Different Septic Tank
The septic tank which uses a pumping unit will have multiple chambers. The waste product is broken down and processed in the first chamber and only the liquid residue enters the second chamber of the tank. The two chambers are divided by a baffle. The waste liquid will flow over the top of the baffle, while the sludge remains in the first chamber.
The pumping unit is electric and will be a fully submersible unit. While designed to handle liquids, the pump will also handle small amounts of sludge and sediment which may occasionally find its way into the second chamber. The septic tank should be cleaned out regularly to avoid large amounts of sludge entering the second chamber and clogging the pump.
Drain line to Filed Lines
In a normal gravity septic system, the drain line from the septic tank to the field lines is a 4-inch PVC pipe. This size pipe will not be necessary for a pumping system and would, in fact, not function properly since the pump could not push that amount of liquid. The pipe should be either 1 1/2 or 2 inches, depending on the size and style of pump you are installing.