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Non-Transient Non-Community Water System · PWS AZ0414513

Gowan Milling LLC

Operator location Somerton, Arizona - smaller served population (≤ 999) at 350 people served; 79 SDWIS violations on record from groundwater sources.

350
People served (this PWS)
79
EPA violations (this PWS)
2
Health-based (this PWS)
Untested
UCMR5 (this PWS)
Follow published updates (RSS)

Gowan Milling LLC standing, high SDWIS violation third

350 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 3% is middle-third health share (≤ 23%).

The verdict

Gowan Milling LLC sits in the upper third of the sitemap cohort by violation count (79), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (350; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 3% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.

79
Total EPA violations on record
3%
Health-based (MCL / treatment failure)
350
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
Non-Transient Non-Community
Owner Type
Private
Connections
27
County
Yuma
School/Daycare
No
MCL Violations
0
Monitoring Violations
59
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Total Haloacetic Acids (HAA5) MR 12 2025
TTHM MR 12 2025
Coliform (TCR) MR 11 2013
Chlorine MR 11 2024
Lead and Copper Rule MR 8 2021
Revised Total Coliform Rule RPT 4 2021
Revised Total Coliform Rule MON 3 2024
LEAD AND COPPER RULE REVISIONS TT 2 2024
LEAD AND COPPER RULE REVISIONS RPT 2 2024
Nitrite MR 2 2012
Public Notice Other 1 2024

Violation Count vs. the National Corpus

Gowan Milling LLC has 79 recorded EPA violations, 68% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 32% carry more. 3% of this system's own violations are health-based (2 of 79), 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)

79 Around the middle fewer violations than 32% 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

Population served record for Gowan Milling LLC

EPA SDWIS lists 350 people served and 27 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.

Sources: EPA SDWIS · Arizona DEQ, Drinking Water Program

Nationwide peers

79 violations · 350 served: nearest cross-state SDWIS matches.

What to do with Gowan Milling LLC

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

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