Coulee Dam, WA: High Radon Risk — 66/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Drilling into federal monitoring figures for Coulee Dam in WA, the pattern is middle-of-the-road — some utilities have documented MCL exceedances or treatment technique violations in recent years, while others have operated without a single flag, making the city's grade a genuine average rather than a rounded-down high.
How Coulee Dam Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Coulee Dam Residents
- Average lead level: 0.0017 mg/L.
- Homes built before 1986: 87% — older plumbing may contain lead solder.
- Estimated remediation: $1,200 per household.
- CDC health risk index: 14.12 — above typical levels.
Coulee Dam's Water Providers
Supply infrastructure in Coulee Dam, WA runs through a single dominant provider — the main entity among 1 tracked system through which rate decisions, infrastructure work, and federal compliance are managed.
Overview
We track water quality and home safety data for 1 ZIP code in Coulee Dam, Washington, covering 1 community water system serving approximately 1,649 people.
No EPA violations recorded across any ZIP codes in Coulee Dam — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Coulee Dam: C (66/100)
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
Coulee Dam water systems draw from: Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0017 mg/L (EPA action level: 0.015 mg/L)
- 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 |
|---|---|---|---|
| 99116 | C | Coulee Dam Water Department | 1,359 |
All ZIP Codes in Coulee Dam
- 99116 [C]
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.
Coulee Dam Community Health Snapshot
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
Coulee Dam Infrastructure Age
With 87% 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
Pre-1986 plumbing is not a rare legacy case in Coulee Dam — it's the dominant profile. The median build year of 1956 indicates a housing stock where lead-soldered copper joints are a common structural feature of residences across the city.
Over half of homes in Coulee Dam 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.
How Remediation Costs Compare in Coulee Dam
While no remediation project is entirely without cost, the relationship between estimated remediation and property values in Coulee Dam is notably favorable — the equity share is small enough that the household financial perspective is one of proportionality rather than pressure, and most homeowners can treat it as routine planning rather than a significant financial event.
Remediation costs in Coulee Dam are relatively low compared to home values. The $800–$1,500 estimated range is a small fraction of median property value. Home values are 54% below the Washington average.
Coulee Dam: Lead Risk & Vulnerable Populations
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.
Older interior plumbing shapes the local picture: 87% of Coulee Dam homes predate the federal solder ban, and aggregate sampling either approaches or crosses the action benchmark. That mix makes a single-home draw a standard pre-purchase or pre-occupancy step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Coulee Dam
- 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 87% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Coulee Dam, WA