When is an intermittent sand filter with a disinfection system chosen over a septic tank system?

An intermittent sand filter with a disinfection system is typically chosen over a septic tank system when there are specific soil and site conditions that necessitate enhanced treatment. In particular, option B aligns with situations where the use of a standard drainfield may not be sufficient or suitable. Class Ia soils, characterized by their high permeability and good drainage properties, can often handle treated effluent effectively. However, the addition of a disinfection system provides an extra layer of treatment, ensuring that pathogens are effectively eliminated before effluent reaches the ground water or surface water.

This is crucial in maintaining environmental health, especially in areas where groundwater resources may be sensitive or where regulations require a higher level of treatment. Other scenarios, like low-density areas, limited space, or composting purposes, do not necessarily indicate the need for an advanced treatment system like an intermittent sand filter with disinfection; those situations may be adequately managed by conventional septic systems. Therefore, for areas with specific soil types that could necessitate enhanced treatment to protect public health and the environment, the choice of an intermittent sand filter becomes particularly beneficial.