Subject to (h), below, a large quantity generator accumulating hazardous wastes in containers, tanks, drip pads, and containment buildings shall meet the following conditions for exemption prior to closing a waste accumulation unit at the facility, or prior to closing the facility:

1. (a) A large quantity generator shall perform one of the following when closing a waste accumulation unit, but not all waste accumulation units:

   1. (1) Subject to (b), below, place a notice in the operating record within 30 days after closure identifying the location of the unit within the facility; or
   2. (2) Meet the closure performance standards of (d) through (g), below, as applicable, and notify the department using Form HWM-2 “RCRA C Site Identification Form” as amended August 2025, within 90 days after closing the unit that it has complied with the applicable closure performance standards of (d) through (g), below, as applicable.
2. (b) For purposes of (a)(1), above, if the waste accumulation unit is subsequently reopened, the generator may remove the notice from the operating record;

3. (c) When closing a facility, a large quantity generator:

   1. (1) Shall notify the department using Form HWM-2 “RCRA C Site Identification Form” as amended August 2025, no later than 30 days prior to closing the facility;

   2. (2) Subject to (c)(3), below, shall notify the department using Form HWM-2 “RCRA C Site Identification Form” as amended August 2025, within 90 days after closing the facility:

      1. a. That it has complied with the applicable closure performance standards of (d) through (g), below; or

      2. b. If the facility cannot meet the applicable closure performance standards of (d) through (g), below, that it will close:

         1. 1. Under the standards of 40 CFR 265.310 in the case of a facility with container, tank, or containment building unit(s); or
         2. 2. Under the standards of 40 CFR 265.445(b) in the case of a facility with drip pads; and
   3. (3) Within 75 days after the date provided in (c)(1), above, may request additional time to meet the applicable closure performance standards of (d) through (g), below, by notifying the department using Form HWM-2 “RCRA C Site Identification Form” as amended August 2025, and providing an explanation as to why the additional time is required;

4. (d) The generator shall close a container, tank system, or containment building waste accumulation unit or facility in a manner that:

   1. (1) Minimizes the need for further maintenance by controlling, minimizing, or eliminating, to the extent necessary to protect human health and the environment, the post-closure escape of hazardous waste, hazardous constituents, leachate, contaminated run-off, or hazardous waste decomposition products to the ground or surface waters or to the atmosphere; and
   2. (2) Removes or decontaminates all contaminated equipment, structures and soil and any remaining hazardous waste residues from waste accumulation units including containment system components, such as pads and liners, contaminated soils and subsoils, bases, and structures and equipment contaminated with waste, unless Env-Hw 401.01(c) applies;
5. (e) Any hazardous waste generated in the process of closing either the generator’s facility or unit(s) accumulating hazardous waste shall be managed in accordance with all applicable standards of Env-Hw 500, Env-Hw 600, Env-Hw 700, and Env-Hw 1200, including removing any hazardous waste contained in these units within 90 days of generating it and shipping these wastes to a facility authorized under the destination state’s rules to handle the hazardous waste;
6. (f) If the generator demonstrates that any contaminated soils and wastes cannot be practicably removed or decontaminated as required in (d)(2), above, then the waste accumulation unit shall be subject to 40 CFR 262.17(a)(8)(iii)(A)(4);
7. (g) At closure of a drip pad waste accumulation unit, the generator shall comply with the closure requirements of (d)(1), and (e), above, and 40 CFR 265.445(a) and (b); and

8. (h) The closure requirements of this section:

   1. (1) Shall not apply to satellite accumulation areas; and
   2. (2) Shall apply to any generator that was a large quantity generator on one or more occasions for a total of greater than 30 days.

Source. #14280, eff 8-1-25, EXPIRES: 8-1-35