In almost any landlord-tenant situation, it really helps to know if there is a written lease, and if so, what are the terms of that lease? In this case, does the lease require the tenant to switch the utilities to their name? What does it say about whose responsibility the utilities are? If you have a good lease, the tenant's failure to pay the utilities could constitute grounds for you to terminate the lease and force them to move out.
As to the security deposit, again it depends on what the lease says the deposit can be used for. Most security deposits are only used to repair damage to the premises, but it's possible that you can apply the money to utilities. Again, it just depends on the lease terms.
If you're renting the house without a written lease, that's not a great idea. However, that would make this a month to month lease which you can terminate with just a written notice.
*This answer is intended for informational purposes only and does not establish an attorney-client relationship or give rise to any privilege.