Primary treated wastewater from the septic tank(s) flow first to the Recirculation tank, where mixing and natural biological treatment takes place.
Pumps in the recirculation tank deliver the wastewater to the Sand Filter bed in frequent, time-controlled doses. With each dose, the wastewater sifts through the sand and contaminants are removed and broken down by naturally occurring microorganisms living on the sand particles, in what is called an aerobic flow.
The aerobic flow then drains back to the recirculating tank for mixing with incoming wastewater. After a few more passes (recirculations) through the sand filter and recirculation tank the treated wastewater is ready for discharge to a drainfield.