Tonasket Water System
EPA ID: WA5388700 · 2,392 people served · 1 ZIP code
Tonasket Water System earns a clean bill from EPA monitoring — no violations in five years across a service area of 2,392 people.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Stable · Risk tier: High · 69% chance of violation in next 12 months
Violations went from 1 (2021) to 1 (2022). Violation counts have remained relatively steady.
Service Area Map
Coverage area for Tonasket Water System Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Tonasket Water System serves a community with a median household income of $51,063 and an estimated 5,615 residents across its service area. Approximately 57% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 90% 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?
Tonasket Water System'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 Okanogan 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
Tonasket Water System (EPA ID: WA5388700) is a community water system in Washington that serves approximately 2,392 people from groundwater sources.
This system serves ZIP code 98855 in Tonasket.
Violation History
Lead & Copper
No Lead and Copper Rule sampling data available for this water system.
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
- 98855 — Tonasket
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Tonasket Water System (WA5388700) on EPA.gov.
Frequently Asked Questions
Is Tonasket Water System water safe to drink?
Based on EPA records, Tonasket Water System has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Tonasket Water System serve?
Tonasket Water System serves approximately 2,392 people across 1 ZIP code in Washington.
Where does Tonasket Water System 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.