The Case Against Septic Tank Additives

The Case Against Septic Tank Additives

Additives are a big topic in the septic industry. The beneficial effects of additives are constantly debated. Many septic additives companies have come onto the market in the last few decades promising to restore a failing system but fail to do so. The simple fact is septic tanks are designed to take care of waste disposal themselves, no additives needed. With regular septic tank pumping and inspections, a septic system should last decades. To understand why a septic system does not need additives you must first understand how a septic tank functions.

The septic tank is essentially a holding tank that provides the first step in a treatment process for solids and wastewater coming from the home. The main functions of a septic tank include receiving all wastewater and solids, letting the solids and wastewater separate with the help of microorganisms, and then extracting the clear effluent layer to be purified by the drain field. This process begins with the separation of wastewater and solids when it enters the tank and breaks into three layers. The first layer is a fat or grease layer, the middle layer is clear wastewater known as effluent, and the bottom layer is solid waste. The microorganisms that live in a septic tank are anaerobic bacteria, meaning they live without air, and are added naturally to a tank from waste sent down the drain. Their primary function is to help separate and break down the solids in the tank, however, regular pumping is always needed to extract the build up of solids from the tank.

Any addition of additives like a drain cleaner, disinfectants, or bleach to the tank can actually kill off all the healthy bacteria in the tank and put the system in jeopardy of failing, according to a study from the University of Arkansas-Little Rock. They also found that water softeners not only killed microorganisms in the tank but also interfered with solids settling in the tank, therefore putting the system at greater risk of failure. Septic tank additives actually cause enough system failures that the state of Washington has banned all use of septic system additives.

There are many out of date beliefs held about septic tank additives as well that have been debunked. According to John H Timothy Winneberger, Ph.D., adding yeast to your tank is only beneficial if “you eat it first”. Another common belief is that adding a recently killed chicken can help save a failing septic system. While we don’t encourage readers to go to this length, we believe the addition of the healthy bacteria from the chicken could have been a factor in this belief. In most cases keeping yourself healthy and introducing waste naturally to the system is the best way to increase healthy bacteria in the tank.

Many septic tank additives include corrosive matter, such as sulfuric acid, which can harm not only the bacteria but also the structural integrity of your tank and pipes. Several additives advertising to help control odor can contain formaldehyde, quaternary ammonium, and zinc sulfate which can act as a biocide poisoning the system and its bacteria. Finally, some additives containing heavy amounts of everyday products like hydrogen peroxide might not harm the bacteria in the tank but could hurt the soil in the drain field causing the purification process of wastewater in the drain field to be less effective.

No septic tank additive will be better than a septic tank’s natural function and use of healthy bacteria. No product will allow a homeowner to escape regular septic tank pumping and inspections. In fact, some additives can harm the system and cause septic system failure and replacement. If you have a question about a certain additive or want more information we recommend calling your state government office that regulates wastewater and septic systems.

This article was originally published in February 2016 by Speedy Septic on the Angie’s List Experts Blog.