NorthLink WA
NorthLink WA will take the pressure off the Great Northern Highway by shifting the majority (around 80%) of heavy vehicles over to the new route. It has been designed to cater for the traffic volumes associated with a future Perth population of 3.5 million. The Federal and State Governments have invested $1.12 billion in NorthLink WA, which will improve freight capacity, efficiency and productivity as well as reduce urban congestion now and into the future. It will improve road safety in line with the State’s ‘Towards Zero’ policy whilst maximising sustainability through economic, social and environmental responsibility.
eTool were engaged by John Holland to perform an Life Cycle Assessment (LCA) for the Southern Section as part of the Infrastructure Sustainability (IS) Rating. The contract between the end client Main Roads WA and John Holland required an Excellent IS Rating and eTool Life Cycle Design Services helped provide evidence to multiple credits and additional value on integrated design. John Holland and eTool have worked together in the past and are now collaborating in infrastructure projects, working together with ISCA. The LCA helped identify key impact areas for the whole project over it’s life cycle including initial construction, operations and end of life impacts. Initial focus was on construction impacts and given the nature of the project, other impact areas like lighting and product durability & maintenance were highlighted.
John Holland Sustainability Manager, Patrick Ilott said “eTool’s Life Cycle Assessment helped us better understand the impacts of our work. The net result was improved decision making and better outcomes“.
Sophie Wallis, Strategy & Sustainability Consultant at Upthink who also worked on the project said “By bringing together the calculations for energy, materials and water into one tool, eTool allowed us to see the project impacts from different perspectives. We could see how changes to one area would impact on others, and to prioritise the most effective treatments“.
Infrastructure Sustainability Council of Australia (ISCA) who manages IS Rating had to review the LCA and validade the project data and assumptions to meet the technical evidences required. ISCA approved the LCA approach following worldwide direction on integrated analysis with long term strategy on environmental sustainability.
- Client: John Holland
- Location: Northern suburbs of Perth, Western Australia
- Date: September 2016
Results Summary
Multiples credits used Life Cycle Assessment approach to provide technical evidence including:
- Man6 – Knowledge Sharing
- Man7 – Decision Making
- Ene1 – Energy and Carbon Monitoring and Reduction
- Ene2 – Use of renewable energy
- Mat1 – Materials Lifecycle Impacts Monitoring and Reduction
- Wat1 – Water Use Monitoring and Reduction
- Wat2 – Replace potable water
- Innovation
IS Enviro Points are weighted and normalised results for multiple impact indicators including Global Warming Potential, Abiotic Resource Depletion, Eutrophication Potential, Acidification Potential, Ozone Depletion and POCP.
The lower the total Enviro Points results in lower overall project environmental impacts.
| Description | % Reduction | |
| Total Enviro Points | 17% | |
| Materials | 22% | |
| Water Consumption | 26% | |
| Operational Energy | 10% | |
| Construction Energy | 13% | |
Project features
A Life Cycle Design process has been completed for the NorthLink Southern Section Infrastructure project. The Life Cycle Assessment of the Project has shown an overall reduction in the IS Enviro Points of 17% from the Base case to the 100% design. This is due to the implementation of several environmental initiatives through the detailed design phase.
Functionality
Increased design life of the main pavement type in project has reduced the environmental impacts associated with the maintenance and refurbishment. The 100% design pavement is modelled such that the top 30mm is replaced every 14 years and every 28 years both the top 30mm and the next 40mm is replaced.
Reduced concrete consumption – reduced depth of piles Reduced steel consumption – Collier Road Bridge design
The initial design of the concrete piles had the depth at 20m. Favourable geotechnical results have allowed a reduction to a length of 14m.
Reduced steel consumption – Collier Road Bridge design
The proposed design for the Collier Road bridge has improved on the base design, reducing the quantity of steel required by 522 tonnes. The design uses post-tensioned concrete beams with insitu concrete deck.
30% Blast furnace slag cement replacement in all major concrete elements
The manufacturing process for cement produces substantial greenhouse gas emissions. By using blast furnace slag, which is by product of steel production, as a cement substitute, it is possible to reduce the environmental impact of concrete.
Use of renewable energy
During the life cycle design process, the options for solar PV were investigated. This process began with a consideration of the operational energy profile and demand. Providing renewable energy for components of the infrastructure was considered, such as the main alignment lighting and eliminated for practical reasons. Solar power for smaller elements such as the vehicle management system and underpass lighting were also considered.
Environmental Initiatives
A number of environmental initiatives that were studied in the early stage of the design have since been implemented in the Issued For Construction (IFC) design, these include:
• Lighting controls
• Increased pavement design life
• Fuel efficiency standards for construction equipment
• Designing out of irrigated landscaping on main alignment
Materials
The Life Cycle Assessment provides a holistic assessment of the environmental impacts of the whole project over it’s whole of life. Within the LCA, all significant building products and materials are accounted for.
Key Initiatives that decrease the environmental impacts associated with the use of materials in the Project include;
• Asphalt design life of 100 years
• Noise wall design life of 100 years
• Barrier design life
• EME Asphalt pilot
• Lean design of bridges at the intersections with Collier Road, Morley Road and Benara Road
• Reduced extent of noise wall, pit and pipe, retaining walls
• Lower Impact Concrete – using Blast furnace slag to reduce Portland cement content
This assessment was conducted by Tom Beckerling and certified by Henrique & Richard from eTool.
