Lake Cushman System 5
EPA ID: WA5303529 · 3,675 people served · 2 ZIP codes
Dating back across the full five-year EPA tracking window, Lake Cushman System 5 encountered 1 violation, each subsequently remedied and closed — today the utility meets all federal drinking water requirements for the 3,675 residents in its service area and holds no open enforcement actions.
Data: EPA SDWIS Last verified: 2026-04-02
Service Area Map
Coverage area for Lake Cushman System 5 Source: EPA SDWIS service area boundaries.
Service area boundary — Grade A
Service Area Demographics
The Lake Cushman System 5 serves a community with a median household income of $64,119 and an estimated 2,549 residents across its service area. Approximately 54% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
Environmental Justice Note: 36% 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?
Lake Cushman System 5'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 Mason 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
Detected Contaminants
How Lake Cushman System 5 compares to EPA limits
What This Means For You
Lead at 1 mg/L (action level) exceeds the EPA maximum of 0.015 mg/L (action level). Brain damage in children, kidney & blood pressure in adults. Consider reverse osmosis filtration.
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 2 detections recorded.
Lead was detected in this water system. reverse osmosis filtration can reduce exposure.
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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
Lake Cushman System 5 (EPA ID: WA5303529) is a community water system in Washington that serves approximately 3,675 people from groundwater sources.
This system provides water to 2 ZIP codes across 2 communities.
Average Home Safety Score: A (95/100)
Based on water quality violations, lead levels, and radon risk across all ZIP codes served by this system.
Violation History
Contaminants Detected
The following contaminants have been flagged in EPA records for this water system:
| Contaminant | Category | Violations | Health-Based |
|---|---|---|---|
| Lead | Inorganic | 1 | No |
Lead & Copper
EPA Lead and Copper Rule sampling data for ZIP codes served by this system:
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
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by WA or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Lake Cushman System 5 (WA5303529) on EPA.gov.
Frequently Asked Questions
Is Lake Cushman System 5 water safe to drink?
Lake Cushman System 5 has only monitoring/reporting violations, which are procedural in nature. The system meets federal health-based standards.
How many people does Lake Cushman System 5 serve?
Lake Cushman System 5 serves approximately 3,675 people across 2 ZIP codes in Washington.
Where does Lake Cushman System 5 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 →
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
Lake Cushman System 5 (EPA ID: WA5303529) — request the latest Consumer Confidence Report or ask about specific contaminants.