Some people wonder if the use of water softeners will damage their septic system. The real concern over water softeners is not with the water itself, but with the by-product of the softening process. Brine water is created as water softeners do their job of removing minerals from the water. This brine water (also known as water softener regeneration discharge) goes into your septic system.
Experts disagree on whether the brine water can negatively affect the decomposition of solid matter in a conventional septic system. Some believe it can contribute to drainfield failures and other problems. If you are concerned about the briney by-products of your water softeners, consider investing in a softener system with a large mineral tank. This will allow the brine water to be stored in the tank longer, cutting down on the number of times brine is discharged into your septic system.
You can also use a water softener system that is not timer-based, but on a periodic schedule. This can also help control brine in your septic system, but limiting the number of times per year it is introduced into the septic tank.