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All About Greywater
                                   Greywater (also spelled Graywater) is water from showers/baths, washing machines and sinks. Water from toilets, clothes washer with diaper wash water, greasy rags, or other chemicals is known as Blackwater and is not legally allowed to be reused.  In the state of California wastewater from Kitchen sinks or dishwashers are also considered Blackwater.  

                                                                           Saves water; Saves energy used to transport, clean and treat water; Reduces demand on septic systems and sewage treatment plants; Encourages healthy product choices; Connects people to their backyards; Facilitates local food production; Returns vital nutrients to soil.  

                                                         Greywater can be reused for outdoor irrigation through low tech- gravity fed systems, or high tech- systems including filtration, tanks, pumps and drip irrigation. Greywater can also be reused indoors (example: toilet flushing), though requires filtration and disinfectant and currently is not allowed under California code                                                   

                                                                                       Greywater systems can reduce a household's water use by 10% to 50%. A Greywater system from the laundry machine alone provides an estimated annual savings of 6,400 gallons per household.  

                                 If it goes down the drain it ends up in the water.  Hair, lint, grease, food, possibly chemicals-thousands of types (soap, cleaning products, etc.), nutrients.

                                             There has never been a documented case of illness from greywater, regardless all systems should be designed to avoid the possibility of ingestion/infection, there is the potential for contact with pathogens; Improper design could create a cross connection where greywater could enter potable water pipes; Potential environmental pollution (if harmful chemicals are in greywater they can enter the groundwater & surface water; Nutrients in greywater can contaminate creeks by consuming oxygen; diseases vectored by mosquitoes; Potential problems with neighbors. 

                                                       Cleaning Products Effect Greywater quality and soil/plant health.  Avoid products that contain Salt (sodium compounds), Boron (borate), and Chlorine bleach (hydrogen peroxide bleach okay). Recommended products are Salt/boron/ free. For laundry detergent recommended brands include Oasis, ECOS, Biopac, and others.

*Don't store Greywater 
*Infiltrate into mulch 
*Minimize contact
*Include a way to switch back to the sewer
*Best for trees, shrubs  
*Know what you put down the drain


1. Notification of installation of the system to Enforcing Agency.
2. User can easily redirect flow to sewer.
3. No potable water connection.
4. The greywater shall be contained on the site where it is generated.
5. Greywater shall be directed to and contained within an irrigation or disposal field.
6. Ponding or runoff is prohibited and shall be considered a nuisance.
7. At least two (2) inches of mulch, rock, or soil, or a solid shield covers the release point.
8. Minimize contact with humans and domestic pets.
9. Water used for diaperwashing and similarly soiled or infectious garments shall be diverted to the building sewer.
10. Greywater shall not contain hazardous chemicals derived from activities such as cleaning car parts, washing greasy or oily rags, or disposing of waste solutions from home photo labs or similar hobbyist or home occupational activities.
11. An operation and maintenance manual shall be provided.

-clothes washer system (aka Laundry to Landscape)  
-laundry drum
-branched drain (gravity fed shower and bathroom sink systems)
-constructed wetland
-subsoil infiltrators

-Drum with effluent pump
-Sand filter to drip irrigation

-Clothes Washer System (Laundry to Landscape). Utilizes only one single domestic clothes washing machine in a 1 or 2 family dwelling.
-Simple System. Serves 1 or 2 family dwelling with a discharge of 250 gpd or less.
-Complex System (may require design of an engineer). Discharge exceeds 250 gpd.
How much water can be saved by reusing greywater? 
What are the benefits of reusing Greywater?     
Whats in Greywater?    
Concerns with Greywater?    
Recommended cleaning products    
Basic Greywater Guidelines
Greywater Guidelines under california code (CPC Chapter 16A)
Low tech systems
High tech systems
Different types of systems as defined in the California code
How can we reuse  Greywater?
What is Greywater?