This bill mandates the Oklahoma Department of Environmental Quality to establish numeric water quality criteria for aluminum in surface waters by December 31, 2027. The criteria must align with the federal Clean Water Act and current U.S. Environmental Protection Agency (EPA) guidance, incorporating site-specific conditions that affect aluminum toxicity. The Department is authorized to adopt or reference EPA criteria and guidance documents to facilitate the implementation of these rules.

Once the rules are promulgated, the Department will apply the aluminum criteria to all Oklahoma Pollutant Discharge Elimination System (OPDES) permits where aluminum discharges may occur. The bill outlines requirements for monitoring and reporting, establishing effluent limits, and considering site-specific conditions in compliance evaluations. Additionally, the aluminum criteria will be included in the triennial review of Oklahoma Water Quality Standards, with provisions for revisions based on new scientific data or updated EPA recommendations. The act is set to take effect on November 1, 2026.