Sustainability

Sustainability is at the heart of the design and delivery of Suburban Rail Loop (SRL) and is embedded across all parts of the project – from planning and construction all the way through to operations.

With tunnelling of SRL East between Cheltenham and Box Hill now underway, here are some of our sustainability objectives and actions already in place to help build a greener future.

Leadership

Ratings systems

SRLA uses rating systems to drive, verify, and benchmark progress in sustainability during planning, design, and construction.

SRL East contractors are working to achieve a gold design rating from the Infrastructure Sustainability Council (ISC) for the tunnelling works, and we continue to work with the Green Building Council of Australia (GBCA). All stations will target a 5-star Green Star rating.

Ground freezing

An innovative ground freezing technique is being used to build some of the safety passages between the twin tunnels, avoiding the need for ground treatment from the surface. This will reduce disruption to residents and roads on the surface by more than 90%. This approach also reduces emissions and material requirements.

The ground freezing technique involves pipes drilled deep underground and injected with chilled brine (salt and water). The brine will temporarily freeze the surrounding soil – stabilising it and making it safe for our teams to build the safety passages.

Energy and carbon

Electric plant and vehicles Powered by renewable electricity, our crews are using electric vehicles on site, cutting noise and air pollution. As of mid 2026, electric vehicles, machinery and equipment have saved an estimated 166,000 litres of fuel across Tunnels South and North.
Powered by renewables All tunnel boring machines used on SRL East will be powered by 100% renewable electricity. The fleet of new SRL trains will also be powered by 100% renewables.

Low carbon concrete alternatives

An innovative low-carbon concrete mix using calcined clay has been trialled applied across SRL East sites at Glen Waverley, Heatherton, Clayton and Monash.

Calcined clay replaces a portion of the cement traditionally used in concrete, significantly reducing the material’s embodied carbon while maintaining the performance needed for construction.

Electric crawler crane

A 250-tonne electric crawler crane is being used at the SRL East site at Heatherton, helping reduce emissions from construction activities.

Unlike conventional diesel-powered cranes, the electric crawler crane can operate using mains electricity – reducing fuel use, greenhouse gas emissions and noise on site.

Water

Reducing water use

Since the earliest phase of construction of SRL East, polymer dust suppressants and binders have been used to stabilise soil and reduce dust during works on site. This technique is non-toxic, biodegradable and reduces water use.

Where possible, non-potable water is being used during construction and operation – including additional targets for use in station buildings and the train stabling facility.

Materials & Waste

Concrete hardstand

Recycled concrete hardstand – a type of pavement – is being used at the tunnel boring machine launch site at Clarinda to reinforce the ground so it can withstand heavy loads from trucks and equipment. Each layer of pavement is made from recycled materials including asphalt, ceramics and crushed concrete.

Noise walls

Walls made from recycled plastic milk bottles are helping reduce noise from ventilation fans at the tunnel boring machine launch site in Burwood. The walls and acoustic materials inside them can also be recycled.

Guard barriers

In an Australian first for a major infrastructure project, 100% recycled ‘crumb rubber’ barriers are being used at the SRL East Heatherton and Clarinda sites. The barriers are made from recycled tyres – each one is made from approximately 56 passenger vehicle tyres.

Recycled asphalt

A low-carbon asphalt mix incorporating recycled materials is being used to build internal haul roads at the SRL East Burwood construction site.

The asphalt is made with soft plastics, waste glass, used printer toner, tyres and reclaimed pavement. This mix has diverted 260,000 plastic bags from landfill and saved an estimated 3.9 tonnes of greenhouse gas emissions compared with traditional hot mix asphalt.

Silt socks

Silt socks are used on construction sites to catch dirty water and debris following rain, and are 100 per cent recycled, made from temporary banner mesh and reclaimed aggregate.

Image shows recycled rubber guards on SRL worksite — Recycled rubber guards

Large recycled rubber guards being used on SRL worksite. — Recycled rubber guards

Image shows recycled concrete hardstand being used on SRL site — Concrete hardstand

Image shows recycled and reusable noise walls being used at SRLs Burwood site — Noise walls

Kids playing basketball in Claytons new open space. — Recycled surface

Transport & mobility

Traffic safety

In preparation for major construction, we built and upgraded traffic signals and streets, and moved and upgraded walking and cycling paths in the neighbourhoods around the new SRL East stations. These works will ensure traffic, pedestrian and cycling safety during major construction of SRL East. The 109 tram terminus in Box Hill was also moved and upgraded to ensure tram services can continue while SRL East is being built.

