“Acidic” water - a concern on Lan Toong peak
After the fish deaths on Nam Huong stream at the end of June 2024, concerns about “acid-contaminated” water on Lan Toong mountain (Chau Hong commune) were known. However, at present, this toxic water is still flowing from the mountain to the entrance of the tin mining tunnel of Ha An Tin Company Ltd., while the cause is still unclear.
Nhat Lan• November 9, 2025
In mid-October 2025, we were informed by the People's Committee of Chau Hong Commune: The act of discharging water that did not meet environmental standards by Thiec Ha An Company Limited on September 6, 2025 was punished. Nghe An Newspaper, Radio and Television reported this incident through the article "Ha An Tin Company Limited discharges waste into the environment again, Chau Hong commune requests the Department of Agriculture and Environment to inspect and handle violations!” on Baonghean.vn on September 7, 2025. Regarding the fact that businesses with violations are punished according to regulations, it is natural. But what is of concern is the subsequent exchange of the Chairman of Chau Hong Commune People's Committee, Mr. Cao The Bao: "Water with low pH (acidic - PV) continues to overflow from the mine entrance of Thiec Ha An Company Limited, while the cause has not yet been determined. Because of this problem, we are very worried...".
The reason why the Chau Hong commune government is worried, as discussed by Mr. Cao The Bao, is because for more than a year, the enterprise has stopped all mining activities, focusing on treating "acid-contaminated" water every day to ensure the environment. Meanwhile, the provincial authorities, such as the Department of Natural Resources and Environment (old), the Department of Environmental Protection, the People's Committee of Quy Hop district (old), and now the Chau Hong commune government, have focused on inspecting and carefully examining all tin mine areas on Lan Toong mountain (including the mine of Ha An Tin Company Limited and the mine of Nghe Tinh Non-ferrous Metals Joint Stock Company). However, the cause has not been determined to be able to come up with a definitive solution. “The enterprise is very tired. They have invited a highly specialized third party to inspect but still cannot find the cause. With this situation, when the enterprise no longer has enough resources and gives up, Chau Hong commune will have to bear great pressure in environmental protection work...” - Chairman of Chau Hong Commune People's Committee Cao The Bao confided.
...When businesses no longer have enough resources and give up, Chau Hong commune will have to bear great pressure in environmental protection work...”.
Chairman of Chau Hong Commune People's Committee Cao The Bao
On October 23, 2025, we were present in Chau Hong commune to go up Lan Toong mountain to verify the problem of "acid-contaminated" water. The mine of Thiec Ha An Company Limited is located at an altitude of about 700m above sea level. At 9:30 a.m., it was raining and cold, but there were about 10 workers treating "acid-contaminated" water. One group focused on reinforcing and clearing the pipes. The reason was that "acid-contaminated" water had a high iron content, causing sediment to clog the pipes. Another group used lime powder and flocculants to neutralize "acid-contaminated" water, operated the sludge separation system, and transported the sludge to the holding area. Observation showed that the "acid-contaminated" water, after being neutralized and separated, was transferred through the pipeline system to the settling tank system, before being released into the environment.
Regarding the source of "acid-contaminated" water, from the cracks and crevices in the mountain, it overflowed into the tunnel of tin mining No. 1. When we arrived, water from deep inside the mine overflowed to the entrance of the mine, flowing into the ditch with a fairly large flow. The water was cloudy and light blue. When asked to check the pH of the water, a worker soaked litmus paper in the water flowing out of the mine. In about half a minute, the litmus paper turned from purple to red. Comparing it with the color chart, the worker said: "With a dark red color like this, the pH in the water is definitely <3, the acidity in the water is very high." Also here, the workers said that from 2024 until now, "acid-contaminated" water from the mountain has continuously flowed out of the tunnel entrance of Mine No. 1. In the dry season, the water flow has decreased, but in the rainy season, a lot of water flows out. "During this period, the amount of water released was measured at 1,500 - 1,800m3/day. On average, the company has to use 3 tons of lime powder every day to treat water..." - said a worker.
Dark red like this, the pH in the water is definitely <3, the acidity in the water is very high".
