PITTSBURGH (AP) — Chevron has become the first energy company to meet a new set of voluntary shale gas drilling standards that aim to go beyond existing state laws in Pennsylvania, Ohio and West Virginia, the Pittsburgh-based Center for Sustainable Shale announced Thursday.

The center is a partnership between major energy companies, environmental groups and charitable foundations. Its certification process consisted of an independent review of Chevron documents and 22 of its production sites in the three states.