If your septic system should back up into your house, and you have a fail-safe system, the first person that should be contacted is a plumber. OMNI RSF systems with a fail-safe system design are specifically designed not to back-up into your house, even if the system is not functioning due to a power outage.
The most probable cause for your septic system backing up into a house is a clog in the main line. This can be quickly resolved by "snaking" the line to break up the obstruction.
If you are unsure if your system is fail-safe contact OMNI for details.