Workers of Ha An Tin Company Limited
According to Mr. Nguyen Van Ba - Factory Manager of Thiec Ha An Company Limited, water flowing from the mountain is usually very clear and clean. But here the water is cloudy and highly acidic, so there is a suspicion of impact. However, after many inspections, the cause could not be determined, so no definitive solution could be found. This led to the Company not being able to produce, which was very costly in terms of resources. Mr. Nguyen Van Ba said: "We are salaried workers, but we are also very tired...".
Back in 2024, on June 30 - July 1, the Nam Huong stream (formerly Chau Thanh commune) suddenly turned yellow and had dead fish. Organizing an inspection, the authorities of Quy Hop district (formerly) determined that Thiec Ha An Company Limited discharged wastewater, causing environmental pollution. In response to this incident, on July 4, 2024, the Provincial People's Committee issued Official Dispatch No. 5603/UBND-NN directing inspection and handling in accordance with the provisions of law.
By July 8, 2024, the direction of the Provincial People's Committee was coordinated by the Department of Environmental Protection and the People's Committee of Quy Hop district (old). Through on-site inspection, it was determined that Ha An Tin Company Limited had stopped production (according to the company's report, it stopped from January 30, 2024 to complete related procedures). However, this company arbitrarily adjusted the overall site plan of the tin mining project. At the same time, it did not reuse wastewater from the mine as stated in the approved environmental impact assessment report. Instead, it pumped and filtered the wastewater before discharging it into the casto cave and let it flow naturally to the starting point of the North stream, joining the Nam Huong stream at Trung Thanh spillway, Chau Thanh commune (old). The act of pumping wastewater from the mine into the casto cave, then flowing out to the source of Bac Stream, caused Nam Huong Stream to have a dark yellow color (inspected and recorded by the People's Committee of Quy Hop district and the People's Committee of Chau Thanh commune in the Minutes of the meeting on July 2, 2024).
On the side of Thiec Ha An Tin Company Limited, at the working session on July 8, 2024, they explained to the Department of Environmental Protection and the People's Committee of Quy Hop district about the water situation arising from the mine. According to the company's representative (recorded in the working minutes), the amount of water arising from the mine is much larger than the demand for use in the ore selection process, which is not in accordance with the content of the approved environmental impact assessment report. In addition, the water is contaminated with iron and has a low pH, so the Company must treat it before discharging...
In the following period, from August to September 2024, the "acid-contaminated" water continued to flow out in large quantities, so Thiec Ha An Company Limited had to send reports to the People's Committee of Quy Hop District (old) and provincial agencies. As in Report No. 42/BC-THA dated September 30, 2024 sent to the People's Committee of Quy Hop District (old), Thiec Ha An Company Limited informed that on September 28, 2024, a large amount of opaque green and white water was discovered flowing out from tunnel No. 1. At 9:30 a.m. on September 30, 2024, the amount of water measured was up to 1,679 m3/day and night, heavily contaminated with acid (pH=3). Thereby, we request the People's Committee of Quy Hop district: "Soon conduct inspection and assessment to grasp the unusual water problems happening in Quy Hop district and help us find a way to resolve this potentially dangerous difficulty".
The inspection by the People's Committee of Quy Hop district (old) later determined that at the location of the mine door No. 1 (coordinates x = 2146006, y = 534956) of Thiec Ha An Company Limited, there was a water source flowing from the mine door to the outside with a large flow. The water was opaque white; using litmus paper to test showed that the water had a high acid content (pH <3). The working group went deep into the mine to inspect but could not detect where the water was flowing from; was it caused by mineral exploitation and processing activities? The People's Committee of Quy Hop district (old) also made a surprise inspection at the mining tunnels of Nghe Tinh Non-ferrous Metals Company Limited (above the mine of Thiec Ha An Company Limited) but still could not detect the cause.
