City of Mossyrock Public Utility
EPA ID: WA5356350 · 1,553 people served · 2 ZIP codes
The five-year EPA compliance file for City of Mossyrock Public Utility contains 9 violations, each documented and subsequently closed — the utility now operates in full compliance and continues to supply approximately 1,553 residents with water meeting current federal standards, including both health-based and monitoring requirements.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for City of Mossyrock Public Utility Source: EPA SDWIS service area boundaries.
Service area boundary — Grade B
Service Area Demographics
The City of Mossyrock Public Utility serves a community with a median household income of $52,347 and an estimated 3,812 residents across its service area. Approximately 70% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 40% of the population in this service area is classified as disadvantaged under EPA's EJScreen criteria. Communities with higher disadvantaged populations often face disproportionate environmental and health burdens, including aging water infrastructure and limited resources for remediation.
💧 Where Does Your Water Come From?
City of Mossyrock Public Utility'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 1% of homes in Lewis County, Washington rely on private wells rather than public water systems. Private well owners are responsible for their own water testing and treatment.
Superfund Proximity Note: This service area ranks in the 70th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
Detected Contaminants
How City of Mossyrock Public Utility compares to EPA limits
What This Means For You
Surface Water Treatment Rule at 8 mg/L exceeds the EPA maximum of mg/L.
Stage 1 DBP Rule at 1 mg/L exceeds the EPA maximum of mg/L.
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
City of Mossyrock Public Utility (EPA ID: WA5356350) is a community water system in Washington that serves approximately 1,553 people from groundwater sources.
This system provides water to 2 ZIP codes across 2 communities.
Average Home Safety Score: B (84/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Recent Violations
| Date | Contaminant | Type | Status |
|---|---|---|---|
| July 1, 2025 | Surface Water Treatment Rule | Monitoring | Resolved |
| April 1, 2025 | Stage 1 DBP Rule | Health-based | Resolved |
| July 1, 2024 | Surface Water Treatment Rule | Monitoring | Resolved |
| July 1, 2023 | Surface Water Treatment Rule | Monitoring | Resolved |
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Surface Water Treatment Rule | Treatment Failure | 8 | No |
| Stage 1 DBP Rule | Treatment Failure | 1 | Yes |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
| ZIP Code | Lead Level | Exceeds Limit | Sample Date |
|---|---|---|---|
| 98564 | 0.003 mg/L | No | N/A |
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 3 (Low Risk)
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
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for City of Mossyrock Public Utility (WA5356350) on EPA.gov.
Frequently Asked Questions
Is City of Mossyrock Public Utility water safe to drink?
City of Mossyrock Public Utility has recorded 1 health-based violation in the past 5 years. While the system is required to treat water to meet federal standards, you may want to consider additional precautions such as a certified water filter.
How many people does City of Mossyrock Public Utility serve?
City of Mossyrock Public Utility serves approximately 1,553 people across 2 ZIP codes in Washington.
Where does City of Mossyrock Public Utility 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.
Frequently Asked Questions
What You Can Do
Test your water
Home test kits can detect lead, bacteria, and other contaminants at your tap. Find the right filter →
Check your specific ZIP code
Water quality can vary within a system. View nearest ZIP report →
Contact your utility
City of Mossyrock Public Utility (EPA ID: WA5356350) — request the latest Consumer Confidence Report or ask about specific contaminants.