One farm couple says they haven't had their septic tank cleaned in more than 20 years. They have two kids and a garbage disposal. Their theory is that if it isn't broken, don't fix it. Their system isn't broken.
Are they taking the right strategy? Randy Pease, an official with the Johnson County Health Department, says that the counter argument is that if you don't have the tank pumped on some type of regular basis, you risk solids getting high enough to allow some solids into the septic field. Over time it can cause fingers to clog.
"What's at the bottom of the tank are solids that settle out," he says. "Bacteria in the system digest them, but they don't digest them completely. Over time the level of solids will gradually build up."
So should you have it cleaned every year, every fifth year, every 10th year, or never? There is no magic number, Pease acknowledges. The general recommendation is typically something like three to five years, but it varies depending upon several factors.
Gary Steinhardt, Purdue University Extension soils specialist, says how many people are in the house, whether or not a garbage disposal is connected and size of their tank are all factors. As garbage disposal can put considerably more load on a system, he notes. If your washing machine is tied into the septic system, as many are, that can also put load on a system.
What about adding a commercial product advertised to help septics down the toilet occasionally? Pease notes that those usually aren't recommended, and he's not aware of any proof that they work.
In fact, Steinhardt points out when he speaks to groups about septics that those products could actually aggravate a situation. By promoting bacteria to do more work, they tend to keep solids in suspension instead of settling to the bottom of the tank as they should in a functioning system. He doesn't recommend adding these types of products either.