Basic Guidelines
Graywater Systems
Reuse responsibly.
Follow these basic guidelines to use graywater safely and responsibly.
Be able to switch back.
Have an easy way for the user to redirect flow back to the sewer or septic in case you have to wash something toxic or hazardous (ie. automotive grease, paint brushes, chemicals from home photo lab, diaper water etc.), or if seasonal weather conditions such as high groundwater or precipitation levels makes it difficult to infiltrate graywater without causing runoff or contamination to local environments. Diversion is usually accomplished through what’s called called a 3-way valve, and must be labeled and easily accessible.
Keep it subsurface.
Discharge greywater below the surface under a minimum 2″ cover of mulch, plastic shield, or stones so that its not accessible to people or pets. Theres never been a documented case of illness from graywater, but nevertheless all systems should be designed to avoid the possibility of contact or ingestion.
Contain it onsite.
Don’t let graywater overflow or runoff, keep the water on the same property it is produced from and follow the set-backs listed in the code (1.5 ft from a property line, 2 ft from a building, 100 feet from streams, lakes, or water wells). Even naturally occurring nutrients in greywater can contaminate creeks and other surface water so be sure your system has sufficient surge capacity and infiltration area to handle all the graywater you produce.
Choose healthy products.
Cleaning products effect Greywater quality and soil and plant health. Avoid products that contain Salt (all sodium compounds), Boron (borate), and Chlorine bleach (hydrogen peroxide bleach okay), which may ultimately damage the soil and make conditions inhospitable to plants and beneficial soil biology. Recommended products are Salt/boron free.
Operation & maintenance manual
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Because graywater systems are part of a buildings permanent infrastructure, there needs to be documentation to pass on important details about the system in case new owners buy the building or the system needs to be maintained. Common info to include in an O & M Manual are:
•Diagrams of the system and location of components.
• How and when to turn the system off and on.
•Appropriate products to use
• Any maintenance needed
• Contact info for the installer and/or manufacturer