Installing a Water Softener System Part 1: The Drain

A water softener system will regenerate producing discharge water that needs a place to drain to. Because of this, you will need access to a effective drain for the discharge water. The most common places to drain the water system discharge to is the washing machine drain or utility sink, run it on the ground to a spot that is suitable, or install a French Drain. Depending on the hardness of your water and the size of your family will determine the drain frequency. However, most systems will regenerate producing discharge water once a week. Some systems like our 89 HE (high efficiency) will discharge as little as 34 gallons per regeneration. Additionally, some older systems can discharge as much as 100 gallons of water per regeneration. As a result, the drain will have to be capable of handling water on a regular basis.

Before we look at acceptable drains for water softeners lets first address what is unacceptable.

We are often asked if it is ok to drain the water softener drain line to the sewer clean out. The answer is NO. Even though water softener companies in our area elect to drain the water softener to the sewer clean out tee it is illegal and not permitted. Just under the main sewer cap is raw sewage bacteria. Once a drain line is inserted it opens a path for sewer bacteria to enter your potable water. Because, you are connecting raw sewage bacteria to your potable water through the drain line. Overtime and in case of a sewage backup, raw sewage bacteria can be transferred into your water softener then into your homes water supply through the drain line itself. It’s a $5,000 fine in most counties because it’s dangerous to the public. A French Drain is far better.

The specific code that addresses this illegal drain is addressed by Florida Air Gap codes. To properly drain to the sewer clean out tee would require a trap seal, and appropriate stand pipe followed by an air gap. However, most companies that say it’s fine don’t follow this safety requirement. In my experience they simply drill a hole in the sewer cap and insert the drain line. This type of drain should not be done.

Drain to Washing Machine

Drain to Washer

When installing a water softener system inside the garage draining to the washer is the most used drain location. Naturally, most laundry rooms are nearby the garage which makes plumbing a drain line to it easy. The biggest question you are faced with is do I run the drain up into the attic, across the attic then drop it down into the washer drain (up and over)? Or should you run the drain line down along the base board then over to the laundry room, installing the line through the wall to access the washer drain. Both of these options will work great it’s really a matter of logistics. Our site estimator will help you determine the best drain location.

Drain to Ground

Another option is to simply run the drain on the ground. In some homes accessing the washing machine drain is simply not practical. In fact, some water softener systems are not even installed inside the garage, they are installed outside on the side of the house. And on well water, the water softener is often installed at the pump. This is where draining a water treatment system on the ground may make the most sense. On well water near the pump is usually ideal for simply running the drain on the ground. And some city water system installs that are outside drain to ground into a bed of rock mulch or some other conducive surface.

Will draining a water softener system to the ground hurt anything?

As long as the surface that you are draining to is acceptable then nothing will be harmed. The discharge is mostly water with very little sodium. So, as long as there is mulch or decorative rock you will be ok. Sometimes there is a tree line a few feet away we can use as well. Then only place we wouldn’t drain to ground is directly onto grass. The amount of water may drown the water. Our site estimator can help you to determine if a drain to ground will work or not.

Install a Drain Field or French Drain

A popular option for draining a water softener is installing a French Drain. A properly installed French Drain will receive the discharge water for years and years. We dig a 10 ft. trench roughly 2 ft. deep. Then we add rocks and a corrugated drain pipe covered in weed net. Rocks give the water a place to go, the corrugated pipe holds a large amount of water giving it time to percolate, the weed net wrapped around the corrugated pipe keeps dirt from filling it in. A French Drain is ideal for a water softener system that is installed near grass. By the way we install lots of French Drains with great success in the Jacksonville FL area.

Will the discharge water harm the environment?

No. The EPA conducted a test of water softener system discharge water. They concluded that the wastewater did not contain sodium or harmful chemicals. Rather, it was mostly water with some hardness minerals that they found was good for the soil. Download the EPA Fact Sheet here.


We now know a water softener filtration systems drain will depend on where it is installed. So, what decides where it is installed? The main water supply pipe. Next week, we will look at how a water supply pipe is connected to your home.


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