The effect of Soft Water in Septic Systems


Water that has been softened through an ion exchange process has a higher salt content than hard water. This simple fact has led to misinformation being published again and again about the effects of increased salt content on septic tanks systems. The argument has been made that the increased saltwater content can cause damage to the bacteria in the septic tank, which are key in breaking down waste.  It has been further claimed that the salt can cause damage in the leach field from the septic tank, principally to the biomass in the ground.The effect of Soft Water in Septic Systems

Examining the first contention, there is an abundance of scientific research regarding the effects of increased salinity in water released from a residential water softener on the bacteria in the septic tank.   Separating fact form fiction, the reality is a lot of what people believe is incorrectly repeated over and over again and is largely the same inaccurate information again and again.

The brine discharge from a home water softener Doesn’t Harm Bacteria

A properly set up and managed water softening system will not affect the health of the bacteria in your septic system. In fact, the Ohio Department of Health contracted NSF International to do a study on this very subject. What they found was that a water softener discharge actually helps increase the efficiency of the septic tank. To be CLEAR, this is not to imply that installing a water softener is a proper way to enhance your septic tank’s efficiency, but it does underscore that the myth of a water softener diminishing the effectiveness of your septic tank is patently false.

According to NSF International’s research, the salt added to the water by a softener can in fact improve the environment for the bacteria in the septic tank. Bottom line, based on hard science, not only should there not be any concern about installing a water softener if you have a septic tank, there may be actually some benefits for the bacteria.

The Soil 

Reporting from the University of Wisconsin Small System Waste Management Project Research indicates that another common misconception, regarding water softeners and septic tanks, is also false. That myth is that the water softener discharge into the leach field, being saltier due to the brine, will somehow affect the soil quality and, therefore, impact biomass.

Viewed from a purely scientific and pragmatic perspective it was again only found not to be true, but that actually the opposite may be the case. The research found that drain field percolation in septic systems was actually superior, where water softening systems were installed, than those which did not have water softening systems.

Science fact…  not Science fear

It’s important to keep in mind that many well-meaning folks, concerned with their homes and the environment, do believe things that are inherently untrue, written by others who are neither scientists nor true experts. Whenever you want scientifically ACCURATE information about water softening and its impact on your household and the environment at large, look at the research published by reputable universities or the WQA. The information from those sources is the result of actual test case studies and comparative analysis based on data, not by drawing conclusions based on what somebody heard from somebody else and repeated to you.

About The Author, Terry Reeh, Partner EcoWater Systems of Nebraska:

With more than 25 years experience in the residential and commercial water treatment space , Terry is a WQA (Water Quality Association) certified water specialist, LEVEL 3, as well as a WQA certified sales representative.  In addition to running the day-to-day operations of EcoWater Systems of Nebraska, one of the biggest water treatment and water delivery enterprises in the state, Terry currently sits on EcoWater Systems (a Berkshire Hathaway Company) national Peers committee, as a water treatment expert advising other water professionals with less experience on best trade and technology practices.

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