Are you sure about your research that the paper plant is still in operation. Could any activity be due to cleanup of the property in preparation for redevelopment?
PaperWorks Industries, which owned the plant in 2017 when it was closed, doesn't even list the plant on its' locations website (not a great website, rather clunky early 2000s like). Their HQ is listed in Philly, but the address is over a mile from the old Venice island plant. On the web there are a few proposed redevelopment plans for the property, the kind you get when you let unimaginative corporate urban planners loose.
Google Aerial wasn't much help, I think their 3D overhead is from 2014 as I zoomed in on the entrance and it dumped me on a 2014-date street-view of the entrance gatehouse. The 3D view did capture a a black and cream[?] switcher (probably in one of the images posted previously) parked at the sooth end of the property, near the bus turnaround.