Sixteen environmental groups have sent a letter to the Army Corps of Engineers with concerns about increasing oil tanker traffic in the Salish Sea. They say a final environmental impact statement for expansion of an oil refinery north of Bellingham is long overdue — and needed now more than ever. BP added a second dock to its refinery at Cherry Point , near Ferndale, in 2001. Known as the North Wing, it was originally built without formal environmental analysis, though it doubled the facility’s