Stephan, SD: High Radon Risk — 40/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
For households across Stephan, below-average water safety data and recurring compliance violations documented by SD EPA records make it worthwhile to verify the specific system serving your address — system-level detail is the most actionable reference point available.
How Stephan Compares
Data: EPA SDWIS Last verified: 2026-06-03
Stephan Water: The Quick Version
- Homes built before 1986: 36% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 14.44 — above typical levels.
Water Systems Serving Stephan
One utility dominates residential water service in Stephan, SD — out of 1 system in federal records.
Overview
We track water quality and home safety data for 1 ZIP code in Stephan, South Dakota (population ~7), covering 1 community water system serving approximately 682 people region-wide.
No EPA violations recorded across any ZIP codes in Stephan — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Stephan: D (40/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Stephan water systems draw from: Surface water.
Lead & Copper
- Lead data: not yet available for Stephan
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 57346 | D | HIGHMORE | 682 |
All ZIP Codes in Stephan
- 57346 [D]
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
Updated daily.
CDC Health Data for Stephan
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
How Old Is Stephan's Housing Stock?
Housing age data helps assess potential lead pipe and infrastructure risks. Newer housing stock generally means lower plumbing-related contamination risk.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Development in Stephan unfolded across multiple decades, and the median build year of 2007 reflects a housing inventory where eras of construction are genuinely mixed — including portions that predate the federal prohibition on lead solder in plumbing.
Most homes in Stephan were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Protecting Children from Lead in Stephan
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Wherever 36% of local housing was built before solder rules changed — as is the case in Stephan — a faucet-level sample closes the gap that aggregate utility data cannot.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Stephan
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. With 36% of homes built before 1986, lead solder is a real possibility.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Stephan, SD