An Australian-owned gold mine in Laos has been polluting a nearby river with toxic chemicals especially during the rainy season, according to a non-governmental group which claims local authorities are covering up the issue.
But environmental officials at the Phu Kam copper and gold mine 100 kilometers (60 miles) northeast of the Lao capital Vientiane said that based on villagers' complaints, they had jointly monitored the water quality of the Nam Mo River with the Lao authorities and found it was within a "standard" level.
A source with an environmental group, speaking on condition of anonymity, said the toxic chemicals were released occasionally from a treatment plant at the mine, warning that the pollutants could accumulate over the years and put the population nearby at risk.
The local authorities are aware of the problem but have looked the other way, the source said.
"It’s something that they want to keep a lid on. The issue is between the company, the local population, and the government. In reality, we are in no position to say more,” he said.
He acknowledged that the Phu Bia Mining company, the Lao arm of Australian company PanAust, took steps to address the problem in the past but said that it had not dealt with it on a "permanent" basis.
"Gold mining will still go on for at least 10 years and during that period of time, toxic chemicals will accumulate, putting the local population at risk," the source said.
Cyanide spillover
A Vientiane provincial environmental official said pollution at the mine located in Xaysomboun district in Vientiane province occurs during the rainy season.
The current pollution, he said, stems from the spillover of cyanide, a chemical often used in mining to dissolve gold so that it flows out of the rock in a process called leaching.
The cyanide can be leaked into the soil and then into the water supply. Mineral residues from mining operations also release toxic components if left in the open.
“The company has taken safety measures. During the dry season there is not much of a problem," he said.
"But during rainy season, there is an issue if the amount of water [in the treatment plant] is too much," resulting in the spillover of cyanide, he said
When asked whether villagers are aware of the problem and have been notified about the cyanide spillage into the river, he replied, “They have been notified [and] monitoring and protection measures have been taken.”
“The company has taken safety measures but problems occur during the rainy season," he said. "The local population are aware of this, as most of them work at the mine as employees or laborers.”
In 2005, Phu Bia Mining acknowledged it had contaminated a nearby river and agreed to compensate villagers living along it, media reports had said.
Monitoring water quality
Officials at the Phu Kam mine said they had been constantly monitoring water quality in the Nam Mo River and found no traces of toxic pollution as claimed.
When asked if the company had monitored the water quality levels of the Nam Mo River, an official of the mine said, "Yes, yes, every day."
But the official said that any environmental impact on the surrounding areas is not based on Phu Bia Mining's operations alone, citing gold panning activity nearby.
"Phu Bia is just one small part, there is gold panning in the northern part of the Nam Mo river by an unknown group ... who use chemical and mercury to extract gold in a process called alluvial mining,” he said.
Acidic pH
He said the water quality levels at the river were "normal" and that the monitoring was done together with district environment officials and officials from the Natural Resources and Environment Ministry.
In response to a question on charges that pollution in Nam Mo was hazardous, he said the quality of water released from the treatment reservoir "is within the [specified] standard.”
Phu Kam mine officials said the pH test, measuring the alkalinity or acidity concentration in water, on the Nam Mo River showed a level of between 7 and 8. A pH of 7 is neutral, below 7 is acidic, and above 7 is basic or alkaline.
The officials said there was a spill from the treatment reservoir in 2005 during the rainy season but that the problem has been fixed and the water quality is "normal."
A source familiar with the issue said that from a scientific point of view, the pH level does not indicate the amount of cyanide, mercury, and other toxic chemicals in the water.
The pH level can be manipulated by adding other chemical components, the source said, adding that there are many environmental tests that Lao environment officials have no role in.
Mining is a key source of revenue for land-locked Laos.
The significant cash flow generated by the Phu Kham mine has also supported PanAust’s growth while contributing to a strong balance sheet, the Australian company said on its website.
The operation comprises a large open-pit mine feeding ore to a process plant with recovery of copper and precious metals into a saleable concentrate using conventional flotation technology. The final product is a copper-gold concentrate.
Most concentrate is trucked in covered containers to Sriracha Harbor, south of Bangkok in Thailand, for shipment to smelters in Asia. A second, shorter, export route via the South China Sea port of Vung Ang in Vietnam was established in 2012.
Reported by RFA's Lao Service. Translated by Viengsay Luangkhot and Somnet Inthapannha. Written in English by Parameswaran Ponnudurai and Rachel Vandenbrink.