Orange STP Re-Use Disinfection Reference Concept Design

  • ASpect’s Client: Orange City Council
  • Head Client: Orange City Council
  • Plant Configuration: MLE
  • Plant Size: 60,000 EP
  • Project Value: $160k (ASpect Fee $40k)
  • Project Duration: January 2017 to Ongoing

Orange STP Re-Use Disinfection Reference Concept Design, Client Representative for OCC (NSW).

Orange STP is a 40,000 EP facility that services the majority of the city of Orange in NSW.  Orange STP utilises gaseous chlorination for disinfection, with the majority of the disinfected effluent pumped to the Cadia mine for re-use.  Changes in licence conditions made it difficult to simultaneously meet discharge limits for free chlorine residual and faecal coliforms.  A re-use risk assessment also suggested that additional barriers would be required to attain the degree of re-use safety that OCC desired.  An options report had narrowed the solution to providing UV as an additional barrier either upstream or downstream of the existing chlorination facility.  OCC commissioned a Reference Concept Design using ASpect as the client representative and independent technical reviewer.  The scope of the concept design was to further investigate the two shortlisted options, verify the future design flows and quality, confirm the pathogen log reductions required from each disinfection barrier, upgrading of the chlorination control, installation of UV, plus the incorporation of critical control points for re-use.  ASpect’s role was to write the brief, undertake a re-use yield assessment to determine the appropriate design capacity, call for and assess quotations, interface with the design team and review all deliverables including loadings, options assessment, equipment duties, P&IDs, operating and control philosophy, HAZOPs, and the draft reference concept design report.