Which factor is NOT included in the calculation of MLSS?

The calculation of the Minimum Lot Size for Septic Systems (MLSS) typically involves various factors that influence the design and function of a septic system. These factors can include the flow factor, which accounts for the volume of wastewater generated per household; the perc factor, referring to the percolation rate of the soil, which affects how quickly water can be absorbed into the ground; and the hydraulic factor, which deals with the movement of water within the system.

The soil factor, while relevant to overall septic system performance—including the choice of soil for installation—is not a direct component of the MLSS calculation itself. Instead, the calculation focuses primarily on how these other factors contribute to determining the minimum lot size needed for safe and effective sewage disposal. Thus, the correct identification of the soil factor as not included in MLSS highlights the specific elements that are paramount in ensuring septic systems comply with regulatory standards while effectively handling wastewater.