More recently, anonymous top-down (TD) sampling of facility-scale emissions has be-come more common. These methods have been exceptionally useful for rapidly estimating emissions from large numbers of facilities in short periods, and identifying patterns in the frequency and magnitude of large emitters. With the exception of a 2016 study, most of these studies utilize facility-scale aerial methods or, less commonly, anonymous deployment of downwind methods without observers on the facility. Studies of this design lack coordinated on-site observations, making it dicult to dierentiate maintenance venting or combustion slip emissions, which are typically known and reported, from fugitive emissions, which are reported only if independently discovered (Reported values vary in accuracy and may not always reect actual emissions). Recent campaigns have attempted to account for maintenance emissions by estimating emitter persistence. However, questions remain, namely: What fraction of emitters discovered by anonymous, TD surveys are due to known maintenance events?