If there's a water source above that drain line then when water is drained, it will come out the hole you made.

. $1500 lesson after the water in the ceiling damage)2.

Just watch for fees, usually there is a service charge if you try to use a card for a water bill or something like that. 

What is the best way or how can I past the water bill along to the tenents?

Different investors have different risk/reward profiles and that's what drives the whole range of the market. 

Houses in the area range from 50-60k.

I am a little paranoid about water accidents as I lost a relative to drowning so I do warn tenants on signing.

For example call the water company and the power company to find the average monthly costs for the last six months.

I had a tenant once that had a leak in his toilet, water was coming from underneath the toilet,a light amount but consistently all day and night.

They did, and wind up having no money to pay for electric, gas, water etc. and special assessments had to be made to pay these utilities before they are cut off.Financially, I think it's better that this repair be made out of your own pocket, at the time of your choosing, if there's nothing wrong with it right now.