Model Irrigation District #18
EPA ID: WA5355550 · 7,903 people served · 32 ZIP codes
Water monitoring for Model Irrigation District #18: clean, five years, 7,903 residents.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Model Irrigation District #18 Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Model Irrigation District #18 serves a community with a median household income of $73,723 and an estimated 427,330 residents across its service area. Approximately 59% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 31% 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?
Model Irrigation District #18'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 Spokane 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 80th percentile nationally for proximity to Superfund (NPL) sites. Groundwater sources near contaminated sites may face elevated risk from industrial chemicals.
Infrastructure Risk
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 63 detections recorded. 17 exceed federal EPA limits (4 ppt for PFOA/PFOS).
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
Model Irrigation District #18 (EPA ID: WA5355550) is a community water system in Washington that serves approximately 7,903 people from groundwater sources.
This system provides water to 32 ZIP codes across 4 communities.
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
Coverage: 5 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 27 additional ZIPs inferred from SDWIS registry data. The EPA-confirmed set is the most reliable; SDWIS-inferred entries may be narrower than the real deployment area.
This system serves 32 ZIP codes:
99016 · 99023 · 99037 · 99201 · 99202 99203 · 99204 · 99205 · 99206 · 99207 99208 · 99209 · 99210 · 99211 · 99212 99213 · 99214 · 99215 · 99216 · 99217 99218 · 99219 · 99220 · 99223 · 99224 99228 · 99251 · 99252 · 99256 · 99258 99260 · 99299
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Model Irrigation District #18 (WA5355550) on EPA.gov.
Frequently Asked Questions
Is Model Irrigation District #18 water safe to drink?
Based on EPA records, Model Irrigation District #18 has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Model Irrigation District #18 serve?
Model Irrigation District #18 serves approximately 7,903 people across 32 ZIP codes in Washington.
Where does Model Irrigation District #18 get its water?
The primary water source is groundwater.
Federal UCMR5 PFAS Monitoring: Detected
This water system was tested under the federal EPA Unregulated Contaminant Monitoring Rule (UCMR5). PFAS compounds were detected below the current state-enforceable MCL.
Current MCL reflects the lowest state-enforceable limit (NYS 10 ppt for PFOA/PFOS, effective August 2020). The federal final MCL of 4 ppt for PFOA/PFOS (EPA April 2024 rule) is not enforceable until April 2029. Detections above 4 ppt but below 10 ppt are below current MCL but above the future federal limit.
Source: U.S. EPA UCMR5 (Unregulated Contaminant Monitoring Rule, 5th cycle) — per-system federal sampling, 2023–2025. EPA UCMR5 monitoring program →