What About Gray Water?

What exactly is gray water?

Graywater is “used” water originating from washing machines, sinks, showers and bathtubs. It is water that contains some soap, but is clean enough to water plants.   Graywater specifically does not include wastewater from dishwashers, garbage disposals, toilets, wastewater from the washing of cloth diapers or wastewater that contains hazardous chemicals.

Reusing water is a great way to stretch the water you have already worked on conserving.  It lowers our demand on fresh, treated water, especially for tasks that do not require potable water, like basic landscape irrigation.

Laundry to Landscape: The simplest, most effective way to irrigate a home landscape with greywater

The Laundry to landscape gray water systems is simply a modernization of a very old idea.  Basically before plumbing, water from laundry was often directed back to the garden with a hose.  Today with a few adjustments to our indoor plumbing, laundry water can be used for irrigation.  Department of Environmental Quality has issued guidance to ensure this is done in a healthy and environmentally friendly way.   There guidance can be found in the resources section.

Watch a clip of a laundry to landscape grey water system.

Why reuse gray water?

Using gray water for landscape irrigation is a smart way for homeowners to adopt sustainable water practices and conserve our limited drinking water supplies for activities requiring high-quality water. Gray water systems can significantly reduce the amount of water you use during the summer to water your garden and landscaping.   Homeowners also see a modest cost savings on their water bill. When Oregonians reuse gray water, less water is withdrawn from rivers and streams, which helps keep our waterways healthy for fish and people. (DEQ)

There are many benefits to the homeowner, the city and the environment from using gray water too including:

  • Lower Fresh Water Demand and Treatment Needs
  • Less Strain On Septic Systems and Treatment Plants
  • Less Energy and Chemical Use
  • Groundwater Recharge
  • Increased Awareness of Natural Cycles

Steps for developing a gray water system

State law requires all gray water reuse and disposal systems in Oregon to be designed and permitted. Designing, permitting, operating and maintaining a system to use gray water in the landscape is a relatively simple process accessible to the average homeowner.  Check out this Guide to get started planning your project:

Reusing Gray Water on Your Landscape- A Guide for Oregon Homeowners

Is Gray Water Legal?

Getting a Permit for your gray water project

Driven by a need for water conservation, Oregon’s new legal gray water program started in April 2012 by DEQ.

In Oregon, to use gray water for your garden and landscaping, you’ll need to get a few permits before installing the system at your home.

  1. Plumbing permit for the local jurisdiction
  2. Gray water permit from the OR Department of Environmental Quality

Once installed, the annual fee can be waived be submitting a short report.  For more information on the permitting process, see the OR DEQ Gray water website.

Gray water Resources

City Of Ashland Gray Water

Reusing Graywater in Your Landscape: A Guide for Oregon Homeowners

Questions and Answers: Permits for graywater reuse and disposal systems

Graywater Presentation

Water Conservation Systems Oregon Smart Guide

San Francisco Graywater Guide

Greywater Action 

Oasis Design