Is Humboldt Water System water safe to drink?

Humboldt Water System (PWS ID: AZ0413052) has 239 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. EPA SDWIS lists this system's service population as 825 people using Groundwater sources.

How many people does Humboldt Water System serve?

EPA SDWIS reports that Humboldt Water System serves 825 people (this public water system's service population, not the municipal population of Mayer or any other city). It is a Private-owned system using Groundwater water sources with 414 service connections. The operator address is listed in Mayer, Arizona.

What type of violations does Humboldt Water System have?

Humboldt Water System has 239 total violations: 34 health-based violations (MCL exceedances or treatment failures), 192 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in Humboldt Water System water?

No PFAS testing data is available for Humboldt Water System under the EPA's UCMR5 monitoring program.

What water source does Humboldt Water System use?

Humboldt Water System uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.

Where does this data come from?

All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

Where does Humboldt Water System sit among U.S. public water systems?

According to EPA SDWIS population_served among sitemap-advertised systems (serving 500+), Humboldt Water System ranks #22,066 of 29,740 by people served, and #303 of 413 in Arizona. Ordinals use population_served DESC among systems serving 500+ (the sitemap cohort). See /methodology#corpus-placement.

How does Humboldt Water System's violation count compare nationally?

Humboldt Water System has 239 recorded EPA SDWIS violations, fewer than 12% of the 29,740 public water systems serving 500 or more people nationwide (the same sitemap cohort used for the corpus-placement ranking above). 88% of that cohort has fewer violations than Humboldt Water System. A system can have zero recorded violations and still be actively monitored, and a high violation count often reflects a system that reports thoroughly, not necessarily one with worse water.

States → Arizona

Community Water System · PWS AZ0413052

Humboldt Water System

Operator location Mayer, Arizona - smaller served population (≤ 999) at 825 people served; 239 SDWIS violations on record from groundwater sources.

Compiled by PlainWater · May 15, 2026

825
People served (this PWS) Smaller third of systems: 239
EPA violations (this PWS) Upper third of systems: 34
Health-based (this PWS) Middle third by health-based share: Untested
UCMR5 (this PWS) No UCMR5 result

Follow published updates (RSS)

Humboldt Water System standing, high SDWIS violation third

825 people served (SDWIS) - smaller served population (≤ 999). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 14% is middle-third health share (≤ 23%). Population rank #22,066 of 29,740 among systems serving 500+.

The verdict

Humboldt Water System sits in the upper third of the sitemap cohort by violation count (239), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (825; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is 14% (middle-third health share (≤ 23%)). No UCMR5 PFAS test appears for this system in this extract.

#22,066 of 29,740
Population · /systems: #303 of 413
Population · AZ: 239
Total EPA violations on record: 14%
Health-based (MCL / treatment failure)

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

Water Safety Score

2/100

Humboldt Water System

Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.

Health-based violations F

EPA SDWIS health-based violations on record (MCL, MRDL, treatment technique)

Monitoring & reporting violations F

205

Non-health SDWIS violations (monitoring, reporting, and other compliance)

PFAS contamination N/A

Not UCMR5-tested

Highest PFAS compound level detected in UCMR5 testing

System Details

System Type: Community
Owner Type: Private
Connections: 414
County: Yavapai
School/Daycare: No
MCL Violations: 34
Monitoring Violations: 192
Treatment Tech Violations: 0

