Is Ennis, MT Tap Water Safe to Drink?
Graded B+, with 4 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
83.9/100
waterverge.com Ennis, MT — Water Quality Report
Ennis's drinking water received a grade of B+ (83.9 out of 100), indicating good water quality. The city's 2 water systems serve approximately 1,595 residents using groundwater.
Lead levels were measured at 0.0 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 122 violations on record, including 3 health-based violations. 4 remain unresolved.
What to know about Ennis's water
Ennis ranks #23 out of 115 cities in Montana for water quality, placing it above average in the state.
Ennis 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, Ennis may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Ennis, MT water safe to drink?
Ennis's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (83.9/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 2 water systems serve approximately 1,595 residents using groundwater (wells).
Recent water quality updates for Ennis
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Ennis's water quality assessment. Grade: B+ (83.9/100).
Contaminants: Lead and Copper Rule.
Contaminants: Lead and Copper Rule.
Contaminants: Benzo(a)pyrene, Pentachlorophenol, Chlordane.
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 Ennis's water supply.
Well within EPA limits.
Violation history
Ennis's water system has 122 total violations on record, including 3 health-based violations. 4 remain unresolved. 1 violation was issued in the last 5 years.
Flood & environmental risk
Madison County has experienced 1 federally declared disaster 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 Madison River Near Cameron, Madison River At Ennis, Madison River Ab Powerplant Nr Mcallister, Madison River Bl Ennis Lake Nr Mcallister.
Where does Ennis's water come from?
Ennis's drinking water comes from groundwater (wells), supplied by 2 water systems serving approximately 1,595 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Madison River Near Cameron (river), Madison River At Ennis (river), Madison River Ab Powerplant Nr Mcallister (river), Madison River Bl Ennis Lake Nr Mcallister (river).
What Ennis residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Ennis'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
D3 — extreme droughtMadison County is currently in D3 (extreme 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
Madison County has experienced 1 federally declared disaster since 2005. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
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. | 0.0 | 15 | ppb | Inorganic | Safe |
Lead level trend (90th percentile)
See how Ennis compares by contaminant
Explore where Ennis ranks among all Montana cities for specific contaminants.
Water source & infrastructure
Where Ennis's water comes from
Ennis'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 1,595 people through 2 water systems.
Water bodies near Ennis
Ennis is located near 4 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Ennis
| System Name | PWSID | Population | Source |
|---|---|---|---|
| ENNIS TOWN OF | MT0000208 | 1,400 | GW |
| VALLEY GARDEN GOLF VILLAGE HOA | MT0003597 | 195 | GW |
How Ennis compares
Full Montana rankings →Ennis's score of 83.9/100 is above the average of 45/100 among major Montana cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Montana rankings →About Ennis, MT
Wikipedia →Ennis is a town in Madison County, Montana, United States, in the southwestern part of the state. The population was 917 at the 2020 census, up from 838 in 2010.
Learn more about your water
Guides and resources related to Ennis's water quality findings.
Explore water quality across Madison
Frequently asked questions
Is Ennis, MT tap water safe to drink?
Ennis's water quality earned a grade of B+ (83.9/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #23 out of 115 cities tested in Montana.
What contaminants are in Ennis's water?
Lead was measured at 0.0 ppb (90th percentile). 122 violations are on record.
How is Ennis'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 Ennis?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Ennis's water come from?
Ennis's water is sourced from Groundwater. The city has 2 water systems serving approximately 1,595 residents.
What health violations has Ennis's water system had?
Ennis has 3 health-based violations on record. The most recent violation was recorded in October 2023. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 4 violations remain unresolved.
Is Ennis's groundwater at risk of contamination?
Ennis 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 122 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 Ennis's water compare to other cities?
Ennis ranks #23 out of 115 cities in Montana (better than 80% of state cities) and #6188 out of 15744 cities nationally (61th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.