Loading rates aren’t determined at the drop of a hat, well at least they shouldn’t be. They should be based on the soil characteristics, wastewater strength and the design configuration.
With single-family home design and septic tank effluent, we focus on the hydraulic loading rate. For any given soil treatment area (STA), the hydraulic loading rate is the quantity of effluent applied to the soil expressed as volume per area per unit time (e.g., gallons per day per square foot). A site with finer texture, poor structure, poor consistency or horizons that restrict water movement should be assigned a lower loading
