Boston Gas Company v. Century Indemnity Company

HOWARD, Circuit Judge.

This appeal is the latest chapter in a long-running dispute between Boston Gas Company (“Boston Gas”) and one of its insurers, Century Indemnity Company (“Century”). What’s more, the insured’s activities giving rise to the dispute stretch back more than a century. During the latter part of the 19th and well into the 20th century, Boston Gas produced gas fuel at facilities known as manufactured gas plants (“MGPs”). Faced with liability under Massachusetts law for the costs of investigating and remediating environmental contamination discovered at a number of former MGP…