What Is in Phoenix Tap Water? A 2024 Data Summary for Metro Homeowners

Phoenix tap water meets all federal Safe Drinking Water Act standards as of 2024. The City of Phoenix 2024 Consumer Confidence Report, published annually at phoenix.gov/waterservices, documents compliance across all regulated contaminants. At the same time, the Environmental Working Group's analysis of ADEQ-reported utility test data identifies 23 contaminants detected in Phoenix supply and 8 that exceed EWG's independent health guidelines, which are set below federal legal limits because most EPA maximum contaminant levels have not been revised in more than 20 years (ewg.org/tapwater/system.php?pws=AZ0407025). Phoenix draws approximately 95 percent of its supply from surface water delivered by the Salt River Project and Central Arizona Project reservoirs, with groundwater wells covering the remainder. That source water blend shapes the mineral load, disinfection chemistry, and contaminant profile at your tap. This guide synthesizes what 2024 reports from the EPA, ADEQ, USGS, and the City of Phoenix show homeowners about the contaminant categories that most directly affect how Phoenix water looks, tastes, and interacts with plumbing and appliances.

If you want a direct assessment of what is in your water and what treatment, if any, makes sense for your household, Aqua Wellness provides free on-site water testing across Phoenix, Scottsdale, Tempe, Mesa, Chandler, and Ahwatukee. Call Jorge Tejada at (928) 451-1591 to schedule.

Where does Phoenix tap water actually come from?

Phoenix Water Services is one of the largest municipal water utilities in the United States, serving roughly 1.6 million people across the city. Approximately 95 percent of Phoenix's supply comes from surface water (phoenix.gov/waterservices). The two primary sources are the Salt River Project, which stores water in a chain of reservoirs on the Salt and Verde rivers east of Phoenix, and the Central Arizona Project, which delivers Colorado River water through a 336-mile aqueduct from Lake Havasu on the Arizona-California border (cap-az.com). The remaining 5 percent of supply comes from groundwater wells operated by the city, primarily in managed aquifer recharge and recovery programs designed to store surplus surface water underground for dry-year withdrawals. This surface-water-dominant supply matters because large reservoir surface water generally carries less naturally occurring arsenic, uranium, and nitrates than deep confined aquifers in desert geology, though it carries its own contaminant signature from upstream agriculture, urban stormwater, and the mineral load of the Colorado River basin. Phoenix treats its supply at three water treatment plants: Val Vista, Deer Valley, and Lake Pleasant. Treatment includes coagulation, flocculation, sedimentation, filtration, and disinfection with chloramine as the secondary residual disinfectant. The finished water entering the distribution system meets or exceeds all federal Safe Drinking Water Act standards before it leaves the treatment plants. Your specific neighborhood and service zone determines the exact blend of CAP and SRP water reaching your tap in any given month.

What does chloramine disinfection mean for Phoenix homeowners?

Phoenix Water Services uses chloramine as its secondary disinfectant. Chloramine is formed by combining chlorine with ammonia. Utilities choose chloramine over free chlorine for two primary reasons. First, chloramine is more chemically stable, maintaining a protective disinfection residual over the long distribution distances of a geographically spread-out system like the Phoenix metro. Second, chloramine reacts with organic matter in source water to produce lower concentrations of certain trihalomethane disinfection byproducts compared to free chlorine (epa.gov/dbp). Disinfection byproducts (DBPs) are a regulated category of chemicals that form when disinfectants react with naturally occurring organic compounds in water. The EPA regulates two primary DBP categories: total trihalomethanes (TTHMs) with a maximum contaminant level of 80 micrograms per liter, and haloacetic acids (HAA5s) with an MCL of 60 micrograms per liter. Phoenix's 2024 Consumer Confidence Report confirms levels for both categories are within compliance. Long-term exposure to TTHMs and HAA5s above their respective MCLs is associated with increased bladder cancer risk, according to EPA health effect summaries at epa.gov. While Phoenix remains compliant with federal DBP limits, EWG notes that its independent health guidelines for TTHMs and HAA5s are set considerably lower than the federal MCLs, reflecting research that suggests health concern at concentrations below current legal limits. Chloramine does not remove itself from water during normal household use. A whole-home catalytic carbon filter is the appropriate treatment to reduce chloramine and its associated disinfection byproducts before they reach showers, sinks, and appliances. Standard activated carbon media does not reliably remove chloramine. Catalytic carbon specifically is required.

What is the total dissolved solids level in Phoenix water, and does it matter?

