Twin Brooks, SD: High Radon Risk — 40/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
The latest EPA cycle for Twin Brooks shows a low safety grade within SD — compliance gaps have persisted over multiple reporting periods, and the city currently holds a low grade in available EPA data.
How Twin Brooks Compares
Data: EPA SDWIS Last verified: 2026-06-03
Twin Brooks Water: The Quick Version
- Homes built before 1986: 58% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 14 — above typical levels.
Water Systems Serving Twin Brooks
At present, 2 utilities serve the bulk of Twin Brooks, SD's residential water connections out of 2 systems active in the area, spread across independent providers with separate infrastructure and compliance obligations.
Overview
We track water quality and home safety data for 1 ZIP code in Twin Brooks, South Dakota (population ~257), covering 2 community water systems serving approximately 8,594 people region-wide.
No EPA violations recorded across any ZIP codes in Twin Brooks — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Twin Brooks: 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
Twin Brooks water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Twin Brooks
- 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 |
|---|---|---|---|
| 57269 | D | GRANT-ROBERTS RURAL WATER SYSTEM | 5,050 |
All ZIP Codes in Twin Brooks
- 57269 [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 Twin Brooks
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 Twin Brooks's Housing Stock?
With 58% 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
Because the majority of Twin Brooks's housing predates 1986, when lead solder was banned from new plumbing, the median build year of 1973 reflects a city where lead-era plumbing materials are common rather than exceptional.
Over half of homes in Twin Brooks 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.
Twin Brooks: Remediation Cost in Perspective
At current valuations, Twin Brooks sits in the low remediation-share tier — the equity impact of fixing documented issues is proportionally minor.
Remediation costs in Twin Brooks are relatively low compared to home values. The $800–$1,500 estimated range is a small fraction of median property value. Home values are 136% above the South Dakota average.
Protecting Children from Lead in Twin Brooks
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.
Even where utility-side monitoring meets Lead and Copper Rule requirements, the 58% pre-rule share in Twin Brooks keeps interior-plumbing variation as a household-level question that aggregate data cannot resolve.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Twin Brooks
- 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 58% 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 Twin Brooks, SD