Dredging Solutions
A breakthrough report on the effects of dredging has helped build confidence for environmental regulators.
A REPORT on one of the largest single-issue environmental research programs in Australia, compiled after gaining unprecedented access to industry dredging data, has been recognised as a ground-breaking step forward for environmental regulation.
“Strategic Integrated Marine Science: Dredging - new knowledge for better decisions and outcomes”, a synthesis of research from the WA Marine Science Institution Dredging Science Node, was released by WAMSI CEO Luke Twomey at the AMSA Conference in Fremantle, WA, recently.
The findings from the five-year study are expected to contribute to increased confidence, timeliness and efficiency of the environmental approval and regulatory processes associated with dredging projects, ultimately expected to reduce the cost to government and industry.
Over the past decade there have been a number of large scale dredging projects in WA alone.
As part of the environmental approval of these projects, the dredging proponents collected considerable amounts of environmental monitoring data for two main purposes: to support the environmental impact assessments and to support compliance monitoring of the environmental approval conditions (through implementation of dredge management plans).
According to WA Environmental Protection Authority chairman Tom Hatton, it’s estimated that monitoring and management costs can exceed $100m on a major dredging program in addition to the predictive uncertainty of risks to the environment itself.
“This program has delivered on its promise in full and in a form that has increased the confidence, timeliness and efficiency of the environmental approval and regulatory processes associated with dredging projects,” Dr Hatton said.
Woodside Energy chief environmental scientist Luke Smith said the $19m program – $9.5m of which came from industry offsets – had delivered a valuable set of information on environmental dredging thresholds.
“The Dredging Science Node was valuable for industry and the state – it provides important technical data to improve our environmental impact assessments and support industry approval documentation,” he said.
“By bringing together the key stakeholders – state, industry, ports and research agencies – we maximised the available funding and the scientific knowledge that came from the Node.
“This knowledge will support better and more concise dredging-related environmental impact assessments moving forward.”
Project details
The WAMSI Dredging Science Node was a strategic research initiative that evolved in response to uncertainties in the environmental impact assessment and management of large-scale dredging operations and coastal infrastructure developments.
Its goal was to enhance capacity within government and the private sector to predict and manage the environmental impacts of dredging in WA, delivered through a combination of reviews, field studies, laboratory experimentation, relationship testing and development of standardised protocols and guidance for impact prediction, monitoring and management.
For the five most recent capital dredging projects in WA, some $250m was spent by industry on the collection of environmental monitoring data before, during and after dredging.
The Node’s 114 scientists from 26 research organisations gained unprecedented access to environmental monitoring data on four large-scale capital dredging projects in the Pilbara region: the Pluto LNG project at Burrup Peninsula (Woodside), Cape Lambert A and B projects (Rio Tinto), the Gorgon project at Barrow Island (Chevron), and the Wheatstone project at Onslow (Chevron).
This included information on both the physical environment (e.g. water quality and sediment deposition) as well as the biological environment (e.g. the health of the coral reefs, seagrass beds and other benthic habitats).
There was considered to be great value in learning from these successive dredging projects and applying that knowledge to future projects but, until recently, this has been hampered by the fact that the data was treated as ‘ commercial in confidence’ and hence not available to other proponents and the scientific community.
The reports states that a corporate commitment to share monitoring datasets can lead to accelerated learning and improvements in impact prediction methodology, greater certainty in decision making and a streamlining of approvals processes and monitoring requirements.
Since 2010, approval conditions in WA require that proponents make the Node’s environmental monitoring data publicly available.
But that left two underlying issues, according to the report.
Firstly, there was no capacity within government to collate and analyse the data so the ability to value add to the existing knowledge base was limited. Secondly, there remained a large amount of valuable data collected pre-2010 that could be of enormous value.
A desktop exercise identified past, present and future (pending approval) dredging projects in tropical northwest Australia and evaluated the potential of any available monitoring datasets, ancillary studies and other relevant information.
The respective proponent companies were approached individually to negotiate access to data.
These negotiations were complex, requiring considerable time and effort, with multiple levels of approval within each company, partly due to fear of potential legal implications (the potential for post-project discovery of non-compliance issues and associated issues of liability and indemnity), but all eventually agreed.
Data sharing agreements were developed between WAMSI and the companies to govern the use of the datasets for relevant research activities.
This constituted an unprecedented breakthrough, as environmental monitoring data of this detail and scale had never been made publicly available before in Western Australia.
Access to these valuable monitoring datasets enabled the scientists to turn data into information for use in many different individual projects and themes, and provided an immense source of detailed information that would feed into improving the ability to predict and manage the effects of dredging.
WAMSI Dredging Science Node leader Ross Jones said the group had brought together a raft of scientific literature on sediments in the water column in relation to dredging.
“Little of the available research on sediments was able to be used by dredging proponents and regulators to adequately assess risk, so we have designed the Node as a tool that gives industry and regulators greater confidence to better predict environmental outcomes around dredging,” Dr Jones said.
Dr Twomey said the more than 55 scientific publications produced by the Node so far was an extraordinary achievement for the investment, and would go a long way towards much more informed debate and decision-making on how best to predict and manage the potential impacts.
Dredging results in use
Key findings from the project have been incorporated in the newly published Maintenance Dredging Strategy for Great Barrier Reef World Heritage Area Ports by the Queensland Government, a dredging management plan for maintenance dredging in Darwin Harbour (INPEX), a series of Sustainable Sediment Management Studies underway at various ports in northern Queensland (commissioned by the North Queensland Bulk Ports Corporation), and in a forthcoming publication by PIANC on Best Practice Guidelines for Dredging and Port Construction near Coastal Plant Habitats.
Internationally, relevant findings of the Node are being incorporated into dredging programs in the USA, the Netherlands, Monaco, South Africa, Kazakhstan and Saudi Arabia.
The new insights from the program are now being translated into improved dredging guidelines that will serve to streamline monitoring by focusing on the relevant and most sensitive aspects and help to improve the effectiveness of management approaches to minimise the hazards from dredging.
New guidelines for dredge plume modelling are being developed by CSIRO. The guidelines focus on establishing a consistent and sound approach to the modelling of dredge plumes for predicting the pressure field of suspended sediments when seeking environmental impact assessment approval.
The WAMSI Dredging Science Node has been shortlisted for the WA Department of Mines, Industry Regulation and Safety’s 2019 Golden Gecko Award for Environmental Excellence, which recognises outstanding contributions to innovation and environmental outcomes in the resources sector.