Here are my thoughts, nuisance code violations (garbage , debris, overgrown grass ect.) seem to be a quick fix for the investor, but also for the owner.

Maybe they are have garbage piled 4 ft high throughout the house.

This gives your effective gross revenue.Next are all your operating expenses (utilities, taxes, garbage, snow removal, maintenance allowance (10%), management allowance (this pays you: 7 - 10%), etc.)A little subtraction and we have the Net Operating Income.Now you have debt service {mortgage(s)} your capital expenditure reserve (8 -10% of effective gross revenue) and {income} taxes which must come from your NOI.Whatever is left goes into the kid's education funds ;-)[Note:  I missed the been a 7-yr {live-in} landlord before I typed the above ... most of it you undoubtedly have mastered.  

There is this weird idea that since he put some solid-gold stuff out there, that everything he ever does and says will equally be solid gold. no, actually it's been various degrees of garbage, it really has. 

We get $450/mo from the single family and we will get $1850/mo from the 4plex (after water and garbage are paid).  

Now this was a house that you simply could not even enter it stunk so bad to the rafters with garbage rodents etc etc.

What about the garbage bill per unit?

.—(1) A landlord of any dwelling unit governed by this part shall not cause, directly or indirectly, the termination or interruption of any utility service furnished the tenant, including, but not limited to, water, heat, light, electricity, gas, elevator, garbage collection, or refrigeration, whether or not the utility service is under the control of, or payment is made by, the landlord.It also says tenant can sue for 3 months' rent and attorney fees, or something similar.  

Overgrown garden, broken down cars in the driveway, garbage bags being used as window-blinds.  

The HOA fee includes water, garbage and landscaping.