Greywater Recycling Systems


What is greywater recycling?

Greywater recycling is the practice of reusing water produced from the shower, washing machine and bathroom or laundry sinks. The water produced from these household fixtures is typically fairly clean and when properly filtered can be reused in a number of different ways. Toilet, dishwasher and kitchen sink water is considered blackwater and cannot be reused for any purpose without extensive chemical treatment.


How can greywater be reused?

Greywater is typically reused in two different ways:


Toilet Flushing

Reusing greywater for toilet flushing is not generally recommended. Modern, low or variable flushing toilets require a fairly low amount of water per flush and the water savings generated by reusing greywater for this function is typically insignificant. In order for greywater to be reused indoors the water must be chemically treated, dyed and processed through a sophisticated filter which often requires frequent maintenance and extensive permitting. Additionally, according to a greywater study from Kohler, greywater can cause excessive wear on toilets and is therefore not recommended.

Landscape Irrigation

The most efficient application for reused greywater is in a drip irrigation system. Drip irrigation provides efficient water delivery to plants, trees and flowers throughout the landscape while greatly reducing evaporation. Because the greywater is being reused outdoor where minimum human contact is expected, permitting is far less rigorous than when reused in an indoor application. Greywater is not recommended for irrigating lawns as grass areas are best irrigated by spray irrigation which is against code in virtually every municipality in the United States.


When using greywater in the landscape for irrigation the complexity of the greywater system to be installed can vary by the specific landscape's needs. The following examples are the three most common Flotender greywater irrigation system configurations:


Recycling Greywater in an Instant Distribution Application

The instant distribution application is the most straight forward and preferred application for the Flotender Greywater Recycling System. In this type of installation, when greywater enters the Flotender Greywater Filter (processor) it is immediately filtered, pressurized and pumped out to the drip irrigation system. The Flotender Greywater Filter provides surge capacity to handle the flow of the greywater fixtures being used. The amount of surge capacity required coincides with the amount of greywater flowing into the fixture simultaneously.


Greywater Recycling System for use with drip irrigation


When & Why Instant Distribution is Favorable

An instant distribution greywater system is favorable when the objective is to reuse greywater in irrigation without having to deal with the system complexity or permitting process of involved with a greywater storage system. Instant distribution is the most commonly used configuration for residential greywater systems and is very straight forward in it's operation. Most landscapes require more greywater for proper irrigation than the amount of greywater the home actually produces. Due to this deficiency a greywater storage option as detailed below would not be utilized as there would be very little if any greywater to store on a regular basis.


Recycling Greywater in a Delayed Distribution Application

In more complex greywater recycling scenarios the Flotender Greywater Filter can be placed “downstream” from a any 3rd party greywater storage tank. In this system application the greywater from the storage tank will be pumped out to the Flotender Greywater Filter on a timed schedule. The Flotender Greywater Filter will then operate as an instant distribution system but only when greywater is transported from the storage tank.


grey water recycling


When & Why Delayed Distribution is Favorable

A delayed distribution greywater irrigation system is favorable when very delicate plants requiring a specific amount of water daily are attached to the drip irrigation system. With a delayed distribution system, a specific amount of water can be allocated to the plants based on a pre-determined schedule. Another form of a delayed distribution system is the GreyLink system which features a built-in reservoir, an irrigation controller and multi-zone function.


Integration with a Rainwater Harvesting System

Rainwater collection can be integrated with both the instant distribution and delayed distribution greywater systems. A rainwater catchment cistern can be installed “upstream” from the Flotender Greywater Filter. A Filtrific Rainwater Filter can be installed at the downspout to catch any debris before it enters the cistern. (the example below is based on an instant distribution system, rainwater collection can also be integrated with a delayed distribution system as well)


Greywater Reuse with Rainwater

Providing supplementary water for the greywater recycling system, the stored rainwater can even be supplemented with a potable water fill valve to ensure that there is always an ample supply of backup water available. This option would best be exercised in dry months when rainfall is unlikely.


Additional Information

Please visit the Flotender System and GreyLink System websites for additional information on our greywater recycling systems. Available resources include specification sheets, CAD details, detailed system illustrations, accessories and system pricing.

The vast majority of Flotender systems that are installed fall into one of the categories above. If you have a custom application that you would like to discuss please feel free to give us a call at (800) 906-0604.