For major road development projects, the big ideas that shape our overall approach to sustainability can be challenging to implement at a project level.

With long development timeframes and a complexity of stakeholders and project contributors, collecting these elements into a holistic approach can be difficult.

Project formulation and planning phases provide the best opportunity, however sustainable outcomes can also be achieved in detail design and construction phases.

The duplication of the Hume Highway in south western New South Wales (NSW) from Woomargama to Table Top shows how sustainability can be incorporated into a major road infrastructure project.

The Hume Highway linking Sydney and Melbourne forms a key component of one of Australia’s busiest inter capital road corridors. Approximately 67 kilometres of the 807 kilometre highway consists of single lanes in each direction. Most freight is moved by road, particularly overnight. Completing the duplication of the highway has major benefits in improved safety and freight efficiency.

In 2006, funds were committed by the Federal Government to complete the duplication of the highway so that there will be a high grade dual carriageway suitable for current and predicted freight and other traffic.

Upgrading the highway involves significant earthworks and associated engineering activities in a predominantly rural area that also has areas of significant remnant vegetation, habitat and heritage. Another important aspect is that this part of Australia is in the grip of long-term drought conditions, so availability of water is scarce.

Upgrading the highway poses many challenges in relation to balancing the development of a safe and efficient transport system, while maintaining the amenity of the area and minimising additional environmental and/or social stress.

Infrastructure agencies recognise the inherent tensions in reconciling the goal of sustainability with activities that initially present limited opportunities for sustainability. Agencies such as the NSW Roads and Traffic Authority (RTA) are seeking opportunities to incorporate sustainability principles in projects.

Assessments may be undertaken at the strategic level to consider the way a project contributes overall to sustainability goals and to ensure a strategic fit. At the concept level a range of options are considered against environmental, social and economic criteria.

However, project development, including route development and detailed environmental impact assessment, is where it will be most effective to investigate and identify key sustainability principles and opportunities.

The Hume Highway duplication involved rigorous and comprehensive assessment of route options, identification of potential impacts, and mitigation of impacts through route refinement and in the design of appropriate environmental management measures. 

Key considerations included traffic and transport efficiency, biodiversity, heritage, water management, community impacts and long-term and cumulative impacts.

To deliver the project successfully, the RTA decided to use an alliance framework, with the work being awarded to two alliances; the Northern Alliance and the Southern Alliance.

The Hume Highway Southern Alliance, comprising the RTA, Sinclair Knight Merz (SKM) and Abigroup, is delivering the Woomargama to Table Top section of the duplication.

Delivering Sustainability Within The Alliance Framework

The unique structure of the alliance team and the identification of key result areas for the RTA that go beyond traditional construction time and cost drivers provide the opportunity for prominence of sustainability in a road development project. The Hume Highway Southern Alliance Management Team comprises individuals with specific accountability for design, quality, construction, engineering, occupational health and safety (OHS), environment and sustainability. Each area has overall and equal commitment to the project’s outcomes.

This ensures that environment and sustainability performance is as crucial to the successful delivery of the project as other factors are.

Delivering the project as an alliance is a way of working that fosters collaboration and innovation. A diverse range of skills come together with the same goal in mind and this can promote the development of ideas that on other projects would be seen too difficult to implement, or the responsibility of others.

The alliance framework also opens communication channels that would otherwise not be available or most certainly more difficult to utilise.

The alliance is a significant adaptation to a way of working and opens the means to create a changed culture within the organisations involved. Culture change is a fundamental step in incorporating sustainable thinking into projects.

Importantly, the alliance culture provides opportunities to recognise and implement opportunities to achieve sustainability outcomes that are better than ‘business as usual’ and that do not necessarily increase costs.

Sustainability Outcomes

A sustainability workshop early in the project identified outcomes and objectives that would leave a legacy to the community, improve the sustainability of delivery methods for the project, and involved RTA personnel outside the Alliance in the development of the project, as well as other key stakeholders.

Water savings and rehabilitation of landfill waste are among key innovations achieved by the Hume Highway Southern Alliance, resulting in successful environmental management and sustainability.

Water is an essential component during construction of road works being used in compaction of earthworks, dust suppression activities and revegetation of the construction site. Due to the project’s large scale, significant volumes of water are required.

Preliminary hydrological investigations undertaken as part of the environmental assessment indicated there was a severe shortage of reliable water available in close proximity to the project.

Norske Skog Paper Mill (approximately 10km south west of the Project) was identified in this analysis as having a significant surplus of treated effluent and cooling water used in its paper milling process.

Working in conjunction with Norske Skog, the Hume Southern Alliance connected a pipeline from the irrigation system to the project alignment, transferring water to a series of interlinked storage dams. By using Norske Skog’s existing pumps and pressure within the irrigation system, minimal energy is required to transfer water to the construction site.

The recycled water from the Norske Skog facility is providing approximately 50 per cent of construction water, significantly reducing the reliance on Lake Hume.

The partnership with Norske Skog has also extended beyond the use of wastewater, with the use of bio solid materials. These materials are a bi-product of the paper milling process. This paper mulch-like product is being used during revegetation and for erosion control. This is beneficial reuse of an otherwise discarded product and consistent with achieving sustainable outcomes for the project.

Sustainability principles and practices used in the design and construction of the project site compound are reducing energy costs, with recycled water and rainwater harvesting significantly reducing the need to import potable water to the remote site.

Prior to construction, the Mullengandra tip was located under the new road alignment and contained burnt waste material and putrescible wastes that needed to be addressed.

The solution adopted included sorting material that could be recovered and recycled including metals and tyres, excavating and sieving the waste material to separate ash and soil for re-use in earthworks, with any remaining putrescible material then removed to the Albury landfill tip.

The outcome has eliminated the ongoing liability of a waste cell for the RTA, with an overall benefit to the local environment and the reduction of potential risks to the local surface and groundwater reserves.

There has been very effective collaboration between the environmental and design teams, along with the RTA environmental specialists to maximise the retention of Box Gum Woodland and minimise disturbance of heritage sites through alignment and cross section modifications.

The project has also made a very significant contribution to the Murray River Re-snagging Project, by donating felled trees and root balls.

Value engineering sessions identified drainage modifications to shorten the length of culverts that lowered cost and also reduced the length of underpass for fauna to cross through the corridor. 

The Hume Highway Southern Alliance has made a significant contribution to establishing, implementing and managing an environmental management system with innovations that demonstrate how sustainable construction principles can successfully be applied to road infrastructure projects.

© Sinclair Knight Merz
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