How Often Does a Septic Tank Need to Be Pumped?

Just about the only routine maintenance required for your septic system is a periodic pumping (emptying) of the septic tank. By preventing the tank from overfilling you can avoid the vast majority of septic problems.

When Is The Tank Full?

How long it takes your septic tank to fill with solid waste, or sludge, depends on the number of people using the system, the types of things entering the system (such as grease or food) and the size of the tank itself. A septic tank is considered to be full when solid waste takes up 35 percent or more of the tank. Allowing the tank level to go above 35 percent will create the danger of solid waste entering the field lines or clogging the tank inlet. Both of these can result in very nasty problems.

How Often to Pump?

Some homeowners empty their tanks annually, while others wait 10 to 15 years without a problem. As a general rule, you should have your tank pumped out every three to five years. The clean-out will be done by a licensed, professional contractor who will have a legal means of disposing of the waste. You can expect to spend between $300 and $500 to have your tank emptied, although these prices can vary depending on your location.

Can Pumping Be Done Less Often?

When the contractor empties your tank, he should be able to tell you how full the tank was. If it has been three years since it was cleaned out and you are told it was only 15 percent full, then you know you can probably wait another five or six years before cleaning it out again. If you learn it was 40 percent full, you may want to wait only two years before having it pumped out. Conserving water and watching what goes into the system will help reduce the amount of sludge and thus the need for more frequent pumping.