Fort Thompson, SD: High Radon Risk — 40/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
In recent EPA cycles, Fort Thompson shows a persistent below-average water quality pattern within SD — documented violations span multiple service areas and have appeared consistently across reporting periods.
How Fort Thompson Compares
Data: EPA SDWIS Last verified: 2026-06-03
Fort Thompson Water: The Quick Version
- Homes built before 1986: 76% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 17.15 — above typical levels.
Water Systems Serving Fort Thompson
Residential water in Fort Thompson, SD is supplied by 2 separate utilities — not one centralized authority. Each of those providers operates under its own service territory boundary, maintains its own distribution infrastructure, and files compliance documentation with the EPA on its own timeline. Federal data counts 2 water systems in the area, with these providers collectively accounting for the dominant share of household connections.
Overview
We track water quality and home safety data for 1 ZIP code in Fort Thompson, South Dakota (population ~1,310), covering 2 community water systems serving approximately 14,306 people region-wide.
No EPA violations recorded across any ZIP codes in Fort Thompson — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Fort Thompson: 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
Fort Thompson water systems draw from: Surface water.
Lead & Copper
- Lead data: not yet available for Fort Thompson
- 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 |
|---|---|---|---|
| 57339 | D | Mid-dakota Rural Water | 11,833 |
All ZIP Codes in Fort Thompson
- 57339 [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 Fort Thompson
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 Fort Thompson's Housing Stock?
With 76% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
The lead that enters tap water in older homes often comes not from the municipal supply but from the home's own plumbing — from solder used in copper joints before the 1986 federal ban, or from lead pipes installed before 1970. In Fort Thompson, where the median build year is 1975, these older materials are widespread. More than half the residential stock predates the 1986 solder ban, and a significant fraction predates 1970 as well. For residents in those homes, the city-wide water quality picture is a less relevant frame than the specific materials inside their own walls and under their own street.
Over half of homes in Fort Thompson were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Fort Thompson: Remediation Cost in Perspective
For most Fort Thompson homeowners, estimated remediation represents a moderate equity share — manageable with planning.
Remediation costs are moderate relative to home values in Fort Thompson. The estimated $800–$1,500 range is manageable for most homeowners but still worth budgeting for. Home values are 42% below the South Dakota average.
Protecting Children from Lead in Fort Thompson
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.
Locally, 76% of Fort Thompson homes carry interior plumbing from the era when lead solder was still permitted in new builds, and citywide monitoring approaches or crosses the EPA action benchmark. Households can find a draw-test kit and certified filtration through verified retailers.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Fort Thompson
- 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 76% 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 Fort Thompson, SD