Water Quality in Interior, SD: No Violations — Grade D
Grade D · Score 53/100 · 1 water system · Updated 2026-05-03
Interior's water has significant violations. Water testing and filtration are recommended.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
Across all available EPA tracking data for Interior, SD, the record has remained clean — 1 public water system on file, zero violations recorded, and no enforcement proceedings initiated at any point in the federal dataset.
Water Quality by ZIP Code in Interior
Water quality varies across Interior's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 57750 | D | 53 | 0 | 0 | View report → |
Water Quality Overview
Interior, South Dakota receives a water quality grade of D with an overall score of 53 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
No EPA violations have been recorded for the 1 water system serving Interior. This is a positive indicator, though it does not guarantee the absence of all contaminants — some substances (like PFAS) are not yet fully regulated.
What Grade D Means
A grade of D indicates significant compliance issues. Interior's water systems have accumulated violations that suggest ongoing water quality challenges. Residents should check their specific ZIP code report and consider water testing or filtration.
Lead Levels
Lead testing data for Interior is currently being collected. The EPA requires all community water systems to test for lead under the Lead and Copper Rule.
With 67% of homes built before 1986, Interior 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
Interior is in EPA Radon Zone 2 (Moderate risk). Testing is recommended, especially for homes with basements or ground-level living spaces.
Water Systems Serving Interior
Interior is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 699 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
How to Check Your Water in Interior
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
Interior vs. Nearby South Dakota Cities
How Interior's water quality compares to similar cities in South Dakota:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Interior | D | 0 | 1 | 699 |
| Quinn | D | 0 | 1 | 699 |
| Wall | B | 0 | 1 | 699 |
| Armour | B | 1 | 1 | 698 |
Common Questions About Interior Water
These are the most common questions residents search for about water quality in Interior, South Dakota:
Is Interior water hard or soft? Water hardness varies by source. Interior's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Interior tap water? Interior's water receives a grade of D (53/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Interior? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Interior vs. South Dakota Average
Understanding how Interior compares to the broader South 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 Interior.
ZIP Codes in Interior
Interior spans 1 ZIP code. 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.