Appalachian Basin giant EQT Corp., the nation’s largest natural gas producer, is pushing to ensure most of its supply is responsibly sourced and marketed as the globe transitions from fossil fuels.

The pilot program, set to be launched this month, is designed to certify around 4 Bcf/d gross from 200-plus well pads in Pennsylvania’s Greene and Washington counties. The certification would be based on environmental, social and governance (ESG) initiatives, with methane emissions also quantified.

Certification would be based on separate standards developed by Equitable Origin (EO) and MiQ to advance what has become known in the industry as “responsibly” sourced gas production. EQT in January separately began a certification pilot with Project Canary for production from two...