A few 11 sump pumps can thus easily overwhelm a sanitary sewer system.

I think the 50% rule for out of state investors who put 20 to 25% down is a very good napkin math rule of thumb to triage deals up front.. and it works for basically any rents at 1200 to 1400 and under.. once you get over that amount of rent the 50% can go down a tad.. as your generating enough gross revenue to operate..conversely when buying lower rent properties say in the 600. 

Some simple back-of-the-napkin calculations show that is far from a cash flowing investment.

Those are basic and you can do it on a napkin if you need to quickly.

No napkins, hair, dental floss, or anything else that doesn't belong.

I am not sure we are comfortable with that from a sanitary perspective, but I am interested in what others do and what is most common practice.There seems to be three options:1.

A landlord owes it to all his tenants to do what he can to provide a sanitary living environment. 

Larger property, we also do napkins.

Just back of the napkin, being a broker/lender who offers them, Yes you could buy a small 2-4 unit property with them. 

It includes its water-distribution system, sanitary-sewer system, gas lines, and site electric in the former category, placing everything else in the latter.