When To Pump Your Tank

You pump out your septic tank to get rid of the solid sludge that accumulates at the bottom of the tank and the grease that accumulates as scum floating near the top. Both sludge and grease can foul the leaching field and potentially lead to its failure. Other things that can lead to pumping failure can be found on our Don’t Flush These Items section. How often to pump your septic tank depends on your tank size, family size, and how much of your waste water is solid waste.

For example: suppose your tank is 1,500 gallons, utilized by four people, and containing the average amount of solids- the ideal pumping schedule is every 3-4 years. See Guidelines in the reading below. On the other hand, suppose there is only one person using a 1,500-gallon tank- pumping it every 19 or so years is fine. The number of people dumping wastewater down the drain makes a big difference in how often the tank needs pumping.

The frequency with which you will need to pump depends primarily on these variables:
1. the size of your tank
2. the number of people in the household contributing to the volume of your wastewater
3. the volume of solids in your wastewater
4. use of a garbage disposal.

The volume of solids in the wastewater varies with things such as: garbage disposals, laundry loads and where you live. A family with a garbage disposal (compared with one that scrapes the dishes into a trash can) dumps up to 50 % more solid waste down the drain, and, therefore, needs to pump their septic tank twice as often.


These figures were calculated assuming there was no garbage disposal unit hooked up to the system.