We have told them to stop flushing any wipes (even if they say flushable).

The banking regulations are heavily biased towards banks flushing out any REOs and a lease option causes the opposite to happen (the property stays on the bank's books as the bank would still be the owner).

One lady on this thread suggested they buy a low end 20k rental  well that's great advice to someone with no real estate knowledge or background you mines as well flush that money down the toilet all that's going to teach you is to not do that again.. 

Whelton and the other researchers concluded that users should flush out pipes before using them, because they are not cleaned sufficiently before they’re used by consumers.Moving toward workable solutionsTasha Stoiber, a senior scientist at the Environmental Working Group, comments on the potential for ongoing risks after the pipes are flushed and long-term exposure to PEX pipes.

If you're flush with cash, I have several I can recommend, but it sounds like you your initial research and learning can be done online.

Also add downspout extensions so the water from the roof hits the ground further away from the house.For the sewer, ask them to put a camera down it to see if something was flushed down there that shouldn't have been or if there is a break in the pipe.

(After 10+ years wholesaling, I am still looking for those people :-))You wouldn't go to your eye doctor to have your gall bladder removed. 

He requested the city to flush the mainline, however they refused. 

Some landlords and property owners will call you assuming they can scam you into overpaying for their property...these may be motivated sellers later on, but at the moment, they're not worth dealing with and your screening process needs to be able to flush them out.Financials Asking PriceMortgage loan balanceAny 2nd mortgage on property?

Your fill and flush valves are also Owner responsibility.