The Pennsylvania Department of Environmental Protection has created a draft plan to curtail emissions from thousands of existing oil and natural gas wells, according to Kallanish Energy.

The proposal is part of Governor Tom Wolf’s 2016 strategy to reduce methane emissions. Pennsylvania adopted the regulations on air emissions from new wells and other facilities last fall. however, existing wells were left out.

The new draft plan; however, covers existing wells, compressor stations, storage tanks, pneumatic controllers and pumps at wells sites, processing plants and gathering stations. If adopted, it could have a costly impact on oil and gas drillers.

Learn more: Kallanish Energy > Pennsylvania proposes methane rules for existing wells, facilities