Orange STP Re-Use Risk Assessment

  • ASpect’s Client: Orange City Council
  • Head Client: Orange City Council
  • Plant Configuration: MLE
  • Plant Size: 60,000 EP
  • Project Value: $20k (ASpect Fee $7k)
  • Project Duration:  May 2012 to May 2012

Orange STP Effluent Re-use Risk Assessment Workshop participation for OCC (NSW).

Orange STP is a 60,000 EP facility that services the majority of the city of Orange in NSW.  During dry weather, most of the effluent is re-used on the site or at the Cadia goldmine.  Orange City Council (OCC) carried out a risk assessment of the two re-use applications to ensure compliance with the Australian Guidelines for Recycled Water.  The risk assessment workshop was facilitated by Risk Edge, with ASpect participating to provide sewage treatment process risk advice.  The workshop involved the Bow-Tie risk assessment methodology that identifies threats, vulnerability, risk (likelihood and consequence) and controls to prioritise risks and risk reduction.  The key outcomes for consideration included a greater emphasis on upstream STP control,  improving current disinfection practices by affording a higher chlorine residual with subsequent de-chlorination of any surplus discharges, the possible including UV as an additional barrier and roofing the re-use water tank to prevent post disinfection contamination.