Water Quality in Thompson, ND: 2 Violations — Grade C
Grade C · Score 61/100 · 2 water systems · Updated 2026-05-03
Thompson's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Looking at EPA compliance data for Thompson, ND, the record shows 2 violations — findings that span health-based exceedances, monitoring lapses, and enforcement events tied to local utilities in the SDWIS database.
Water Quality by ZIP Code in Thompson
Water quality varies across Thompson's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 58278 | C | 61 | 2 | 0 | View report → |
Water Quality Overview
Thompson, North Dakota receives a water quality grade of C with an overall score of 61 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 2 water systems serving Thompson have accumulated 2 EPA violations (all monitoring/reporting type). These violations are tracked across 1 ZIP codes serving approximately 8,795 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Thompson's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
The average 90th percentile lead level across Thompson water systems is 0.0011 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 67% of homes built before 1986, Thompson 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
Thompson 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 Thompson
Thompson is served by 2 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 8,795 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 Thompson. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Thompson
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 Thompson Water Systems
The following contaminants have been detected or caused violations across Thompson's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Revised Total Coliform Rule | Microbiological | N/A | 1 | 1 | No |
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 Thompson. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-08 | State Informal Action |
| 2025-07-24 | State Informal Action |
| 2025-07-24 | State Informal Enforcement |
| 2025-06-16 | State Informal Action |
| 2025-05-17 | State Informal Action |
| 2025-05-17 | State Informal Enforcement |
| 2021-05-24 | State Order Extension |
| 2021-02-19 | State Informal Action |
| 2021-01-31 | State Informal Action |
| 2021-01-31 | State Informal Enforcement |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-08.
Thompson vs. Nearby North Dakota Cities
How Thompson's water quality compares to similar cities in North Dakota:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Thompson | C | 2 | 2 | 8,795 |
| Wahpeton | C | 0 | 1 | 7,766 |
| Grafton | D | 0 | 2 | 7,284 |
| Watford City | C | 12 | 3 | 10,317 |
Common Questions About Thompson Water
These are the most common questions residents search for about water quality in Thompson, North Dakota:
Is Thompson water hard or soft? Water hardness varies by source. Thompson's 2 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Thompson tap water? Thompson's water receives a grade of C (61/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Thompson? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Thompson vs. North Dakota Average
Understanding how Thompson compares to the broader North Dakota 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 Thompson.
ZIP Codes in Thompson
Thompson spans 1 ZIP code. The ZIP with the lowest water quality score is 58278. 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.