What is the minimum depth of undisturbed soil required for the placement of a mound after site development is complete?

The minimum depth of undisturbed soil required for the placement of a mound after site development is completed is 12 inches. This requirement is critical because undisturbed soil provides the necessary conditions for effective water absorption and filtration, ensuring that the septic system operates efficiently and minimizes environmental impact.

When the soil is undisturbed, it retains its natural structure and permeability, which are essential for the proper functioning of a mound system. Adequate depth allows for sufficient space for the mound to function as intended, facilitating adequate drainage and treatment of effluent. If the soil is too shallow, it may not provide the required absorption and may lead to potential system failures or contamination of nearby water sources.

The specified depth of 12 inches serves as a guideline to ensure that installations are conducted with the natural soil characteristics intact, ultimately supporting the long-term sustainability of the septic system.