According to WAC regulations, for mounds using Treatment Level C, what is the minimum original soil depth required?

The minimum original soil depth required for mounds using Treatment Level C, as per WAC regulations, is indeed 24 inches. This depth is critical because it ensures there is enough soil to adequately filter and treat the wastewater coming from the septic system. The 24 inches serves as a guideline to promote effective wastewater treatment, which relies heavily on the soil's ability to absorb and process effluent.

The requirement for this specific depth also addresses issues related to hydraulic capacity, soil composition, and the natural filtration processes that occur within the soil. Having a sufficient depth helps to accommodate the microbial activity necessary for breaking down pollutants, preventing groundwater contamination and ensuring that the system functions as intended.

Understanding this requirement is essential for septic system installers, as inadequate soil depth can lead to system failures and environmental hazards. Consequently, adhering to this regulation is vital for both compliance and the maintenance of public health.