Components  
   
To be an effective system 200-300 gallons of Greywater is need to be produced per day. An average family of four only produces approximately 200 gallons per day. In this case the Greywater system may be supplemented by normal drinking water. For an underground drip irrigation system, the installation of split plumbing for wastewater and Greywater is needed. This plumbing meets the same standards as normal plumbing however Greywater output must be clearly labeled and never be combined with Blackwater. Since little treatment is needed for the underground drip system, the requirements are simple: a large holding tank, a self-cleaning filter, and an overflow connection to the main sewer system. The size of the large tank is determined by the size of your system. A self-cleaning filter is also necessary. The holding tanks require a 3.5'x3' to 5'x7' slab of concrete and in some cases can be placed underground if desired. Overflow connections that return into the main sewer are required in the event of excess Greywater.  
   
Any greywater system should be able to work if it is designed properly. A decision has to be made at the beginning of a design on where the water is coming from, rainwater, bath water, sink water, or washing machine water. This needs to be decided so those sources can be separated from the normal blackwater system. Then depending on what this greywater will be used for a number of components will be designed in. First a piping system needs to be created to keep this greywater separate from other blackwater sources. The second component in a greywater system is treatment. While some water may not need treatment, for most uses it is a good idea. The treatment components range from settling tanks to sand filters. These cleaning components don’t bring the water up to potable quality but they do clean it enough for other uses. The next component is the use of the greywater. These pieces range from toilets, to planting beds, to larger irrigation systems. The following is a series of examples and case studies of greywater systems.  
 

Figure 4

 FIgure 5  
 
In Figures 4 and 5 we see the inner workings of a soil-box planter, one of the basic elements of a good greywater system for the home or business. The idea within the box is for the greywater to move its way through several different layers and to clean itself with this movement. The water enters through gravity feed pipes, which is then released, into the soil-box so the plants have the first crack at the soil. While the plants are soaking up the water through their roots about 4-6” below the rest is percolating through the soil into a sand layer for a second stage of cleaning. After the sand the water travels through pea gravel layer then finally through a coarser stone at the bottom of the box. Each layer can have a membrane to help filter larger particles and to stop one layer from mixing with another. Once through the soil-box where the water goes can be to several different places to perform several different functions. The water could be used to flush toilets, irrigation of planting beds or even for heating purposes in the home.