Tin mines kill the Nam Ton river

Dead River

For many years now, the people of Quy Hop district have been all too familiar with the red-tinged image of the Nam Ton River. They call it the “dead river” because it no longer has any benefits for them, not even for irrigation.

Nam Ton and Nam Huong are two main tributaries of Dinh River - one of the natural symbols of Quy Hop district. Nam Ton River originates from the mountain ranges in the communes of Chau Hong, Chau Tien and Lien Hop. In many sections of these communes, the river flows underground at the foot of the mountains, forming many karst caves. When reaching Chau Quang commune, Nam Ton merges with Nam Huong, forming Dinh River.

Nam Ton River (left) at its confluence with Nam Huong. Photo: TH

“It’s red all year round. It’s dead! Only when the mines stop discharging waste, will the river come back to life,” Mr. Lo Dinh Ha (72 years old, Chau Hong commune) shook his head in disappointment. In Mr. Ha’s memory, the Nam Ton River used to be crystal clear, and local people often came to its house to use the water for daily activities. It was also full of shrimp and fish, which was a great source of income for them. During the dry season, the river water was also used to irrigate the rice fields here. However, the fate of this river had to change when the first mineral exploitation enterprises came here.

According to Mr. Lang Van Hanh - Chairman of Chau Tien Commune People's Committee, it was about 30 years ago, when the first tin ore mining and processing factory was licensed right next to the upstream of Nam Ton River.

“Previously, environmental issues were not taken into account. The mine discharged waste directly into the river without treatment. The Nam Ton River has been polluted ever since,” said Mr. Hanh.

Most of the year, this river is red. Photo: TH

To date, dozens of licensed mineral mines have been established in the Nam Ton upstream area, in the communes of Chau Hong, Chau Tien and Lien Hop. This area is therefore known as the “mineral capital” of Nghe An. Among them, tin mines are the main culprits that have turned Nam Ton into a dead river.

Most of the year, the Nam Ton River water is a frightening red. Fish and shrimp are gradually dying, and people no longer dare to bring water to irrigate their fields. Because after each irrigation, the rice gradually withers, and the land is also degraded due to polluted water. Without water for irrigation, they have to change crops.

The pollution of the Nam Ton River has become increasingly serious in recent years. As more and more tin mines are licensed and put into operation. According to the Nghe An Provincial Department of Environmental Protection, water samples taken from the monitoring point on the Nam Ton River have a fairly high turbidity, and the TSS index exceeds the standard many times. Specifically, in 2017, the TSS index exceeded the standard by 2.4-3.3 times, in 2018 it exceeded by 1.63-4.73 times, and in 2019 it exceeded by 1.43-10.86 times. In particular, in 2020, the TSS index appeared in the third wave at 808mg/l, while according to the Vietnamese standard it is 30mg/l (26.93 times higher). In the sediment sample also monitored by this unit for the first time in 2021, the arsenic index was more than 157mg/kg while according to Vietnamese standards it is 17mg/kg (9.28 times higher), the mercury index Hg exceeded 1.01 times.

However, these are only water samples taken at the monitoring station on the river through Quy Hop town, dozens of kilometers from the upstream area of ​​Nam Ton. From the upstream, where there are mines, the river has been merged from many small streams. The level of pollution may therefore have been reduced significantly.

Nam Ton has been turned into a dead river. Photo: TH

Sophisticated tricks of mine owners

According to the reporter's investigation, in Quy Hop district, as of January 2022, there are 13 licensed tin mines with remaining exploitation period. Of these, 10 tin mines are located upstream of Nam Ton in 3 communes: Chau Hong, Chau Tien and Lien Hop. Mine owners often pump up groundwater to select ore, separate other compounds and metals from tin. According to regulations, wastewater after being used to select ore must be sent to settling pits, go through treatment steps and then be reused, and must not be discharged into the environment.

However, many mine owners, after selecting ore, find ways to discharge waste directly into the environment. This not only pollutes the environment but also causes groundwater to be pumped to the point of depletion. In recent years, also in this “mineral capital”, hundreds of houses and offices have cracked, collapsed, and wells have dried up. According to the conclusion of the inspection team, the cause is the depletion of groundwater.

A pipe buried deep underground leads into a karst cave after being dug up. Photo: TH

A leader of Quy Hop district said that the Nam Ton River has been dying for decades, which is one of the most pressing issues in the locality. Local authorities and departments have regularly inspected the mines, but it is very difficult to detect violations.

During a recent inspection, when one of the mine's discharge pipes had a problem, the inspection team discovered that two businesses were secretly discharging waste directly into the Nam Ton River. Accordingly, taking advantage of the underground river sections running through karst caves deep in the mountains, the two tin mines installed pipes up to 800m long, then buried them underground and ran straight into the caves to discharge. The discharge point was deep in the cave, so no previous inspection teams discovered it.

Authorities test water samples. Photo: TH

Specifically, when inspecting the tin mining and processing mine of Hong Luong Company Limited in Hung Noi area (Chau Hong commune), the inspection team accidentally discovered a large amount of red wastewater spraying from underground. The leaders of Quy Hop district directly inspected the scene and immediately sent an excavator to discover a pipe with a diameter of 150 mm buried deep underground. Following this pipe, the inspection team discovered the discharge end point deep in the karst cave, where the Nam Ton River flows underground.

"If the pipeline had not burst, no one would have discovered this secret dumping," said an officer in the inspection team.

At the settling tank of Hong Luong Company Limited, the inspection team also discovered a pump of about 11 KW used to pump wastewater. Notably, also in the karst cave, the inspection team also discovered 2 other pipe mouths. These 2 pipes have a diameter of 140mm, about 400m long leading to the wastewater settling tank of Ha Cuong Company Limited. This is a business licensed to exploit and select tin ore in the Thung Xen area (Chau Tien commune). Although these 2 mines are located in 2 communes, they are adjacent to each other and are both located next to the Nam Ton River.

According to the environmental impact assessment report of Ha Cuong tin mine approved by Nghe An Provincial People's Committee, the wastewater after the ore selection process will flow into the sludge settling pond. Here, most of the suspended solids in the water will be deposited. Then the water will flow to the water settling pond for further sedimentation and flow to the reuse reservoir and be reused by circulating pump back to continue using for the next ore selection process. The settled sludge from the ponds will be periodically dredged and dried in the sludge drying yard with an area of ​​1,400 m2, then transported for disposal, reinforced by building the sedimentation pond wall with waste rock and soil products of the mine...

However, at the time of inspection, the embankment of a settling pit was broken due to heavy rain and flooding, but the company had not yet reinforced or repaired it. The sludge and soil discharged during the production process deposited in the waste ponds, causing water to overflow into the environment. The company's behavior was to not properly implement one of the contents of the environmental impact assessment report approved by the Provincial People's Committee.

Taking advantage of the karst terrain, mine owners run pipes deep into the caves to discharge waste. Photo: TH

At the company's settling tank system, the delegation discovered that the company had installed two 11kW pumps connected to two pipes from the settling tank to the karst cave. At the time of inspection, the company did not pump and discharge wastewater directly into the environment. However, through work, the company admitted that the purpose of installing the pumps and pipeline system was to pump and drain wastewater into the karst cave when the settling tank was full or during heavy rains and floods. These two mines were later fined 420 million VND by the People's Committee of Quy Hop district. At the same time, construction activities that generated waste were suspended for 2 months to correct the violations.

Mr. Tran Duc Loi - Vice Chairman of Quy Hop District People's Committee said that after suspending operations at these two mines, the Nam Ton River is showing signs of revival and becoming clear again.