Finally, comparing CMS-based measurement-informed inventories to bottom-up inventories reveals that similar oil and gas sites do not necessarily have the same emission characteristics. CMS-based emission estimates were closely aligned with bottom-up inventories on two of the four production sites studied here, but were much larger than bottom-up inventories on the remaining two production sites. This variability in emission volume between similar sites underscores the importance of repeated site-level measurements when creating measurement-informed inventories at the site-level, as aggregating survey-based measurements across similar sites may fail to capture large differences in emissions.