Transurban, its contractors and partners also monitor environmental metrics including water and waste management as key performance indicators during construction and operation.
A large portion of our water usage and potential environmental impact from water is in our tunnels. Underground tunnels experience ingress from the surrounding groundwater table, which we collect and treat before discharging back into waterways. In our CityLink tunnels in Victoria, we also recharge this treated water back into the groundwater aquifer to maintain appropriate aquifer conditions near our assets.
Potable water use on our assets generally includes irrigation, tunnel wall-washing and asset cleaning purposes. There is also potable water usage in our offices.
Bulk material consumption and waste primarily arise from the construction phase of our road assets, where we set sustainability standards for contractors - such as IS ratings - to encourage the use of recycled materials and minimise material use and waste generation. This may include requiring certain percentages of recycled materials to be used in construction, as well as ensuring minimum percentages of major project waste are recycled. This is particularly relevant for bulk materials such as crushed rock, concrete, steel, soil and plastic which are highly reusable and recyclable materials.
Water and waste impacts and discharge are closely regulated on each of our assets, and Transurban follows Operational Environment Management Plans to ensure appropriate handling and disposal in line with these requirements.