Use Arizona ADHS's current commercial drinking-water laboratory directory, then confirm the selected laboratory can perform your particular drinking-water analyses. A laboratory name or nearby address does not establish every testing capability. Ask about the required bottles, sample collection and delivery before collecting water, and keep the laboratory's current scope with your results.
Start with the state directory
Arizona ADHS maintains a commercial drinking-water laboratory directory. Its introduction specifically warns that not every listed commercial laboratory performs every drinking-water test. The directory includes contact information and a facility-detail area with licensed program parameters.
Find the facility you intend to use, rather than assuming every branch with the same company name has the same location or capabilities. ADHS explains that a shared license number can cover multiple in-state laboratories. Confirm where your sample should actually go.
Name the analysis and the water source
Tell the laboratory whether the sample is municipal tap water, private-well water, or water collected after a treatment device. Name the concern, such as lead, arsenic, bacteria or hardness. A general request for a complete water test can mean different panels and leave your actual concern unanswered.
EPA's private-well guidance says to use laboratories certified for drinking-water testing. Its condition-and-contaminant table also shows why the requested analysis depends on the concern. A stain, plumbing material or nearby activity is a reason to select a relevant test, not a diagnosis from appearance.
The existing home lead-testing guide covers that particular concern. The Arizona well-contaminant guide helps frame a well discussion; it does not replace laboratory scope confirmation.
Ask before collecting
Ask the laboratory which container it supplies, how the sample should be collected, any preservation or temperature requirement, and when it must arrive. Follow its written instructions for the selected analysis. Do not reuse a drinking bottle or combine several taps into one sample without approval.
For a regulated public water system using ADEQ’s baseline contractor, separately review the Monitoring Assistance Program owner duties to identify analyses that still need system-arranged sampling and laboratory service. This is a public-system workflow, not a household testing requirement.
For a filter comparison, arrange before-and-after sampling before collection. The sample location and operating conditions matter to what the results can answer.
Keep enough information to interpret the report
Record the facility, requested tests, sample point, collection time and any treatment in use. Confirm how results and reporting units will be supplied. A negative result for one requested analyte does not establish that all possible drinking-water concerns were tested.
If you are choosing treatment afterward, use the certified-claim verification guide. Match a demonstrated water concern with the exact product's claim, rather than treating a laboratory report as an endorsement of any particular filter.