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Blue Skies & Greywater

I would like to say it loud and clear: GREYWATER IS LEGAL IN CALIFORNIA. Many of you have heard rumors about greywater becoming legal over the past six months. On January 13, 2010, Chapter 16 of the Universal Plumbing Code was updated by the Building Standards Commission.

This summer Arnold Schwarzenegger  mandated the legalization of greywater under emergency drought measures (his best deed ever). The Department of Housing and Community Development wrote the new emergency code. With a few changes it has just been made permanent.

Simple mulch basin systems without tanks are allowed in the new code, making greywater systems affordable and easy to install. The components of a basic system can cost under $50. Professionally installed greywater systems range in price from $1,000 to $5,000 for a single dwelling.

The potential annual water savings is high, up to 50,000 gallons per family. The actual water conserved would be the amount of irrigation water that greywater replaces. If 5% of the California residents replaced irrigation water with greywater, over 26 billion gallons of water would be saved annually (800,000 acre-feet). That is about 100 Lake Mendocinos when full to the top. If you already let your lawn and yard go brown in the summer, than think of this as potential, guilt-free, irrigation water and create an oasis!

Clothes Washer Systems do not require a permit by state law provided that they meet certain criteria. A permit for a Simple System is required for bath, shower, and lavatory sink. For systems of over 250 gallons/day a permit for a complex system is necessary. Multi-family dwellings (3 or more) must get a Complex permit, but can still develop a joint greywater system. Residential and commercial buildings both are covered under this code.

All of the above greywater systems may be used for irrigation of landscape and food crops for which food does not come in contact with soil. This may be done via mulched basins, gravel trenches, underground emitters, soil boxes, or other appropriate designs. Filters and tanks are not required but a connection to the sewer/septic is. The permitless Clothes Washer Systems have the following requirements (abridged: see the code before proceeding):

1) Notify the Enforcing Agency (Environmental Health) about the location and installation.

2) Be able to direct greywater to sewer or septic.

3) No mechanizations (pumps, except for washer’s own) and does not affect infrastructure.

4) Greywater contained on property where it is made.

5) Greywater directed to and contained within disposal field.

6) No ponding or runoff

7) Greywater may be directed above soil surface provided that at least 2 inches of mulch, rock, or shield covers it.

8) Minimize contact with humans and pets.

9) Water used to wash diapers or infectious garments must be directed towards sewer.

10) Shall not contain hazardous chemicals.

11) May not be constructed in a way that violates other codes and ordinances.

12) Operations and maintenance manual must be provided for the life of the building.

Simple Systems have a few more requirements (a permit, a three-foot hole to check groundwater, consulting with water utility about contamination, and plans) but are still quite approachable. The code for both complex and simple systems allow for creative design, leaving decision making to local jurisdictions. This is the biggest change from the old code that created a stranglehold on greywater regulation.

In checking in with David Jenson of Mendocino County Environmental Health, I was told that the Mendocino County would adopt the state law as it is and that they had no time to create further greywater regulations.

In Mendocino County one may seek professional greywater design and installation services through Village Ecosystems, Being Water, and the Mendocino Ecological Learning Center. Find a copy of the new code at

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