What is the Best Way to Discharge Water Softener Backwash?

If you have a water softener system installed in your home, it’s important to know how to properly discharge the backwash water. The backwash process removes built-up sediment and minerals from the softener resin beads to keep your system working efficiently. Discharging the backwash water correctly is key for maintaining your water softener and avoiding potential hazards.

Why Proper Backwash Discharge Matters

Backwashing your water softener flushes out hard mineral deposits, dirt, and sediment that accumulates in the resin tank. This helps regenerate the ion exchange beads so they can continue removing minerals that cause hard water. If the backwash water is not discharged properly, it can lead to a few problems:

  • Environmental contamination – Backwash water contains high concentrations of sodium, minerals, and other contaminants that can pollute groundwater if dispersed into the environment.
  • Equipment damage – Letting backwash water flow back into pipes or the softener system can damage valves and other components.
  • Clogged drains – Backwash discharge contains sediment that can clog up drains if allowed to accumulate.
  • Unsafe drinking water – Improper backwash discharge may contaminate potable water lines.

Following the right backwash discharge method helps avoid these issues and keep your water softener working optimally.

water score banner 2

Overview of Backwash Discharge Methods

There are several ways to safely discharge water softener backwash. The best method for your home will depend on your specific plumbing setup. Here are some of the most common backwash discharge options:

Drain Pipe

Connecting a dedicated drain line specifically for backwash discharge is the most direct method. This involves installing a drain pipe from the water softener’s backwash outlet to a suitable drainage point. The options include:

  • Floor drain – Pipe the backwash water to a floor drain in a basement or utility room.
  • Outside drain – Run a drain line from the water softener to an exterior drain or sewer grate.
  • Septic system – Pipe the backwash into a septic tank if you have a septic system.

Garden Hose

Using a garden hose to direct backwash water outside is another common approach. To do this:

  • Connect a garden hose to the water softener’s backwash outlet.
  • Extend the hose to an outside area where backwash can drain safely, such as a lawn, flower bed, or gravel area.
  • Make sure the hose end is secure so it doesn’t splash backwash onto exterior walls or hardware.

Sewer Line

If your water softener system is located near a sink, you may be able to discharge into the sewer line:

  • Attach a flexible drain pipe from the backwash outlet to the sink drain pipe.
  • Install an air gap fitting to prevent potential backflow of sewage.

This option only works if local codes permit backwash discharge into sewers.

Backwash Filtration System

Specialized backwash filtration systems allow you to recycle backwash water through sediment filters. These systems connect to the backwash outlet and drain the filtered water to a suitable disposal point. This conserves water usage.

Best Practices for Backwash Discharge

Regardless of the discharge method you choose, follow these guidelines for proper water softener backwash discharge:

  • Safety first – Wear gloves and eye protection when handling backwash hoses. The water contains contaminants that can irritate skin and eyes.
  • Keep it flowing – Make sure the backwash outlet hose runs downhill so the discharged water can flow freely. Avoid kinks that restrict flow.
  • Watch for leaks – Inspect fittings and connections for leaks during backwashing. Fix any leaks immediately to prevent water damage and slip hazards.
  • Discharge fully – Allow the entire backwash cycle to fully complete discharging. Partially discharging can cause backflow into the softener.
  • Clean debris – Flush away any debris in backwash outlet lines to prevent clogging.
  • Extend hose reach – Make sure backwash hoses can reach drainage points from the softener tank’s location. Use extenders if needed.
  • Secure the hose – Anchor hoses with weights or ties to control the discharge stream and prevent splashing.
  • Slope away – Position the hose to drain at least 3 feet away from buildings and equipment. This prevents foundation flooding.

Water Softener Types and Backwash Discharge

The steps for discharging backwash water may vary slightly depending on the specific type of water softener you have:

Ion Exchange Softeners

Ion exchange softeners use resin beads to remove hard water minerals and discharge a brine solution during regeneration. To discharge backwash:

  • Locate the backwash outlet, typically a plastic hose connection.
  • Attach a drain line hose before starting the backwash cycle.
  • Make sure the backwash water flows out the hose until the cycle finishes.
  • Detach and store the hose until the next backwash cycle.

Salt-Free Conditioners

Salt-free water conditioners use filters and do not discharge brine, but still require periodic backwashing to flush filter media. To discharge backwash water:

  • Connect a discharge hose to the backwash outlet, typically found at the bottom of the tank.
  • Initiate a manual backwash cycle and let the water flow through the hose until it runs clear.
  • Disconnect the hose and resume normal operation.

Reverse Osmosis Systems

For reverse osmosis systems, you need to empty the storage tank that accumulates backwash water:

  • Shut off incoming water supply and depressurize the tank.
  • Locate the drain outlet valve near the base of the tank.
  • Attach a discharge hose to the drain valve.
  • Open the drain valve and allow all backwash water to drain out.

FAQs About Water Softener Backwash Discharge

Here are answers to some frequently asked questions about properly discharging water softener backwash:

Where should the backwash discharge hose be directed?

Ideally, the backwash discharge hose should be directed to a drain located at least 3 feet away from buildings and equipment. Avoid discharging onto grass, plants, or flower beds.

How often does a water softener need to backwash?

Most water softeners backwash every 3-5 days. The frequency depends on your water usage and hardness level. Harder water requires more regular regeneration cycles.

What should I do if I don’t have an outdoor drain for backwash?

You can discharge into a sink or other indoor drain as long as it flows into a sewer line. Make sure to install an air gap fitting between the hose and drain pipe. Alternatively, you can discharge into a gravel bed or street gutter.

Is it safe to let backwash water run into my septic system?

It’s generally safe to discharge softened backwash water into a septic tank in limited quantities. Avoid discharging excessive volumes that could potentially flood or overload the septic drainage field.

Can I discharge backwash into my sump pump?

You should avoid sending water softener backwash into a sump pump basin, as it contains sediment and minerals that can damage the pump or clog drainage pipes. Discharge backwash separately from the home’s foundation drainage system.


Regular backwashing and proper discharge of backwash water is crucial for keeping water softeners functioning at optimal efficiency. While the best discharge method depends on your specific home setup, you should always take safety precautions and discharge softened backwash water in a manner that avoids contamination, equipment damage, and clogged drains. With the right backwashing routine and discharge process, your water softener will run smoothly for years.

Key Takeaways:

  • Discharge backwash properly to avoid environmental pollution, equipment damage, and clogged drains.
  • Common discharge options include drain pipes, garden hoses, sewer lines, and backwash filtration systems.
  • Follow safety precautions like wearing gloves and securing the hose during discharge.
  • Allow the backwash cycle to fully complete discharging each time.
  • Adjust the process based on your ion exchange, salt-free, or reverse osmosis water softener type.
  • Do not discharge into sump pumps, only sanitary sewers or dedicated drainage points.

Leave a Reply

Your email address will not be published. Required fields are marked *