Well Water Testing Requirements in Arizona (AZ)
Arizona does not require ongoing private well testing. New wells must be tested for bacteria and nitrate. Arsenic and fluoride are common contaminants due to desert geology. Well permits are required through the Arizona Department of Water Resources. The state has approximately 200,000 private wells.
Required Contaminant Tests in Arizona
Arizona requires testing for the following 2 contaminants for new wells:
Common Contaminants in Arizona Well Water
Based on geological conditions, land use patterns, and historical testing data, these contaminants are commonly found in Arizona private wells. Even if not required by law, testing for these contaminants is recommended.
Testing Requirements by City in Arizona
Local testing requirements may vary from state-level regulations. Some counties and municipalities have stricter rules than the state minimum. Below are details for major cities in Arizona.
| City | Testing Required | Notes |
|---|---|---|
| Phoenix | No | Limited private wells in metro area |
| Tucson | No | Pima County recommends annual testing |
| Flagstaff | No | Higher elevation; different geology |
| Prescott | No | Many private wells in Yavapai County |
| Sierra Vista | No | Near Fort Huachuca; arsenic concerns |
Testing Recommendations for Arizona Well Owners
- Even though your state does not require testing, the EPA recommends testing private well water annually for bacteria and nitrate.
- Arsenic is a known contaminant in your state. Test for arsenic at least once, even if not required.
- Nitrate contamination is common in your area. Test annually, especially if near agricultural land.
Understanding Arizona's Well Water Regulations
Testing Frequency
Arizona does not require ongoing testing of private well water. However, the EPA recommends all private well owners test annually for bacteria and nitrate, regardless of state requirements. Proactive testing is the only way to ensure your well water is safe.
New Well Requirements
Arizona requires testing when a new well is constructed or an existing well is significantly modified. The required tests include bacteria (coliform/e. coli), nitrate, and the well must pass these tests before being put into service for drinking water. Well construction must comply with state standards and a permit is required before drilling.
State Laboratory and Testing Resources
Arizona does not operate a state laboratory for private well testing. Well owners must use private certified laboratories for water testing. Contact your state health department for a list of certified labs in your area. Testing costs may be higher than in states with subsidized state lab programs. The average cost for a comprehensive well water test in Arizona is approximately $175, though a basic bacteria and nitrate screen may cost significantly less.
How Arizona Compares
Arizona has a minimal level of well water testing regulation. Below are other states with similar regulatory approaches.
| State | Testing Required | Test at Sale | Required Tests | Avg. Cost |
|---|---|---|---|---|
| Arizona (AZ) | No | No | 2 | $175 |
| Alabama (AL) | No | No | 1 | $150 |
| Alaska (AK) | No | No | 2 | $200 |
| Arkansas (AR) | No | No | 1 | $125 |
| California (CA) | No | No | 2 | $250 |
| Colorado (CO) | No | No | 1 | $175 |
Check Other States
Use our well water testing lookup tool to check requirements for any state, or browse all 50 states ranked by testing strictness. If you are moving to or buying property in Arizona, understanding the testing requirements is an important part of your due diligence.