GEORGETOWN, Guyana, March 25, Cana - In the wake of one of the largest cyanide spills to occur in this hemisphere, the management of Omai Gold Mines Limited (OGML) says measures are being taken to prevent the possibility of another spill.
General Manager and Vice President of the majority Canadian-owned mine, Rejean Gourde, told reporters last week that in keeping with the terms of resumption stipulated by the government, Omai is already installing systems for monitoring and managing the potentially dangerous cyanide tailings discharge from its operations.
That system includes carbon columns to reduce the cyanide content in the tailings eMuent, the construction of a peroxide oxidization plant, removal of suspended solids from the effluent, sampling of the tailings water to ensure a cyanide presence of under 1.5 ppm (parts per minute) and the installation of a multi-port diffuser in the Essequibo River.
"There will be absolutely no discharge of tailing water held in the No. 2 pond from commercial production until the entire system is in place and fully operational," Gourde said.
The first discharge of tailings water from the tailings pond now being constructed, is scheduled for June, 1996.
The mineral agreement signed between Omai and then People's National Congress (PNC) government provided for an cyanide discharge in the Essequibo River of 2 ppm. "We have however agreed with (this) Government to an end-of-pipe (into the Essequibo River) criteria of 1.5 ppm," Gourde told reporters during a press briefing following the tour of the Omai operations some 150 miles south west of the capital.
On August 191ast, the failure of the tailing pond dam caused millions of cubic meters of cyanide tainted water to pour through breaches in the dam into the Omai and Essequibo Rivers causing a huge outcry from international and local environmental groups and forcing the closure of the mine for five months.
The spill also caused severe disruption in the lives of riverain residents along the Essequibo River, Guyana's largest waterway.
Under the terms of resumption agreed by Omai and the government in February, the company is duty bound to install a government-approved system for treating, managing and monitoring the tailings effluent before any discharge of tailings water from the new pond into the Essequibo River.
OGML management says the new tailings pond will cover an area of 211 hectares and will be continuously raised to accommodate an increasing tailings level.
The five-dam emplacements for this new pond has been designed by Canadian specialists, Golder Associates, C. Brawner and Professor M. Morgenstern and was also given the stamp of approval by Canadian consultants Klohn-Crippen who were commissioned by the government.
Reporters were taken on a tour of the former tailings pond at the mine for which the company says it is submitting a final closure plan for government approval by the end of June.
There is evidence of vegetation already beginning to spout in parts of the pond in which pools of cyanide eMuent are still visible.
The company also says it will be providing the government with a comprehensive Minesite Closure Plan for approval by year end. The plan will cover in detail a review of the environmental date prior to commencement of the mine operation, examine the operational effect of the mine, propose the necessary rehabilitation to ensure health and safety, physical and chemical stability and land utilization.
It will also feature a schedule and costing for implementation with financial guarantees. Gold production at the mine for 1994 touched the 250,642 ounce mark.
Omai officials say the projected increase in production will be a direct result of a US58 million dollar investment in a mill expansion program. The new mill will see some the mine processing some 13,500 tonnes of hard rock a day instead of 6,500 tonnes. "The purpose of the expansion is to increase gold production by accelerating hard rock million capacity and holding down production costs by improving economies of scale," Gourde said.
Some 1,000 Guyanese and 200 expatriate workers are employed at the mine and the company projects employing about 500 more workers during the current mill expansion process. Omai, owned on a 65-30-5 basis by Cambior Incorporated, Golden Star Resources and the Guyana government, has a total investment of US273.6 million dollars.
Under the Omai Mineral Agreement, the government stands to receive 48.9 per cent of the cash flow of the company once it pays off its investors. It would mean that the Guyana government will receive US97.3 million dollars.
This is US12 million dollars more than what government was supposed to get under the agreement and will come from royalties, corporate and withholding taxes and its 5 per cent equity shareholding.
Since the mine started operations in 1993, nearly US12 million dollars in royalties in gold have been paid to government. Income tax paid to government since 1991 amounted to US8.7 million dollars, duty and consumption tax US 1.2 million dollars and wages and salaries amounted to US36.8 million dollars.
Omai is looking to expand its operations by acquiring leases to the Quartz Hill and Omai River properties said to have high grade soft rock which can be easily mined and milled.
Government has so far not reacted to a proposal put to it in 1994 for Omai to explore the Omai River and Quartz Hill properties adjacent to its Omai mine. "The Omai River and Quartz Hill properties are yet to be adequately explored, but clearly reveal potential for expanding Omai's operation with an appreciable return for Guyana and for Omai", Gourde says adding that the company is asking government to consider its expansion proposal "within the terms of our mineral agreement".