tenants have a dispute with each other regarding utility bills

I have a unit with three roomates splitting the rent. I pay for water/sewer; they are responsible for gas, electric, cable, etc… They have had an arrangement for paying these bills, now to realize, one of the roomates hasn’t been keeping their end of the deal. Allegedly, this tenant has been taking money on a monthly basis to cover two of the utility bills; although these services are now scheduled to be shut-off, due to non-payment. I told the tenants that I really have nothing to do with this, and reminded them that they are all individually, and equally responsible for fulfilling the terms of the lease. I informed them that they may be able to file a suit against the other tenant. What are my legal obligations, if any? What are there legal obligations?

It should explicitly state in your lease that you provide water/sewer and the tenants are responsible for the rest. If your tenants are in the dark/cold with no TV or internet, that’s generally their problem (unless you live in a hippie state that has some funky laws). Now if the two roommates need to “convince” the other roommate to pay up, that’s their issue. All you can do is keep providing what you say you’re responsible for.

Set clear expectations in the beginning. If you are responsible for repairs and paying for the water, tell them so. And that’s it.

Don’t make their problems your problems.

Don’t we have enough to deal with already?