What is the minimum land area requirement outlined for intermittent sand filters in WAC 246-272A?

The minimum land area requirement for intermittent sand filters as outlined in WAC 246-272A is primarily linked to treatment performance levels. This means that the size of the land needed for an intermittent sand filter system is determined by how effectively the system can treat wastewater to meet specified performance standards. These standards are based on factors such as the expected volume of wastewater, the quality of that wastewater, and the environmental impact of its discharge.

While soil type, local regulations, and engineering practices might influence design and implementation of septic systems, the core requirement for sizing in this specific context focuses on treatment performance. Therefore, ensuring adequate land area is fundamentally about achieving the required treatment efficacy for protecting public health and the environment.