(a) Within 90 days after the final volume of hazardous waste is sent to a unit, you must treat or remove from the unit all hazardous wastes following the approved closure plan.
(b) You must complete final closure activities in accordance with the approved closure plan within 180 days after the final volume of hazardous wastes is sent to the unit. The Director may approve an extension of 180 days to the closure period if you comply with all applicable requirements for requesting a modification to the permit and demonstrate that:
(1) The final closure activities will take longer than 180 days to complete due to circumstances beyond your control, excluding ground water contamination; and
(2) You have taken and will continue to take all steps to prevent threats to human health and the environment from the unclosed, but not operating hazardous waste management unit or facility, including compliance with all applicable permit requirements.
(3) The demonstration must be made at least 30 days prior to the expiration of the initial 180-day period.
(c) Nothing in this section precludes you from removing hazardous wastes and decontaminating or dismantling equipment in accordance with the approved final closure plan at any time before or after notification of final closure.