Guideline PNG035: Estimating Venting and Fugitive Emissions has been created to aid industry in estimating and reporting vent gas, which includes fugitive emissions, by providing tools and estimation formulas. Due to the high complexity of determining vented gas volumes at some sources, a Gas Estimation Tool has been developed to allow industry to input site-specific field operation information into the tool, and the tool will calculate the volume of gas being vented from sources associated with that site.