Grab your pliers, sneak over, and yank a valve stem or two from their car tires.

Call police, sit inside your comfy house, make popcorn and wait for the show.

Safe or not, I don't believe it's accessible to the public. Last I knew, the facility was gated and there is a person working there to keep out the hooligans. Safety-wise, I think you could walk around, but you wouldn't want to kick up dust, do donuts in your car, or be there on a windy day. A respirator or mask wouldn't hurt either way. Don't drink the water.