How Septic Tank Pump Stations Work

Most septic tank systems work off of gravity.

Different Septic Tank

Each component of the system is slightly lower than the preceding component. This allows the even movement of waste material and liquids without the need for mechanical devices. When this type of system is not possible, a pump must be used.

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.

Pumping Unit

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.

About the Author

Tom Raley is a freelance writer living in central Arkansas. He has been writing for more than 20 years and his short stories and articles have appeared in more than 25 different publications including P.I. Magazine, Pulsar and Writer's Digest.