Production of high quality solar salt relies on a healthy environment. It is therefore vital that through our activities we, in turn, respect and take care of that environment.
The long term success and sustainability of our business depends on how well we manage our impacts and maximise our opportunities to protect the environment. The Dampier Salt ‘One Business’ policy and the Rio Tinto environment standards, provide the framework for how we manage our potential environmental impacts.
Water is a vital resource for communities and ecosystems and is essential to our operations. Sea water is Dampier Salt's source of salt production*. For this reason it is monitored and measured at every step of the process.
Bitterns, which is seawater outflow from the production process with 70 per cent of the NaCl salt removed, is discharged to the sea under approved conditions for two sites and into an evaporation pond at the third site.
The use of potable water is minimised as far as practicable in the production process, replaced with sea water where possible. Depending on the site, potable water may be used in flushing pumps and in the final rinse when washing equipment.
We continually look for ways to reduce potable water use. Dampier Salt has set ambitious targets to reduce potable water use and has implemented projects to substitute up to 50% of our potable water with seawater supply at our Dampier operations.
*Our Lake MacLeod operation draws salt water from an underground saline aquifer, however this is originally sourced, and replenished by the ocean.
In 2018 Rio Tinto implemented a new biodiversity protection and natural resource management standard, with external input from partners including BirdLife International, IUCN, and Fauna & Flora International. The standard seeks to minimise our impact by balancing conservation needs with development priorities through four key actions. Our first priority is to avoid having an impact, after which we seek to minimise, restore, and finally offset those impacts that do arise.
Dampier Salt operations are somewhat unique in a mining context because all three of our sites are recognised as being important for biodiversity. Port Hedland, Dampier and the northern part of Lake Macleod are designated Important Bird Areas (IBAs) due to globally important numbers of shorebirds which are resident at or visit the sites on their migratory journey’s from the Northern hemisphere.
Biodiversity also extends to the plant life at our operations. Our Lake Macleod site contains inland saltwater ponds that are fringed by one of the largest inland populations of grey mangrove. It is one of only three such occurrences known in the world.
During our mining and processing operations, we generate both mineral and non-mineral waste. In order to limit the negative environmental impact of our waste, and reduce our operating costs and risks, we focus on characterising, planning and managing waste effectively.
Rio Tinto have mineral waste and non mineral waste standards that we follow to ensure waste is minimised and where appropriate, properly disposed.
Greenhouse gas emissions
Rio Tinto recognise the need to understand and adapt to the physical impacts of climate change, which will affect our operations, particularly through the potential increase in extreme weather events. We believe that global energy and climate challenges are best met by companies, governments and society working together. Our strategy is to maximise shareholder returns by making our assets more resilient against uncertain carbon and energy market risks.
Dampier Salt is a low energy intensity business compared to the overall minerals industry. Our operations utilise sun and wind energy to evaporate water to produce our salt. The majority of our emissions come from the fuel used during the harvesting and hauling of our products.
All Rio Tinto managed sites are required to have closure plans. We are guided by the Rio Tinto Closure Standard in the preparation of these plans.
The intend of the Standard is "to ensure that our managed activities are left in a condition which minimises adverse impacts on the human and natural environment, and that a legacy remains which makes a positive contribution to sustainable development."
Dampier Salt closure plans are reviewed every year and full updated every five years.
Dampier Salt operations are classified as ‘indefinate life’ under the Rio Tinto classifications due to the potential long term sustainable nature of our production, therefore plans for closure are conceptual only.