A conventional water softener uses ion exchange to replace calcium and magnesium ions within hard water with sodium ions. To keep this process going the system periodically needs to be 'charged' by flushing it with excess amounts of sodium.
Every time the system regenerates you are left with gallons of water containing a high sodium concentration, along with the previously removed calcium and magnesium ions.
To get rid of this backwash your water softener system will need a drain, however, as the salt concentration within this backwash is so high some considerations should be taken into account when picking a drainage option for your system.
Where Can You Drain Your Water Softener?
The most convenient way of getting rid of the water softener backwash from your brine tank is to attach it straight to your local sewage system.
However, in some remote areas, a direct connection to the sewer system might not be available and even if there is, some municipalities have restrictions concerning discharging water softener backwash directly into the sewer system.
Luckily there are lots of other options available to get rid of your backwash.
How Can You Drain Your Water Softener Outside?
The easiest way to drain your water softener backwash is to simply run it onto the ground, however, as there is a lot of salt in the backwash it can be very harmful to the ecosystem and the local water treatment facilities.
Keep in mind that in some places local rules and regulations might prohibit you from using this option as groundwater might be used as a source for the local drinking water supply.
Even if it is allowed, simply discharging your water softener backwash into the ground could damage nearby plants. Therefore, you might want to look into one of the options listed below to mediate the effects that backwash can have on the environment.
If you source your water from a local water well, make sure that the drain is located at the maximum possible distance from the source of your well to avoid any contamination.
If you are in doubt of the distance between your drain and the well it might be better to have a look at offsite discharging options for your backwash.
If none of the options listed below is a fit for you, you might consider using your water softener backwash for other applications like killing weeds or deicing your driveway.
Best Backwash Drain Options Outside
If you are planning on draining your system outside be sure to inquire with your local municipality regarding any rules and regulations or permits necessary before applying any of these drainage options.
Dry well - A dry well is a deep hole with a porous wall that allows for a slow soak of backwash into the ground and groundwater.
As long as a dry well is implemented above the water table it can accept large amounts of water in a short amount of time which can then slowly make its way into the surrounding ground over a longer time.
This prolonged dissipation makes it a perfect solution for draining water softener backwash as it prevents a sudden increase in sodium concentrations in the surrounding soil.
French drain - A french drain is like a dry well, except instead of using a deep hole, the backwash is dispersed over a larger area horizontally.
A pipe with interspaced holes is placed along a long ditch and is covered by pebbles. The longer the ditch the more dispersed the backwash will be thereby avoiding any high concentrations within an area.
The pebbles assure there is enough space for the water so it does not overflow.
Septic drain field - A septic tank with a drain field are a great way of dispersing the salt over larger area's and many are successfully using this setup.
Although over the years some have raised concerns over the effect of brine discharge into a septic system. Studies have never conclusively shown any negative effects to the digestion taking place within the tank.
Alternatively, an old septic tank can serve as a perfect substitute for a dry well. To convert your existing tank clean your tank and disconnect the outlet pipe, clean it out, and make small holes scattered around the bottom of the tank.
Finally, fill up the tank with pea stone attach the water softener drain and your tank is ready for use.
Best Backwash Drain Options In The Basement
Most water softener systems can use the water pressure to allow for a drainpipe to elevate up to 8 feet above the floor that houses the system.
If your system does not have this feature or the attributed height is not enough there are pumps available that can overcome greater height differences.
Use caution when selecting a pumping system, because of the high salt concentration, brine is very corrosive. To extend the lifetime of your pump make sure the pump is not installed in standing water for prolonged periods. Alternatively, some stainless steel or plastic pumps are available.
Sump pump - A sump pump, usually placed in a sump basin, ensures water is pumped away whenever the water level in the sump basin reaches a critical level.
By running the water softener drain directly into the sump basin the sump pump will pump the backwash to the desired level where it can then be drained further into either a drain that leads to a sewage system or other form of drainage.
If the basement is above the water table it could be an option to combine the sump pump with a dry well located in the basement. In this setup, the sump pump will only activate if the backwash is unable to be taken up by the soil.
Sewage ejector pump - A sewage ejector pump is very similar to a sump pump system as it will pump up any water from a basin to the desired height.
The difference between the two is that a sewage ejector pump, as stated, ejects the water, directly into your sewage system.
A sewage ejector is attached to the sewage system through a vent that blocks any raw sewage from streaming back into your drain line and vents any gases that are produced within the piping.
Why Does Your Water Softener Drain Line Need An Air Gap?
Your water softener system provides your house and its residents with a clean supply of water. To ensure this supply stays clean the plumbing code requires you to install an air gap in the drain line of your system.
With an air gap installed, water will only be able to flow out through the waste line, this prevents any contaminated drain water from flowing back into your system thereby contaminating your water supply.
Why Does My Water Softener Keep Draining?
If your system is producing more backwash than expected something might be wrong with it. First, be sure to check your system for any leaks in the seals, hoses, or connectors.
Alternatively, there might be a leak somewhere inside your home and your water softener might be continuously working without you even knowing it. Check all faucets and other water outlets like the supply to the washing machine for leaks.
If there is a continuous flow through your water softener even at times when no water is being used, you might have leaks somewhere in your piping. This often occurs in colder climates after pipes crack when they are frozen during winter.