PlainWater
States → Arizona

Community Water System · PWS AZ0412004

Nogales City Of

Nogales, Arizona 85621 - drinking water served from groundwater sources to 22,000 people, tracked in EPA SDWIS and UCMR5.

22,000
People served
1,954
EPA violations
36
Health-based
No PFAS
UCMR5 result

The verdict

EPA records 1,954 drinking-water violations at Nogales City Of, 2% of them health-based - above the Arizona per-system average.

1,954
Total EPA violations on record
2%
Health-based (MCL / treatment failure)
22,000
People served by this system
0
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Nogales City Of

Nogales City Of is a local-owned community water system that delivers drinking water to 22,000 residents in Nogales, Arizona (Santa Cruz County) through 5,400 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 1,954 total violations for this system , of which 36 (2%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 1,860 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 Arsenic, recorded in 98 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%).

Nogales City Of's 1,954 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
22,000
Total Violations
1,954
Health-Based Violations
36
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
5,400
County
Santa Cruz
School/Daycare
No
MCL Violations
25
Monitoring Violations
1,860
Treatment Tech Violations
11

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Arsenic MR 98 2024
Nitrate MR 82 2023
TTHM MR 55 2024
Total Haloacetic Acids (HAA5) MR 55 2024
Chlorine MR 39 2025
2,4-D MR 34 2018
Coliform (TCR) MR 33 2016
Pentachlorophenol MR 32 2018
Di(2-ethylhexyl) adipate MR 31 2018
Simazine MR 31 2018
Di(2-ethylhexyl) phthalate MR 31 2018
Picloram MR 31 2018
Dinoseb MR 31 2018
Hexachlorocyclopentadiene MR 31 2018
Carbofuran MR 31 2018
Atrazine MR 31 2018
LASSO MR 31 2018
2,3,7,8-TCDD MR 31 2018
Heptachlor MR 31 2018
Heptachlor epoxide MR 31 2018
2,4,5-TP MR 31 2018
HEXACHLOROBENZENE MR 31 2018
Benzo(a)pyrene MR 31 2018
1,2-DIBROMO-3-CHLOROPROPANE MR 31 2018
ETHYLENE DIBROMIDE MR 31 2018
Chlordane MR 31 2018
Methoxychlor MR 31 2018
Endrin MR 31 2018
BHC-GAMMA MR 31 2018
Diquat MR 31 2018

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 286 samples detected PFAS.

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

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 AZ0412004 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 Nogales City Of 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 Chlorine MR 39 SDWIS / AZ0412004 / 0999
2024 Arsenic MR 98 SDWIS / AZ0412004 / 1005
2024 TTHM MR 55 SDWIS / AZ0412004 / 2950
2024 Total Haloacetic Acids (HAA5) MR 55 SDWIS / AZ0412004 / 2456
2024 Public Notice Other 6 SDWIS / AZ0412004 / 7500
2024 LEAD AND COPPER RULE REVISIONS RPT 4 SDWIS / AZ0412004 / 5200
2024 LEAD AND COPPER RULE REVISIONS TT 4 SDWIS / AZ0412004 / 5200
2023 Nitrate MR 82 SDWIS / AZ0412004 / 1040
2023 Revised Total Coliform Rule RPT 11 SDWIS / AZ0412004 / 8000
2021 Groundwater Rule TT 4 SDWIS / AZ0412004 / 0700
2018 2,4-D MR 34 SDWIS / AZ0412004 / 2105
2018 Pentachlorophenol MR 32 SDWIS / AZ0412004 / 2326
2018 Di(2-ethylhexyl) adipate MR 31 SDWIS / AZ0412004 / 2035
2018 Simazine MR 31 SDWIS / AZ0412004 / 2037
2018 Di(2-ethylhexyl) phthalate MR 31 SDWIS / AZ0412004 / 2039

How Nogales City Of Compares

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

Metric Nogales City Of Arizona avg Federal benchmark
Total violations 1,954 153.3 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 36 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 22,000 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 Nogales City Of water safe to drink? ▼
Nogales City Of (PWS ID: AZ0412004) has 1954 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 22,000 people using Groundwater sources.
How many people does Nogales City Of serve? ▼
Nogales City Of serves 22,000 people in Nogales, Arizona. It is a Local-owned system using Groundwater water sources with 5,400 service connections.
What type of violations does Nogales City Of have? ▼
Nogales City Of has 1,954 total violations: 36 health-based violations (MCL exceedances or treatment failures), 1,860 monitoring/reporting violations, and 11 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Nogales City Of water? ▼
No. Nogales City Of was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.
What water source does Nogales City Of use? ▼
Nogales City Of 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.

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.