Is Willcox, AZ tap water safe?
The short answer
1 of the 2 utilities serving Willcox has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and CDC’s records: Cs Winchester Water Company.
City of Willcox, which serves the most people here, has 1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 34.7 ppb, above EPA’s health benchmark. Health goals are stricter than legal limits and are not enforced.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Willcox’s ZIP codes, from EPA’s estimates.
- Open report
City of Willcox
Arizona · serves 3,236 people · under 100 in Willcox
1 result above the health goal and 1 result above EPA’s health benchmark. The worst: Lithium at 34.7 ppb, above EPA’s health benchmark.
No health-based violations since 2016
- Open report
Cs Winchester Water Company
Arizona · serves 402 people · under 100 in Willcox
1 result above the health goal. The worst: Arsenic at 1.2 ppb, above the health goal.
2 health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in City of Willcox’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Arsenic
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Arsenic
Water testing near Willcox
The 3 labs Arizona certifies closest to Willcox, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Turner Laboratories, Inc.
Tucson, AZ · about 57 miles
Complete Analytical Services, LLC
Tucson, AZ · about 57 miles
Legend Technical Services of Arizona, Inc. DBA Legend Analytical
Tucson, AZ · about 57 miles
ZIP codes in Willcox
Which ZIP codes are in Willcox: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: Arizona Department of Health Services, Arizona certified commercial drinking water laboratories; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Willcox
Other towns in Graham County with a page of their own.
What to do next
- Read City of Willcox’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- About LithiumWhat it does to health, where it comes from, and the certification claim that addresses it.About Lithium
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water