Significant Issues
The Porgera mine operates under a comprehensive permit issued by the Government of Papua New Guinea (PNG). Under this permit, Porgera is required to follow a stringent government-approved environmental management and monitoring program.
Riverine tailings and erodible waste rock disposal were in place before Barrick acquired its interest in the mine in 2006. During the planning and development phase of the mine, the PNG Government approved the practice of riverine tailings in 1989.
Given the limited practical and feasible alternative approaches to riverine tailings disposal, Barrick has taken significant steps to improve environmental performance and ensure that the Porgera mine deposits fewer tailings in the river system. These actions are in keeping with Barrick’s commitment to a responsible course of action at Porgera, as well as the “precautionary principle” and OECD Guidelines’ commentary, which calls for “continual improvement of the system” of environmental management.
Progress to date includes:
- A new $42 million tailings paste plant commissioned in mid-2011, which has had a significant positive impact on the tailings stream. The plant process removes significant portions of the coarser content of the tailings mixture. Cement is then added to these coarser solids and the mixture is used to fill the voids in the underground mine, a process known as “cemented paste backfill.”
- The environmental benefits of this process are two-fold: it reduces the total quantity of the tailings solids discharged by approximately eight percent and it creates a finer tailings mix in general, which tends not to settle onto the riverbed, and is more likely to be carried through the river system as washload, rather than being retained in natural accumulation zones. Porgera plans to use this tailings paste plant to produce paste in the maximum amount that can be stored in available underground areas. Additionally, plans to increase ore production from the underground mine will result in an opportunity to store more tailings in the underground voids in the mine as backfill, thus diverting further tailings from the river.
- In November 2009, Porgera was officially certified under the International Cyanide Management Code for safe and responsible management of cyanide use and disposal. This achievement is consistent with Barrick‘s commitment to implement the Code, worldwide, at its operations that use cyanide. The cyanide destruct circuit commissioned by the mine in 2008 has reduced cyanide discharge concentrations four-fold. Significantly, the use of the cyanide destruct circuit has also resulted in reductions in dissolved metal concentrations detected at our downstream monitoring point.
- Porgera is implementing Barrick‘s global Environmental Management System (EMS), a framework of policies and obligations that govern environmental performance and is aligned with international standards. In 2012, the operation will pursue International ISO 14001 standard certification. To achieve this certification, an EMS must be formally certified by a third-party to meet all requirements. Meeting ISO 14001 is an important tool that confirms the operation’s ability to control environmental impacts, improve environmental performance, and systematically set, manage and achieve environmental objectives. The standard can also provide assurances to stakeholders.
Potential impacts of transportation of products, goods and materials used at our operations and transportation of the workforce to and from our sites include an increase in greenhouse gas emissions, the potential for traffic accidents and increased exposure of employees to dust from travel on unpaved roads.
At many of our operations we provide bus transportation for our employees to and from a site which reduces the risk of accidents, decreases the amount of dust and reduces our carbon footprint. Other operations have camp facilities so daily transportation of people is not required. Teleconferencing and video-conferencing have contributed to a reduction in employee plane travel over the past few years.
We discharge mine impacted water after treatment to the environment at 15 of our sites; six operations, eight closure sites and one project. At these sites, we monitor the discharged water quality to ensure that discharged effluents meet permit compliance limits, and we monitor the receiving water quality to ensure no impacts. Biological monitoring at some sites also ensures that we are not having a negative impact. In 2011, there were no significant environmental impacts from the permitted global discharge of 91.6 million cubic meters of water. For a discussion on our riverine tailings disposal at the Porgera mine, please see Porgera and Riverine Tailings Disposal (above).
At our operations, we direct storm water runoff and local streams away from the active mine areas so this water does not come into contact with mine chemicals. If runoff water does contact process solutions or chemicals, we can capture and treat it or use it in our processing activities.
Barrick has in place an Environment Incident Reporting Standard which is a critical part of our environmental management process. Significant spills and wildlife incidents are reported to regulatory authorities, the corporate environmental department, and then to the EHS Committee of the Board. These incidents are investigated and measures put in place, where appropriate, to prevent a recurrence.
Environmental incidents at our operations most often involve small spills of oils, fuels, and chemical or process solutions. Spill response includes cleanup and recovery, rehabilitation of the impacted area, and investigation and action to prevent subsequent incidents. In 2011, there were 15 corporate reportable spills at ten operations and three at our closed properties. Most were spills of hydrocarbons or process solutions which flowed out of containment. They were cleaned up and the areas remediated. Three of these spills flowed off the mine property. They are described in the table below.
Protection of wildlife is a priority at our operations. We exclude animals and birds from our operations by such activities as netting and covering liquids, and by fencing our active mine areas. However, each year we have a number of incidents where wildlife come into contact with chemical and process solutions or mine machinery. Investigation of these wildlife incidents promotes the opportunity for improvements. In 2011, there were 83 wildlife mortalities, at three sites, involving chemical and process solutions. The table below provides information on these incidents.
| Off-property Spills | |||
|---|---|---|---|
| Operation | Substance | Amount | Description of Incident |
| Lumwana, Zambia | Diesel Fuel | 6,200 litres | A diesel tanker delivering fuel to the mine overturned en route to the site. Fuel leaked from the tanker compartments. Spilled fuel was pumped into storage drums. Contaminated soil taken to the site bio-farm for remediation. |
| Kidston closed property, Australia | Seepage Pond Water | 5,000,000 litres | Following above average rainfall, the seepage pond and reclaim pond reached capacity and discharged seepage water to the environment. All seepage collection and pumpback systems were fully operational at the time of the release. Receiving water compliance monitoring was undertaken in accordance with the government requirements. |
| Croydon closed property, Australia | Pit Water | 6,500,000 litres | Following above average rainfall, the mine pit reached capacity and discharged mine pit water to the environment. Receiving water compliance monitoring and macro invertebrate population sampling was undertaken both upstream and downstream of the release in accordance with government requirements. Barrick is undertaking regular monitoring of the pit lake water levels and water quality and continuing hydrogeological investigations to guide the long-term management requirements for the site. |
| Wildlife Mortalities | ||
|---|---|---|
| Operation | Species | Description of Incident |
| Bald Mountain | 4 birds | Found in the Truck Wash Bay sediment cells, coated in oil |
| Buzwagi | 43 birds | Found in the Tailings Storage Facility in 20 separate incidents |
| 20 birds | Exposed to HCN gas in one incident at the Process Plant | |
| 15 birds | Found in the Process Plant area | |
| Pierina | 1 cow | Broke through fence into Tailings Storage Facility |
One of our goals is to operate in full compliance with all environmental regulatory requirements and permits. Any written directive from a regulatory agency, even those relating to minor housekeeping issues, is considered by us to be a regulatory action. In 2011, we received 57 regulatory actions at six sites. By the end of 2011, most of these actions had been addressed, with corrections underway for the remainder. We received a total of three fines at three operations totaling $75,800 for environmental non-compliance.