Acidic water – a concern on Lan Toong peak.
Following the fish kill in the Nam Huong stream at the end of June 2024, concerns about "acidic" water on Lan Toong mountain (Chau Hong commune) became known. However, this toxic water continues to seep from the mountain into the tin mine shafts of Ha An Tin Company Limited, while the cause remains unclear.
Nhat Lan• November 9, 2025
In mid-October 2025, we were informed by the Chau Hong Commune People's Committee that the Ha An Tin Company Limited's discharge of wastewater that did not meet environmental standards on September 6, 2025, had been penalized. This incident was reported by Nghe An Newspaper and Radio & Television in an article titled "Ha An Tin Company Limited is once again discharging waste into the environment."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 the enterprise is penalized according to regulations, that is natural. But what is concerning is the subsequent statement by the Chairman of the Chau Hong Commune People's Committee, Mr. Cao The Bao: "Water with low pH (acid contamination - PV) continues to overflow from the mine entrance of Ha An Tin Company Limited, while the cause is still undetermined. Because of this issue, we are very worried..."
The reason the Chau Hong commune authorities are concerned, as explained by Mr. Cao The Bao, is that for over a year, the company has ceased all mining activities and has been focusing its efforts daily on treating the "acid-contaminated" water to ensure environmental protection. Meanwhile, provincial authorities, such as the former Department of Natural Resources and Environment, the Environmental Protection Sub-Department, the former Quy Hop District People's Committee, and now the Chau Hong commune authorities, have thoroughly inspected all tin mining areas on Lan Toong mountain (including the mines of Ha An Tin Company Limited and Nghe Tinh Non-Ferrous Metals Joint Stock Company). However, they have still been unable to determine the cause and find a definitive solution. “The businesses are exhausted. They have invited a highly qualified third party to conduct an inspection, but they still couldn't find the cause. With this situation, if the businesses no longer have the resources and give up, Chau Hong commune will have to bear immense pressure in environmental protection efforts…” - Chairman of Chau Hong Commune People's Committee Cao The Bao expressed his concerns.
"...When businesses run out of resources and give up, Chau Hong commune will have to bear immense pressure in environmental protection efforts..."
Chairman of Chau Hong Commune People's Committee Cao The Bao
On October 23, 2025, we were in Chau Hong commune to trek up Lan Toong mountain to verify the problem of "acid-contaminated" water. The mine of Ha An Tin Mining Company Limited is located at an altitude of approximately 700 meters above sea level. At 9:30 AM, despite the rain and cold weather, more than 10 workers were dealing with the "acid-contaminated" water. One group focused on reinforcing and clearing the pipes. This was because the "acid-contaminated" water had a high iron content, causing sedimentation and clogging the pipes. Another group used lime powder and flocculants to neutralize the "acid-contaminated" water, operated the sludge separation system, and transported the sludge to the storage pit. We observed that after neutralization and sludge separation, the "acid-contaminated" water was transferred through a pipeline system to a settling tank before being released into the environment.
Regarding the "acid-contaminated" water, it seeps from cracks and crevices in the mountain into the No. 1 tin mine tunnel. At the time of our visit, water from deep within the tunnel was overflowing into the tunnel entrance and flowing into the ditch at a considerable volume. The water was murky and pale green. When asked to check the pH of the water, a worker dipped litmus paper into the water flowing out of the tunnel. After about half a minute, the litmus paper changed from purple to red. Comparing it to a color chart, the worker said: "With this dark red color, the pH of the water is definitely <3; the acidity is very high." The workers also stated that since 2024, "acid-contaminated" water from the mountain has continuously flowed out of the No. 1 tunnel entrance. During the dry season, the water flow decreases, but during the rainy season, a large amount of water flows out. "During this period, the amount of water released measured between 1,500 and 1,800 cubic meters."3"On average, the company uses 3 tons of lime powder daily to treat the water..." - a worker said.
"With such a dark red color, the pH of the water is definitely <3, meaning the water is very acidic."
Workers of Ha An Tin Company Limited
According to Mr. Nguyen Van Ba, the workshop manager of Ha An Tin Company Limited, water flowing from the mountains is usually very clear and clean. However, the water here is turbid and highly acidic, raising suspicions of external interference. Despite numerous inspections, the cause has not been determined, and no definitive solution has been found. This has resulted in the company being unable to resume production, incurring significant resource losses. Mr. Nguyen Van Ba stated, "We are salaried workers, but we are already exhausted..."
Back in 2024, on June 30th - July 1st, the Nậm Huống stream (formerly Châu Thành commune) suddenly turned a murky yellow color and fish died. Following an inspection, the Quỳ Hợp district (formerly) authorities determined that the pollution was caused by Hà An Tin Company Limited discharging wastewater. In response to this incident, on July 4th, 2024, the Provincial People's Committee issued Official Letter No. 5603/UBND-NN directing an investigation and handling of the matter according to the law.