Total dissolved solids (TDS) is the aggregate measure of all dissolved mineral content in water, expressed in milligrams per liter or parts per million. Phoenix tap water typically measures between 550 and 700 ppm TDS, above the EPA secondary drinking water standard of 500 mg/L (epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals). The EPA secondary standard for TDS is a non-enforceable guideline for taste and aesthetics, not a health-based maximum contaminant level. Phoenix and utilities across Maricopa County are not required to stay below it. The elevated TDS in Phoenix water comes primarily from the Colorado River, which carries a high dissolved mineral load accumulated over its long course through mineral-rich western geology. By the time Colorado River water arrives at the Central Arizona Project headworks at Lake Havasu and travels another 336 miles through the CAP aqueduct, it carries approximately 600 to 700 mg/L TDS depending on season and reservoir conditions (cap-az.com). Salt River Project water, drawn from snowmelt runoff and upstream Salt and Verde river flows, typically carries a somewhat lower TDS of 400 to 500 mg/L. Phoenix blends these two sources at varying ratios throughout the year based on supply availability and delivery contracts, resulting in the 550 to 700 ppm range at the tap. At these TDS levels, many residents notice a distinct mineral taste in tap water compared to bottled water, which commonly ranges from 30 to 150 ppm TDS. A four-stage reverse osmosis system at the kitchen tap reduces TDS to under 25 ppm, delivering drinking water at a purity level comparable to premium bottled water. The same RO system also removes arsenic, PFAS, fluoride, and nitrates as it filters dissolved minerals.

How hard is Phoenix tap water, and what does it cost your home over time?

Water hardness measures the concentration of dissolved calcium and magnesium, expressed in grains per gallon (GPG) or milligrams per liter. The U.S. Geological Survey Water Science School classifies water above 10.5 GPG (180 mg/L) as very hard (usgs.gov/special-topics/water-science-school/science/hardness-water). Phoenix surface-water-fed service zones typically read 10 to 13.4 GPG based on Consumer Confidence Report data from the City of Phoenix (phoenix.gov/waterservices). Zones in Mesa, Gilbert, and East Valley cities that draw more heavily from groundwater during peak summer demand can read 16 to 22 GPG, among the highest in the metro. Phoenix metro hardness varies seasonally because utilities shift their source water blend between CAP surface water and groundwater wells based on reservoir levels and demand, meaning tap water can be measurably harder in late summer than in winter. At 12 to 22 GPG, Phoenix metro tap water falls well into the very hard classification for virtually every zone in the metro. That hardness level has documented mechanical effects on homes. Scale (calcium carbonate deposits) accumulates inside water heaters, dishwashers, ice makers, washing machines, and plumbing fixtures. The Water Quality Research Foundation published a study showing scale buildup from hard water can reduce water heater heating efficiency by up to 29 percent over time, shortening appliance service life and raising energy costs. Soap, detergent, and shampoo react with calcium and magnesium to form soap scum rather than lather, leaving residue on skin, dishes, laundry, and glass shower enclosures. An ion-exchange water softener sized to your household hardness and flow rate removes calcium and magnesium before they reach fixtures and appliances, extending appliance service life and cutting soap consumption by roughly half in a typical Phoenix household.

Arsenic, nitrates, fluoride, and other regulated trace contaminants in Phoenix water

The City of Phoenix 2024 Consumer Confidence Report documents arsenic in treated distribution water at 2 parts per billion, well below the EPA maximum contaminant level of 10 ppb (phoenix.gov/waterservices; epa.gov/sdwa/arsenic-drinking-water). Phoenix's low arsenic reading reflects its surface-water-dominant supply. Central Arizona Project water sourced from the Colorado River typically contains arsenic below 2 ppb in treated deliveries, and Salt River Project water from upstream mountain reservoirs carries similarly low concentrations. Arizona's volcanic geology generates naturally high arsenic concentrations in deep groundwater, documented in USGS National Groundwater Atlas data (pubs.usgs.gov), but Phoenix limits its groundwater use primarily to managed aquifer recharge operations rather than direct potable blending. Nitrate is another regulated primary contaminant in Phoenix CCR data. The EPA MCL for nitrate is 10 mg/L as nitrogen, and Phoenix municipal supply tests well below this limit. Nitrate enters source water primarily from agricultural runoff, septic system leachate, and fertilizer applications in the watershed. Phoenix's Salt and Verde river reservoirs are upstream of significant agricultural areas, limiting nitrate loading from those sources. Fluoride is added to Phoenix water as a public health measure, targeting approximately 0.7 mg/L per U.S. Department of Health and Human Services guidance at hhs.gov. The EPA MCL for fluoride is 4 mg/L, and Phoenix water remains well below it. Fluoride at 0.7 mg/L is supported by the CDC and the American Dental Association for cavity prevention. Households that prefer to remove fluoride from drinking water can do so using a reverse osmosis system certified to NSF/ANSI Standard 58.

