The natural gas gathering Revolution Pipeline in Western Pennsylvania has been cleared to restart service after operator ETC Northeast Pipeline LLC reached a settlement with the state’s Department of Environmental Protection (DEP) addressing safety concerns over slope stability.

The settlement, a consent order and agreement that requires ETC to pay a $125,000 civil penalty, allows the 40.5-mile pipeline to return to service more than two years after a landslide in Center Township, Beaver County, caused the line to rupture and explode.

In November, the DEP ordered ETC not to fill Revolution with natural gas because of concerns over sections of the pipeline located on unstable slopes. ETC subsequently submitted a revised plan that included steps for safely emptying the pipeline...