Reuters » Pennsylvania environmental regulators on Thursday allowed Sunoco Pipeline LLP to resume work on its Mariner 2 East natural gas liquids pipeline after the company agreed to pay a $12.6 million fine for violations. The Pennsylvania Department of Environmental Protection (DEP), which ordered the company to stop work on the $2.5 billion project on Jan. 3, said in a release that the fine was one of the largest civil penalties in a single settlement.