OPERATORS of a gold mine said yesterday that its tailing storage facilities did not cause cyanide and other heavy metals to contaminate the local environment, as claimed by residents in Phichit, Phitsanulok and Phetchabun.
Akara Resources, an Australian-Thai joint venture, hosted a media visit to its mine yesterday after residents in seven central provinces filed a complaint with the Department of Special Investigation last week. They claim Akara's Chatree gold mine on the border of Phichit and Phetchabun leaked toxins into local water sources.
Head of Akara's corporate affairs Cherdsak Utha-aroon said that two tailing storage facilities within the Chatree gold mine were not the source of leaked toxins.
"We have two such storage facilities; the old one already land-filled and not in use, and the new one, which is currently in use. The old storage couldn't release any toxin as the deposits from gold mining were buried under a thick layer of clay. We also built the new storage area using Penta Locks TSF technology, which has five barriers to prevent leaking," Cherdsak said.
He said a polyethylene sheet covered the base of the new facility to prevent any cyanide leakage, even in heavy rain.
"The water within the tailing storage facility contained only 1-2 ppm of cyanide. That cannot compare with the alleged leaked water which contained as high as 8ppm of cyanide," he said.
Cherdsak said cyanide would dissolve in two weeks when exposed to UV rays and the firm used a tailing storage facility with a cyanide dilution method.
Khao Mor village resident Suekanya Teerachartdamrong said the cyanide- contaminated water sprang from the ground in a paddy field near the tailing storage facility.
Her claim referred to an inspection at the area last month by a team from Phichit Environment Office.
"The water sprang [from the ground] while the operation in the gold mine was halted, so the water level in the tailing storage facility was high. Small fish in the paddy field died," Suekanya said.
Cyanide-disposal expert-turned activist Dalin Sirisuwankit argued that substances can leak from a tailing storage facility, as the ground was sinking and there were some cracks in the floor.
"The cyanide level in the tailing storage facility is higher than what the company claims. The cyanide level on the surface is low because cyanide in water evaporates to become hydrogen cyanide in the atmosphere," she said.
Dalin said open disposal of cyanide- contaminated matter into the environment was wrong because cyanide, whose boiling point is only 26 degrees Celsius, could easily evaporate into the air.
"Long-term exposure to hydrogen cyanide can cause myasthenia gravis [muscular weakness] and many villagers around the mine have already shown the symptoms. Exposure to high amounts of cyanide will cause sudden death," she said. "The government should be on the people's side and make the gold mine dispose of cyanide in a closed system via international standards," Dalin said.