Water Quality Monitoring Program

Tucson Water is responsible for ensuring that the water it delivers is safe, clean, and meets all local, state, and federal drinking water health standards. It monitors water quality throughout its systems to ensure delivery of the highest quality water to all of our customers.

Source or Well Monitoring

Tucson Water operates approximately 219 drinking water wells that are located in 11 public water systems (PWS). The Safe Drinking Water Act requires PWS to monitor their Entry Points to the Distribution System or EPDS to ensure compliance with EPA and ADEQ drinking water regulations. Every active EPDS is tested for at least 89 regulated drinking water parameters at established monitoring frequencies. Additional parameters are tested as well to further evaluate water quality.

Distribution System Monitoring

Tucson Water measures more than 150 water quality parameters at 266 permanent water sampling taps located throughout its distribution systems.

These designated sampling taps are primarily used to meet the monitoring requirements of the Safe Drinking Water Act. Coliform bacteria, disinfection by-products, asbestos, and water quality measurements are some examples of the parameters we monitor for at our water sampling taps.

The results from our distribution system monitoring and EPDS monitoring are used to evaluate the trends in water quality for each water quality zone.

Continuous Online Monitoring

The Clearwater Project is an important step toward the development of renewable drinking water resources and the delivery of a water supply that meets all of the health and aesthetic goals of Tucson's customers. Tracking the water quality of Clearwater and all other water resources is critical to Tucson Water. To do this, we implemented a continuous online monitoring program.

Since 2001, Tucson Water has been tracking real-time water quality throughout the distribution system at 22 key locations in our distribution system. The water quality parameters measured using online instruments at these sites include chlorine residual, conductivity, total dissolved solids, pH, temperature, nitrate, sodium, hardness, and fluoride.

Results of the water quality monitoring are compiled and available from Tucson Water's Water Quality page (which offers access to charts, tables, and maps of water quality information).

Tap Water Monitoring

water faucet (or tap)Water samples from approximately 150 representative customer taps are tested for lead and copper every three years. The primary source of lead in tap water comes from the pipes and fixtures in individual homes. Our participating customers collect water from their taps and submit the samples for analysis by our state-certified laboratory. If more than 10% of the sites exceed the drinking water regulatory level, the water will be treated to make it less corrosive, as corrosive water can leach lead from plumbing fixtures. The results are mailed to both our participating customers and our regulators.