PFAS in Arizona drinking water

Every Arizona public water system that reported a PFAS detection during EPA UCMR 5 monitoring, how many sit above the 2024 federal limits, and the standard Arizona applies. Concentrations are in nanograms per litre, the same unit as parts per trillion.

This is the United States view of the North American PFAS dataset. The complete dataset, including all 3,452 US systems and 97 Canadian sites, lives on the main PFAS contamination map.

Systems reporting a PFAS detection

Systems above a 2024 federal limit

Systems above the mixture Hazard Index

Large systems in the results

What Arizona requires

Federal EPA limit applies

Agency

Arizona Dept. of Environmental Quality

Citation

AAC R18-4; federal MCL adopted

Effective

2024-06-25

Compliance date

2029-04-26

ADEQ conducting statewide sampling; Tucson (Morris Air Guard) among priority AFFF sites.

Compound

Limit (ng/L)

Note

PFOA

PFOS

PFHxS

PFNA

HFPO-DA (GenX)

Mixture

Not numeric

Hazard Index ≤ 1 (PFHxS, PFNA, HFPO-DA, PFBS)

Citations

ADEQ PFAS Program

US EPA PFAS National Primary Drinking Water Regulation (2024)

US EPA UCMR 5 occurrence data

Last reviewed 2026-08-13. Verify against the agency source before making a compliance or remediation decision.

Full Arizona regulatory brief

All US state limits

Arizona systems with the highest reported results

Ranked by how far the worst single compound sits above its 2024 federal limit. Values are the maximum each system reported during its UCMR 5 monitoring period.

Water system

PWSID

Worst compound

Max ng/L

Times the limit

Tempe City Of

AZ0407100

PFOS

55.8

13.9x

Payson Town Of

AZ0404032

PFOS

42.2

10.6x

Liberty Water Rio Rico

AZ0412011

PFOS

40.9

10.2x

Marana Municipal - Hartman Vistas

AZ0410329

PFOS

5.8x

Big Park Water Company

AZ0413012

PFOA

5.3x

Johnson Util - Anthem At Merrill Ranch

AZ0411136

PFOA

4.8x

Marana Municipal - Marana

AZ0410150

PFOS

17.9

4.5x

Liberty Water Lpsco

AZ0407046

PFOS

14.1

3.5x

City Of Avondale

AZ0407088

PFOA

13.5

3.4x

Usaf Luke Air Force Base

AZ0407305

PFOS

11.7

2.9x

Prescott City Of

AZ0413045

PFOA

11.4

2.9x

Arizona Water Co - Sedona

AZ0403003

PFOA

2.5x

Phoenix International Raceway

AZ0407406

PFOS

2.5x

Gilbert, Town Of

AZ0407092

PFOS

9.8

2.5x

Arizona Water Co - Bisbee

AZ0402001

PFOA

9.7

2.4x

Globe City Of

AZ0404008

PFOS

9.5

2.4x

Goodyear Water Department

AZ0407094

PFOS

7.9

2.0x

Epcor Water - Mohave

AZ0408032

PFOS

7.3

1.8x

Us Army Fort Huachuca

AZ0402078

PFOA

1.8x

Ponderosa Park Dwid

AZ0413044

PFOA

1.8x

Open the full map and filter Arizona pins

Where the numbers on this page come from

Every count above is read straight from a published government file. Nothing is modelled, averaged, or estimated. The rules below are the exact rules used to produce the figures for Arizona.

Dataset used for the system counts

Source

US EPA Unregulated Contaminant Monitoring Rule 5 (UCMR 5) public occurrence data, January 2026 release

File

UCMR5_All.txt, the full public results file released by EPA

Extracted

2026-08-13

Units

Nanograms per litre, equivalent to parts per trillion. EPA publishes micrograms per litre and those values are multiplied by 1,000.

Open the EPA source page

Coverage rules that decide what is counted for Arizona

Who is in UCMR 5. All public water systems serving more than 3,300 people, plus a national sample of 800 smaller systems. Private wells and most small systems are not monitored, so they cannot appear here.

Which systems are listed. Only systems whose state field is AZ and that reported at least one measured PFAS detection. Systems that monitored and found nothing are not shown, and their absence is not evidence of contamination. That gives 59 systems in Arizona.

Systems that cannot be placed. 87 systems nationally reported a detection but have no serviced ZIP code published by EPA, so they carry no location and are excluded from these counts. National totals on the map page include them.

Which value is used. The highest result a system reported for each compound across its sampling events. Results flagged by EPA as non-detects are excluded, as are the lithium results carried in the same file.

The above a limit count. A system is counted when its maximum result for a compound exceeds the 2024 federal Maximum Contaminant Level: 4 ng/L for PFOA and PFOS, 10 ng/L for PFHxS, PFNA, and HFPO-DA. That is 25 systems in Arizona.

The Hazard Index count. Calculated with EPA's own mixture method for PFHxS, PFNA, HFPO-DA, and PFBS. A system is counted when the index is above 1. That is 10 systems in Arizona.

What monitoring data is not. Exceeding a 2024 limit in this dataset is not a compliance violation. The federal limits carry a 2029 compliance date, which EPA proposed on 18 May 2026 to move to 2031 for PFOA and PFOS in a rule that is not final, and treatment may have been installed since the sample was taken.

If any figure on this page does not match its source file, tell Nelson and it will be corrected or removed.