How to Repair the Distribution Box on a Septic System

Things You'll Need

  • Shovel

  • Hacksaw

  • PVC cement

  • PVC cleaner

  • PVC pipe

  • PVC pipe coupler(s)

  • Wood planks

  • Cement

  • Wheelbarrow

  • Level

  • Trowel

The distribution box on a septic system is a fairly rugged piece of equipment and hard to damage. Vehicle traffic over the area or someone digging in the wrong place, however, can cause significant damage that will need to be repaired to return your septic system to an optimum performance level.

Step 1

Dig away the dirt from around the distribution box, being certain not to cause any further damage to the box or the piping. Clear the dirt away for at least 12 inches all the way around the distribution box. If waste water has been leaking in the area, be certain to wear thick boots, preferably rubber boats, to keep the water away from your skin. Mound the dirt a short distance from the hole to allow yourself plenty of room to work.

Step 2

Inspect the damage to the box and piping. If the PVC pipes are cracked or broken, they need to be repaired first. Move 3 to 4 inches beyond the damaged area of the pipe and make a clean, straight cut. Remove the broken section of pipe and take a careful measurement for the replacement section. Cut the needed pipe and properly clean both ends using the PVC pipe cleaner. Apply the PVC cement to the pipe as well as both ends of a pipe coupler and insert the replacement piece in line with the old pipe. Once the pipe is in place, turn it a quarter-turn clockwise to help set the cement. Repeat this process for each pipe that needs to be repaired.

Step 3

Remove any large broken pieces of cement that have been chipped or broken off the distribution box. Once the box edges are clear of loose debris, you are ready to build your form. The easiest way to form the frame is to frame in the entire outside as well as inside of the distribution box. On the interior you can cut the boards to the needed length and wedge them into place. Make certain all of the boards are secure and will remain in place when the cement is added.

Step 4

Mix the cement in the wheelbarrow, keeping the consistency just slightly on the wet side. You want the new concrete to seep into all the open cracks and crevices of the broken areas to form the best bond possible. Once you have the cement at the consistency you want, pour it slowly into the form. Fill the form to the level of the original top of the distribution box.Tap the sides of the form to encourage the cement to settle into the open areas and to help remove any trapped air bubbles. Add additional cement as needed to bring it to the required height. Allow the concrete to set for at least 24 hours.

Step 5

Remove the frame and check for a good bond in all the repaired areas. While the distribution box is exposed, seal around all of the pipes going into and coming out of the box. Maintain a good seal to prevent any leakage. Before covering the box with dirt, make certain it is level. The distribution box must be level for it to evenly distribute the waste water to each of the field lines. If left uneven, it will force all of the water into one field line and you could experience backups and other major problems. Level the box by inserting dirt or flat stones/pavers under the box. Once level, the hole may be refilled.


If the damage to the distribution box is extensive, it may be more cost-effective to replace the unit rather than making repairs.


Make certain the interior of the box remains clear of any debris, excess cement or dirt. This is a pivotal point in your septic system, and a clog here can be costly.