Grand Mound
EPA ID: WA5307158 · 3,764 people served · 13 ZIP codes
Zero EPA violations over five years — Grand Mound has kept tap water compliance clean for its full service population of 3,764.
Data: EPA SDWIS Last verified: 2026-04-02
Compliance Trajectory
Worsening · Risk tier: High · 95% chance of violation in next 12 months
Violations went from 11 (2022) to 11 (2025). The pattern suggests growing compliance challenges.
Service Area Map
Coverage area for Grand Mound Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Grand Mound serves a community with a median household income of $93,853 and an estimated 240,172 residents across its service area. Approximately 45% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Grand Mound'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 Thurston 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
PFAS Detected in Service Area
PFAS ("forever chemicals") have been detected in water serving this system's area. 32 detections recorded. 9 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
Grand Mound (EPA ID: WA5307158) is a community water system in Washington that serves approximately 3,764 people from groundwater sources.
This system provides water to 13 ZIP codes across 3 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: 2 ZIP codes confirmed via EPA Community Water System Service Area Boundaries v3 plus 11 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.
- 98501 — Olympia
- 98502 — Olympia
- 98504 — Olympia
- 98505 — Olympia
- 98506 — Olympia
- 98507 — Olympia
- 98508 — Olympia
- 98512 — Olympia
- 98513 — Olympia
- 98516 — Olympia
- 98531 — Centralia
- 98579 — Rochester
- 98599 — Olympia
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Grand Mound (WA5307158) on EPA.gov.
Frequently Asked Questions
Is Grand Mound water safe to drink?
Based on EPA records, Grand Mound has no recorded violations in the past 5 years — a positive indicator of water quality management.
How many people does Grand Mound serve?
Grand Mound serves approximately 3,764 people across 13 ZIP codes in Washington.
Where does Grand Mound 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.