August 3, 2015

When in D(r)oubt: Use Gray Water


A recent OPB story on the use of gray water (spelled “graywater” by the Oregon Department of Environmental Quality) in Oregon reports that Oregonians may not be taking advantage of the opportunity to capture and recycle their water.

In Oregon, “gray water” includes shower, bath, bathroom sink, kitchen sink, and most laundry waste water.  ORS 454.605(7).  Because Oregon has legalized gray water usage, homeowners can use gray water for flushing toilets or irrigating trees and plants.

Not all gray water is created equally.  Oregon rules separate gray water into three categories (Types 1-3) based on the quality of the water and the level of treatment. Type 1 is generally untreated and is typically used for irrigation whereas type 3 gray water is highly treated to reduce the amount of bacteria or pathogens present.

The Department of Environmental Quality also has three permits available for gray water reuse:

  • Tier 1 general permit (2401) – This permit is for residential use of less than 300 gallons per day of Type 1 gray water solely for irrigation or compost.
  • Tier 2 general permit (2402) – This permit is for any structure using Types 1 or 2 gray water at a rate less than 1,200 gallons per day.
  • Tier 3 individual permit – This permit is a “catchall” for any use not covered by Tier 1 or 2. 

Gray water users must report annually to DEQ that they are operating their systems in compliance with their permit.

Remarkably, according to the OPB account, DEQ has issued only 20 gray water permits.  Of course, this figure does not take into account DIY gray water users.  This number will likely be on the rise given Oregon’s drought conditions as it is one of the more cost-effective ways to reduce water use at home.

For more information on this topic, please contact or call (888) 598-7070.


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