Vietnamese authorities say they are carrying out inspections at a controversial bauxite-mining plant where a break in a waste containment reservoir caused a spillage of sludge last week, raising public alarm about its environmental impact, according to reports.

Local news organizations that reported on the spill at the Tan Rai bauxite plant in Lam Dong province in southern Vietnam’s central highlands cited scientists who had previously warned about the adverse environmental effects of such reservoirs if they overflow and pollute rivers.

According to reports, red-colored sludge flowed out of the reservoir at the plant after the embankment gave way.

But the Vietnam National Coal and Mineral Industries Group (Vinacomin), which owns the plant, and the Ministry of Natural Resources and Environment said the sludge was not what is known as red mud, a toxic byproduct of the process that refines bauxite, raw aluminum ore, into aluminum oxide, or alumina.

Because the majority of Vietnam’s bauxite reserves are located at high elevations in the central highlands, any breaks in waste reservoirs pose the threat of flooding low-lying areas.

A red mud reservoir is believed to be located four kilometers (2.5 miles) from the burst reservoir at Tan Rai, located in Loc Thang town in Lam Dong province’s Bao Lam district about 700-800 meters (2,300-2,624 feet) above sea level.

“If a [red mud] reservoir breaks [in an area of high elevation], all the areas below will be flooded as with flash floods, jeopardizing the ecology, damaging people’s gardens and [potentially] killing animals and people who are exposed to the red mud,” Le Huy Ba, director of the Institute for Environmental Science, Technology and Management at the Ho Chi Minh University of Industry in Ho Chi Minh City, told RFA’s Khmer Service.

Sludge discharge

The Tan Rai reservoir, which has a total capacity of 2 million cubic (70.6 million cubic feet), holds waste and water discharged from the ore-cleaning process, a report by state-owned Vietnam News said.

It discharged about 5,000 cubic meters (176,573 cubic feet) of sludge on Oct. 8 when an embankment broke and spilled its contents into Cai Bang Lake, said the report, citing Lam Dong Province’s Department of Natural Resources and Environment as the source.

Authorities contend that the spillage has not harmed local residents or crops.

But Ba said although the sludge from the Tan Rai reservoir was not toxic mud, it was a kind of “organic mud” harmful to the environment.

The latest incident has prompted scientists and activists to question the safety of Tan Rai’s operations, with some indicating that authorities should stop the project.

They continue to voice concerns about equipment quality, the technical capacity of those who invest in and run the operations, and the ability to deal with possible breakdowns at the bauxite mining plant, which is part of the larger Lam Dong aluminum bauxite complex.

“They [authorities] cover up the information and always say that this project is good,” Ba said. “[But] the technology is outdated, machines are not good, and [there is] a low level of safety. I’ve already said that this project has no economic benefits, and the environment has been damaged.”

Nguyen Van Thuan, head of the General Department of Geology and Minerals at the Ministry of Natural Resources and Environment, said it was difficult to say whether the spillage occurred because of lax management, according to the Vietnam News report, but added that a prolonged heavy downpour and slow water drainage from the reservoir had contributed to the breach.

He said authorities would inspect the site and propose solutions, and that his department had asked local authorities to enact measures to address problems created by the spill, the report said.

Heavy rains

Vo Quy, former director of the Center for Natural Resources Management and Environmental Studies at Vietnam National University in Hanoi, pointed out that heavy rains and flooding can occur unexpectedly and more frequently in Vietnam’s central highlands due to climate change.

“We [scientists] all came to the conclusion that we have to stop these projects,” he said, referring to bauxite mining operations in the central highlands where violent and unpredictable storms pose a threat to waste reservoirs. “There is no other way around it.”

Vietnam has rich reserves of bauxite that is generally strip-mined.

Nguyen Hue Chi, a scholar who started a website devoted to bauxite production and mining, agreed that heavy rains in the country’s central highlands present a serious risk of causing waste reservoir overflows.

He called on government officials, who had played down any cause for concern over the issue, to review their stand.

Some scientists also believe that the Tan Rai plant’s harmful side effects will outweigh any eventual profit the operations may yield.

Vinacomin expects Tan Rai to incur losses for up to four years following the start of operations last October, according to a Vietnam News report.

“I think we should halt this project regardless of losses,” Ba said. “It’s better than following through with it to the end because the consequences will be much greater than the [financial] losses.”