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Community Water System · PWS CA2210001

Mariposa Public Utility Dist

Operator location Mariposa, California - 96% of 184 violations are health-based (upper-third health share (> 23%)); surface water source; 2,000 served per SDWIS.

2,000
People served (this PWS)
184
EPA violations (this PWS)
176
Health-based (this PWS)
Untested
UCMR5 (this PWS)
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Mariposa Public Utility Dist standing, high SDWIS violation third

96% of 184 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 96% is upper-third health share (> 23%). Population rank #13,537 of 29,740 among systems serving 500+.

The verdict

Mariposa Public Utility Dist sits in the upper third of the sitemap cohort by violation count (184), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is mid-pack at 2,000 (mid served population (≤ 3,309)). Health-based share is 96% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.

#13,537 of 29,740
Population · /systems
#902 of 1,701
Population · CA
184
Total EPA violations on record
96%
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
Community
Owner Type
Local
Connections
684
County
Mariposa
School/Daycare
No
MCL Violations
162
Monitoring Violations
6
Treatment Tech Violations
14

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Total Haloacetic Acids (HAA5) MCL 99 2012
TTHM MCL 63 2013
CARBON, TOTAL TT 12 2013
CARBON, TOTAL MR 2 2004
Nitrate MR 2 2005
Surface Water Treatment Rule TT 2 1995
Lead and Copper Rule MR 2 1993

Violation Count vs. the National Corpus

Mariposa Public Utility Dist has 184 recorded EPA violations, 84% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 16% carry more. 96% of this system's own violations are health-based (176 of 184), and it ranks #13,537 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)

184 Higher than most more violations than 84% 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 Mariposa Public Utility Dist

176 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for CA2210001.

Sources: EPA SDWIS · California State Water Resources Control Board, Division of Drinking Water

Nationwide peers

184 violations · 2,000 served: nearest cross-state SDWIS matches.

What to do with Mariposa Public Utility Dist

Use this system's EPA-reported record as a starting filter, not a final verdict.

  • See how every tracked system in California compares on the same EPA violation measures. California 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