In what context are intermittent sand filters typically used as part of a mitigation strategy?

Intermittent sand filters are specifically designed to treat wastewater when there are concerns about horizontal separations being reduced. These systems offer a method of treating effluent in scenarios where the distance from the septic tank to potential groundwater sources or surface water is minimal, thereby requiring enhanced treatment processes to protect water quality.

The design of intermittent sand filters allows for effective filtration and treatment of effluent before it reaches the groundwater or nearby surface water bodies. By providing an additional layer of treatment, these filters help mitigate the risks associated with lower horizontal separations, ensuring contaminants do not seep into drinking water sources or impact ecosystems.

When vertical separations increase or during abundant rainfall, other strategies may be more applicable, as they typically do not present the same level of risk associated with reduced horizontal separation, where wastewater might directly influence nearby bodies of water.