China-backed mine in Sumatran seismic hotspot rings safety alarms

By Hans Nicholas Jong

JAKARTA — Protests are mounting in Indonesia against a China-backed zinc and lead mine being developed on the island of Sumatra in defiance of opposition from local communities.

On June 11, protesters from communities that would be affected by the mine in Dairi district demonstrated outside the Chinese Embassy in Jakarta. They demanded the Chinese government stop financing the project, following news that a Chinese state-controlled company has agreed to loan $245 million to mine developer PT Dairi Prima Mineral (DPM ).

The company, Carren Holdings Corporation Limited, approved the loan despite multiple independent experts warning that the project poses extreme risks to people and the environment. Among those experts is Steve Emerman, an associate professor of hydrology at Utah Valley University in the U.S. Following his review of the Dairi project’s environmental impact assessment, Emerman described the mine as “the worst cases I have ever seen” and said “the flagrant disregard for people’s lives and the environment is staggering.”

The World Bank’s internal watchdog, meanwhile, said it would put the project in the highest environmental and social risk level due to “potential significant adverse environmental or social risks and/or impacts that are diverse, irreversible, or unprecedented.” The watchdog is involved because a client of the World Bank’s International Finance Corporation, the state-owned Postal Savings Bank of China, has also issued a loan to DPM.

Among the identified risks are the very high possibility of the mine’s tailings dam collapsing, given that it would lie on a tectonic fault line, as well as the risk of acidic drainage from the dam contaminating surface and groundwater sources that serve local communities.

There are 11 villages located around or downstream of the proposed tailings dam, making the prospect of its collapse potentially disastrous. Some homes and houses of worship lie less than a kilometer (0.6 miles) from the dam, while an entire village of 2,010 people, called Pandiangan, is just 1.8 km (1.1 mi) from the dam.

This would make the project illegal if it was built in China, since that country’s regulations prohibit the construction of a tailings dam within a kilometer of a populated area, according to Emerman.

Mangatur Lumbantoruan, a resident of the village of Sumbari, also in the area affected by the mine, questioned why the project has been allowed to proceed in Indonesia given the immense risks it poses.

“The world knows what happens with tailings dams on unstable ground. It kills people. It destroys the environment,” he said. “All the flat land in that area is unstable. Why are these Chinese government agencies financing something that will kill us? This would not even be allowed in China!”

Rainim Purba, from Pandiangan village, questioned why Carren Holdings Corporation Limited, which is ultimately controlled by China’s State Administration of Foreign Exchange (SAFE), would agree to finance the project.

“Maybe they have been kept in the dark about the risks,” she said.

Rainim also questioned why the Chinese government would risk financing the mine while a legal case against the project’s environmental approval is still underway.

The approval was issued in August 2022 by Indonesia’s Ministry of Environment and Forestry. In response, 11 residents filed a challenge against the permit at the Jakarta State Administrative Court in February 2023.

In August 2023, the court ruled in favor of the villagers, finding that the mining area to be prone to disaster and thus not suitable for mining. The court also ordered the ministry to revoke its environmental approval of the project.

Both DPM and the environment ministry appealed the ruling to the high administrative court, winning the case in November 2023.

The villagers then filed an appeal at the Supreme Court, which hasn’t issued a ruling yet.

On the same day as the protest outside the Chinese Embassy, the villagers also staged a protest outside the Supreme Court, calling on the justices to listen to their fears and rule fairly.

“It’s ridiculous that the Ministry of Environment and Forestry has provided environmental approval to DPM,” said Rainim, one of the plaintiffs in the lawsuit. “The ministry’s mandate is to protect people and the environment. Instead, they are supporting a dangerous mine that is likely to kill us and poison the environment. We need the Supreme Court to put an end to this, and put an end to it soon.”

Map of the planned PT Dairi Prima Mineral tailings dam . Image courtesy of Richard Meehan.

Troubles in the design

Sabam Sibarani, the speaker of the Dairi district legislature, has defended the project, telling local media the ministry issued the environmental approval through a long and prudent process.

However, an analysis by Emerman of the project’s latest environmental impact assessments in 2022 and environmental approval found the project riddled with irregularities.

For one, the dam might not be big enough to store all the tailings produced by the mine. DPM initially designed the dam height at 25 meters (82 feet), before increasing it to 28 m (92 ft), which means it should be able to hold back 1.67 million cubic meters (441 million gallons) of tailings. But Emerman found that the volume of tailings that will require permanent aboveground storage, which is the basis for the tailings dam design, had been greatly underestimated.

The actual volume of tailings needed to be stored is probably closer to 2.5 million m3 (660 million gal), 50% more than what DPM estimated, he wrote in his analysis. To meet that parameter, the dam height would have to be considerably taller than currently planned. This means DPM will need more non-acid-generating waste rock to build the dam, which there might not be enough of, Emerman wrote.

Second, the environmental impact assessments contain no analysis of what would happen should the tailings dam fail, Emerman wrote. Such an analysis is required under guidelines from the Australian Committee on Large Dams (ANCOLD), which the 2022 environmental impact assessments claims to follow.

