What additional feature is needed on top of the filter material in a greywater disposal field?

In a greywater disposal field, the addition of a layer of straw or building paper serves a crucial role in the treatment and distribution of greywater. This layer helps to enhance the filtration process and encourages the growth of beneficial microorganisms that assist in breaking down organic material present in the greywater.

The presence of straw or building paper can also facilitate the absorption of excess moisture and helps to manage surface erosion while allowing air and moisture to pass through, which is vital for a healthy subsurface ecosystem. This layer acts as a protective barrier and helps maintain moisture levels in the soil, thereby promoting vegetation growth that can further assist with the uptake of water and nutrients.

By including this feature, the overall efficiency of the greywater disposal system is improved, which is essential for effective sustainable landscape practices.