Environment and Conservation, Department of - As enacted, makes various changes related to fees set by the department for environmental regulatory programs; makes changes to the regulation of coal combustion residuals disposal units. - Amends TCA Title 68, Chapter 203, Part 1 and Title 68, Chapter 211, Part 1.

HB 124 amends Tennessee's environmental laws to adjust fees for regulatory programs and update rules for coal ash disposal. It increases certain fees (e.g., raising a fee from $18.75 to $38) and defines "coal combustion residuals" (coal ash from power plants) and "disposal units." The bill requires liners and final caps for new coal ash disposal facilities, with limited exceptions like agricultural use. It also creates a cost-recovery mechanism for the Department of Environment and Conservation to cover oversight costs of coal ash disposal, while exempting these units from standard fee structures. The bill became law as Public Chapter 399 on May 13, 2025.