Please explain the formal, legal, and/or organization ties that Evergreen has to Sunoco and/or Energy Transfer.

Evergreen is an affiliate of Sunoco (R&M), LLC (formally known as Sunoco, Inc. (R&M), a former operator of the refinery), and both companies are indirect subsidiaries of Energy Transfer L.P.  In November 2013, Evergreen was formed to manage Sunoco’s legacy environmental cleanup at the Philadelphia Refinery.

Response also answers a similar question:

What is [Evergreen’s] relationship with Sunoco present-day?