|(a) Post-closure care maintenance requirements for municipal solid waste management units subject to the applicable requirements of this subsection. (1) For a minimum of the first five years after professional engineer certification of the completion of closure as accepted by the executive director, the owner or operator shall retain the right of entry to and maintain all rights-of-way of a closed municipal solid waste management unit in order to conduct periodic inspections of the closed unit. The owner or operator shall correct, as needed, erosion of cover material, lack of vegetative growth, leachate or methane migration, and subsidence or ponding of water on the unit. If any of these problems occur after the end of the five-year post-closure period or persist for longer than the first five years of post-closure care, the owner or operator shall be responsible for their correction until the executive director determines that all problems have been adequately resolved. The executive director may reduce the post-closure period for the unit if all wastes and waste residues have been removed during closure. (2) Any monitoring programs (groundwater monitoring, resistivity surveys, methane monitoring, etc.) in effect during the life of the unit shall be continued during the post-closure care period. (3) If there is evidence of a release from a municipal solid waste unit, the executive director may require an investigation into the nature and extent of the release and an assessment of measures necessary to correct an impact to groundwater. (b) Post-closure care requirements for municipal solid waste management units subject to the requirements of this subsection. (1) After professional engineer certification of the completion of closure requirements for a municipal solid waste management unit as accepted by the executive director, the owner or operator shall conduct post-closure care for the unit for 30 years, except as specified by paragraph (2)(A) or (B) of this subsection. Post-closure care shall consist, at a minimum, of the following. (A) The owner or operator shall retain the right of entry to the closed unit and shall maintain all rights-of-way and conduct maintenance and/or remediation activities, as needed, in order to maintain the integrity and effectiveness of all final cover, facility vegetation, and drainage control system(s), to correct any effects of settlement, subsidence, ponded water, erosion, or other events or failures detrimental to the integrity of the closed unit and to prevent any surface run-on and run-off from eroding or otherwise damaging the final cover system. (B) The owner or operator shall maintain and operate the leachate collection system in accordance with the requirements in §330.331 and §330.333 of this title (relating to Design Criteria and Leachate Collection System, respectively). The executive director may allow the owner or operator to stop managing leachate if the owner or operator demonstrates to the approval of the executive director that leachate no longer poses a threat to human health and the environment. (C) The owner or operator shall monitor groundwater in accordance with the requirements of Subchapter J of this chapter (relating to Groundwater Monitoring and Corrective Action) and maintain the groundwater monitoring system, if applicable. (D) The owner or operator shall maintain and operate the gas monitoring system in accordance with the requirements of Subchapter I of this chapter (relating to Landfill Gas Management). (E) The owner or operator shall continue earth electrical resistivity surveys at the frequency stated in the approved site development plan. (2) The length of the post-closure care period may be: (A) decreased by the executive director if the owner or operator submits to the executive director for review and approval a documented certification, signed by a licensed professional engineer and including all applicable documentation necessary to support the certification, that demonstrates that the reduced period is sufficient to protect human health and the environment; or (B) increased by the executive director if it is determined that the lengthened period is necessary to protect human health and the environment. If there is evidence of a release from a municipal solid waste unit, the executive director may require an investigation into the nature and extent of the release and an assessment of measures necessary to correct an impact to groundwater. (3) The owner or operator shall place a copy of the post-closure plan in the operating record by the initial receipt of waste. The post-closure plan shall include, at a minimum, the following information: (A) a description of the monitoring and maintenance activities required in paragraph (1) of this subsection for each unit, and the frequency at which these activities will be performed; (B) the name, address, and telephone number of the office or person responsible for overseeing and/or conducting the post-closure care activities at the closed unit or facility during the post-closure period; (C) a description of the planned uses of any portion of the closed unit during the post-closure period in accordance with §330.465 of this title (relating to Certification of Completion of Post-Closure Care); and (D) a detailed written estimate, in current dollars, of the cost of post-closure care maintenance and any corrective action as described in the post-closure care plan or required by the executive director or the commission and which satisfies the requirements specified in Subchapter L of this chapter (relating to Closure, Post-Closure, and Corrective Action Cost Estimates).