In regards to the plumbing, that is strange because I could clearly see all the pipes and drains and it looks like the plumbing was done professionally but the overflow looked to be pushed in and caulked over.  

They left the unit in very bad shape (holes in walls, cigarette smoke smell, soiling and damage from unauthorized pets, graffiti and intentional damage, unflushed turd and vomit in the toilet, drug paraphernalia and liquor bottles, disgusting furniture and trash left behind, fridge, dishwasher and oven looked like crime scenes, cockroaches in the cabinets, grease down the drain, literally the works).

This made her angry and now she wants us to water proof her basement because a very small amount of water passes to the drain during heavy rains and snow melt (no standing water at all). 

They'll just all be total flakes and you'll end up with concrete in your drains when they vanish.Look for industries that require background checks and occupations that systematically fire irresponsible people.3x rent is not stupid at all.

@Bob RomanoMake sure the washer has a drain pan!

In the interest of world class customer service, I got dressed, went over and squished the arachnid post haste then dispatched his little corpse down the drain.

Plumbing drains may be cast iron.

Around Plumbing, check where plumbing drains Go into the wall.

I would only consider this if he can use a concrete floor with a floor drain.

Disposals can be dangerous, clog at least some of the time, wear out, and encourage tenants to dump crap down the drain.