Marine Environment

Research has shown that there are no significant impacts on seawater quality or aquatic ecology from the seawater concentrate.

Protecting the Ocean and Botany Bay

Structures on the seabed off the Kurnell coast draw seawater into a tunnel and then into the plant. Seawater concentrate returns to the sea through another tunnel and then disperses via specially designed nozzles.

 

A Marine and Estuarine Monitoring Program was conducted to protect the ocean and Botany Bay. The six year program provided information on seawater, ecology and marine life in the affected areas before, during and after construction.

 

Research has shown that there are no significant impacts on seawater quality or aquatic ecology from the seawater concentrate beyond the near field mixing zone. The research also confirmed that there is minimal toxicity impact on seawater quality or aquatic ecology from operations within the near field mixing zone.

 

Take a look at the seawater outlet during operation. 

 

 

Marine and Estuarine Monitoring Program 

As part of the desalination project, the Marine and Estuarine Monitoring Program (MEMP) was developed to protect the Ocean and Botany Bay. The six year program provided information on seawater, ecology and marine life in the affected areas before, during and after construction. The program is one of the most comprehensive and extensive of its kind in the world. It was designed in consultation with government departments and was reviewed by a panel of experts.

 

It was a requirement of the project's planning approval that there were no significant impacts on seawater quality or aquatic ecology from the seawater concentrate beyond the near field mixing zone and toxicity impacts within the near field mixing zone during operation were minimised.

 

In April 2005, Sydney Water collected seawater samples in the ocean off Kurnell during varying weather and ocean conditions. For more than a year, fortnightly water samples were taken from the ocean surface, and close to the seabed, where the intake and outlet structures were placed.

 

Currents, temperature and salinity were logged and measured in the ocean around the area where the outlets would disperse the seawater concentrate. This information became the baseline against which the future performance of the outlet system dispersing the seawater concentrate would be measured.

 

The types of fish and other marine life were surveyed regularly. This information was matched against future surveys when the plant began operations and also after operations ceased.

 

The program’s methodology was independently reviewed by experts from the CSIRO, UNSW and UTS and endorsed as robust. The program was designed to detect a change of 10% in the marine environment with 80% confidence. This was leading edge analysis.

 

The MEMP concluded in 2014 and the research has shown that, once dishcarged to the ocean, the seawater concentrate returns to normal temperature and salinity within 50 - 75 metres from the outlet. This is called the near field mixing zone. It has been found that there are no significant impacts on seawater quality or aquatic ecology from the seawater concentrate beyond the near field mixing zone and minimal impact within near field mixing zone during operation.  

 

Environmental Monitoring Programs

Marine and Estuarine Monitoring Program (PDF, 0.5 MB) 

Marine Water Quality and Ecosystem Environmental Management Plan (PDF, 0.2 MB)

Beach and Foreshore Monitoring Program, Botany Bay Sector (PDF, 1.8 MB)

Ecosystem Monitoring Program, Botany Bay Sector (PDF, 1.6 MB)