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Community Water System · PWS AZ0408040

Epcor - Willow Valley/King Street

El Mirage, Arizona 85335 - drinking water served from groundwater sources to 3,408 people, tracked in EPA SDWIS and UCMR5.

3,408
People served
121
EPA violations
11
Health-based
No PFAS
UCMR5 result

The verdict

EPA records 121 drinking-water violations at Epcor - Willow Valley/King Street, 9% of them health-based - below the Arizona per-system average.

121
Total EPA violations on record
9%
Health-based (MCL / treatment failure)
3,408
People served by this system
0
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Epcor - Willow Valley/King Street

Epcor - Willow Valley/King Street is a private-owned community water system that delivers drinking water to 3,408 residents in El Mirage, Arizona (Mohave County) through 1,421 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 121 total violations for this system , of which 11 (9%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 98 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 27 violations (MR). This system was sampled under EPA's UCMR5 PFAS monitoring program and no PFAS compounds were detected above the minimum reporting level.

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%).

Epcor - Willow Valley/King Street's 121 violations sit below 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
3,408
Total Violations
121
Health-Based Violations
11
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
1,421
County
Mohave
School/Daycare
No
MCL Violations
11
Monitoring Violations
98
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 27 2006
Chlorine MR 17 2021
TTHM MR 8 2021
Total Haloacetic Acids (HAA5) MR 8 2021
Coliform (TCR) MCL 7 2007
Consumer Confidence Rule Other 6 2015
Nitrate MR 5 2006
Chlorite MR 4 2022
Chlorite MCL 3 2025
Lead and Copper Rule MR 1 2002
1,2,4-Trichlorobenzene MR 1 2004
cis-1,2-Dichloroethylene MR 1 2004
Xylenes, Total MR 1 2004
o-Dichlorobenzene MR 1 2004
1,2-Dichloroethane MR 1 2004
1,1,1-Trichloroethane MR 1 2004
Carbon tetrachloride MR 1 2004
1,2-Dichloropropane MR 1 2004
Trichloroethylene MR 1 2004
Tetrachloroethylene MR 1 2004
CHLOROBENZENE MR 1 2004
Benzene MR 1 2004
Ethylbenzene MR 1 2004
TTHM MCL 1 2012
Cadmium MR 1 1988
Arsenic MR 1 1988
Mercury MR 1 1988
p-Dichlorobenzene MR 1 2004
DICHLOROMETHANE MR 1 2004
Fluoride MR 1 1988

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 58 samples detected PFAS.

Contaminant Date Result MRL Status
PFUnA 6/8/2023 <2.00 ppt 2.00 ppt Not Detected
PFOA 6/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFMBA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 6/8/2023 <2.00 ppt 2.00 ppt Not Detected
PFBS 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxS 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFNA 6/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFOS 6/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFDA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
ADONA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFEESA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
NFDHA 6/8/2023 <20.00 ppt 20.00 ppt Not Detected
PFPeS 6/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFHpS 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFHxA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 6/8/2023 <5.00 ppt 5.00 ppt Not Detected
HFPO-DA 6/8/2023 <5.00 ppt 5.00 ppt Not Detected
PFBA 6/8/2023 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 6/8/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 6/8/2023 <5.00 ppt 5.00 ppt Not Detected
PFMPA 6/8/2023 <4.00 ppt 4.00 ppt Not Detected
PFDoA 6/8/2023 <3.00 ppt 3.00 ppt Not Detected
PFTA 5/2/2023 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 5/2/2023 <7.00 ppt 7.00 ppt Not Detected
NEtFOSAA 5/2/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 5/2/2023 <6.00 ppt 6.00 ppt Not Detected
HFPO-DA 11/27/2023 <5.00 ppt 5.00 ppt Not Detected
PFPeS 11/27/2023 <4.00 ppt 4.00 ppt Not Detected
NFDHA 11/27/2023 <20.00 ppt 20.00 ppt Not Detected
PFEESA 11/27/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 11/27/2023 <3.00 ppt 3.00 ppt Not Detected
PFTA 11/27/2023 <8.00 ppt 8.00 ppt Not Detected
PFTrDA 11/27/2023 <7.00 ppt 7.00 ppt Not Detected
NEtFOSAA 11/27/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 11/27/2023 <6.00 ppt 6.00 ppt Not Detected
PFPeA 11/27/2023 <3.00 ppt 3.00 ppt Not Detected
PFMPA 11/27/2023 <4.00 ppt 4.00 ppt Not Detected
8:2 FTS 11/27/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 11/27/2023 <3.00 ppt 3.00 ppt Not Detected
PFBS 11/27/2023 <3.00 ppt 3.00 ppt Not Detected
PFBA 11/27/2023 <5.00 ppt 5.00 ppt Not Detected
PFHpS 11/27/2023 <3.00 ppt 3.00 ppt Not Detected
ADONA 11/27/2023 <3.00 ppt 3.00 ppt Not Detected
9Cl-PF3ONS 11/27/2023 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 11/27/2023 <5.00 ppt 5.00 ppt Not Detected
PFUnA 11/27/2023 <2.00 ppt 2.00 ppt Not Detected
PFHxA 11/27/2023 <3.00 ppt 3.00 ppt Not Detected

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 Epcor - Willow Valley/King Street.

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 AZ0408040 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 Epcor - Willow Valley/King Street 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 Chlorite MCL 3 SDWIS / AZ0408040 / 1009
2022 Chlorite MR 4 SDWIS / AZ0408040 / 1009
2021 Chlorine MR 17 SDWIS / AZ0408040 / 0999
2021 TTHM MR 8 SDWIS / AZ0408040 / 2950
2021 Total Haloacetic Acids (HAA5) MR 8 SDWIS / AZ0408040 / 2456
2015 Consumer Confidence Rule Other 6 SDWIS / AZ0408040 / 7000
2012 TTHM MCL 1 SDWIS / AZ0408040 / 2950
2007 Coliform (TCR) MCL 7 SDWIS / AZ0408040 / 3100
2006 Coliform (TCR) MR 27 SDWIS / AZ0408040 / 3100
2006 Nitrate MR 5 SDWIS / AZ0408040 / 1040
2004 1,2,4-Trichlorobenzene MR 1 SDWIS / AZ0408040 / 2378
2004 cis-1,2-Dichloroethylene MR 1 SDWIS / AZ0408040 / 2380
2004 Xylenes, Total MR 1 SDWIS / AZ0408040 / 2955
2004 o-Dichlorobenzene MR 1 SDWIS / AZ0408040 / 2968
2004 1,2-Dichloroethane MR 1 SDWIS / AZ0408040 / 2980

How Epcor - Willow Valley/King Street Compares

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

Metric Epcor - Willow Valley/King Street Arizona avg Federal benchmark
Total violations 121 153.3 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 11 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 3,408 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 Epcor - Willow Valley/King Street water safe to drink?
Epcor - Willow Valley/King Street (PWS ID: AZ0408040) has 121 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 3,408 people using Groundwater sources.
How many people does Epcor - Willow Valley/King Street serve?
Epcor - Willow Valley/King Street serves 3,408 people in El Mirage, Arizona. It is a Private-owned system using Groundwater water sources with 1,421 service connections.
What type of violations does Epcor - Willow Valley/King Street have?
Epcor - Willow Valley/King Street has 121 total violations: 11 health-based violations (MCL exceedances or treatment failures), 98 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Epcor - Willow Valley/King Street water?
No. Epcor - Willow Valley/King Street was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does Epcor - Willow Valley/King Street use?
Epcor - Willow Valley/King Street 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. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.
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.