- (a) Applicability. Owners or operators of new Class 4 landfills and expansions of the area permitted for waste disposal must demonstrate that engineering measures have been incorporated into the unit's design to ensure that the integrity of the structural components of the unit will not be disrupted.
(b) The owner or operator must consider the following factors, at a minimum, when determining whether an area is unstable:
- (1) On-site or local soil conditions that may result in significant differential settling;
- (2) On-site or local geologic or geomorphologic features; and
- (3) On-site or local human-made features or events (both surface and subsurface).