(a) The owner or operator of a closed landfill where an end use is proposed, including landfills that were closed prior to the effective date of this Part or were not subject to closure, post-closure care, or custodial care requirements, must demonstrate that the proposed end use:

1. (1) will not adversely impact the final cover system and will not have a significant adverse impact on public health and the environment. The demonstration must consider migration of landfill gases and leachate, settlement or disturbance of waste, alteration of the final cover, soil, or other material that overlies the landfill or any other landfill components, and public access; and
2. (2) will not interfere with post-closure or custodial care monitoring and maintenance of the landfill, if applicable.

(c) Any buildings constructed on-site must be designed and constructed to prevent gas migration into the buildings and include:

1. (1) continuous methane gas sensors installed inside the building that will trigger an audible alarm and notification signal to emergency personnel when methane gas concentrations are detected;
2. (2) periodic methane gas and soil vapor monitoring inside all buildings and underground utilities; and
3. (3) a written certification by a professional engineer that engineering controls incorporated into the landfill closure design and/or the proposed structure are adequate to preclude any significant threat to public health and safety assuming normal occupation and use of the structure.