Respondent is the owner and/or operator of five (5) cold storage facilities. Two of the facilities are both in the same industrial group, are located across a road from each other and are therefore located on one or more contiguous properties. Both are under the control of Respondent and are buildings that contain equipment that uses, stores, manufactures, or handles anhydrous ammonia and from which an accidental release of anhydrous ammonia may occur. Therefore these two (2) facilities constitute a single “stationary source” as defined in 40 C.F.R. § 68.3. One facility has one machine room with interconnected ammonia refrigeration equipment that has at all relevant times contained more than 10,000 pounds of anhydrous ammonia, and constitutes a single “covered process” under 40 C.F.R. § 68.3. The covered process exceeded the 10,000 pound TQ for anhydrous ammonia on or about August 26, 2010, became a “covered process” within the meaning of 40 C.F.R. § 68.3 at that time, and became subject to the requirements of 40 C.F.R. Part 68 at that time. The other facility has three (3) machine rooms: Machine Room 1, constructed prior to 2012, that has at all relevant times contained approximately 8,507 pounds or anhydrous ammonia; Machine Room 2, constructed in approximately Jul} 2015, that has at all relevant times contained approximately 13.045 pounds of anhydrous ammonia; and Machine Room 3, constructed prior to or in 2016, that has at all relevant times contained approximately 13,335 pounds of anhydrous ammonia.