Environmental & Social Review Summary
Project Number
7192
Company Name
Zeravshan Gold Company
Date ESRS Disclosed
Feb 5, 2010
Country
Tajikistan
Region
Central Asia and Turkiye
Last Updated Date
Dec 31, 2016
Environmental Category
B - Limited
Status
Completed
Previous Events
Approved : Oct 10, 1996
Signed : Mar 3, 1997
Invested : Jun 26, 1997
Sector
Gold
Industry
Metals and Mining
Department
Gbl Infrastructure & Natural Resources
Project Description
Environmental Review Summary (ERS)
Project Name Tajikistan-Zeravshan Gold
Region Commonwealth of Independent States
Sector Mining
Project No. 007192
1. The Zeravshan Gold Company (ZGC) is a joint venture between the Tajik Government and Commonwealth and British Minerals Ltd, a 100 percent subsidiary of Nelson Gold Corporation. ZGC was established to develop the Jilau, Taror and Chore mineral deposits and to operate the existing facilities in the Zeravshan Valley area, northwest Tajikistan. This project (Phase 1) comprises the modification of the existing processing facility with the installation of a conventional carbon- in- leach (CIL) to treat 750,000 tonnes of oxide ore per year from the existing Jilau Pit. ZGC is currently undertaking a feasibility study of Phase II which would involve the construction of a heap leach facility to treat up to 5 million tonnes per year of lower grade ore from the Jilau pit. An environmental assessment covering both phases is being undertaken by an international consulting firm as part of this feasibility study.
2. This modification of the existing operation (Phase 1) is a category B project according to 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 site visit by Technical and Environment Department staff, a review of the environmental assessment undertaken for the proposed operation, and further information supplied by the sponsor. Phase II, if it were to prove feasible and become the subject of an additional IFC investment, would be a category A project.
3. The key issues that have been addressed as part of the environmental review include the following:
· land use modifications/cultural impacts;
· tailings treatment and disposal;
· liquid effluent and solid waste;
· water resources;
· particulate emissions;
· socio-economic impacts;
· rehabilitation;
· general worker safety /cyanide handling; and
· monitoring.
Land use modifications
4. Comprehensive baseline studies have been undertaken of the whole concession. No parks or natural protected areas or historic sites are located within the areas that could be affected by the proposed development. Project development is expected to have minimal impact on land usage, which consists mostly of occasional grazing by livestock in the project area. The construction of the CIL plant is occurring on previously disturbed land and does not impact vegetation. 15.6 ha will be affected by the tailings retrofit and construction of a 12m raise for the tailings impoundment, however these areas are also disturbed by current mining activites. A small cultivated field at the downstream toe of the existing embankment will be impacted by the raise.
5. Placement of the projected 8.7 million tonnes of waste rock resulting from two year pit development will have clearly defined unavoidable impacts in the Kuduk valley. Approximately 24.5 ha of grazing land will be affected. In consultation with interested parties and representatives of the Kalinin collective farm, ZGC have developed a mutually acceptable compensation package for the herdspeople. Impacts to livestock grazing should be further mitigated by the availability of similar terrain nearby. From an ecological perspective the vegetation communities (Sagebrush-Desert community) found in the valley are not unique and are extensively present elsewhere in the locality.
6. Several species of mammal listed as threatened or endangered in the International Union for the Conservation of Nature (IUCN) Red Data book could potentially be present in the area. These include the snow leopard Unica unica and several species of bat. Areas affected by the development are not suitable habitat for the snow leopard and field investigations did not support the presence of critical habitat (e.g., roosting sites) for bat species. The peregrine falcon, is also present within the wider concession; however due to the current level of disturbance, it is unlikely that this species will nest in the vicinity of the mine workings during active mining operations.
Tailings Treatment and disposal
7. Cyanide remaining in the waste tailings from the CIL plant will be neutralized by ozonation to reduce cyanide concentrations to 10ppm or less in the tailings. A level of 50ppm is widely recognized as the upper level for safety for wildlife. The treated slurry will be piped to the tailings impoundment where cyanide concentrations in the tailings supernatant will degrade further via ultraviolet degradation and volatilization. Pilot testing performed by US metallurgical laboratories indicates that the resulting cyanide concentration in the supernatant may be as low as 1ppm or less. The supernatant will be recovered by a barge mounted pump and transferred by a multistage pump into concrete return storage tanks above the mill areas. The supernatant will be recycled via gravity back to the mill.
8. As part of the CIL expansion the existing tailings impoundment has been modified in a manner that is consistent with the engineering design criteria required by the State of Nevada for a retrofitted facility. Furthermore, the retrofitted facility must also be suitably protective of groundwater resources to the extent that the groundwater quality remains at least as good as it was prior to implementation of the retrofit. These standards were chosen as the climate in the project area approximates that of the State of Nevada, and these engineering standards are considered state-of-the-art for this climate. To provide for the protection of groundwater, the minimum Nevada requirement for liners in tailings impoundments is one foot of soil with a permeability of no more than 1 x 10-6 cm/sec. This has been installed in the basin expansion area. In addition a geosynthetic membrane has been placed in the area where the supernatant will accumulate. Modifications to the tailings distribution system will result in a reduction of hydraulic head on the basin liner, which in turn will significantly reduce the volume of water that can escape from the facility as seepage. Because the existing facility had significant seepage losses to groundwater, the retrofit will improve groundwater quality through a substantial reduction in seepage contributions.
Liquid effluent and Solid waste
9. Liquid effluent from the mine site, camp and hospital are treated and discharged to surface waters. Daily samples are collected and analyzed. The effluent complies with World Bank and Tajik guidelines. Solid waste is transported to a landfill site.
Water resources
10. The site receives water from the Kosatarosh well field. The operation and maintenance of this well has been taken over by ZGC by mutual agreement with the local authority. The Territorial Committee on Mineral Reserves has confirmed a sustainable pumping capacity of 7170 cubic metres per day, which will sustain both the mine and local users with no significant adverse effects on supply.
Particulate emissions
11. To reduce dust levels, conveyors and ore crushing equipment will be fitted with atomized water sprays to suppress fugitive emissions. Water bowsers are regularly used to minimize particulate emissions on the haul roads and waste disposal areas.
Socio-economic impacts
12. Significant favorable socio-ecomomic impacts are expected to result from the expansion of the mine, including increased employment of local workers in a region of very high unemployment, low income and small industrial base. The number of jobs for local residents is expected to be 161, with an ex-patriate staff of 10. Increased secondary development will also emanate from the payroll. ZGC has already made contributions to the Sogdiana hospital, school system and municipal water supply and road improvements.
Reclamation
13. The company is implementing an appropriate decommissioning and land reclamation program for the site.
General safety/cyanide handling
14. ZGC has employed a full time health and safety officer and has implemented a comprehensive safety policy and procedures. Cyanide make-up will be largely automatic, although operators will be required to lift bulk bags of cyanide briquettes by crane into a closed hopper. Water spays will be fitted into the hopper to rinse the empty bags before they are lifted out of the hopper. The empty bags and crates are incinerated. A cyanide detection alarm will be installed in the make up area to warn operators if hydrogen cyanide gas exceeds acceptable exposure limits. Appropriate training schemes are being implemented.
Monitoring
15. Monthly surface water sampling was instituted at 23 sites within the project area to develop a baseline database for surface and groundwater quality. A suitable monitoring program will continue throughout the life of the project.
Conclusion
16. 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.
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February 6, 1996 11:31 AM
Environmental and Social Mitigation Measures
Broad Community Support
Related SII
