The home water treatment systems that produce wastewater in the treatment process are reverse osmosis systems and water softeners. Point-of-use water filters that attach to the kitchen sink faucet do not produce wastewater as part of treatment. The amount of wastewater produced by a home water treatment system will vary depending upon the type and size of the system. The manufacturer should be able to provide wastewater amounts. Ways to reduce the amount of wastewater produced can be seen at Best Ways to Save and Drought Tips.
Wastewater from water treatment systems is typically drained to the sewer/septic system. However, emerging technologies have begun to look at ways to reuse wastewater from the reverse osmosis process. Unfortunately, the mineral content of home water treatment wastewater may be too high to use for most irrigation purposes.