---|---|
| BIG TIMBER CITY OF | MT0000463 | 1,650 | Surface Water |
| STROBEL TRAILER COURT | MT0000125 | 60 | Groundwater |
| COTTONWOOD ESTATES | MT0004006 | 50 | Groundwater |
Water bodies near Big Timber
As a surface-water system, these water bodies may directly influence Big Timber's drinking water supply.
05Pressure on Big Timber's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Industrial discharge
1 facility within 10 miles reported 0 lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.
Flood & storm history
2 federal disaster declarations on record for Sweet Grass County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Sweet Grass County is in D3 (extreme drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Big Timber compares
Scores for nearby Montana cities on one line, with the average marked.
dashed line = Montana average (48/100)
Big Timber scores 81.8/100 — above the Montana average of 48/100. It outscores 9 of 10 nearby cities. Full Montana rankings →
39.6 / 100FMissoula, MT
42.6 / 100FBozeman, MT
43.4 / 100FGreat Falls, MT
34.5 / 100FKalispell, MT
40.1 / 100FHelena, MT
39.1 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Big Timber's water — not generic advice.
Filter drinking & cooking water
NSF-certified water filter. Copper exceeds the EPA action level of 1.3 mg/L
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Big Timber alerts
We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.
All water alerts →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 #30 out of 110 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 1,710 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 #30 out of 110 cities in Montana (better than 73% of state cities) and #7224 out of 15382 cities nationally (53th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.