Water Softeners and Septic Tanks - Wisler Plumbing & Air

Water Softeners & Septic Tanks

Most people share the common fear that the salt used in a water softener’s regeneration process will be harmful if discharged down the drain and into the septic tank. We have always done our best to combat this untrue, misleading information. It’s obvious that the use of salt can hurt bacteria or concrete, so it’s understandable that someone could come to the incorrect conclusion that it would be bad to discharge salt into a concrete environment that depends on bacteria. Here’s why that’s not actually the case.

New, More Efficient Water Softeners

One of the first things to understand is that there’s a huge difference between water softeners made today and water softeners made 20 years ago. A lot of the information still being circulated is just old and outdated. Water softeners today are much, much more efficient than the models of old. In fact, they only use a small fraction of the salt an old model would have required. Virginia Tech here in Blacksburg is performing an ongoing study about how water softeners affect septic tanks. Experts from both the water softening industry and the septic industry are working together to better understand the interactions between water softeners and onsite wastewater systems. It’s truly a collaborative effort and not just a one-sided view.

What the Study Showed

In the study, they use the terms high efficiency or efficiently operated units. This is an important distinction in which they are talking about new units/technology versus old units/technology, which definitely makes a big difference. According to the authors of the study, the data indicates that the use of an efficiently operated water softener improves septic tank performance. Previous experimentation has shown that the ideal amount of calcium and magnesium are put into the wastewater stream along with the sodium, which actually helps the settling process of the septic tank. In other words, an efficiently operated water softener performs the exact opposite of what someone may fear—it is actually beneficial to the septic system.

How Does this Affect the Septic Tank?

Another thing to understand is that a septic tank is 1,000 gallons or larger, so if you put a little bit of sodium into that thousand gallon tank, it’s going to be extremely diluted, pretty much rendering it ineffective at disturbing bacteria or harming the actual concrete tank. It really is just a drop in the bucket.

We share documentation with all of our clients whenever we’re in their home so they can understand exactly how water softeners interact with septic tanks. We also recommend that the softener is discharged into the septic system whether it’s public septic or a private onsite system. For more information, contact us online or give us a call at 540-483-9382.