Garbage Disposals and Septic tanks

Quick Review of How Septic Systems Work

A septic system is an on-site waste treatment facility with two main components: a septic tank and a drain field. Waste and wastewater from the home leads through an inlet pipe into the septic tank. In the septic tank, waste is separated into three layers: top layer of scum, middle layer of wastewater, and a bottom layer of solid waste. The wastewater is readily transported through an outlet pipe into the drain field, an area in the yard where wastewater percolates through the soil for treatment. Meanwhile, the solid waste and scum in the septic tank is broken down by bacteria into sludge. Eventually, this sludge is pumped or cleaned out so that the septic tank does not overload.

What Do Garbage Disposals Do?

Garbage disposals break down food waste into smaller pieces that are less likely to cause blockages in the plumbing system. This device is helpful but can turn into a liability. Owners of garbage disposals are susceptible to complacency and over-reliance on these devices. Tossing anything and everything into the garbage disposal can turn into a problem, especially if you own a septic system. For example, while an average homeowner might toss food scraps into the trash and pour fats and greases into a special bin, a homeowner with a garbage disposal might toss it all into the garbage disposal.

The Risks of a Garbage Disposal

Tossing any and every food scrap into the garbage disposal can be harmful to your plumbing system and will burden the vital bacteria in the septic tank. So, a garbage disposal can turn into a liability if you end up depending too much on the device. 
As you know, greases and fats have different physical properties at different temperatures. While hot fats, oils, and greases (FOG) are liquid, they harden when they cool down. Pouring these down into plumbing systems are problematic for this reason; they can harden in the pipes and cause clogs. Meanwhile, the ground up food particles make their way into the septic tank where they must be broken down into sludge. Too much solid waste can overwork the bacteria and lead to a septic tank that fills too quickly.