B
78

Record-only indicator: B

Not a safety rating. Missing or old measurements can produce a high score.

Coverage: 1/1 mapped systems have a dated lead result; 0/1 have copper results; 1/1 have UCMR monitoring.

Tempe, AZ 85284

Maricopa County · Population served: 165,000 · SDWIS 2026-07-21 · UCMR5 August 2026

Service-area evidence: EPA service-area records associate the listed system with this ZIP. Boundaries may still overlap or change.

Water Systems Serving This Area

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TEMPE CITY OF
Surface water · Pop. 165,000

Lead: 4.4 ppb; period end 12/31/2024. Copper: not available ppb; period end unknown.

PWSID: AZ0407100

Reported lead and copper results

ContaminantReported value or boundHistorical comparison valueInterpretationStatus
Lead
4.4 ppbPeriod end: 12/31/2024
15 ppb Largest reported value or bound among mapped systems; not necessarily the largest actual concentration. At/below comparison value

PFAS / Forever Chemicals

9 detected 3 above comparison value

UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.

CompoundLevelEPA MCLInterpretationStatus
PFHxS70.5 ppt10 ppt10 pptAbove comparison value
PFOS55.8 ppt4 ppt4 pptAbove comparison value
PFOA38.7 ppt4 ppt4 pptAbove comparison value
PFBS25.7 pptNo standard100 pptNo federal MCL shown
PFHxA22.5 pptNo standard400 pptNo federal MCL shown
PFPeA14.4 pptNo standard—No federal MCL shown
PFBA9.9 pptNo standard500 pptNo federal MCL shown
PFPeS8.0 pptNo standard—No federal MCL shown

Public-record summary

Understanding Your Water in Tempe

Record-only indicator — incomplete or old records can produce a high score. A score of 100 is not a safety finding. Coverage: 1/1 mapped systems have a dated lead result; 0/1 have copper results; 1/1 have UCMR monitoring. Tap water quality in Tempe, Arizona (85284) receives an record-only indicator of B (Moderate-low record-based concern) with a score of 78 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 6 points above the Arizona state average of 72. The area is served by Tempe City Of, a surface water system providing water to approximately 165,000 people. Notably, 3 PFAS compounds exceed the EPA final MCL value used for comparison — a significant concern given the persistent nature of these chemicals. The area has a clean violation record over the past 5 years — a positive indicator of consistent water quality management.

Record-only score 78/100 B
vs State ▲ 6 pts above Arizona avg (72)
Comparison limits No national safety ranking: coverage and service areas overlap.

What a Grade B Means

Grade B summarizes the records available to this model, not household safety. Missing, bounded or old measurements can produce a high score, including 100. Review coverage, dates and the current utility report before interpreting this indicator.

Surface water: sourced from rivers, lakes, or reservoirs

Health Information

What These Contaminants Mean for You

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Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

The record-only indicator is B (78/100). It cannot determine whether your tap water is safe. Missing, bounded or old measurements can produce a high score. Check the coverage and sampling dates below and your utility's current notices.

ZIP code 85284 is served by 1 water system using surface water sources, providing water to approximately 165,000 people. Surface water systems are more susceptible to contamination from agricultural runoff, industrial discharge, and weather events, but typically undergo more extensive treatment including filtration and disinfection.

The largest reported lead value or bound is 4.4 ppb, for the sampling period ending 12/31/2024. This is a system-level 90th-percentile record, not a measurement at your tap. Compare the sampling date and original utility report before interpreting it.

Yes — 9 PFAS compounds were detected in records associated with water serving Tempe, Arizona, and 3 results exceeded the numerical EPA MCL value used for comparison. UCMR5 occurrence results alone are not a regulatory compliance determination. PFAS rules and compliance timelines are evolving; verify current information with the utility and EPA.

Water systems serving Tempe, Arizona have zero violations in the last 5 years. No recorded violation does not establish compliance or tap-water safety; records may be delayed or incomplete.

This public-record indicator cannot select household treatment. Confirm your supplier, current utility report and tap-testing results first; match any treatment to a certified contaminant-reduction claim and follow its maintenance instructions.

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