Why Select a Subsurface Flow Design for Graywater Treatment?

Advantages of Subsurface Flow

A subsurface flow design for graywater treatment offers numerous benefits, including reduced odors and algae growth, lower water loss through evaporation, and easier maintenance compared to traditional above-ground wetland systems. This design also allows for greater flexibility in layout and can be easily integrated into existing landscapes. By treating graywater beneath the surface, it minimizes the aesthetic impact on the area.

Design Considerations

When designing a subsurface flow graywater treatment system, several key factors must be considered. The system should be sized based on the amount of graywater generated, taking into account factors such as water usage, fixture count, and flow rates. A general rule of thumb is to allocate 0.5-1.0 cubic feet per minute (CFM) of flow per fixture for residential applications. The system should also be designed to achieve a minimum of 70% removal of total suspended solids (TSS) and 80% removal of biochemical oxygen demand (BOD) within a 24-hour period. Additionally, the design should take into account local building codes, regulations, and climate conditions.