How to Read Your Phoenix or Mesa Consumer Confidence Report

The Consumer Confidence Report lands in your mailbox or inbox every July. Most homeowners glance at it and recycle it. That is a mistake. Phoenix and Mesa are legally required to publish exactly what their treatment plants remove and what remains in your tap water, and the most recent reports contain numbers worth understanding. Not because anything on the list violates federal law. It does not. But EPA legal limits and current health research have drifted meaningfully apart over the last decade, and the CCR tells you what you are dealing with without any editorial filter. This article walks through the Phoenix and Mesa CCRs line by line: what each contaminant is, what the legal limit says, what independent health researchers currently recommend, and what, if anything, a homeowner should do about it. No alarm-ringing. No omissions. Just the numbers from the reports plus the context your utility is not required to give you.

What is a Consumer Confidence Report

The Safe Drinking Water Act requires every community water system that serves more than 25 people to publish a Consumer Confidence Report by July 1 each year. Phoenix and Mesa mail this document to customers on account and post the full report at their utility websites: phoenix.gov/waterservices and mesa.gov respectively. The CCR is a legally required disclosure, not a marketing document. It lists every regulated contaminant tested for in the preceding calendar year, the highest level detected, the legal Maximum Contaminant Level (MCL), and compliance status. It also discloses any violations that occurred. The important context: the CCR reports compliance with federal law, not alignment with current health research. Those two things are not the same, and the gap between them is what this article covers.

Phoenix 2025 CCR: the numbers that stand out

• Total hardness: 12 to 22 grains per gallon depending on distribution zone. Southern zones serving Ahwatukee and south Phoenix test at the upper end. Hardness is not regulated under the Safe Drinking Water Act; it appears in the CCR as a secondary standard informational note only.
• Chloramine residual: 2.0 to 3.5 milligrams per liter at the tap. Phoenix Water uses chloramine as its primary residual disinfectant for long distribution runs. Current measured values are documented at phoenix.gov/waterservices.
• Haloacetic acids (HAA5): measured as the running annual average per EPA's Stage 2 Disinfectants and Disinfection Byproducts Rule. Current Phoenix values are at phoenix.gov/waterservices. The EWG health guideline (ewg.org) is far more stringent than the EPA MCL of 60 micrograms per liter.
• Arsenic: historically measured near but below the EPA MCL of 10 micrograms per liter in Phoenix distribution. The EWG guideline of 0.004 micrograms per liter reflects cancer risk at parts-per-billion concentrations. Current Phoenix values at phoenix.gov/waterservices.
• PFAS: monitored under EPA's Unregulated Contaminant Monitoring Rule 5 (UCMR5) since 2023. Current detected concentrations documented in the annual CCR at phoenix.gov/waterservices.
• Fluoride: adjusted to approximately 0.7 milligrams per liter per U.S. Department of Health and Human Services community water fluoridation guidance (hhs.gov).

Mesa CCR: where it differs from Phoenix

Mesa Water operates independently from Phoenix Water and publishes its own Consumer Confidence Report at mesa.gov. Mesa serves the East Valley from a blend of Salt River Project surface water and Central Arizona Project canal deliveries, with a groundwater component in some zones. Key differences from the Phoenix CCR: Mesa's hardness typically runs 18 to 22 grains per gallon, similar to Phoenix's harder southern zones, and consistently in the very-hard classification per the USGS threshold of 10.5 GPG (water.usgs.gov). Mesa also uses chloramine as its primary residual disinfectant. HAA5 and TTHM measured values appear in each annual CCR at mesa.gov. The practical treatment picture for Mesa homeowners is essentially the same as Phoenix: very hard water requiring an ion-exchange softener, chloramine best addressed with catalytic carbon at the whole-home stage, and PFAS concerns handled by an NSF-certified reverse osmosis system at the kitchen sink.

EPA legal limits vs. EWG health guidelines

The most important gap the CCR does not surface is the distance between the EPA Maximum Contaminant Level and current health research. EPA MCLs are legally binding limits set by Congress under the Safe Drinking Water Act. Many were established in the 1990s and have been updated slowly or not at all as science has advanced. The Environmental Working Group Health Guidelines, published at ewg.org, reflect peer-reviewed studies that postdate those regulatory limits. For contaminants like HAA5 and arsenic, the EWG guideline is orders of magnitude more stringent than the EPA MCL. The CCR will show your utility in compliance if measured levels fall below the EPA MCL. That is accurate. It does not mean those levels are below what current research considers protective for long-term exposure.

What to do with the information

For Phoenix and Mesa homeowners, the CCR is a starting point, not a verdict. The hardness numbers alone justify a water softener in most homes: at 18 to 22 GPG, scale accumulation on water heaters, fixtures, and appliances is not a question of if but when. Chloramine at 2 to 3.5 mg/L at the tap means a whole-home catalytic carbon block on the main line, not just a pitcher filter under the sink. PFAS detections, even below the EPA MCL, make an NSF-certified RO system at the kitchen sink the appropriate response for drinking and cooking water. A free on-site water test takes 45 minutes and gives you the specific numbers for your tap, not the utility-wide averages in the CCR. That is the right level of detail for sizing equipment correctly.