How to Replace an Outlet Baffle in an Existing Septic Tank

Locate the septic tank. Most newer tanks have two access hatches, one on each end of the tank. Dig to the top of the septic tank and remove enough dirt to expose both access hatches and allow you adequate room to work. Make sure you will not be knocking dirt into the tank while you work.

Open both hatches and have the septic tank pumped out by a professional. A licensed professional has the equipment to properly pump out the waste materials and dispose of them properly as well as legally. You should not enter the septic tank or allow anyone to enter the tank. The fumes are toxic and the lack of oxygen can cause rapid suffocation.

Build your replacement baffle using the PVC pipe and coupling. Cut one section of pipe to connect to the existing drain and pass through the wall of the septic tank. Attach the tee coupling to the pipe on the interior of the tank. Add a piece of pipe 24 inches long to the bottom of the tee and a 6-inch piece to the top of the tee. In the top section install a grate cap, which will allow gases to escape but prevent solids from entering.

Check all fittings and couplings to be certain they are secure and firmly in place. Confirm that the seal is secure around the pipe where it enters the septic tank to prevent any leakage. The baffle on the outlet end of the septic tank needs to be 4 to 6 inches longer than the inlet side to help control the flow of liquids into the field line. The 24-inch section of pipe added should be more than adequate to meet this requirement.

Replace the access hatches, making sure that they fit securely in place, then back-fill the hole. Re-inspect the new baffles the next time the tank is pumped out to be certain they are still in place and in good condition.