Another analysis of the latest environmental impact assessments, by Richard Meehan, a Stanford University engineer with expertise in dams in areas with seismic activity, also found no analysis of the consequences of a tailings dam failure.

“There was no plausible planned abatement of public risks from the proposed dam,” he wrote. This despite the likelihood of the dam failing as it’s underlain by volcanic ash deposits rather than stable bedrock, Meehan wrote. The proposed dam is also located within one of the most seismically active and rainiest areas of the world, further compounding the risk of failure, he added.

In the latest environmental impact assessments, DPM wrote that it had acknowledged the potential hazard and had thus designed the tailings dam to the highest standard. To address the issue of unstable soil, DPM wrote that it would improve the weak ash soils in the foundations.

“This, however, is a massive and extremely expensive undertaking,” Meehan wrote. “My analysis is that it may never actually be carried out.”

Third, the dam is only designed to withstand a 100-year flood, which means a flood that statistically has a 1% chance of occurring in any given year. This, Emerman wrote, falls short of the standard set by international guidelines, which require dams to be designed to withstand either a 10,000-year flood (with a 0.01% chance of occurring in a given year) or a “probable maximum flood” — the largest flood event that could reasonably be expected to occur at a particular location — due to the probable loss of life in the event of dam failure.

Villagers of Dairi stage protest in front of the Chinese Embassy in Jakarta in June 2024. Image by Falahi Mubarok/Mongabay Indonesia.

Trouble in the data

The engineering assumptions underlying the design are also based on inadequate rainfall data, Emerman wrote. The 2022 environmental impact assessments used monthly rainfall fata for 2009-2018, which wouldn’t be enough to estimate a 100-year extreme event.

There are also indications the “improved” data in the 2022 environmental impact assessments may have been doctored from the same data in the 2021 assessments. For example, the 2022 assessments give rainfall figures of 134 and 334 millimeters (5.3 and 13.1 inches) for July 2012 and November 2012. But the 2021 document lists 194 and 394 mm (7.6 and 15.5 in) for the same respective months.

These changes aren’t just typos, but actual changes in data, since for both tables, the averages for July and November rainfall are consistent with the numbers that are stated in the tables.

There’s no explanation on why the data have been changed, Emerman wrote.

“At this point, the contradictions among the data that have been used by PT DPM to develop the various Addenda to the EIS [environmental impact studies] are so overwhelming that all of those environmental data should be rejected and it should be assumed that there are no environmental data,” he wrote. “Even without all of the other shortcomings, the proposal for the DPM mine could be rejected on this basis alone.”

Lack of data is a common issue throughout the assessments, both Emerman and Meehan found. Meehan wrote the assessments had withheld geological and engineering data even though they’d been revised twice.

“Without this data, and necessary laboratory tests as well, and without extensive review by independent experts of international and independent stature, it cannot be said that ANCOLD standards have been or can be fulfilled,” Meehan wrote.

And since the environmental approval issued by Indonesia’s environment ministry is based on these assessments, then it “can only be regarded as premature,” he added.

“In summary, I see that the ANCOLD standards that DPM claim to follow have not been correctly applied. I am confident that oversight of this project by any credible expert or agency will join me in my recommendation that the Indonesian Ministry of Environment and Forestry responsibly reverse their environmental approval,” Meehan wrote.

Syahrial Suandi, an external consultant for DPM, criticized the accuracy of the analyses by Emerman and Meehan, saying they’d used the wrong location for the tailings dam.

“PT DPM already has a detailed study on the distance that is safe between the tailings storage facility and the nearest fault line,” he told local media. “We’d like to stress that the construction of the tailings storage facility will use the best construction standard to withstand earthquakes.”

The mouth of the PT Dairi Prima Mineral’s mine tunnel. Image by Verse S. Karokaro for Mongabay Indonesia.

Litmus test

Given the overwhelming risks and shortcomings in the design and assessments of the project, the mine is a litmus test for the future of mining safety in Indonesia, Emerman said.

Failure by the government to revoke the project’s environmental approval would show the world that Indonesia lacks the mechanisms required to ensure environmental and human rights protection related to mining, he said.

“If the DPM mine is allowed to continue, any manufacturing company that is looking for minerals for a clean energy transition should just walk away from Indonesia,” Emerman added.

That would severely undermine the Indonesian government’s plans to turn Indonesia into a global hub for responsibly sourced energy transition minerals, according to Tongam Panggabean, the director of BAKUMSU, a legal advocacy group representing the communities opposed to the mine project.

“The DPM case is a test case of international significance. If a mine that is clearly going to be a disaster is allowed to proceed, then there is no substance whatsoever in the claim that Indonesia can assist the world with a clean energy transition,” he said.

Should DPM be allowed to proceed with its plan, Rainim said, she and the other villagers in the area will continue to fight.

“We have no choice,” she said. “Our lives, our livelihoods, and our Indigenous culture are at risk.”

Banner image: Villagers of Dairi stage protest in front of the Chinese Embassy in Jakarta in June 2024. Image by Falahi Mubarok/Mongabay Indonesia.

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