Tempe, Arizona
Tempe Water Quality
Tempe water meets federal drinking water standards, and the 2024 mix was mostly Salt and Verde River water via SRP — not a CAP-first East Valley blend. Hardness still ran from about 10 to 33 grains. Both are true, and they call for different answers.
In 2024 Tempe reported arsenic up to 5 ppb, TTHM with an LRAA of 52 ppb, and hardness from 9.9 to 33 grains per gallon — all while meeting every federal limit. The SRP-heavy mix is why Tempe is not a Mesa clone.
The short answer
Tempe tap water is treated to federal standards by City of Tempe Water Utilities, public water system AZ0407100. What households notice is hardness that is not one number — the 2024 Consumer Confidence Report lists 169 to 569 ppm (9.9 to 33 gpg), averaging about 11.3 grains — plus the chlorine byproducts that come with treating surface water in a hot climate.
Reverse osmosis addresses dissolved contaminants at the tap; activated carbon addresses disinfection byproducts; an ion-exchange softener addresses hardness. Buying the wrong one is the expensive mistake, which is why the useful first step is a test at your own tap rather than a citywide average.
Get a free test
Tell us your Tempe-area address. We confirm coverage first, then schedule a licensed technician to test at your tap — no charge, no obligation.
What filtration does — and does not
Sediment, carbon, softening and reverse osmosis each address a different part of the Tempe profile. Buying the wrong stage is the expensive mistake a tap test is meant to prevent.
Which water system serves you?
Enter a ZIP code. We will name the utility that supplies it and its public water system identifier, so you can look up that system's own annual report. No contact details needed for this part.
Phoenix-metro ZIP codes are covered here. Five digits will do it.
A licensed technician tests at your own tap and tells you which findings actually apply to your house — including when the answer is none of them. Coverage is confirmed per service area rather than promised as blanket availability.
Where Tempe water comes from
Two treatment plants and a portfolio that was mostly SRP in 2024. This is the part a national filtration site cannot tell you.
Salt and Verde Rivers via SRP — about 71%
In 2024 the Salt River Project supplied about 11 billion gallons to Tempe and Guadalupe, roughly 71 percent of the potable mix. Surface water from the Salt and Verde watersheds, stored in SRP reservoirs and diverted at Granite Reef. This is the backbone of Tempe's year, and it is why Tempe's source story is not a CAP-first story.
Eight groundwater wells — about 23%
About 3 billion gallons in 2024, averaging around 10 million gallons per day. Wells are the arsenic and hardness wild card: when surface supplies tighten, groundwater share rises, and a neighbour on a different blend is not a specification for your house.
Colorado River via CAP — about 6%
About 965 million gallons in 2024. A smaller slice than Mesa's CAP-heavy eastern zones, but still part of the disinfection-byproduct story when Colorado River water is treated and delivered in a hot climate.
What is in the system, and what the 2024 report actually says
Federal Maximum Contaminant Levels are fixed. The ranges next to them are from the City of Tempe 2024 Consumer Confidence Report for PWS ID AZ0407100 — system-level figures, not a reading at your tap. A later CCR supersedes them.
Arsenic
Naturally occurring in Valley groundwater. The federal Maximum Contaminant Level is 10 ppb. Tempe's 2024 report lists a range of not-detected to 5 ppb — below the MCL, and not zero. Reverse osmosis is the residential treatment that addresses dissolved arsenic; a carbon pitcher does not.
Total trihalomethanes (TTHM)
A disinfection byproduct, not a source-water pollutant. The federal MCL is 80 ppb as a locational running annual average. The 2024 report lists an LRAA of 52 ppb and a sample range of 5 to 63 ppb. Activated carbon addresses it; a softener does not.
Haloacetic acids (HAA5)
The other regulated family of chlorine byproducts. The federal MCL is 60 ppb as an LRAA. The 2024 report lists an LRAA of 15 ppb and a sample range of not-detected to 18 ppb. Activated carbon is the matching treatment.
Chromium (total)
The 2024 report lists total chromium as not-detected to 10 ppb against a federal MCL of 100 ppb. Hexavalent chromium has no separate federal MCL. Reverse osmosis is the residential option for dissolved chromium.
Hardness — and why the range is wide
The 2024 aesthetic table lists hardness from 169 to 569 ppm (9.9 to 33 grains per gallon), with an average of 193 ppm / 11.3 gpg. That spread reflects SRP surface water blended with well water and a smaller CAP share — not a measurement at your kitchen tap.
What we are not putting on this page
A reading for your address. Citywide ranges come from the utility's CCR and from EPA SDWIS. They cannot account for your service line, your fixtures, or a softener a previous owner left behind.
Where these figures come from
Every concentration on this page is taken from the utility's own 2024 Consumer Confidence Report and every legal limit is the EPA Maximum Contaminant Level. Independent compilations exist; they are not the source used here.