Realizing that this is a worrying issue, the People's Committee of Quy Hop District (old) has sent a written report to the Provincial People's Committee and the Department of Natural Resources and Environment (old). The report clearly stated the current situation of a large flow from the mine of Ha An Tin Company Ltd., with high acidity (pH <3), which is an unusual phenomenon but the cause cannot be found; and stated that if this water source is not treated according to the correct process and standards, when it flows out, it will pose a risk of environmental pollution, greatly affecting people's health. The People's Committee of Quy Hop District (old) also reported that Ha An Tin Company Ltd. has stopped mining and processing activities since the beginning of 2024, but every day it still has to collect water into a 3-compartment tank, neutralize it with lime powder and flocculants, then pump it out into the environment, leading to a waste of the company's resources.
According to the People's Committee of Quy Hop District (old), the district does not have specialized staff and necessary equipment to find out the cause of the unusual phenomenon, as well as to evaluate the current treatment of Ha An Tin Company Limited to ensure the technical process, and also cannot determine whether the treated water is allowed to be discharged into the environment or not? Thereby, it is recommended that the Provincial People's Committee direct relevant departments and branches to inspect and determine the cause, and take measures to completely handle the risk of environmental pollution.
Returning to the violation on September 6, 2025 of Thiec Ha An Company Limited, after more than 1 month of Chau Hong Commune People's Committee focusing on verifying and clarifying related acts, it issued Decision No. 361/QD-UBND dated October 116, 2025 to fine the violation of "Discharging water containing hazardous environmental parameters into the environment", with a total fine of 315 million VND.
On October 15, 2025, the Department of Agriculture and Environment also issued Document No. 9219/SNNMT-BVMT requesting Thiec Ha An Company Limited to "Urgently complete the survey, assessment, determine the cause and propose a radical solution to the phenomenon of abnormal water flow at tunnel No. 1 at the Suoi Bac mine of the Company; during the implementation process, absolutely do not discharge wastewater that does not meet standards into the environment. Report the implementation results to the Department of Agriculture and Environment and the People's Committee of Chau Hong commune before November 30, 2025". Requesting Nghe Tinh Non-ferrous Metals Joint Stock Company to proactively coordinate and create conditions for Thiec Ha An Company Limited to determine the cause and handle the phenomenon of abnormal wastewater at tunnel No. 1. At the same time, requesting the People's Committee of Chau Hong commune to continue to supervise the overcoming of existing problems and compliance with the law in mineral and environmental activities of Thiec Ha An Company Limited.
However, it is worrying that, stemming from the problem of "acid-contaminated" water in the tin mine area of Ha An Tin Company Limited, from August 21, 2024, the Provincial People's Committee issued Document No. 7451/UBND-NN to the Ministry of Natural Resources and Environment (now the Ministry of Agriculture and Environment). Here, the current exploitation status of enterprises licensed by the Ministry of Natural Resources and Environment (old) to exploit tin ore in the Suoi Bac area, Quy Hop district (old), along with environmental incidents that have occurred. To do so, the Provincial People's Committee proposed that the Ministry establish an interdisciplinary team to inspect the overall compliance with the law in the field of natural resources and environment. Not only that, on November 29, 2024, the Department of Natural Resources and Environment (old) had to issue Document No. 8590/STNMT-BVMT to the Ministry of Natural Resources and Environment (old). The content reiterated that the Provincial People's Committee had sent a document to the Ministry of Natural Resources and Environment (old) to continue to request the Ministry to establish an interdisciplinary team to inspect the law compliance of enterprises licensed to exploit tin ore in the Bac stream area. However, after two requests, the Ministry of Natural Resources and Environment (old) has not yet established an interdisciplinary team to inspect.
On November 7, 2025, when writing about this issue, we contacted the Chairman of Chau Hong Commune People's Committee, Mr. Cao The Bao, to grasp the situation. He said that due to the continuous rain, "acidic" water from the mountain overflowed into the entrance of the No. 1 mine of Ha An Tin Company Ltd. with a large flow rate, up to approximately 3,000m3/day. Therefore, Thiec Ha An Tin Company continued to report and request guidance on emergency handling measures. Mr. Cao The Bao said: "The enterprise reported that the water overflowing from the mine had a large flow rate exceeding the treatment capacity, while the settling tanks were full and could not ensure the capacity, so it was very easy to cause an overflow incident. The commune is very worried, but with the current conditions, it can only urge and remind the enterprise to focus on treatment, request not to discharge water that does not meet standards into the environment, but cannot offer any solutions...".
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