What type of soil fill must be added to a shallow installed system?

The requirement for adding soil fill to a shallow installed septic system focuses on ensuring proper drainage and filtration. Soil texture plays a crucial role in the performance of a septic system because it affects how water moves through the soil and how well contaminants are filtered out.

Choosing soil of group three texture or better is essential because group three textures typically offer a moderate permeability that can adequately support the treatment of effluent while providing suitable drainage characteristics. This means that water can move through the soil at a rate that prevents surface ponding, allowing sufficient time for treatment to occur as the effluent percolates through the soil layers.

Additionally, using soil that is categorized as group three or better aids in maintaining the overall health of the surrounding environment by ensuring that the effluent is adequately treated before it reaches the groundwater or nearby water bodies. This practice helps to prevent pollution and ensures compliance with environmental regulations. Therefore, the requirement for group three texture or better reflects the need for effective functioning of the septic system while also protecting public health and the environment.