Short of there simply being a clog in the system that can be routed out the bacterial mat that is typically the problem cannot be destroyed other than allowing the trench to completely dry out for a few months.
Can you repair a septic drain field.
To repair the septic drain field you will need to unclog the septic tank as well as take corrective steps to prevent the septic drain field from becoming clogged again.
This would require a new trench system be put in its place.
A clogged septic tank will back up into the home and cause a mess.
If you suspect one of the leach field pipes has a clog the easiest way to clean it is with a pressurized sewer jetter.
Unfortunately there is not a quick easy fix for a failed drainfield.
Instead of trying to repair the old lines it is much easier and effective to install new lines.
A septic drain field that goes untreated for a number of years or has certain types of materials like grease and oil constantly flushed into it will eventually clog.