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
Nitrate	MR	81	2014
Arsenic	MCL	30	2015
Chlorine	MR	13	2013
Consumer Confidence Rule	Other	9	2017
Lead and Copper Rule	MR	8	2008
Coliform (TCR)	MR	4	2004
Nitrate	MCL	4	2012
Fluoride	MR	3	1992
DICHLOROMETHANE	MR	2	1998
o-Dichlorobenzene	MR	2	1998
p-Dichlorobenzene	MR	2	1998
trans-1,2-Dichloroethylene	MR	2	1998
1,1,1-Trichloroethane	MR	2	1998
Carbon tetrachloride	MR	2	1998
1,1,2-Trichloroethane	MR	2	1998
Tetrachloroethylene	MR	2	1998
Ethylbenzene	MR	2	1998
TTHM	MR	2	2004
Total Haloacetic Acids (HAA5)	MR	2	2004
Selenium	MR	2	1989
1,1-Dichloroethylene	MR	2	1998
Barium	MR	2	1989
Cadmium	MR	2	1989
Chromium	MR	2	1989
Trichloroethylene	MR	2	1998
Mercury	MR	2	1989
Arsenic	MR	2	1989
Toluene	MR	2	1998
Styrene	MR	2	1998
1,2-Dichloroethane	MR	2	1998

Violation Count vs. the National Corpus

Humboldt Water System has 239 recorded EPA violations, 88% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 12% carry more. 14% of this system's own violations are health-based (34 of 239), and it ranks #22,066 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)

239 Higher than most more violations than 88% 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

How many violations vs. how serious, among peer systems

Humboldt Water System plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.

30 public water systems (500+ people served), EPA SDWIS current release.

How to read this

Each dot is one public water system; the highlighted dot is Humboldt Water System. A system to the right has more recorded violations; a system higher up has a larger share of those violations classified health-based rather than monitoring or reporting.

Rare but serious: few violations, but most of them are health-based.
Frequent, mostly paperwork: many violations, but mostly monitoring or reporting, not health-based.
Clean record: below-median on both counts, the tinted corner.

View all 30 systems as a list

City of Ballinger: 372 violations, 85% health-based
Nooksack Valley Water Association: 16 violations, 31% health-based
Montgomery Co RWD 12: 7 violations, 29% health-based
Irvin Water District #6: 11 violations, 27% health-based
Ticonderoga WD: 47 violations, 26% health-based
Pine Valley Plantation: 37 violations, 24% health-based
McLouth, City Of: 29 violations, 17% health-based
Kipling Oaks 1: 25 violations, 16% health-based
South Deerfield Water Supply District: 96 violations, 16% health-based
Sunset Ridge Water District: 82 violations, 15% health-based
Orange Water Dept: 136 violations, 14% health-based
Humboldt Water System: 239 violations, 14% health-based (this system)
Mount Pleasant Water Sys #1: 167 violations, 11% health-based
Lake Gibson Estates: 42 violations, 2% health-based
Benson Culinary Improvement District: 212 violations, 1% health-based
Conemaugh Twp Muni Auth: 567 violations, 1% health-based
Miccosukee Service Plaza: 0 violations, 0% health-based
Brazoria - Fort Bend Counties MUD 3: 0 violations, 0% health-based
Tanglewilde Thompson Place 600: 2 violations, 0% health-based
Center Water Co: 5 violations, 0% health-based
Spring Mills Elem School/Hvs: 9 violations, 0% health-based
Great Bend Industrial Park: 14 violations, 0% health-based
Glen Park Village: 19 violations, 0% health-based
Camp Is-Sho-Da: 22 violations, 0% health-based
Hamilton: 33 violations, 0% health-based
Town of Welaka: 54 violations, 0% health-based
Township of Blairstown Dpw: 61 violations, 0% health-based
McIntosh Water & Fire Pro Authority: 71 violations, 0% health-based
Clarkdale Municipal Water System: 114 violations, 0% health-based
Eureka Water Association: 273 violations, 0% health-based

Population served record for Humboldt Water System

EPA SDWIS lists 825 people served and 414 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.

EPA SDWIS · PWS AZ0413052 AZ primacy agency

Sources: EPA SDWIS · Arizona DEQ, Drinking Water Program

Nationwide peers

239 violations · 825 served: nearest cross-state SDWIS matches.

Cross-state systems with comparable violation load

Nearest cross-state community systems (500+ served) by total SDWIS violations on record.

4 peers

Cross-state systems with smaller service footprints

Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).

4 peers

What to do with Humboldt Water System

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

Compiled by PlainWater, Drinking Water Quality Editorial Process · May 15, 2026

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.