Dayton Water Department
EPA ID: WA5318250 · 3,283 people served · 1 ZIP code
Five clean years on EPA record — Dayton Water Department, 3,283 residents served.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Dayton Water Department Source: EPA SDWIS service area boundaries.
Service area boundary — Grade B
Service Area Demographics
The Dayton Water Department serves a community with a median household income of $72,233 and an estimated 3,595 residents across its service area. Approximately 82% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Dayton Water Department's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
About 2% of homes in Columbia County, Washington rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in Washington
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Dayton Water Department (EPA ID: WA5318250) is a community water system in Washington that serves approximately 3,283 people from groundwater sources.
This system serves ZIP code 99328 in Dayton.
Average Home Safety Score: B (78/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 99328 | 0.001 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
- 99328 — Dayton
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Dayton Water Department (WA5318250) on EPA.gov.
Frequently Asked Questions
Is Dayton Water Department water safe to drink?
Based on EPA records, Dayton Water Department has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Dayton Water Department serve?
Dayton Water Department serves approximately 3,283 people across 1 ZIP code in Washington.
Where does Dayton Water Department get its water?
The primary water source is groundwater.
Lead Service Line Inventory
Service line breakdown reported under the federal Lead and Copper Rule Improvements (LCRI) inventory requirement:
This system reports zero confirmed lead service lines in its inventory. Unknown-material counts may still warrant verification.
Federal LCRI rule (effective October 2024) requires every public water system to inventory its service lines and complete lead-line replacement within 10 years.
Source: EPA SDWIS Federal Service Line Inventory (Phase 2) · Submitted 2026
ZipCheckup is not affiliated with the utility or state agency. Inventory figures render verbatim from the public LCRI submission cited above; ZipCheckup does not perform inspections or replacements.