Environmental & Social Review Summary
Project Number
7261
Company Name
Anglogold Ashanti Iduapriem Limited
Date ESRS Disclosed
Feb 5, 2010
Country
Ghana
Region
Africa
Last Updated Date
Dec 31, 2016
Environmental Category
B - Limited
Status
Completed
Previous Events
Approved : Mar 22, 1996
Signed : Jul 10, 1996
Invested : Aug 12, 1996
Sector
Gold
Industry
Metals and Mining
Department
Gbl Infrastructure & Natural Resources
Project Description
ENVIRONMENTAL REVIEW SUMMARY (ERS)
Project Name GHANA:Ghanaian Australian Goldfields Heap Leach
Region Africa
Sector Mining
Project No. 007261
1. Ghanaian Australian Goldfields (GAG) propose to construct a heap leach facility within their existing mining concession at Iduapriem, western Ghana. The facility will be used to process 8.5 million tones of low grade gold bearing ore to yield an estimated 142,000 ounces of gold. The planned operating time of the heap is five years from 1996-2001. The facility will complement the existing main Carbon in Leach (CIL) processing facility. Feed for the heap will be obtained from the existing pits, and from stockpiled ore. The final leach pad will have an area of approximately 180,000m2..
2. Ghanaian Australian Goldfields (GAG) commenced operations at the Iduapriem Gold Mine in 1992. The existing operation is in compliance with World Bank environmental, health and safety guidelines. GAG retain a full time Environment and Safety Officer at the mine to coordinate and implement various environmental programs and annual audits are carried out by an independent consultancy firm.
3. This is a category B project according the IFC’s environmental review procedure because a limited number of impacts may occur, for which there are recognized performance standards and design criteria for minimizing or avoiding impacts. The environmental review comprised a review of the environmental assessment (EA) undertaken for the proposed operation, further information supplied by the sponsor and site visits undertaken by Technical and Environmental staff. A permit for the project has been given by Ghana’s Environmental Protection Agency
4. The key issues that have been addressed as part of the environmental review include the following:
. containment of cyanide;
. hydrological impacts;
. particulate emissions;
. waste disposal
. land use modifications/cultural impacts;
. socio-economic impacts
. rehabilitation;
. general worker safety /cyanide handling;
. monitoring
Containment of cyanide solution
5. The design, construction and operation of the heap leach dump and the process solutions ponds will be to international safety and environmental control standards. The leach pad will be underlain by a High Density Polyethylene Liner (HDPE) liner, laid down with strict quality control procedures to ensure its integrity, A leak detection system will be incorporated under the liner. Ore will be placed by dump truck and sprayed with sodium cyanide solution. Eight process ponds will be built to collect the collected heap leach solution which will be 100% recycled. All ponds will be lined with 2 layers of HDPE separated by geonet, thereby providing a pathway to a sump should a leak occur. Leakage will be monitored by a pipe placed between the membranes which will go to a sump. Because of the capacity of the solution ponds and solution management process, no cyanide detoxification is required. The company has a solution excursion emergency control plan in place in the event of an overflow from one of the ponds or a leak developing in the system. When mining has been completed, water in the process system will be treated to reduce cyanide concentrations to World Bank standards prior to discharge.
6. It is anticipated that rainfall will be sufficient to remove residual cyanide from the dumps once operations cease. It should be emphasized that the chemistry of the GAG orebody is inherently a “clean” operation, with an absence of pyrites and trace metals.
Hydrology
7. The water required for heap leach operations will be drawn from the tailings dam storage capacity. There are no springs or permanent water courses in the area that could be affected by the location of the pads or ponds. The presence of a heap leach facility will alter the hydrological characteristics by enhancing run-off and creating additional water storage in the Anonabeng Basin. However, the land that will be occupied represents less than 0.5% of the total drainage area and consequently effects should be minimal.
Particulate emissions
8. The only point source of dust emissions for the new facility will be the ore crusher/cement plant. Plant operators will be required to wear dust masks and the dust monitoring program will be extended to include this area. GAG conducts a dust control program on unpaved roads with regular spraying undertaken by water bowsers. To date this has proved to be very effective at reducing particulate levels.
Waste disposal
9. Empty cyanide barrels will be washed at the recovery plant. Cyanide boxes and liners are incinerated in a controlled manner under supervision.
Land use modifications
10. Surveys were undertaken of the proposed heap leach site, to determine its ecological, cultural and socio-economic value. The area comprises 1.4 ha of secondary forest, 18.3 ha of secondary forest thicket, 13 ha of abandoned agricultural land for which farmers have been compensated for historically and 5 ha of cultivated land. There is no permanent habitation on site.
11. The loss of this habitat is not considered significant in the context of the Tarkwa region. There are no rare or endangered species in the area. Alternative sites were considered to avoid loss of secondary habitat, however the availability of suitable land within the concession is very limited. Other locations were evaluated and rejected due to potential pad subsistence. The preferred location represents one of the few remaining flat pieces of land on the concession.
12. The are currently two farmers whose land will be marginally affected by the project that need to be compensated. There is also a fetish shrine that will need to be moved. Discussions have been held with elders and a suitable relocation site has been agreed upon. GAG has fabricated a shed to house the shrine and arrangements are being made for the required ceremony to take place.
Socio-economic impacts
13. The socio-economic impacts should be viewed within the context of the existing operation. The new facility will create an additional 30 jobs, for local Ghanaians, which will indirectly result in approximately 90 jobs in the local community.
Reclamation
14. The company will implement an appropriate decommissioning and land reclamation program of the site at the end of its operating life. Research from a neighboring concession has shown that vegetation establishes on the spent dumps. Natural colonization is therefore likely to occur at Iduapriem. Cyanide levels should be sufficiently low for vegetation growth within two months of ceasing irrigation. Future rehabilitation programs will observe colonization on the heap leach dump and evaluate the potential for establishing fuel wood and possible economic crops on the spent dumps. The ponds will be decommissioned by removing the HPDE liners. The area will be regraded and revegetated.
General safety/cyanide handling
15. GAG has a good safety record, and employee training will be an important aspect of the operation, as will the provision of proper protective equipment. With respect to cyanide handling, the on site inventory levels for cyanide are low. The main storage facility will remain in the high security areas of the treatment plant. Minimal amounts would be stored in the second fenced areas for daily usage. All operators of the cyanide mixing facility will be issued with appropriate safety clothes including full face respirators, long gloves, safety boots and wet weather gear. The safety requirements for caustic soda are as those outlined for cyanide.
Monitoring
16. GAG monitor an extensive number of water quality sampling stations. The environmental monitoring program will include sampling and analysis for cyanide from appropriate locations to ensure that no chemicals are escaping from the pad or process pond areas. Underdrains will be checked and analyzed weekly. Additional groundwater monitoring will be undertaken to ensure the effectiveness of cyanide containment. Particular attention will be paid to control and treatment of high pH drainage from spent heap leach dumps at the time of decommissioning. If necessary GAG will investigate and develop treatment methods, other than dilution, to provide an environmentally acceptable discharge
17. The Environment Division is satisfied that the relevant key issues are being adequately addressed, and will monitor the Sponsor’s ongoing compliance with World Bank environmental, health and safety guidelines during the life of the project by the evaluation of annual audits, and by conducting periodic site visits.
L:\WPEU\SALLY\GHANA\GAG\GAGHEAP.ERS
December 12, 1995 3:25 PM
Environmental and Social Mitigation Measures
Broad Community Support
Related SII
