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Community and Q&A

Gray/ grey water system in Southern California

StutsFX | Posted in Green Building Techniques on

I am new to GBA so bear with me if this has come up before. I am in Southern California with severe drought conditions. I think I have a good arrangement for a greywater system- One story house on a medium slope hillside so my crawl space tapers from 2 ft. to 8 ft. Great for dealing with the utilities. It also might be great for natural drainage of a greywater system. I was wondering if I put a large pool size sand filter inline if I could let the water drain through into a say 100 gallon holding tank and use a submersible pump attached to the drip system and/ or perforated pipe drainage. Any backflushing would have to be plumbed into the existing septic system/ leach pit. Tearing up my wife’s landscaping to lay out an extensive underground leach field would be grounds for a divorce.
Or, are there any other ideas floating around out there? Or do I just plumb the 2 bathrooms into a shallow (1 foot?) field with say 1 1/2″ perforated pipe? There would be very few straight runs getting around the trees, bushes, etc.
Thanks in advance for any ideas.

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  1. GBA Editor
    Martin Holladay | | #1

    The most important factor affecting the design of a graywater system is local code approval. Some jurisdictions outlaw these systems; others have strict regulations. A homeowner who makes a mistake with a DWV plumbing alteration can cause a public health problem, so it makes sense to regulate these installations.

    Commercial graywater systems are available; these commercial systems are more likely to gain code approval than a jury-rigged system installed by a homeowner.

    For more information, see GBA Encyclopedia: Gray Water.

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