Is it legal to use reclaimed water for farming in Arizona?

Regulations and Guidelines

Reclaimed water can be used for irrigation in Arizona, but it must be treated and disinfected to meet the Arizona Department of Environmental Quality’s (ADEQ) standards. The ADEQ requires farms to have a permit to use reclaimed water, which involves a thorough review of their treatment and reuse systems. For example, the ADEQ requires a 2-log (99.9%) removal of enteric viruses and a 3-log (99.9%) removal of Giardia and Cryptosporidium.

Treatment and Disinfection Requirements

To ensure the reuse of reclaimed water is safe, farms must implement a comprehensive treatment and disinfection process. This typically involves physical, chemical, and biological processes, such as coagulation, sedimentation, filtration, and disinfection with chlorine or UV light. The treatment process must be designed to remove pathogens, nutrients, and other pollutants that could contaminate groundwater. For example, the City of Phoenix’s reclaimed water treatment plant uses a 4-step treatment process, including coagulation, sedimentation, filtration, and UV disinfection.

Permitting and Monitoring Requirements

Farms using reclaimed water in Arizona must obtain a permit from the ADEQ and comply with regular monitoring and reporting requirements. The permit requires farms to monitor the quality of their treated water, including parameters such as pH, turbidity, and bacteria levels. Farms must also conduct regular inspections and maintenance of their treatment and reuse systems to ensure they meet the required standards. For example, the ADEQ requires farms to monitor water quality on a monthly basis for 12 months after startup.