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States → Arizona

303 DWID

PWS ID: AZ0409053 · ST JOHNS, Arizona 85936

303 DWID serves 75 people in ST JOHNS, Arizona using Groundwater water sources. It has 202 recorded EPA violations, including 12 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: 303 DWID

303 DWID is a private-owned transient non-community water system that delivers drinking water to 75 residents in ST JOHNS, Arizona (Navajo County) through 17 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 202 total violations for this system , of which 12 (6%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 171 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 26 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. 303 DWID's 202 violations sit above the Arizona average. Statewide, 145 of 152 UCMR5-tested systems have reported PFAS detections (95.4%). 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
75
Total Violations
202
Health-Based Violations
12
Water Source
Groundwater

System Details

System Type
Transient Non-Community
Owner Type
Private
Connections
17
County
Navajo
School/Daycare
No
MCL Violations
5
Monitoring Violations
171
Treatment Tech Violations
7

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 26 2016
Chlorine MR 24 2009
Nitrate MR 24 2024
E. COLI MR 6 2022
Coliform (TCR) MCL 5 2010
Public Notice Other 5 2023
Consumer Confidence Rule Other 4 2009
Groundwater Rule TT 4 2025
TTHM MR 3 2009
Revised Total Coliform Rule TT 3 2022
1,1-Dichloroethylene MR 2 1998
trans-1,2-Dichloroethylene MR 2 1998
1,2-Dichloropropane MR 2 1998
CHLOROBENZENE MR 2 1998
Benzene MR 2 1998
Ethylbenzene MR 2 1998
cis-1,2-Dichloroethylene MR 2 1998
Revised Total Coliform Rule MON 2 2017
Revised Total Coliform Rule RPT 2 2018
Nitrite MR 2 2013
Arsenic MR 2 1989
Selenium MR 2 1989
Toluene MR 2 1998
Mercury MR 2 1989
1,2-Dichloroethane MR 2 1998
Cadmium MR 2 1989
Carbon tetrachloride MR 2 1998
DICHLOROMETHANE MR 2 1998
1,1,2-Trichloroethane MR 2 1998
Chromium MR 2 1989

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 303 DWID.

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 AZ0409053 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 303 DWID 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
2025 Groundwater Rule TT 4 SDWIS / AZ0409053 / 0700
2024 Nitrate MR 24 SDWIS / AZ0409053 / 1040
2023 Public Notice Other 5 SDWIS / AZ0409053 / 7500
2022 E. COLI MR 6 SDWIS / AZ0409053 / 3014
2022 Revised Total Coliform Rule TT 3 SDWIS / AZ0409053 / 8000
2018 Revised Total Coliform Rule RPT 2 SDWIS / AZ0409053 / 8000
2017 Revised Total Coliform Rule MON 2 SDWIS / AZ0409053 / 8000
2016 Coliform (TCR) MR 26 SDWIS / AZ0409053 / 3100
2013 Nitrite MR 2 SDWIS / AZ0409053 / 1041
2010 Coliform (TCR) MCL 5 SDWIS / AZ0409053 / 3100
2009 Chlorine MR 24 SDWIS / AZ0409053 / 0999
2009 Consumer Confidence Rule Other 4 SDWIS / AZ0409053 / 7000
2009 TTHM MR 3 SDWIS / AZ0409053 / 2950
2004 Total Haloacetic Acids (HAA5) MR 2 SDWIS / AZ0409053 / 2456
1998 1,1-Dichloroethylene MR 2 SDWIS / AZ0409053 / 2977

How 303 DWID Compares

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

Metric 303 DWID Arizona avg Federal benchmark
Total violations 202 153.3 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 12 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 75 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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is 303 DWID water safe to drink? ▼
303 DWID (PWS ID: AZ0409053) has 202 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 75 people using Groundwater sources.
How many people does 303 DWID serve? ▼
303 DWID serves 75 people in ST JOHNS, Arizona. It is a Private-owned system using Groundwater water sources with 17 service connections.
What type of violations does 303 DWID have? ▼
303 DWID has 202 total violations: 12 health-based violations (MCL exceedances or treatment failures), 171 monitoring/reporting violations, and 7 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in 303 DWID water? ▼
No PFAS testing data is available for 303 DWID under the EPA's UCMR5 monitoring program.
What water source does 303 DWID use? ▼
303 DWID uses Groundwater as its primary water source. It is classified as a Transient Non-Community Water System, serving transient populations.
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.

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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.

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