Yes, you should call an inspector to come and get a complete inspection done.
A septic tanks inspection should done once in a year to avoid big septic tank problems.
The most basic thing is to know how to shut of the main supply valve. These are really good tips, everyone in home should know this for emergency situation.
I agree with the cdimarco. You have only one option to replace the lines by digging up.
Call a professional to do this work to avoid any other damage to the lines.