What were the options?
In response to suggestions from the Port Fairy Pipeline Support Group, an additional detailed comparison was completed of the options to connect Port Fairy to the Otway Water Supply System.
Local treatment
This option would include adding filtration (reverse osmosis) to the existing local groundwater supply to reduce the salt content.
Pipeline
This option involves the construction of a pipeline to connect Port Fairy to the Otway system via the Warrnambool Water Treatment Plant. Three alternative pipe routes have been considered:
- Koroit
- Princes Highway
- An alternative route via Koroit.
How do the options compare?
We engaged engineering consultants GHD to compare the options and assess them using a range of criteria, including all elements raised by the Port Fairy Pipeline Supply Support Group.
A summary of the preferred option according to assessment criteria is provided below.
Need more detail? Simply click on the animated dots below for more information on each criteria.
What was the outcome?
Each option had strengths, however the local treatment option was the recommended approach based on all the assessment criteria. This included the lower costs involved, the greater reliability of both water quality and water security, less upstream impacts on the environment, and greater flexibility for the future.
We also sought feedback from customers and interested stakeholders over several weeks. The results were overwhelming, with more than 75 per cent of people saying they love the project, and the majority favouring local treatment as the preferred option.
Frequently asked questions
Take a look through the frequently asked questions related to the options for Port Fairy.
A detailed analysis of the characteristics of the local groundwater supply has been completed as part of the options assessment and the design work we’ve already completed.
The filtration process we plan to use to remove salt is commonly used to produce high quality drinking water that tastes great.
When we reduce the amount of mineral salts in the water supply, we expect that corrosion of household appliances will be dramatically reduced consistent with experience in other areas where the water quality is better.
When we reduce the amount of mineral salts in the water supply, we expect that car washing will be free from streaks consistent with experience in other areas where the water quality is better.
A routine maintenance program will ensure the filtration plants continue to work well. Routine maintenance is a normal part of operations at all our existing water treatment plants. The filters undergo regular automated cleaning as part of normal plant operations, and from time to time they need replacing.
Ongoing maintenance costs have been allowed for in our planning.
Filtration will remove naturally occurring mineral salts in the groundwater. Known as ‘brine reject’, this removed salt will be sent to mix with the salty ocean through our licensed discharge points at Portland and Port Fairy.
According to the options assessment, local treatment will subtly change how the outfall operates as overall volumes increase, and there may be periods where bring reject is the only discharge.
This change may prompt the need for formal EPA approvals, including revisiting the existing Port Fairly STP discharge licence
As part of the federal funding agreement, water quality improvements in all three towns need to be completed by 2029. We won’t have a specific timeline until the design and approvals are finalised.
The options assessment shows the indicative energy consumption for local treatment at Port Fairy is 550 Megawatt hours a year compared to the pipeline options which ranged from 710 to 810 MWh/y.
The local treatment option allows installed capacity to better match demand, providing a more efficient investment. Demand growth can be accommodated with modular increases if required.
The local treatment option allows installed capacity to better match demand, providing a more efficient investment.
The demand for recycled water will in part depend on its quality. For most re-use applications, a key consideration is salinity. In general, lower salinity recycled water is preferred for uses including irrigation on farms and recreation facilities.
The options assessment states that the salinity of sewage at the sewage treatment plant is expected to be about 1,100 mg/L for both the pipeline and the local treatment options. The additional benefits of water with this level of salinity is likely to be marginal given that water is relatively abundant in the region from low-cost sources such as local groundwater.
