I looked under the furnace filter into the plenum and I could see the whirlpool tub plumbing of the bathroom next room over. Apparently this is the access point to the pump etc. Is this ok?
No sir it is not Ok suppose to be an enclosed loop what your showing is access to beneath the slab where all that Radon hangs out;-)
Besides what Charley stated, other issues exists.
Cut off copper piping explains that problems have occurred and an open slab always introduces unnecessary moisture from the ground below.
Also there is no sign of moisture retarder under the slab that might be causing problems with flooring material elsewhere in the area.
And of course the WWR is exactly where it belongs in the slab, on the ground on the bottom. 
Was all that noted? 
Thank you for the details. I knew it was wrong, just wasn’t up to speed on the details.