Kangaroo Island's new seawater desalination plant

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Updated desalination plant information

New desalination plant location and design

The new desalination plant site is being prepared as per the Development Application granted on 16 February 2022. The approved Development Application provided flexibility in design and siting of the desalination plant as conceptual plans evolve through to final design, within a defined boundary on the site near Hog Bay Road. The refinement from concept to detailed design has resulted in the following changes:

  1. The distance to the furthest edge of the site has been refined to approximately 195 metres resulting in an adjustment to the southern boundary of the plant site of approximately 10 metres. This means the built forms are moved approximately 50 meters south of the originally proposed location. This design balances geotechnical constraints with cost and constructability considerations, while enabling the building footprint to be retained and not to push further north towards neighbouring residents and remains within the site envelope shown in the Development Application.
  1. The floor level of the finished desalination plant will be at approximately 62.7 metres above sea level. The DA noted the elevation would be within approximately 1 metre of the original 61.15 metre elevation.

The plant will still be cut into the natural curve of the hill and the elevation is within the scope provided in the Development Application. This results in a difference of 3.4 metres between the highest point on Hog Bay Road and the final finished floor level of the plant building, which is consistent with the side elevation shown to Council recently, which noted a difference of up to 4 metres.

Additional hard and soft landscaping will provide additional screening.

Noise and acoustic treatments

Noise modelling undertaken to date predicts that noise output during operation will be minimal and will comply with the requirements of the Environment Protection Authority (EPA).

The desalination plant building will be lined with acoustic insultation that is deemed ‘fit for purpose’ by an acoustic treatment specialist. They have considered all factors related to the plant, including machinery, proximity to residential areas, existing noise modelling and predicted noise outputs. Details of the acoustic treatments will be shared when they have been finalised.

The noise output from the dry well pump will also need to comply with the EPA noise limits for this area and noise attenuation measures will be implemented to ensure that compliance is achieved.

Professional noise monitoring will be completed once the desalination plant is in operation to ensure it complies with all requirements, and to inform any remediation in the event of a non-compliance.

Maintaining the marine environment

The marine infrastructure for the new desalination plant will be built adjacent to the existing Penneshaw Desalination Plant’s infrastructure which has been in place for more than 20 years, with no evidence of impact on marine life in the area.

As a result of the new infrastructure being designed in line with contemporary practices and more modern technologies, it is expected that there will continue to be no detrimental impact to marine life in this location.

Ongoing monitoring of the marine environment to meet criteria set by the EPA is a condition of the Development Application, as well as the facility’s operational licences.

Landscaping, fencing and lighting

Excess soil has been deposited adjacent to our desalination plant site with permission of Kangaroo Island Council and they will determine the ultimate use of this area.

As detailed in the Development Application, a landscaping plan will be developed in conjunction with Council and the local community, to reduce the visual impact for the surrounding area.

Security fencing plans will be available on the completion of detailed design and will be shared with the local community.

To enable local input into the facility’s final design, an eight-person working group comprised of local residents and community representatives, was formed and has assisted with key selections for building and fencing materials and colours, and landscape design and screening vegetation.

Construction

John Holland Guidera O'Connor (JHGO) Joint Venture, who are our construction partner, has provided us with a copy of their Construction Environmental Management Plan (CEMP), which can be found here.


The project in a nutshell

We are constructing a new seawater desalination plant and distribution network on Kangaroo Island.

This plant will provide additional water security for the island, improve water quality management to ensure ongoing compliance to Australian Drinking Water Guidelines and expand the network to new customer areas with first water from the plant targeted to be delivered to residents in American River, Baudin Beach, Island Beach and Sapphiretown by the end of 2022.

The new desalination plant will also provide an additional climate independent drinking water supply, boost economic activity, and improve bushfire resilience.

Water produced from the new plant will supplement the existing Penneshaw facility and the Middle River Reservoir, supplying the Island through a connected drinking water network.

A new pipeline will have capacity to service residents in Baudin Beach, Island Beach, Sapphiretown and American River. Our engagement with these communities will explore opportunities and interest in connecting to this new drinking water supply with consultation informing where any new drinking water networks are laid.

To aid firefighting capabilities, we plan to install fire plugs every two kilometres along the trunk main and every 400 metres along the new pipelines in the new communities we aim to supply as part of this project. These fire plugs will allow access by the Country Fire Service for firefighting purposes.

The new desalination plant will produce as much as 80% of the Island’s current water requirements. This will allow for growth and an expected increase in demand.

Updated desalination plant information

New desalination plant location and design

The new desalination plant site is being prepared as per the Development Application granted on 16 February 2022. The approved Development Application provided flexibility in design and siting of the desalination plant as conceptual plans evolve through to final design, within a defined boundary on the site near Hog Bay Road. The refinement from concept to detailed design has resulted in the following changes:

  1. The distance to the furthest edge of the site has been refined to approximately 195 metres resulting in an adjustment to the southern boundary of the plant site of approximately 10 metres. This means the built forms are moved approximately 50 meters south of the originally proposed location. This design balances geotechnical constraints with cost and constructability considerations, while enabling the building footprint to be retained and not to push further north towards neighbouring residents and remains within the site envelope shown in the Development Application.
  1. The floor level of the finished desalination plant will be at approximately 62.7 metres above sea level. The DA noted the elevation would be within approximately 1 metre of the original 61.15 metre elevation.

