What emission units must be included in MAERS?
Which emission units must be included in MAERS depends on whether the facility is subject to the renewable operating permit (ROP) program. If a facility is NOT subject to the ROP program it should include any emission unit (1) included in a permit to install including opt-out permits (2) grand-fathered or (3) not excluded from exemption per Rule 278, and is exempted under Rule 279-290 and listed in the Rule 201 exemption list. If a facility is subject to the ROP program, it should include any emission unit that (1) is included in the ROP; (2) meets the criteria for non-ROP sources (above); or (3) emits greater than 10% of any of the significant levels listed in Rule 119(e). Please see the diagram in the Emissions Unit Instructions & Examples for the Emissions Unit Form. My facility has a collection of space heaters covered under an opt-out permit. Can the collection of space heaters be reported under one emission unit? These space heaters must be reported in MAERS not because they are
