Carlton, WA: High Radon Risk — 53/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Compared to WA averages, Carlton scores below the baseline — health violations appear more frequently than the norm and the city's grade reflects that ongoing shortfall.
How Carlton Compares
Data: EPA SDWIS Last verified: 2026-06-03
Carlton Water: The Quick Version
- Homes built before 1986: 48% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 14.12 — above typical levels.
Water Systems Serving Carlton
Supply infrastructure in Carlton, 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 Carlton, Washington (population ~465), covering 1 community water system serving approximately 1,044 people region-wide.
No EPA violations recorded across any ZIP codes in Carlton — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Carlton: D (53/100)
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
Carlton water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Carlton
- 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 |
|---|---|---|---|
| 98814 | D | TWISP TOWN OF | 1,044 |
All ZIP Codes in Carlton
- 98814 [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 Carlton
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 Carlton's Housing Stock?
With 48% 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
When trying to understand water quality at the household level, the year a home was built often matters more than any city-wide water report. That's because the 1986 federal ban on lead solder in plumbing, and the earlier phase-out of lead pipes before 1970, created sharp discontinuities in residential plumbing risk by construction era. Carlton's median build year of 1983 puts the city in the transition zone: a substantial share of the housing stock postdates the solder ban, but a comparable fraction predates it — with the oldest homes carrying both the solder risk and the pipe risk simultaneously. Whether any individual household sits on the safer or riskier side of these thresholds is the key question, and it's one the city-wide median alone can't answer.
Most homes in Carlton 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.
Carlton: Remediation Cost in Perspective
Equity impact data for Carlton lands in the favorable tier — remediation claims a small slice of what properties here are worth.
Remediation costs in Carlton are relatively low compared to home values. The $2,000–$4,000 estimated range is a small fraction of median property value. Home values are 9% above the Washington average.
Protecting Children from Lead in Carlton
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: 48% of Carlton 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.
Climate-Related Water Risk for Carlton
1 FEMA flood insurance claim are on file for Carlton, and 100% of local ZIP codes fall within federally designated flood zones — enough to put flood exposure on the planning radar, though short of the concentrated-risk threshold where treatment-system vulnerability becomes a primary consideration.
Carlton has a moderate flood history with 1 FEMA claims. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$3,000</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Carlton
- 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 48% 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 Carlton, WA