The plant will still be cut into the natural curve of the hill and the elevation is within the scope provided in the Development Application. This results in a difference of 3.4 metres between the highest point on Hog Bay Road and the final finished floor level of the plant building, which is consistent with the side elevation shown to Council recently, which noted a difference of up to 4 metres.

Additional hard and soft landscaping will provide additional screening.

Noise and acoustic treatments

Noise modelling undertaken to date predicts that noise output during operation will be minimal and will comply with the requirements of the Environment Protection Authority (EPA).

The desalination plant building will be lined with acoustic insultation that is deemed ‘fit for purpose’ by an acoustic treatment specialist. They have considered all factors related to the plant, including machinery, proximity to residential areas, existing noise modelling and predicted noise outputs. Details of the acoustic treatments will be shared when they have been finalised.

The noise output from the dry well pump will also need to comply with the EPA noise limits for this area and noise attenuation measures will be implemented to ensure that compliance is achieved.

Professional noise monitoring will be completed once the desalination plant is in operation to ensure it complies with all requirements, and to inform any remediation in the event of a non-compliance.

Maintaining the marine environment

The marine infrastructure for the new desalination plant will be built adjacent to the existing Penneshaw Desalination Plant’s infrastructure which has been in place for more than 20 years, with no evidence of impact on marine life in the area.

As a result of the new infrastructure being designed in line with contemporary practices and more modern technologies, it is expected that there will continue to be no detrimental impact to marine life in this location.

Ongoing monitoring of the marine environment to meet criteria set by the EPA is a condition of the Development Application, as well as the facility’s operational licences.

Landscaping, fencing and lighting

Excess soil has been deposited adjacent to our desalination plant site with permission of Kangaroo Island Council and they will determine the ultimate use of this area.

As detailed in the Development Application, a landscaping plan will be developed in conjunction with Council and the local community, to reduce the visual impact for the surrounding area.

Security fencing plans will be available on the completion of detailed design and will be shared with the local community.

To enable local input into the facility’s final design, an eight-person working group comprised of local residents and community representatives, was formed and has assisted with key selections for building and fencing materials and colours, and landscape design and screening vegetation.

Construction

John Holland Guidera O'Connor (JHGO) Joint Venture, who are our construction partner, has provided us with a copy of their Construction Environmental Management Plan (CEMP), which can be found here.


The project in a nutshell

We are constructing a new seawater desalination plant and distribution network on Kangaroo Island.

This plant will provide additional water security for the island, improve water quality management to ensure ongoing compliance to Australian Drinking Water Guidelines and expand the network to new customer areas with first water from the plant targeted to be delivered to residents in American River, Baudin Beach, Island Beach and Sapphiretown by the end of 2022.

The new desalination plant will also provide an additional climate independent drinking water supply, boost economic activity, and improve bushfire resilience.

Water produced from the new plant will supplement the existing Penneshaw facility and the Middle River Reservoir, supplying the Island through a connected drinking water network.

A new pipeline will have capacity to service residents in Baudin Beach, Island Beach, Sapphiretown and American River. Our engagement with these communities will explore opportunities and interest in connecting to this new drinking water supply with consultation informing where any new drinking water networks are laid.

To aid firefighting capabilities, we plan to install fire plugs every two kilometres along the trunk main and every 400 metres along the new pipelines in the new communities we aim to supply as part of this project. These fire plugs will allow access by the Country Fire Service for firefighting purposes.

The new desalination plant will produce as much as 80% of the Island’s current water requirements. This will allow for growth and an expected increase in demand.

Kangaroo Island's long-term plan

In 2018, we released the Kangaroo Island long-term water security plan (the Plan).

The Plan was developed in consultation with key stakeholders, including local government, industry, environment, and community groups, and outlined a framework that will ensure we meet increases in water demand for Kangaroo Island for the next 25 years.

Opportunities and challenges identified in the Plan are balanced across a range of factors, both now and into the future with the aim to ensure a safe, secure and reliable water supply for current and future customers while keeping prices as low and stable as possible.

A number of options to ensure water security were considered during the development of the Plan with an additional desalination plant identified as the preferred option.

While the existing Middle River and Penneshaw water supply networks have adequate capacity to meet current needs and sustain organic growth until about 2036, warm and dry conditions, along with the recent bushfires, has seen an increase in demand placing stress on the Middle River Reservoir.

In response, we are now accelerating the recommendation of the Plan to construct a new desalination plant at Penneshaw along with a new pipeline and associated infrastructure that will connect to the existing Middle River-Kingscote water supply network.

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Page last updated: 15 Jun 2022, 09:15 AM