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GW OCOTILLO WATER - THUNDERHEAD

PWS ID: AZ0410179 · MARICOPA, Arizona 85138

GW OCOTILLO WATER - THUNDERHEAD serves 174 people in MARICOPA, Arizona using Groundwater water sources. It has 32 recorded EPA violations, including 0 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: GW OCOTILLO WATER - THUNDERHEAD

GW OCOTILLO WATER - THUNDERHEAD is a local-owned community water system that delivers drinking water to 174 residents in MARICOPA, Arizona (Pima County) through 62 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 32 total violations for this system , of which 0 (0%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 28 monitoring and reporting violations are on file. The most recent violation on record dates to 2013.

The most frequently cited contaminant at this system is Consumer Confidence Rule, recorded in 4 violations (Other). 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. GW OCOTILLO WATER - THUNDERHEAD's 32 violations sit below 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
174
Total Violations
32
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
62
County
Pima
School/Daycare
No
MCL Violations
0
Monitoring Violations
28
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Consumer Confidence Rule Other 4 2006
Beryllium, Total MR 3 2002
Coliform (TCR) MR 2 2013
trans-1,2-Dichloroethylene MR 1 2001
1,2-Dichloroethane MR 1 2001
1,1,1-Trichloroethane MR 1 2001
1,2-Dichloropropane MR 1 2001
Trichloroethylene MR 1 2001
Tetrachloroethylene MR 1 2001
CHLOROBENZENE MR 1 2001
Benzene MR 1 2001
Toluene MR 1 2001
Ethylbenzene MR 1 2001
Chlorine MR 1 2004
Total Haloacetic Acids (HAA5) MR 1 2007
cis-1,2-Dichloroethylene MR 1 2001
DICHLOROMETHANE MR 1 2001
o-Dichlorobenzene MR 1 2001
p-Dichlorobenzene MR 1 2001
Styrene MR 1 2001
1,1-Dichloroethylene MR 1 2001
1,1,2-Trichloroethane MR 1 2001
Nitrate MR 1 2004
Carbon tetrachloride MR 1 2001
Xylenes, Total MR 1 2001
1,2,4-Trichlorobenzene MR 1 2001

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 GW OCOTILLO WATER - THUNDERHEAD.

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 AZ0410179 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 GW OCOTILLO WATER - THUNDERHEAD 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
2013 Coliform (TCR) MR 2 SDWIS / AZ0410179 / 3100
2007 Total Haloacetic Acids (HAA5) MR 1 SDWIS / AZ0410179 / 2456
2006 Consumer Confidence Rule Other 4 SDWIS / AZ0410179 / 7000
2004 Chlorine MR 1 SDWIS / AZ0410179 / 0999
2004 Nitrate MR 1 SDWIS / AZ0410179 / 1040
2002 Beryllium, Total MR 3 SDWIS / AZ0410179 / 1075
2001 trans-1,2-Dichloroethylene MR 1 SDWIS / AZ0410179 / 2979
2001 1,2-Dichloroethane MR 1 SDWIS / AZ0410179 / 2980
2001 1,1,1-Trichloroethane MR 1 SDWIS / AZ0410179 / 2981
2001 1,2-Dichloropropane MR 1 SDWIS / AZ0410179 / 2983
2001 Trichloroethylene MR 1 SDWIS / AZ0410179 / 2984
2001 Tetrachloroethylene MR 1 SDWIS / AZ0410179 / 2987
2001 CHLOROBENZENE MR 1 SDWIS / AZ0410179 / 2989
2001 Benzene MR 1 SDWIS / AZ0410179 / 2990
2001 Toluene MR 1 SDWIS / AZ0410179 / 2991

How GW OCOTILLO WATER - THUNDERHEAD Compares

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

Metric GW OCOTILLO WATER - THUNDERHEAD Arizona avg Federal benchmark
Total violations 32 153.3 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 0 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 174 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 GW OCOTILLO WATER - THUNDERHEAD water safe to drink?
GW OCOTILLO WATER - THUNDERHEAD (PWS ID: AZ0410179) has 32 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 174 people using Groundwater sources.
How many people does GW OCOTILLO WATER - THUNDERHEAD serve?
GW OCOTILLO WATER - THUNDERHEAD serves 174 people in MARICOPA, Arizona. It is a Local-owned system using Groundwater water sources with 62 service connections.
What type of violations does GW OCOTILLO WATER - THUNDERHEAD have?
GW OCOTILLO WATER - THUNDERHEAD has 32 total violations: 0 health-based violations (MCL exceedances or treatment failures), 28 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in GW OCOTILLO WATER - THUNDERHEAD water?
No PFAS testing data is available for GW OCOTILLO WATER - THUNDERHEAD under the EPA's UCMR5 monitoring program.
What water source does GW OCOTILLO WATER - THUNDERHEAD use?
GW OCOTILLO WATER - THUNDERHEAD 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.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Related

Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by PlainWater Editorial