What household water can safely irrigate gardens?
Written by
Paul Reynolds
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Utilizing household gray water for irrigation purposes is an efficient resource conservation practice. Laundry water treated with plant-safe detergent can be used to water ornamentals. Shower and bathing water that does not contain any harsh chemicals can also be used for watering. I use my shower runoff to irrigate the flower beds. Never use water from the kitchen - your plants will suffer from the effects of grease or salts.
Implement the use of collection systems correctly. Have washing machine outflow pipe to mulched basins around trees. Include diverter valves on shower drains. My system uses a hose from the washing machine to the garden. Always filter solids and hair before. Never store greywater for more than 24 hours.
Plant Safety
- Apply only to ornamental plants, never edibles
- Avoid sensitive species like azaleas and blueberries
- Rotate application areas to prevent salt buildup
- Use only on well-draining soils
Health Precautions
- Never use water containing bleach or disinfectants
- Wear gloves during application and system maintenance
- Prevent human contact with applied greywater
- Install backflow preventers in plumbing systems
Use proper detergents for greywater systems. Choose liquid soaps that are free from sodium, boron, and chlorine. I use the Oasis brand detergent for greywater. I would recommend avoiding powder soaps that leave residue and monitoring pH levels monthly to prevent soil alkalinity problems.
Be aware of your legal limitations, which may vary depending on your region. Some states permit the installation of simple bucket systems without a permit. I need a license for the installation of permanent systems in my county. Many areas do not allow for indoor greywater use in any capacity. It's always best to check with your local health department to determine what is permitted before installing anything.
Keep systems in good repair to avoid deviation issues. Weekly, during periods of heavy use, clean the filters. Monthly flush irrigation lines to remove debris buildup. I check my system out for the watering season. Inspect plants for signs of salt stress, such as leaf burn. Good maintenance will allow safe operation for years to come.
Greywater usage has great potential to conserve water significantly. My system saves approximately 40 gallons, with summer use being much greater. When pairing greywater and rainwater, this will conserve the maximum amount of water. Utilizing greywater responsibly will improve your garden and the watershed. These practices must be implemented respectfully to achieve sustainability through conservation.
Read the full article: 10 Essential Water Conservation Gardening Tips
