Cabramurra STP Process Assessment

  • ASpect’s Client: Snowy Hydro
  • Head Client: Snowy Hydro
  • Plant Configuration: SBR
  • Plant Size: 1000 EP
  • Project Value: $19k (ASpect Fee $19k)
  • Project Duration: February 2018 to Ongoing

Cabramura STP Process Assessment (SBR), for Snowy Hydro (NSW).

Cabramurra is located within the Kosciusko National Park.  It is the highest township in Australia and is fully owned by Snowy Hydro (SH) as workforce accommodation.  In winter, it is snow covered and access on icy roads can be problematic.  These cold temperatures, difficulty of access and highly variable sewage load make it one of the more difficult plants in Australia to operate.  The plant consists of a sewage balance tank, a heated SBR bioreactor, tertiary filters, UV, effluent storage, sludge storage, carbon dosing and phosphorus precipitation.  Cabramurra was having difficulty maintaining its strict licence conditions.  Tankers were being used to transport treated effluent to other plants.  This was a high cost and high risk exercise given the icy winter road conditions.  On a suggestion from the NSW EPA, SH engaged ASpect to undertake a process assessment of the plant.  Based on advice from ASpect, SH reconfigured the operation of the SBR and modified the control logic.  This improved denitrification performance as well as nitrification response to the variable loads.  SH also undertook an equipment audit and renewals programme, identifying and rectifying a few critical failures.  This, combined with regular process training and advice from ASpect, resulted in the plant meeting all discharge criteria, even during winter, allowing it to resume discharge to the sensitive alpine waters.