What the EPA's April 2024 PFAS rule means for Phoenix area tap water

In April 2024, the U.S. Environmental Protection Agency finalized the National Primary Drinking Water Regulation for per- and polyfluoroalkyl substances, setting legally enforceable maximum contaminant levels for six PFAS compounds in drinking water (epa.gov/sdwa/pfas-drinking-water-regulation). The new rule establishes individual MCLs of 4 parts per trillion each for PFOA and PFOS, the two most widely studied PFAS compounds, plus limits for PFNA, PFHxS, HFPO-DA, and a hazard index for PFAS mixtures. Public water systems have five years from April 2024 to comply with testing, public notification, and treatment requirements. The Arizona Department of Environmental Quality tracked PFAS monitoring ahead of this rule as part of EPA's Unregulated Contaminant Monitoring Rule 5 (UCMR 5) sampling program (azdeq.gov/PFAS_DW). UCMR 5 required utilities serving more than 3,300 people to test for 29 PFAS compounds between 2023 and 2025 and report results publicly. Phoenix's UCMR 5 data is accessible through the EPA's Safe Drinking Water Information System at sdwis.epa.gov. Phoenix draws from the Colorado River, which has documented PFAS contamination from military installations and industrial facilities at multiple upstream locations. The extent to which those PFAS reach Phoenix finished water depends on the treatment performance at the three Phoenix water treatment plants. For homeowners concerned about PFAS in their drinking water, EPA identifies reverse osmosis systems certified to NSF/ANSI Standard 58 as the point-of-use treatment method effective for PFOA and PFOS reduction (epa.gov/water-research/identifying-drinking-water-filters-certified-reduce-pfas). Confirm NSF/ANSI 58 certification for any system you are considering at nsf.org before purchasing.

Secondary contaminants Phoenix is not required to report in its CCR

Beyond regulated primary contaminants, the EPA maintains a list of secondary drinking water standards, which are non-enforceable aesthetic guidelines for taste, odor, and appearance (epa.gov/sdwa/secondary-drinking-water-standards-guidance-nuisance-chemicals). Phoenix tap water regularly approaches or exceeds several of these secondary standards due to its mineral-rich source water. TDS at 550 to 700 ppm exceeds the 500 mg/L secondary guideline. The EPA secondary guideline for sulfate is 250 mg/L, and Colorado River water contributes meaningful sulfate concentrations to Phoenix supply. Iron and manganese carry secondary standards of 0.3 mg/L and 0.05 mg/L respectively. Phoenix municipal water in treated distribution generally meets these limits, though older service lines can introduce iron from pipe corrosion at the household level, particularly in neighborhoods with aging galvanized infrastructure. pH is monitored by Phoenix Water Services to protect distribution system integrity and minimize corrosivity. Phoenix treated water typically runs pH 7.5 to 8.5, neutral to slightly alkaline and appropriate for home plumbing. Consumer Confidence Reports cover regulated primary contaminants and a selection of secondary parameters. For full secondary contaminant detail, review your utility's complete water quality monitoring data through the EPA's ECHO database at echo.epa.gov, where utilities report additional parameters beyond the CCR minimum. Secondary contaminant levels are not health emergencies, but they directly influence taste, appliance performance, plumbing longevity, and the overall experience of Phoenix tap water in ways that regulated-contaminant compliance alone does not capture.

What Phoenix homeowners can realistically do about their tap water

Phoenix tap water is legally safe under current federal standards. The practical question most homeowners face is not acute safety but chronic quality: what effect does 550 to 700 ppm TDS, 12 to 22 GPG hardness, chloramine disinfection, and residual trace contaminants have on appliances, plumbing, taste, and long-term household economics? A free water test at your tap is the most direct way to answer that for your specific address. Aqua Wellness performs on-site water testing at no charge across Phoenix, Scottsdale, Tempe, Mesa, Chandler, and Ahwatukee. Jorge Tejada and his team test hardness, TDS, chloramine, and other parameters at your tap and review the results with you before recommending any treatment. A whole-home catalytic carbon filter addresses chloramine, chlorination byproducts, taste, and odor across every fixture and appliance in the house. A water softener addresses hardness, protecting water heaters, dishwashers, and pipe interiors from scale accumulation. A reverse osmosis system at the kitchen tap addresses TDS, arsenic, PFAS, fluoride, nitrates, and dissolved minerals at the point of drinking. Most Phoenix households benefit from some combination of these three treatment categories, and the right sizing and sequencing depends on your measured water chemistry, household size, and plumbing configuration. Every system Aqua Wellness installs carries a 25-year warranty on the tank, valve, and electronics. Installation takes four hours. The business is WQA Certified and BBB A+ rated. Schedule your free water test at (928) 451-1591 or through the website.