When I mentioned to friends that I was writing an article about greywater (or graywater) the first response was “What is greywater?” You may be asking the same question. What is greywater and how do I reuse it?

          “Greywater is water from your bathroom sinks, showers, tubs, and washing machines. It is not water that has come into contact with feces, either from the toilet or from washing diapers.”

          “Greywater may contain traces of dirt, food, grease, hair, and certain household cleaning products. While greywater may look “dirty,” it is a safe and even beneficial source of irrigation water in a yard. If released into rivers, lakes, or estuaries, the nutrients in greywater become pollutants, but to plants, they are valuable fertilizer. Aside from the obvious benefits of saving water (and money on your water bill), reusing your greywater keeps it out of the sewer or septic system, thereby reducing the chance that it will pollute local water bodies. Reusing greywater for irrigation reconnects urban residents and our backyard gardens to the natural water cycle.”  (1)

          According to information in the Lincoln JournalStar Newspaper the average household uses: 25 gallons per person per day to water their lawn and fill their pool, 24 gallons per person per day flushing the toilet, 20 gallons of water per person per day for bathing, 8.5 gallons per person per day for laundry, 2.5 gallons per person per day to wash their car, and only 2 gallons per person per day for drinking and cooking. (2) Watering the lawn and filling the pools use the most water. I believe that the majority of Nebraskans use clean drinking water for most household uses. Some of this precious resource could be conserved by recycling water. According to New Mexico State University Extension 65% of domestic wastewater is greywater. (3)

          “Graywater is of lesser quality than tap water, but generally of higher quality than blackwater, or water from sewage systems. Water from the kitchen sink, garbage disposal and dishwasher is considered blackwater in some states because of high concentrations of organic waste and the difficulties of reusing this water safely.”

          “The most obvious advantage of domestic graywater use is that it may potentially replace other water used for landscape irrigation, although many interests are now advocating the use of graywater for toilet flushing” (3) This publication on page 3 has a chart showing the water quality characteristics of selected domestic wastewater.

          We wash and dry dishes by hand. We have been saving the water from rinsing all summer long. My wife has been watering her containers on the front driveway, the flowers along the driveway, and sometimes uses it to wash off the driveway. We have been saving the water from our dehumidifier and reverse osmosis water purifier for years. This is technically not greywater but it works for watering indoor plants, containers outdoors, and flowers and trees in the backyard. We store many indoor plants in front of a south facing window over the winter and this water is perfect for them. With water rationing she has also begun to collect the rinse water (not wash water) from the washing machine and using it to water her containers, flowers, and shrubs in the backyard.

          The easiest way to use greywater is to pipe it directly outside and use it to water ornamental plants, shrubs, or trees. “Washing machines are typically the easiest source of greywater to reuse because greywater can be diverted without cutting into existing plumbing. Each machine has an internal pump that automatically pumps out water. You can use that to your advantage to pump the greywater directly to your plants, trees, and lawns.” (1)

          “Greywater is different from warm-up water (wasted tap water that is allowed to run down the drain before it reaches a desired temperature). Warm-up water that has not been used for bathing or dishwashing is generally free from bacteria and other pathogens.  The amount of wasted warm-up water can be significant in homes where water heaters are located a considerable distance from showers or tubs and where no recirculation system is installed. Catching this water in a bucket and using it to water plants can contribute to home water conservation savings.” (3)

          “Greywater is different from fresh water and requires different guidelines for it to be reused.
1. Don’t store greywater (more than 24 hours). If you store greywater the nutrients in it will start to break down, creating bad odors.
2. Match the amount of greywater your plants will receive with their irrigation needs.” (1)

Copyright 2012


(1) “About Greywater Reuse” from Greywater Action, Inc (

(Greywater Action Inc. Was started by 3 lady plumbers and is located in San Francisco, CA)

(2) “Water Use In Households”, Lincoln Journal Star Newspaper, September 2, 2012 ( source

(3) “Graywater Reuse and Rainwater Harvesting” by R. Waskom and J. Kallenberger, Colorado State University Extension Fact Sheet No. 6.702 (

(4) “Safe Use of Household Greywater” Guide M0106  Revised by Marsha Wright, Extension Research Assistant, Cooperative Extension Service, New Mexico State University. (