Southern Water Treatment Plant

Membrane Replacement Review

Project Description
Dunedin City Council requested a review of options for the replacement of the membranes at the Southern Water Treatment Plant.

Services Provided
Fluent Solutions was engaged to investigate the timing and procurement options for the replacement of the membranes at the Southern Water Treatment Plant.

Specific services included:

• Review of existing membrane performance
• A full flow trial
• Investigation into the availability of alternative membranes for retrofitting the plant
• Discussions with membrane suppliers and users on their experience with membrane replacement
• Cost estimates and reporting

Challenges
Membrane performance relates to the ability of the membrane to remove particles and pathogens from the raw water at the required flow rates, while limiting the frequency of cleaning and the use of cleaning chemicals. As membranes age, there is a breakdown of the fibres and a decrease in effective particle removal. Identifying the condition of the membranes and the timing and programming for their replacement is site specific requiring careful consideration of all parameters.