Water Quality in Sweet Grass, MT: 8 Violations — Grade F
Grade F · Score 28/100 · 2 water systems · Updated 2026-05-03
Sweet Grass's water has serious compliance issues. Independent testing and filtration are strongly recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Water systems in Sweet Grass, MT have accumulated 8 EPA violations across the full compliance record — a dataset that captures reportable health-based exceedances, monitoring lapses, and enforcement actions filed with the federal Safe Drinking Water Information System.
Water Quality by ZIP Code in Sweet Grass
Water quality varies across Sweet Grass's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 59484 | F | 28 | 8 | 1 | View report → |
Water Quality Overview
Sweet Grass, Montana receives a water quality grade of F with an overall score of 28 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 2 water systems serving Sweet Grass have accumulated 8 EPA violations, including 1 health-based violation. These violations are tracked across 1 ZIP codes serving approximately 200 people.
What Grade F Means
A grade of F indicates serious compliance issues. Sweet Grass's water systems have substantial violations. Residents should strongly consider independent water testing and appropriate filtration.
Lead Levels
The average 90th percentile lead level across Sweet Grass water systems is 0.0150 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 73% of homes built before 1986, Sweet Grass has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Sweet Grass is in EPA Radon Zone 1 (High risk). The EPA recommends all homes in Zone 1 areas be tested for radon. Radon is the second leading cause of lung cancer after smoking.
Water Systems Serving Sweet Grass
Sweet Grass is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 200 people across 1 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 10 enforcement actions against water systems serving Sweet Grass. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Sweet Grass
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Sweet Grass Water Systems
The following contaminants have been detected or caused violations across Sweet Grass's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 0.08 mg/L | 4 | 1 | No |
| Stage 1 DBP Rule | Treatment Technique | N/A | 2 | 1 | No |
| E. coli | Microbiological | N/A | 1 | 1 | No |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 0.06 mg/L | 1 | 1 | Yes |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 10 enforcement actions against water systems serving Sweet Grass. Recent actions:
| Date | Action Type |
|---|---|
| 2025-08-14 | State Informal Action |
| 2025-08-14 | State Informal Enforcement |
| 2024-11-07 | State Informal Action |
| 2024-11-07 | State Informal Enforcement |
| 2024-04-25 | State Informal Action |
| 2024-04-18 | State Informal Action |
| 2024-04-18 | State Informal Enforcement |
| 2024-04-18 | State Order Extension |
| 2024-02-27 | State Informal Action |
| 2024-02-27 | State Informal Enforcement |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-08-14.
Sweet Grass vs. Nearby Montana Cities
How Sweet Grass's water quality compares to similar cities in Montana:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Sweet Grass | F | 8 | 2 | 200 |
| Basin | C | 9 | 1 | 200 |
| Elliston | D | 0 | 1 | 200 |
| Loma | C | 0 | 1 | 200 |
Common Questions About Sweet Grass Water
These are the most common questions residents search for about water quality in Sweet Grass, Montana:
Is Sweet Grass water hard or soft? Water hardness varies by source. Sweet Grass's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Sweet Grass tap water? Sweet Grass's water receives a grade of F (28/100). There are 1 health-based violations — consider filtration.
What is the best water filter for Sweet Grass? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Sweet Grass vs. Montana Average
Understanding how Sweet Grass compares to the broader Montana average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Sweet Grass.
ZIP Codes in Sweet Grass
Sweet Grass spans 1 ZIP code. The ZIP with the lowest water quality score is 59484. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.