New Plymouth District Council
The design selected had the lowest cost of ownership and was considered to be the safest option. The dosing and control system were simplified.
Process Design, Contact Preparation, Commissioning
The final disinfection system at the New Plymouth wastewater treatment plant prior to sea discharge is sodium hypochlorite dosing. The hypochlorite storage tanks were aged and required replacement. Lutra were engaged to review alternative disinfection options and determine the optimum long term solution. The conclusion was to continue with sodium hypochlorite dosing but to simplify the batching and dosing infrastructure to make a more robust system that was easier to operate and better covered the very wide duty envelope.
Lutra were subsequently engaged to develop the contract for replacing the tanks and will be assisting NPDC with installation and commissioning.