Asbestos and NIMBY's
The site has a significant mold problem in the HVAC and air evacuation systems which run all over the island. The buildings and lab sites are also insulated with asbestos and the floors are asbestos tile. There's also a shocking (ha!) shortage of 120VAC with most electric being 3-Phase 240VAC; great for large equipment but less than ideal for daily appliance and convenience use. All that can be managed though, the really bad part is the NIMBY colony that has established itself there.
They were unusually rabid when we toured the facility last December with a few other potential buyers. They attempted to physically prevent us from exploring the open paddocks and they succeeded in preventing us from taking ground soundings by stomping in unison and banging on subterranean HVAC ducting. We went with our security team but our Federal escorts prohibited them from restraining or incapacitating the NIMBY's.
We were finally put off completely upon surveying the coast. If we did purchase it we would have to erect significant costal defenses to prevent the NIMBY's and volunteer minions from visiting unexpectedly. The Coast Guard (now part of the DHS) was adamant about no SAM or anti-armor installations and were really concerned about our radar and sonar proposal as there could be risks to the wildlife.
I was highly disappointed as the Plum Island lair would have been within easy range of NYC with only a skeleton crew manning my zeppelin and there is a very nice harbor near the main underground facility that would have been perfect for keeping my submarine away from curious eyes. Alas, I'll have to be content with my West Virginia facility. Washington DC is only 65 miles away but it just isn't as much fun as NYC.