Tightening effluent consents due to river water quality drivers require further investment  for improved removal of nitrogen and phosphorus from Wastewater Treatment Plants (WwTP). 
As a result, tertiary treatment processes have become increasingly important.This has led to a need to gain a better understanding of the process and mechanics  of tertiary removal systems in order to  remain both compliant now, and for the  future lowering of effluent discharge limits.  Efforts have been successfully made to  upgrade and refurbish existing tertiary  continuous sand filters using the novel  Sand-Cycle technology. It has given rise to  a better understanding of the relationship  between sand circulation and filtration  efficiencies. Real-time information acts as  an early warning system to consistently 
meet better effluent qualities through faster  reactive measures, as well as proactive analysis of data.

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