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Community Water System · PWS WA5348300

Mason County Lost Lake

Operator location Port Orchard, Washington - 0% of 68 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 96 served per SDWIS.

96
People served (this PWS)
68
EPA violations (this PWS)
0
Health-based (this PWS)
Untested
UCMR5 (this PWS)
Follow published updates (RSS)

Mason County Lost Lake standing, mid SDWIS violation third

0% of 68 recorded violations are health-based - lower-third health share (≤ 1%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 0% is lower-third health share (≤ 1%).

The verdict

Mason County Lost Lake lands in the middle third by violation volume (68), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (96; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is only 0% - almost all of this trail is monitoring or reporting. No UCMR5 PFAS test appears for this system in this extract.

68
Total EPA violations on record
0%
Health-based (MCL / treatment failure)
96
People served by this PWS (SDWIS)
N/A
PFAS compounds detected (UCMR5)

Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.

System Details

System Type
Community
Owner Type
Private
Connections
93
County
Mason
School/Daycare
No
MCL Violations
0
Monitoring Violations
64
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Heptachlor epoxide MR 5 2005
Di(2-ethylhexyl) adipate MR 4 2005
Simazine MR 4 2005
Hexachlorocyclopentadiene MR 4 2005
Heptachlor MR 4 2005
Chlordane MR 4 2005
BHC-GAMMA MR 4 2005
Endrin MR 4 2005
Di(2-ethylhexyl) phthalate MR 4 2005
LASSO MR 4 2005
Methoxychlor MR 4 2005
Toxaphene MR 4 2005
Atrazine MR 4 2005
Benzo(a)pyrene MR 4 2005
HEXACHLOROBENZENE MR 4 2005
Pentachlorophenol MR 1 2005
Coliform (TCR) MR 1 1991
Lead and Copper Rule MR 1 1998

Violation Count vs. the National Corpus

Mason County Lost Lake has 68 recorded EPA violations, 64% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 35% carry more. 0% of this system's own violations are health-based (0 of 68), and it ranks unranked by population served among that same cohort.

EPA violations vs. the national water-system corpus

Public water systems serving 500+ people (EPA SDWIS)

68 Around the middle fewer violations than 35% 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 Mason County Lost Lake

0 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for WA5348300.

Sources: EPA SDWIS · Washington State Department of Health, Office of Drinking Water

Nationwide peers

68 violations · 96 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.

4 peers

What to do with Mason County Lost Lake

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.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater