(a) Standards. The concentration of explosive gases generated by the facility shall not exceed:

1. (1) Twenty-five percent (25%) of the lower explosive limit for the gases in facility structures (excluding gas control or recovery system components); and
2. (2) The lower explosive limit for the gases at the facility property boundary.

(b) Applicability.

1. (1) Owners or operators of Class 4 landfills shall not be required to implement a routine methane monitoring program unless the Director of the Division of Environmental Quality determines that:

   1. (A) The nature and quantity of waste poses a significant potential for the generation of explosive gases; or
   2. (B) Explosive gases have been detected in concentrations exceeding the standards identified in subsection (a) of this section.
2. (2) The monitoring program, if required, shall meet the requirements of 8 CAR § 60-415.