06-096-100 Me. Code R. § 164
. "Source" (Source or Stationary Source) means any building, structure, facility, or installation which emits or may emit any regulated pollutant where all of the pollutant emitting activities which belong to the same industrial grouping are located on one or more contiguous or adjacent properties, and are under the control of the same person (or persons under common control) except the activities of any vessel. Pollutant-emitting activities shall be considered as part of the same industrial grouping if they belong to the same Major Group (i. e. , which have the same two-digit code) as described in the Standard Industrial Classification Manual, 1972, as amended by the 1977 Supplement (U. S. Government Printing Office stock numbers 4 10 14066 and 00340540 176-0, respectively).
06-096 C.M.R. ch. 100, § 164