PlainWater

Community Water System · PWS CA4700513

Hornbrook C.s.d.

Operator location Hornbrook, California - 30% of 47 violations are health-based (upper-third health share (> 23%)); groundwater source; 280 served per SDWIS.

280
People served (this PWS)
47
EPA violations (this PWS)
14
Health-based (this PWS)
Untested
UCMR5 (this PWS)
Follow published updates (RSS)

Hornbrook C.s.d. standing, mid SDWIS violation third

30% of 47 recorded violations are health-based - upper-third health share (> 23%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 30% is upper-third health share (> 23%).

The verdict

Hornbrook C.s.d. lands in the middle third by violation volume (47), large enough for peer comparisons without matching the fleet's heaviest ledgers. Population served is smaller (280; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 30% - most of this ledger is MCL or treatment-technique exceedance. No UCMR5 PFAS test appears for this system in this extract.

47
Total EPA violations on record
30%
Health-based (MCL / treatment failure)
280
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
Local
Connections
147
County
Siskiyou
School/Daycare
No
MCL Violations
6
Monitoring Violations
5
Treatment Tech Violations
8

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MCL 6 1997
Stage 1 Disinfectants and Disinfection Byproducts Rule TT 5 2024
Surface Water Treatment Rule TT 2 1993
Gross Alpha, Excl. Radon and U MR 2 1981
Coliform (TCR) MR 2 2015
Lead and Copper Rule MR 1 1993
LEAD AND COPPER RULE REVISIONS TT 1 2024
LEAD AND COPPER RULE REVISIONS RPT 1 2024

Violation Count vs. the National Corpus

Hornbrook C.s.d. has 47 recorded EPA violations, 55% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 45% carry more. 30% of this system's own violations are health-based (14 of 47), 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)

47 Around the middle fewer violations than 45% 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 Hornbrook C.s.d.

14 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for CA4700513.

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

Nationwide peers

47 violations · 280 served: nearest cross-state SDWIS matches.

What to do with Hornbrook C.s.d.

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