Collaborative Effort Leads to Ozone Attainment for Northwest Yuma County
PHOENIX (Nov. 19, 2025) — Arizona Department of Environmental Quality (ADEQ) officials announced today that the U.S. Environmental Protection Agency (EPA) has approved the redesignation of Northwest Yuma County to attainment status for the health-based 2015 ozone National Ambient Air Quality Standards, which protect public health and the environment. The redesignated area, which comprises approximately 0.94 percent of the total land area of Yuma County, has demonstrated sustained improvement in air quality through the collaborative efforts of local, state, and federal partners.
EPA’s approval confirms that the area has successfully attained the 2015 ozone standards, implemented permanent and enforceable air quality control measures, developed a comprehensive 10-year maintenance plan, and met all Clean Air Act requirements for redesignation. This achievement transitions the area from its previous “Marginal” nonattainment designation, which had been in place since Aug. 3, 2018.
“Today’s announcement represents a significant victory for public health and the environment in Yuma County,” said ADEQ Air Quality Division Director Daniel Czecholinski. “This redesignation reflects years of dedicated work by our community partners and demonstrates our ongoing commitment to maintaining clean air for all.”
The approved maintenance plan, which will guide air quality management through 2037, was developed through extensive collaboration with local political subdivisions, federal land managers, community stakeholders and residents.
"The ozone redesignation for the Yuma area is a significant accomplishment made possible by the combined efforts of our community, stakeholders and local, regional and state agencies," Yuma County's Director of Development Services Craig Sellers.
The approved maintenance plan includes robust monitoring and control measures to ensure continued compliance with federal standards while also supporting public health, the environment, and sustainable economic growth in the region.
“On behalf of EPA Region 9, I want to congratulate the Arizona Department of Environmental Quality on becoming the first in the Pacific Southwest region to achieve this important milestone,” said EPA Pacific Southwest Acting Regional Administrator Mike Martucci. “This achievement demonstrates the power of collaboration between state, local, Tribal, and federal partners in protecting public health and delivering cleaner air to Yuma County and throughout Arizona.”