Q605. Can data from a state permit-required fugitive emissions monitoring program already in place, which has a lower leak detection rate of 500 ppm, be used to estimate fugitive greenhouse gas emissions under 40 CFR 98.233(q)?

A605. You must follow the methods outlined in the rule. We note that leak survey methods are provided in 40 CFR 98.234(a) and include Method 21 with a leak definition of 500 ppm meaning the results of the leak surveys you are performing for state requirements can also be used for subpart W reporting. However, the reporting facility must ensure that the state permit required surveys meet the satisfy the requirements specified in subpart W. The EPA cannot provide concrete guidance on using State-specified limits that are not directly comparable to subpart W requirements.