National Assessment Guidelines for Dredging 2009

About the publication

A healthy marine environment is essential for Australia's current and future well being. Australia has entered international agreements and implements legislation to help preserve marine ecosystems and prevent marine pollution.

The international agreement relating to the dumping of wastes and other matter in Australian waters, including dredged material, is called the London Convention and Protocol. Australia implements its obligations under the London Convention and Protocol through the Commonwealth Environment Protection (Sea Dumping) Act 1981 (the Sea Dumping Act).

Through the Sea Dumping Act, the Australian Government assesses proposals to load and dump wastes and other matter at sea, permits acceptable activities, and places conditions of approval, to mitigate and manage environmental impacts.

The National Assessment Guidelines for Dredging set out the framework for the environmental impact assessment and permitting of the ocean disposal of dredged material. The framework includes:

• evaluating alternatives to ocean disposal
• assessing loading and disposal sites
• assessing potential impacts on the marine environment and other users, and
• determining management and monitoring requirements.

The Guidelines are intended to provide greater certainty about the assessment and permitting process as well as provide some guidance on opportunities for longer-term strategic planning. These Guidelines should be read in conjunction with the Sea Dumping Act and its Regulations, the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), the Great Barrier Reef Marine Park Act 1975 (GBRMP Act) and Australia's international obligations outlined in the London Protocol.

Clarification of the National Assessment Guidelines for Dredging 2009 on tributyltin (TBT)

Tributyltin (TBT) is a toxic and persistent marine environmental pollutant. TBT is present in anti-fouling paint flakes found on boats and other marine structures. As such its distribution in marine sediments is often concentrated or localised in harbours, ports, and other potential dredge sites.

Due to the nature and distribution of TBT within marine sediments, the National Assessment Guidelines for Dredging refers to some exceptions when assessing for TBT. These exceptions are summarised in the below explanatory note and decision tree. Refer to this decision tree in place of Figure 3 of the Guidelines (page 12) when assessing TBT.

Decision tree and explanatory note for assessment of tributyltin (TBT) in dredge spoil (PDF - 1.13 MB)
Decision tree and explanatory note for assessment of tributyltin (TBT) in dredge spoil (DOCX - 392.52 KB)