PlainWater
States → Arizona

Community Water System · PWS AZ0413052

Humboldt Water System

Mayer, Arizona 86333 - drinking water served from groundwater sources to 825 people, tracked in EPA SDWIS and UCMR5.

825
People served
239
EPA violations
34
Health-based
Untested
UCMR5 result

The verdict

EPA records 239 drinking-water violations at Humboldt Water System, 14% of them health-based - above the Arizona per-system average.

239
Total EPA violations on record
14%
Health-based (MCL / treatment failure)
825
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Humboldt Water System

Humboldt Water System is a private-owned community water system that delivers drinking water to 825 residents in Mayer, Arizona (Yavapai County) through 414 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 239 total violations for this system , of which 34 (14%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 192 monitoring and reporting violations are on file. The most recent violation on record dates to 2017.

The most frequently cited contaminant at this system is Nitrate, recorded in 81 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Arizona, EPA tracks 1,493 public water systems serving 7,322,166 people, with 228,944 cumulative violations and 15,663 health-based violations on record. About 98% of systems in the state carry at least one violation, and state-wide the average per system is 153.3 violations. Statewide, 145 of 152 UCMR5-tested systems have reported PFAS detections (95.4%).

Humboldt Water System's 239 violations sit above the Arizona average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
825
Total Violations
239
Health-Based Violations
34
Water Source
Groundwater

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

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Humboldt Water System.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID AZ0413052 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Arizona Drinking Water Authority

Arizona DEQ, Drinking Water Program is the primacy agency that licenses and inspects Humboldt Water System under EPA-delegated authority.

Open AZ regulator portal

Source: Arizona DEQ, Drinking Water Program

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2017 Consumer Confidence Rule Other 9 SDWIS / AZ0413052 / 7000
2015 Arsenic MCL 30 SDWIS / AZ0413052 / 1005
2014 Nitrate MR 81 SDWIS / AZ0413052 / 1040
2013 Chlorine MR 13 SDWIS / AZ0413052 / 0999
2012 Nitrate MCL 4 SDWIS / AZ0413052 / 1040
2008 Lead and Copper Rule MR 8 SDWIS / AZ0413052 / 5000
2004 Coliform (TCR) MR 4 SDWIS / AZ0413052 / 3100
2004 TTHM MR 2 SDWIS / AZ0413052 / 2950
2004 Total Haloacetic Acids (HAA5) MR 2 SDWIS / AZ0413052 / 2456
1998 DICHLOROMETHANE MR 2 SDWIS / AZ0413052 / 2964
1998 o-Dichlorobenzene MR 2 SDWIS / AZ0413052 / 2968
1998 p-Dichlorobenzene MR 2 SDWIS / AZ0413052 / 2969
1998 trans-1,2-Dichloroethylene MR 2 SDWIS / AZ0413052 / 2979
1998 1,1,1-Trichloroethane MR 2 SDWIS / AZ0413052 / 2981
1998 Carbon tetrachloride MR 2 SDWIS / AZ0413052 / 2982

How Humboldt Water System Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Humboldt Water System Arizona avg Federal benchmark
Total violations 239 153.3 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 34 10.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 95.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 825 4,904 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 1,493 regulated public water systems in Arizona.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

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. This system serves 825 people using Groundwater sources.
How many people does Humboldt Water System serve? ▼
Humboldt Water System serves 825 people in Mayer, Arizona. It is a Private-owned system using Groundwater water sources with 414 service connections.
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.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

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

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