Proposed rule · 2025-08513

Arizona Underground Injection Control (UIC) Program; Class I-VI Primacy

The U.S. Environmental Protection Agency (EPA or Agency) has received a complete Underground Injection Control (UIC) primacy application from the State of Arizona requesting primary enforcement responsibility (primacy) for Class I-VI injection wells under the Safe Drinking Water Act (SDWA) section 1422. The EPA's approval of the State's UIC program primacy application would allow the Arizona Department of Environmental Quality (ADEQ) to authorize underground injection for all underground injection wells regulated under the Federal SDWA and ensure compliance with UIC program requirements. The EPA proposes to issue a final rule approving Arizona's application to implement the UIC program for Class I-VI injection wells located within the State, except those on Indian lands. The EPA proposes amendments to reflect this proposed approval of Arizona's UIC program primacy application.