Well Water Testing Guide for Arizona
Where to test, what to test for, what it costs, and Arizona-specific programs for private well owners.
Finding a Certified Lab
The Arizona Department of Health Services (AZDHS) licenses commercial drinking water laboratories through its Office of Laboratory Services. AZDHS maintains an up-to-date list of certified labs.
Find a lab: Visit the AZDHS Licensed Commercial Drinking Water Laboratories search page. The list is updated on a 24-hour basis.
Phone: Contact AZDHS at (602) 364-0724 for information on currently certified labs.
Testing Labs and Services
Not all labs perform all tests. Here are labs and services commonly used by Arizona well owners:
- AZDHS Licensed Labs The state maintains a searchable database of all licensed commercial drinking water testing laboratories. This is the definitive source — always verify a lab's current certification before using them.
- Complete Water Systems LLC (A2Z Water) Serves Cave Creek, Queen Creek, Prescott, Prescott Valley, Sedona, and many other Arizona communities. Offers free in-office testing of up to three water samples (TDS, hardness, iron, pH). Full lab testing available for detailed analysis.
- Culligan of Northern Arizona Serves Flagstaff, Sedona, Prescott, Prescott Valley, Chino Valley. Free basic water test (TDS, hardness, iron, pH) and full laboratory analysis. Arsenic, bacteria, and nitrate testing available.
- JP Well Water Testing Professional well water testing services across Arizona, including Prescott Valley, Queen Creek, Cave Creek, Sedona, and other locations.
- ADEQ Groundwater Quality Monitoring Program ADEQ monitors groundwater quality across Arizona's 51 basins. Well owners can participate in the monitoring network through an access and data agreement — all water quality results are provided to the well owner at no cost. Contact ADEQ to see if your area is being sampled.
What Does Testing Cost?
| Test | Typical Cost | Notes |
|---|---|---|
| Coliform / E. coli bacteria | $30-$75 | Basic safety test. Should be done annually. |
| Arsenic | $25-$75 | Essential in Arizona. Test every 2-5 years minimum. |
| Domestic water quality package | $150-$300 | Bacteria, nitrates, minerals, metals, pH, TDS. Good baseline. |
| Fluoride | $20-$50 | Naturally elevated across much of Arizona. |
| Gross alpha (radioactivity) | $50-$125 | Tests for radium and other radioactive elements. |
| PFAS panel | $200-$500 | Emerging contaminant; not all labs offer this. |
What Should You Test For?
AZDHS recommends testing private wells on a regular schedule. In Arizona, the contaminant profile is dominated by naturally occurring minerals — arsenic and fluoride above all else.
Every Year
- Coliform bacteria and E. coli
- Nitrate and nitrite
Every 2-5 Years (or at Baseline)
- Arsenic — this is Arizona. Test for arsenic. Period.
- Fluoride — naturally elevated across most of the state
- Gross alpha / radium — natural radioactivity in deep basin-fill wells
- TDS, hardness, pH, iron, manganese — mineral baseline
Additional Testing Triggers
- You just purchased the property — always test before relying on a well
- Any change in taste, odor, or appearance
- After monsoon flooding — shallow wells are vulnerable to surface contamination
- You're near mining operations (active or historical) — add a heavy metals panel
- You're near agricultural operations — test for nitrates and pesticides
- Well was recently repaired, deepened, or had pump work
- Unexplained gastrointestinal illness in the household
- You're in an area with known PFAS — check ADEQ's interactive PFAS map
Community-Specific Recommendations
| Area | Priority Tests Beyond Basics |
|---|---|
| Prescott / Chino Valley / Paulden | Arsenic (!), fluoride, heavy metals near mining areas |
| Cave Creek / Carefree | Arsenic, VOCs near Cave Creek Landfill |
| Queen Creek / San Tan Valley | Arsenic, chromium, DBCP, hardness |
| Sedona / Verde Valley | Arsenic, nitrate (septic system areas) |
| Payson / Rim Country | VOCs (PCE plume area), PFAS, arsenic |
| Willcox Basin | Fluoride, TDS, monitor well depth and yield |
| Green Valley | Arsenic, radium, chromium, heavy metals near mines |
| Sierra Vista | Arsenic, VOCs near Fort Huachuca |
| Gold Canyon / Apache Junction | Arsenic, fluoride (volcanic geology) |
| Wickenburg | Arsenic, fluoride, heavy metals (mining legacy) |
| Pinetop-Lakeside / Show Low | Arsenic, fluoride (C Aquifer) |
| Lower Gila Basin | TDS, chloride, sulfate, arsenic — RO likely needed |
How to Collect a Sample
- Use the container provided by the lab (sterile containers required for bacteria)
- For bacteria: do NOT pre-rinse. Remove the aerator. Run cold water 2-3 minutes before collecting.
- For chemical tests: run water 2-3 minutes, then fill the container
- Keep samples cool (not frozen) and deliver to the lab promptly — bacteria samples have a 24-30 hour hold time
- Label: name, address, date, time, sample location
Free Testing Options
Contact ADEQ at (602) 771-2300 to ask if they are currently offering free testing in your area. The ADEQ Groundwater Quality Monitoring Program provides free results to participating well owners. Some water treatment companies (like Complete Water Systems) offer free basic in-office testing for TDS, hardness, iron, and pH.
Sources
- AZDHS — Test Your Well, Protect Your Family's Health
- AZDHS — Licensed Commercial Drinking Water Laboratories
- ADEQ — Groundwater Quality Monitoring Program
- ADEQ — PFAS Resources for Private Well Owners
- University of Arizona Cooperative Extension — Arizona Drinking Water Well Contaminants (AZ1503)
- University of Arizona Cooperative Extension — Well Owner's Guide to Ground Water Resources (AZ1502)