The repair process for a distribution box typically involves excavating the area surrounding the box to access the distribution pipes and components. Technicians carefully inspect the pipes for leaks, cracks, or blockages and repair or replace damaged sections as needed. I go through step by step how I repaired my old septic distribution box. Dig away the dirt from around the distribution box, being certain not to cause any further damage to. A septic distribution box (D-box) is a concrete or plastic junction that evenly distributes wastewater from your septic tank to all drainfield lateral lines. Fixes range from jetting clogged outlets. - Reen Sure Reen: someone is making things sound like rocket science instead of simple ditch-digging. Clogging If you've had your septic system for a while, you have probably run into clogs from time to time. You might have even experienced backups in the system.