Private Well Water Testing Program

Background

In Arizona, private wells supply drinking water to many households. Regular water testing is not standard practice among most private well owners.

Residents might test their well if buying or selling a home or if they notice changes in how their drinking water looks, tastes, or smells. However, the Safe Drinking Water Act does not require testing for private wells. These wells may be vulnerable to local contaminants like arsenic, uranium, and nitrates. Geographic isolation, limited knowledge of testing, and cost are also barriers to testing private well water.

Key actions

The Arizona Department of Health Services developed a program to improve access to well testing services. The health department is the central hub for facilitating a multi-agency program with the state lab and cooperative extension partner. Key activities included the following:

• Partnering with local agencies to provide lab testing services for private well water owners
• Recruiting well owners to test their wells through an established community-based education network
• Educating well owners with informational materials about free testing opportunities and the specific risks of groundwater contamination in wells
• Providing free well testing services through the state lab, which gives step-by-step instructions for collecting water samples for metals testing

Using this practice

We selected this practice as an example of environmental public health successfully applied in the field. We based our selection on the following four domains:

• Effectiveness: Did it solve or help solve the environmental health problem?
• Feasibility: What conditions and resources are needed to use it?
• Sustainability: Is it realistically able to continue going forward?
• Transferability: Could other health departments use it with little to no changes?

Effectiveness

Preliminary post-testing surveys demonstrated that residents appreciated the opportunity to test their well water.

Feasibility

Based on Arizona's experience, other health departments interested in this practice may need the following capacity:

• Staff time to coordinate with partners at the state lab and with the community education network to recruit interested well owners to test their wells
• Technical expertise in health education, toxicology, and water treatment
• Access to software for managing data, conducting surveys, and registering participants
• Lab equipment and supplies, such as bottles
• Ability to print test kit instructions
• Funding to ship test kits

The program required at least one full-time employee to coordinate the program, answer questions, and help well owners understand their results. Health departments may also need funds to analyze water samples (costs vary depending on contaminant being tested for).

If health departments are able, they could offer mail-in sample return—participation increased when well owners could mail their samples back. Promotion was another cost: The program used a mix of paid advertising and social media. Programs may want to budget up to six months to set up this practice.

Sustainability

Partnering with the cooperative extension was particularly helpful in recruiting well owners in other parts of the state. The program was most successful in areas where the cooperative extension participated in organizing and promoting the workshops for the community.

Transferability

Partnering with the state lab reduced the health department's cost of well water testing. In addition, working with the cooperative extension network helped broadcast the availability of testing services to rural and semi-rural communities.

Health departments may be able to align with other programs doing well testing in other parts of the state. This could facilitate participant recruitment by opening the practice to a wider audience.

Successes and challenges

• Areas where the cooperative extension was actively engaged with the community were noticeably more successful in getting households to test their wells.
• The practice required multiple staff to coordinate activities and respond to well owner concerns.
• Testing costs and lab infrastructure updates caused delays in returning results to well owners and put a pause in recruitment.
• Well owners used these digital tools from the health department:
  • Be Well Informed app for advice on well treatment
  • Contaminant maps (to understand what to test for in their part of the state)

Connections to Essential Services

Documenting how programs contribute to the Essential Public Health Services may help health departments in the accreditation process with the Public Health Accreditation Board. The activities in this practice support and align with these services:

• Investigate and address hazards (2)
• Educate (3)
• Strengthen communities and partnerships (4)
• Improve or innovate (9)

Resources

Well owner routine maintenance practices (National Groundwater Association)

Communicating results of drinking water tests from private wells: Designing report-back materials to facilitate understanding (journal article)

Citation

In citing this practice in articles, presentations, or elsewhere, we suggest the following citation:

Centers for Disease Control and Prevention. National Center for Environmental Health. Environmental Public Health Practices Gateway. Private well water testing program: A practice from the Arizona Department of Health Services. U.S. Department of Health and Human Services, CDC, 2026, https://www.cdc.gov/environmental-health-practice/php/gateway/private-well-water-testing-program.html