Relating to authorizing the Department of Environmental Protection to promulgate a legislative rule relating to control of air pollution from hazardous waste treatment, storage, and disposal facilities.

HB 4209 authorizes West Virginia's Department of Environmental Protection (DEP) to implement a specific air pollution control rule (45 CSR 25) for hazardous waste treatment, storage, and disposal facilities. The bill formally approves a legislative rule that was previously filed in the State Register (July 23, 2025), requiring these facilities to comply with new air pollution standards. This rule directly affects hazardous waste facilities across West Virginia by mandating controls on air emissions from their operations. The bill itself is procedural, simply granting legal authority to the DEP's existing proposed rule without creating new requirements.