- City of Tempe Annual Water Reports (CCR) — also at tempe.gov/ccr. Arsenic, TTHM, HAA5, total chromium, hardness and the 71 / 23 / 6 percent source mix are taken from the 2024 English report for PWS ID AZ0407100.
- EPA National Primary Drinking Water Regulations — federal MCLs, including arsenic 10 ppb, TTHM 80 ppb, HAA5 60 ppb and total chromium 100 ppb.
- EPA SDWIS Federal Reports — search public water system identifier AZ0407100.
Matching treatment to the finding
Filtration is not one product. Each of these addresses a different problem, and none of them addresses all of them.
Reverse osmosis, at the tap
The residential option for dissolved inorganics — arsenic and chromium among them. Under-sink for drinking and cooking. It is not a whole-house answer to hardness.
Activated carbon
Targets chlorine byproducts and the taste that comes with them. It does not remove arsenic and it does not soften water.
Ion-exchange softener
The answer to Tempe hardness when scale is the complaint. It is a plumbing modification, and it adds sodium. Sequence with RO if both are justified.
Sometimes nothing
If a test comes back unremarkable and existing equipment is already handling hardness, that is the finding. A free test that always ends in a recommendation is not a test.
How the free test works
A licensed technician tests at your kitchen tap, walks the plumbing, and tells you which of the problems above applies to your house and which does not. There is no charge and no obligation, and nothing has to be decided while someone is standing in your kitchen.
Seamless Home is the licensed contractor of record on the work that follows. Installation is performed by vetted installing partners engaged as our subcontractors, and the workmanship obligation stays with us. Coverage is confirmed per service area rather than promised as blanket availability.
If softening is part of the answer, one installation detail is worth settling early: the regeneration cycle flushes brine to a drain, and the plumbing code will not let that line connect directly. Where a water softener is allowed to discharge covers the air gap the code requires and the separate question a septic system raises.
Tempe water, answered plainly
Is Tempe tap water safe to drink?+
Tempe water is treated to federal standards by City of Tempe Water Utilities, public water system identifier AZ0407100, and the utility publishes compliance in its annual Consumer Confidence Report. A system can be fully compliant and still contain compounds a household would rather filter. Both of those statements are accurate, and neither one implies the utility is doing anything wrong.
Why does Tempe's source mix look different from Mesa or Chandler?+
Because Tempe's 2024 portfolio was mostly SRP Salt and Verde water (about 71 percent), with wells at about 23 percent and CAP Colorado River water at about 6 percent. East Valley cities that lean harder on CAP will show a different disinfection-byproduct and hardness profile. A valley-wide average is not a Tempe reading.
Do I need a whole-house system or a filter at the sink?+
They solve different problems. Point-of-use reverse osmosis handles what you drink and cook with. A softener handles what your plumbing and water heater experience. Plenty of Tempe houses need both, and plenty need neither. Sequence matters.
Does a pitcher filter fix Tempe water?+
A carbon pitcher improves taste and reduces chlorine byproducts. It will not meaningfully reduce arsenic, and it does nothing for hardness. If white scale is why you are looking, a pitcher does not touch the problem.
How do I find the measured numbers for my system?+
The City of Tempe 2024 Consumer Confidence Report — available at tempe.gov/ccr — is the report for the system. EPA SDWIS carries the compliance record under public water system identifier AZ0407100. Those are system-level figures. They do not describe your service line or a softener already in the garage.
What does water treatment cost in Tempe?+
It depends on which equipment your results justify and on whether the house was built with a softener loop. We do not publish a figure for your house on a web page. The test is free and the conversation that follows is based on what the test found.
Who does the installation, and who is responsible afterwards?+
Seamless Home is the licensed contractor of record. Installation is performed by vetted installing partners engaged as our subcontractors, and the workmanship obligation stays with us. Equipment carries its manufacturer's own warranty, registered in your name at completion. Coverage is confirmed per service area rather than promised as blanket availability.
Related resources
Home water purification and treatment
The national service page behind this one: what each treatment stage removes, and why a test comes first.
Learn more →Phoenix water quality
The Phoenix CCR page: same valley, different utility, different PWS ID.
Learn more →Mesa water quality
Three zones and a CAP-heavier eastern mix — the contrast to Tempe's SRP-first year.
Learn more →Chandler water quality
Arsenic up to 9.5 ppb and TTHM samples up to 77 ppb in the 2025 Chandler CCR.
Learn more →Home battery backup in Phoenix, AZ
Monsoon and heat outages — the battery side of the same metro.
Learn more →All homeowner services
Water treatment, battery backup, HVAC and solar under one licensed contractor of record.
Learn more →Get a free test at your tap
A licensed technician tests at your kitchen tap and tells you which of the problems above applies to your house — and which does not. No charge, no obligation, and coverage confirmed at your address first.
Get a free test