In 2011, for the second consecutive reporting year, Barrick participated in the CDP Water Disclosure.
Our commitment to transparency was recognized in 2010, when Barrick tied for 3rd out of 100 companies benchmarked in a multi-industry study entitled “Murky Waters? Corporate Reporting on Water Risk, A Benchmarking Study of 100 Companies,” ranking water reporting practices of publicly traded companies, conducted by Ceres, a Boston-based coalition of investors.
Rainwater Harvesting
At our Buzwagi operation in Tanzania, to avoid using ground water from the aquifer, we developed an industrial rainwater harvesting system. This system is a 75 hectare ‘giant lined bowl” which collects rainwater and funnels it into reservoirs that can store up to 1.5 million cubic meters of water for use in the mine. The rainwater harvester now supplies the majority of the mine’s annual water requirements. The system is performing as designed and is a success story for this property.
The rainwater harvester at Buzwagi collects rainwater and funnels it into reservoirs. Water management is a global issue for Barrick.
Water Management
Barrick operates in some regions where there is a scarcity of water and in other areas where there is abundant water. However, regardless of where we operate, we understand that water availability is a critical concern for Barrick and for our stakeholders. Global trends in population growth, urbanization and land-use changes demand a strategic response to water risks. We are focused on using water wisely and believe that water should be managed as a community resource, respecting the rights of other water users.
We increased our focus on responsible water use, three years ago, through introduction of a new global Water Conservation Standard. Building on the company’s existing monitoring programs, the Standard has now established water conservation criteria and regular management review procedures at our sites. At a minimum, the Standard requires our operations to conduct risk assessments related to water, to implement systematic monitoring programs of water supply, storage, usage and discharge, to develop and maintain site-wide water balances, and to institute water conservation programs that address significant risks at all stages of the mine life cycle. One of the most significant characteristics of water-related risks is that the impacts of our use vary depending on local hydrological, social, economic and political factors. Therefore, although our Standard provides for consistency in management and reporting across the company, our water management activities need to be site specific.
Water is essential to our mining activities. Water is used for ore processing, dust suppression, drilling rock and other activities. Use is closely monitored at all our operations and conservation opportunities are actively pursued. We obtain water from surface sources such as lakes and streams, from water captured on-site (rainwater or water pumped from an open pit, for example) or from groundwater sources. For all new projects, we review water availability options with numerous experts in the field, identifying alternative water sources and developing contingency plans, should water availability change over time.
Much of the water we use is recycled through our process facilities but some is lost through entrapment in tailings, evaporation in process ponds, through use as a dust suppressant and in other mining activities. We therefore have to add water to our process circuits. This water is called make-up water. In 2011, Barrick used 83.9 million cubic meters of make-up water at our mining operations; 44.0 million cubic meters sourced from groundwater (wells and pit and underground dewatering) and 39.8 million cubic meters sourced from surface water (lakes, rivers, captured rainwater, etc.). We also used 3.8 million cubic meters of purchased water, for both domestic and mine use.
Withdrawals from a water system can lower the water table, reduce biodiversity, cause land surface disturbance, and reduce the volume of water available for others. We manage our water withdrawals to take only the minimum water needed. Our operations also recycle water through our processing systems, use saline water preferentially in arid areas when available, and either use the water pumped out of open pits and underground or, if not impacted by operations, return it to the local aquifer.
Some of our mines require dewatering operations (pumping water out of open pits or underground tunnels) to allow access to the ore bodies. Dewatering results in a temporary depression of the water table adjacent to the mine, therefore we return the water to the same hydrographic basin from which it was removed. Potential environmental impacts from dewatering have been identified in the environmental assessment processes at each site, and measures have been implemented to mitigate impacts.
Water and the Pascua-Lama Project
Construction of a water canal near the Pascua-Lama project.
We are committed to protecting water quality around all our operations. At our Pascua-Lama project, located in the high Andes on the border between Argentina and Chile, we have installed 30 automated water-monitoring stations at strategic points along the watercourses located within the project’s area of influence. The monitoring stations provide real-time information about key water-quality metrics, which will allow us to respond immediately to any anomaly in the data.
We are installing a cut-off wall at Pascua-Lama that will prevent water exposed to the mine’s waste dump from flowing into the local river system. Mine-impacted water will flow instead into two collection ponds and, if testing shows elevated levels of heavy metals or acidity, the water will be treated at an on-site treatment plant.
We also built two diversion canals at Pascua-Lama to prevent water from the upper basin of the Estrecho River from flowing into the site’s waste dump.
The cut-off wall, collection ponds and canals at the Pascua-Lama project are examples of innovative methods to conserve water in this arid landscape.
For information on the icefields/glaciers located near the vicinity of the Pascua-Lama project, please see our website.
Much of the water used for ore processing is recycled or reused at our operations. This occurs either when water from one process is then used for another, such as wash bay water used for dust suppression, or when gold-laden processing water is stripped of the gold and the water recirculated back through the processing system. At Veladero in Argentina, we pump treated wastewater from the site’s mine camp to the processing facilities, to be reused in the closed circuit leaching process. And at the Zaldívar mine in Chile, wastewater is treated using micro-organisms, and is then recycled to the processing facilities. Only six of our operations, most located in areas with an excess of water, discharge any processing water.
Water conservation is a critical issue for Barrick and water use is carefully controlled at all sites.
Along with recycling and reusing, we also look for innovative ways to reduce water use at our operations. For example, ABG currently uses surficial paste tailings technology at the Bulyanhulu mine in Tanzania. This filtering process removes additional water from tailings slurry. The water is then reused in the process plant and the dewatered tailings are placed in an engineered tailings impoundment. Bulyanhulu was the first gold mine of its size to use this process which allows the plant to recycle more than 70 percent its water. In 2009, our Hemlo mine in Canada reduced, by 75 percent, the use of fresh water from a nearby creek by installing a pumping system which recycles dewatering water and storm water runoff back to the process system. The mine is now using less than four percent of the creek water allowed by its permit.
Barrick operates in a number of arid regions where, if available, we preferentially use brackish or saline water to meet our water needs. This practice maximizes the availability of fresh water for other community uses. It also reduces soil salinity, often a problem for farmers and ranchers in arid areas. In 2011, approximately 38 percent of our make-up water was brackish or saline.