A 5 cubic metre nutrient removal tank and 5 cubic metre detention tank were constructed on individual housing lots on a 22 lot residential sub-division close to Lake Macquarie in NSW.

Stormwater initially passes through an AUSDRAIN™ EnviroSump to trap fines and leaf matter. The water then passes into a 5 cubic metre nutrient removal tank designed to collect the first flush and treat the water for nutrients before infiltrating this water back into the ground.

Excess water overflows from the nutrient tank into a 5 cubic metre detention tank where it is stored temporarily. This tank is connected to a discharge control pit containing an orifice plate that slowly discharges any excess water to the lake.