Greywater (also spelled graywater) includes wastewater from bathtubs, showers, bathroom sinks, clothes washing machines, and laundry tubs. It does not include water from toilets, urinals, utility sinks, kitchen sinks or dishwashers. Filtration and disinfection is not usually required for subsurface irrigation, yet is required to meet water quality criteria for reuse for toilet flushing and surface irrigation. Elements of a greywater to treatment to reuse system include: collection, filtration, disinfection, distribution, make-up potable water, and a nonpotable distribution system, commonly referred to as purple pipe or dual plumbing. On single or multi-family residential sites greywater can be diverted from bathroom showers, bathtubs, and sinks and laundry washing machines and directly diverted for subsurface irrigation without additional treatment.
All new construction and building retrofits can be evaluated for opportunities to incorporate a greywater reclamation and reuse system.
Treatment to reuse system costs vary depending upon the size of the system, amount of storage required, and if the building or system where the treated greywater is being delivered has already been dual plumbed to receive non-potable supplies. Greywater to Landscape system cost range from $250-$500 for systems installed by homeowners to $2,000 - $3,000 for systems installed by professionals.
Using greywater reduces our freshwater consumption by reusing water for gardens and landscapes, allowing us to rehydrate our watersheds. Onsite water reuse allows less water to enter our septic and sewage systems, and diverts that water into landscapes, watering trees, shrubs, flowers and other foliage.
- Install a diverter valve in order to direct the flow of water from greywater application to septic/sewer system.
- No diapers, soiled garments or hazardous chemicals.
- Do not allow greywater to pond on surface or run off property.
- Outlet must have 2 inch cover (preventing contact).
- Clearly label all greywater pipes in order to prevent confusion with potable water.
- Greywater system shall not be connected to any potable water system without adequate protection (ie: air gap, RP).
- Greywater cannot discharge into groundwater without minimum 3 ft. separation of soil.
- Owner must determine their soil type. This can be done with a Field Test, Lab Test or Professional Field Test.
- Monitor and maintain system on a regular basis.
- Do not distribute greywater through sprinklers.
- Do not use bleach when greywater system is turned on.