PHOENIX — The Arizona Department of Environmental Quality (ADEQ) today announced that the Governor’s Regulatory Review Council (GRRC) has approved updated Aquifer Water Quality Standards (AWQS), marking a major advancement in protecting Arizona’s groundwater — the state’s primary source of drinking water. The new standards will take effect Aug. 4, 2025.
“This is a win for public health and Arizona communities that depend on groundwater for drinking water,” said ADEQ Water Quality Division Director Trevor Baggiore. “We are proud to deliver on our commitment to modernize these standards to reflect the latest science and federal regulations.”
AWQS are Arizona’s legal safety limits for pollutants in groundwater. The updated standards include new or revised limits for seven contaminants, such as arsenic, uranium, and bromate, which can harm human health at high concentrations. These changes are based on maximum contaminant levels set by the U.S. Environmental Protection Agency (EPA) under the Safe Drinking Water Act.
Most facilities with individual permits under Arizona’s Aquifer Protection Program (APP) will be required to begin monitoring for the new and updated contaminants within three months. At the end of the monitoring period, permit amendment applications must be submitted to ADEQ within four years of the AWQS effective date.
More than 80 percent of Arizona residents rely on groundwater for drinking water, especially those in rural communities and private well households. The AWQS directly protect public health by requiring regulated facilities — such as wastewater treatment plants, landfills and industrial operations — to meet the legal limits. If contamination exceeds those limits, ADEQ can require corrective actions, including treatment, containment, or cleanup.
The Secretary of State will publish the final rule in the Arizona Administrative Register later this month.
In the coming months, ADEQ will work closely with APP permittees to implement the new standards.
To learn more about the AWQS rulemaking, visit: azdeq.gov/awqs-update-active-rulemaking.
