Mesa City of Water Quality (Arizona) – 2025 Report Results

We read 23 results from Mesa City of’s 2025 water quality report. No results over a legal limit; 10 above a health goal or guideline.

Serves about 466,000 people · Water system ID AZ0407095 · Read the district’s 2025 report (opens in a new tab)

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Results from the 2025 report

Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.

Contaminant	Result	Health goal	Legal limit	What it means
Arsenichighest measured · range 0.8 to 8.8 · Water sources · 2025 report, page 12	8.8 ppb	0.004 ppb	10 ppb	Above the health goal2,200x the health goal
Bromatehighest running annual average · range 2.8 to 7 · Treatment plant · 2025 report, page 11	4 ppb	0.1 ppb	10 ppb	Above the health goal40x the health goal
Chloritehighest measured · range 0.12 to 0.38 · Distribution system · 2025 report, page 11	0.25 ppm	0.05 ppm	1 ppm	Above the health goal5x the health goal
Dibromochloropropane (DBCP)highest measured · range ND to 0.02 · printed as 24 ppt · sampled 2022 · Water sources · 2025 report, page 12	0.02 ppb	0 ppb	0.2 ppb	Above the health goalThe health goal is zero
Fluoridehighest measured · range ND to 1.11 · Water sources · 2025 report, page 12	1.11 ppm	1 ppm	4 ppm	Above the health goal1.1x the health goal
Gross alpha (radioactivity)highest measured · range ND to 5.4 · sampled 2020 · Water sources · 2025 report, page 12	5.4 pCi/L	0 pCi/L	15 pCi/L	Above the health goalThe health goal is zero
Lead90th percentile of homes tested, 1 over the action level · sampled 2024 · Customer taps · 2025 report, page 11	5.01 ppb	0.2 ppb	15 ppb (action level)	Above the health goal25x the health goal
Radium (combined 226 + 228)highest measured · range ND to 0.9 · sampled 2024 · Water sources · 2025 report, page 12	0.9 pCi/L	0 pCi/L	5 pCi/L	Above the health goalThe health goal is zero
Tetrachloroethylene (PCE)highest measured · range ND to 0.9 · Water sources · 2025 report, page 13	0.9 ppb	0.06 ppb	5 ppb	Above the health goal15x the health goal
Total coliform bacteriahighest month · Distribution system · 2025 report, page 10	0.5 % positive	0 % positive	5 % positive	Above the health goalThe health goal is zero
Bariumhighest measured · range 0.02 to 0.13 · Water sources · 2025 report, page 12	0.13 ppm	2 ppm	2 ppm	Below the health goal
Chlorinehighest running annual average · range 0.02 to 2.04 · Distribution system · 2025 report, page 11	0.65 ppm	None set	4 ppm	Below the legal limit
Chlorine dioxidehighest measured · range ND to 150 · Treatment plant · 2025 report, page 11	150 ppb	None set	800 ppb	Below the legal limit
Chromium (total)highest measured · range ND to 24.7 · Water sources · 2025 report, page 12	24.7 ppb	None set	100 ppb	Below the legal limit
Copper90th percentile of homes tested, 0 over the action level · sampled 2024 · Customer taps · 2025 report, page 11	0.17 ppm	0.3 ppm	1.3 ppm (action level)	Below the health goal
DEHP (a phthalate)highest measured · range ND to 1.7 · sampled 2022 · Water sources · 2025 report, page 12	1.7 ppb	12 ppb	6 ppb	Below the health goal
Disinfection byproducts (TTHM)highest running annual average · range ND to 64.1 · Distribution system · 2025 report, page 11	57 ppb	None set	80 ppb	Below the legal limit
Nitrate (as N)highest measured · range ND to 8.99 · Water sources · 2025 report, page 12	8.99 ppm	10 ppm	10 ppm	Below the health goal
Seleniumhighest measured · range ND to 3.12 · Water sources · 2025 report, page 12	3.12 ppb	30 ppb	50 ppb	Below the health goal
Trichloroethylene (TCE)highest measured · range ND to 0.71 · Water sources · 2025 report, page 13	0.71 ppb	1.7 ppb	5 ppb	Below the health goal
Turbidity (cloudiness)highest measured · range 0.04 to 0.5 · Surface water plants · 2025 report, page 10	0.5 NTU	None set	1 NTU	Below the legal limit
Hardnessaverage · Eastern and Southern Zones, highest of 2 sources · 2025 report, page 3	16 gpg (274 ppm)	—	—	Very hard
Sodiumhighest measured · range 45 to 212 · Water sources · 2025 report, page 12	212 ppm	None set	None	No health limit

Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper. 1 number we weren’t sure about is held back until a person checks.

EPA testing for PFAS and lithium

EPA’s own nationwide testing (UCMR 5) found these in Mesa City of’s water between Feb 2023 and Nov 2025. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.

PFHxS9.3 pptFound in 4 of 70 samples · highest resultNo federal limit in force for this one
PFBS15.2 pptFound in 10 of 70 samples · highest resultNo federal limit in force for this one
Lithium525 ppbFound in 70 of 70 samples · highest resultAbove EPA’s health reference level of 10 ppb (a guide, not a legal limit)

Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.

What you can do

Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.