Dayton, WA Water Safety: 78/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
How does Dayton tap water hold up under EPA scrutiny? Above average for WA — documented violations are uncommon and the safety grade reflects a clean overall record.
How Dayton Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Dayton Residents
- Average lead level: 0.001 mg/L.
- Homes built before 1986: 82% — older plumbing may contain lead solder.
- Estimated remediation: $1,600 per household.
- CDC health risk index: 13.52 — above typical levels.
Dayton's Water Providers
Federal records track 1 water system in Dayton, WA, and a single provider handles the dominant share of residential connections while carrying primary responsibility for EPA compliance.
Overview
We track water quality and home safety data for 1 ZIP code in Dayton, Washington, covering 1 community water system serving approximately 3,595 people.
No EPA violations recorded across any ZIP codes in Dayton — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Dayton: B (78/100)
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
Dayton water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0010 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate 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 |
|---|---|---|---|
| 99328 | B | Dayton Water Department | 3,283 |
All ZIP Codes in Dayton
- 99328 [B]
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.
Dayton 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
Dayton Infrastructure Age
With 82% 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 Dayton — it's the dominant profile. The median build year of 1942 indicates a housing stock where lead-soldered copper joints are a common structural feature of residences across the city.
Over half of homes in Dayton 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 Dayton
Because property values in Dayton comfortably exceed estimated remediation costs, the equity impact here is proportionally small.
Remediation costs in Dayton are relatively low compared to home values. The $800–$2,600 estimated range is a small fraction of median property value. Home values are 46% below the Washington average.
Dayton: 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.
In recent monitoring under the Lead and Copper Rule, citywide samples for Dayton have approached or crossed the regulatory action level on multiple occasions. Combined with 82% of stock dating from the pre-rule era, the picture supports baseline single-tap reads as a standard household-level step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Dayton: Flood History & Water Damage Risk
Across the NFIP's long tracking period, Dayton shows 50 claims and 100% of ZIP codes within FEMA-designated flood zones — figures that place it in moderate flood exposure territory. At this level, the water-quality implications of flooding — contaminated wells, stressed treatment intake, distribution backflow — move from theoretical edge cases to genuine periodic risks, particularly during higher-severity events.
Dayton has a moderate flood history with 50 FEMA claims averaging $4,381 per payout. 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>$1,600</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.
Deep Dive Reports
Detailed analysis for Dayton, WA