The Pennsylvania Department of Environmental Protection (DEP) has issued new guidance to help determine when oil and gas operations will be considered a single source for air compliance purposes. Under Pennsylvania’s Prevention of Significant Deterioration (PSD) program and permitting under Title 5, activities constitute a single source if they 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. Under Pennsylvania’s non-attainment new source review program, a “facility” is “an air contamination source or combination of air contamination sources located on one or more contiguous or adjacent properties and which is owned and operated by the same person under common control.”

DEP’s guidance describes the factors to consider when making a case-by-case determination as to whether properties are contiguous. According to the guidance, properties located within a quarter mile of each other are considered contiguous or adjacent and “should be aggregated” if they meet the other parts of the “facility” definition. Emission units separated by a railroad, road or other obstacle may be considered contiguous or adjacent, but facilities should not be “daisy-chained” together to establish a contiguous grouping. Properties separated by more than a quarter mile may be considered contiguous or adjacent on a case-by-case basis.

The guidance also sets out factors for deciding whether facilities are under common control and uses familiar Standard Industrial Classification codes to determine whether facilities are in the same industrial grouping for PSD and Title 5 program purposes.