Sparkles on a bike sustainability

Community & social legacy

Tiny Tunnellers Program

The Tiny Tunnellers Program is helping primary school children along the SRL East route to learn more about science, technology, engineering and mathematics, and explore future careers in construction, engineering and infrastructure.

The program was first piloted in 2025 by Suburban Connect, the consortium delivering SRL East Tunnels South, and in partnership with SciencePlay Kids. In 2026, more than 900 students from 10 primary schools participated in hands-on, fun and interactive sessions – developing problem-solving skills and learning more about the giant machines now building SRL East.

Social procurement and local impact

SRL East delivery partners have minimum targets for the employment of Victorian First Peoples, women, priority jobseekers, and apprentices, trainees and cadets. Targets are also set for their procurement from social benefit suppliers; Aboriginal-owned and managed businesses, and social enterprises. This is aligned with Victoria's Social Procurement Framework, Building Equality Policy and Local Jobs First Policy.

So far, our delivery partners have engaged more than 116 certified Victorian social benefit suppliers in civil construction, surveying, traffic management, and training and education services – including 71 Aboriginal-owned and managed businesses, and 44 social enterprises.

Amarapave

Amarapave is a Victorian asphalting business providing supportive career pathways for women, non-binary people, and other under-represented groups in construction. Amarapave is delivering asphalting works at the SRL for Tunnels South contractor Suburban Connect.

Since joining the project in 2024, Amarapave has worked on the Clayton, Monash and Heatherton sites, including asphalting car parks and re-sheeting existing roads to enable smooth operation.

Panku Safety Solutions

Panku Safety Solutions is an Aboriginal-owned business supplying SRL workers on Tunnels South between Cheltenham and Glen Waverley with specialist personal protective equipment (PPE) and tailored support – including gloves and PPE vending solutions.

CareerSeekers partnership

CareerSeekers is a social enterprise addressing employment barriers faced by refugees and asylum seekers.

Five employees who arrived in Victoria as refugees are now working for Tunnels North contractor Terra Verde, which is building the twin tunnels between Glen Waverley and Box Hill.

Australian Spatial Analytics

Tunnels South contractor Suburban Connect has partnered with social enterprise Australian Spatial Analytics (ASA) to create jobs and career pathways for neurodivergent people in the data sector. The 12-month supported work placement on SRL provides entry-level roles in geospatial and digital engineering, supporting neurodivergent people to apply and develop their unique skills and strengths on-the-job.

All women tunnelling crew

The world’s first all-women tunnel boring machine crew is already breaking down barriers and creating new pathways for women in construction.

More than 900 women applied to be part of the tunnelling team. 25 members of the crew are now on board, and undertaking specialist training at the Victorian Tunnelling Centre in Chadstone, as part of a 3-year TAFE course

With tunnelling now underway, crew members will initially be spread across SRL tunnelling operations to gain valuable on-the-job experience. From 2027, the all-women crew will come together as a team.

Environmental protection & enhancement

Tree planting

More than 4000 trees are being planted as part of SRL East to create cool, green and inviting spaces in the areas around the new SRL East stations – with planting already underway.

As part of initial and early works and in partnership with Kooyongkoot Alliance, 500 native plants were planted along Gardiners Creek in 2025 – supporting biodiversity and restoring habitat.

New native trees for Box Hill and Burwood

We’re creating greener, shadier spaces in Burwood and Box Hill, with 750 new native trees being planted in Burwood and Box Hill – well before Suburban Rail Loop (SRL) East is complete.

Buzzing burbs

'Buzzing Burbs' is a program to create more friendly places for native pollinators including birds, bees, bats, butterflies, and other wildlife in the SRL East neighbourhoods.

This will support healthy ecosystems, biodiversity, climate resilience and habitat connectivity.

The program has helped plant more than 5000 native plants and grasses in areas around the new SRL East stations.

Resilience and climate change

SRL East will be designed to be resilient to climate change and natural hazards and to support a resilient transport network.

Our tunnelling contractors for SRL East have completed a Climate Change Risk Assessment and prepared a Climate Change Resilience and Adaptation Action Plan, with ongoing integration of risks and mitigation measures.

Want to learn more about sustainability on SRL?

Check out our latest sustainability report

Clayton March 2025 render sustainability