Transient Non-Community Water System · PWS WA53SP940
Twanoh State Park
Operator location Belfair, Washington - 47% of 32 violations are health-based (upper-third health share (> 23%)); groundwater source; 3,173 served per SDWIS.
- 3,173
- People served (this PWS)
- 32
- EPA violations (this PWS)
- 15
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Twanoh State Park standing, mid SDWIS violation third
47% of 32 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 47% is upper-third health share (> 23%). Population rank #10,223 of 29,740 among systems serving 500+.
The verdict
Twanoh State Park lands in the middle third by violation volume (32), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is mid-pack at 3,173 (mid served population (≤ 3,309)). Health-based share is 47% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.
- #10,223 of 29,740
- Population · /systems
- #254 of 766
- Population · WA
- 32
- Total EPA violations on record
- 47%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Transient Non-Community
- Owner Type
- State
- Connections
- 49
- County
- Mason
- School/Daycare
- No
- MCL Violations
- 15
- Monitoring Violations
- 15
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MCL | 15 | 2006 |
| Nitrate | MR | 7 | 2007 |
| Coliform (TCR) | MR | 7 | 2013 |
| Revised Total Coliform Rule | MON | 1 | 2019 |
Violation Count vs. the National Corpus
Twanoh State Park has 32 recorded EPA violations, 44% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 55% carry more. 47% of this system's own violations are health-based (15 of 32), and it ranks #10,223 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
32 Lower than most fewer violations than 55% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Health-based violations on Twanoh State Park
15 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for WA53SP940.
Sources: EPA SDWIS · Washington State Department of Health, Office of Drinking Water
Nationwide peers
32 violations · 3,173 served: nearest cross-state SDWIS matches.
Cross-state systems near this violation count
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems near this population served
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Twanoh State Park
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Washington compares on the same EPA violation measures. Washington systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.