By July 8, 2024, the directives of the Provincial People's Committee were implemented by the Environmental Protection Sub-Department in coordination with the People's Committee of Quy Hop District (formerly). On-site inspections confirmed that Ha An Tin Mining Company Limited had ceased production (according to the company's report, it stopped on January 30, 2024, to complete related procedures). However, the company had arbitrarily adjusted the overall layout of the tin mining project. Furthermore, it did not reuse wastewater from the mine shafts as stipulated in the approved environmental impact assessment report. Instead, it pumped and pre-filtered the wastewater before discharging it into the karst cave and allowing it to flow by gravity to the head of Bac stream, joining Nam Huong stream at Trung Thanh spillway bridge, Chau Thanh commune (formerly). The act of pumping wastewater from the mine into the karst cave, which then flows naturally into the headwaters of Suoi Bac stream, is the reason why Nam Huong stream has a dark yellow color (as confirmed 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).
Regarding Ha An Tin Co., Ltd., at the meeting on July 8, 2024, they explained to the Environmental Protection Sub-Department and the People's Committee of Quy Hop District about the water generated from the mine. According to the company's representative (recorded in the meeting minutes), the amount of water generated from the mine exceeded the needs for ore processing, which was inconsistent with the content of the approved environmental impact assessment report. In addition, the water showed signs of iron contamination and low pH, requiring the company to treat it before discharging it...
Subsequently, from August to September 2024, the "acid-contaminated" water continued to leak out in large quantities, prompting Ha An Tin Company Limited to submit reports to the People's Committee of Quy Hop District (formerly) and provincial-level agencies. For example, in Report No. 42/BC-THA dated September 30, 2024, sent to the People's Committee of Quy Hop District (formerly), Ha An Tin Company Limited reported that on September 28, 2024, a large amount of cloudy green and white water was found flowing from tunnel No. 1. At 9:30 AM on September 30, 2024, the measured water volume reached 1,679 m3/day, heavily contaminated with acid (pH=3). Therefore, we request that the People's Committee of Quy Hop District: "Promptly conduct an inspection and assessment to identify any unusual water-related issues occurring in Quy Hop District and help us find solutions to these potentially dangerous problems."
Subsequent inspections by the People's Committee of Quy Hop District (formerly) determined that at the location of mine entrance No. 1 (with coordinates x = 2146006, y = 534956) of Ha An Tin Company Limited, there was a large volume of water flowing out from inside the mine shaft. The water was cloudy white; litmus paper testing showed a high acid content (pH < 3). The inspection team went deep into the mine shaft but could not find the source of the water; they did not determine if it was caused by mining and mineral processing activities. The People's Committee of Quy Hop District (formerly) also conducted surprise inspections at the mine shafts of Nghe Tinh Non-Ferrous Metals Company Limited (above the mine of Ha An Tin Company Limited) but still could not find the cause.
Recognizing this as a serious issue, the People's Committee of Quy Hop District (formerly) sent a report to the People's Committee of the province and the Department of Natural Resources and Environment (formerly). The report clearly stated the reality of a large volume of water flowing from the mine shafts of Ha An Tin Co., Ltd., with high acidity (pH<3), an unusual phenomenon whose cause could not be determined. It also concluded that if this water source is not treated according to proper procedures and standards, its discharge into the environment would pose a significant risk of environmental pollution and greatly affect the health of the local population. The People's Committee of Quy Hop District (formerly) also reported that although Ha An Tin Co., Ltd. ceased mining and processing operations at the beginning of 2024, it still collects the water daily into a three-compartment tank, neutralizes it with lime powder and flocculants, and then pumps it out into the environment, resulting in significant resource expenditure for the company.
According to the People's Committee of Quy Hop District (formerly), the district lacks specialized personnel and necessary equipment to determine the cause of the unusual phenomenon, assess whether the current treatment process of Ha An Tin Company Limited complies with technical procedures, and determine whether the treated water meets the standards for discharge into the environment. Therefore, they requested the Provincial People's Committee to direct relevant departments and agencies to investigate and determine the cause, and take decisive measures to address the potential environmental pollution risks.
Regarding the violation on September 6, 2025, by Ha An Tin Company Limited, after more than a month of focused investigation by the Chau Hong Commune People's Committee, Decision No. 361/QD-UBND dated October 16, 2025, was issued, imposing a fine of 315 million VND for the offense of "Discharging water containing hazardous environmental parameters into the environment."
On October 15, 2025, the Department of Agriculture and Environment also issued Document No. 9219/SNNMT-BVMT requesting Ha An Tin Co., Ltd. to “urgently complete the survey, assessment, and determination of the cause and propose a thorough solution for the abnormal water flow phenomenon in tunnel No. 1 at the Suoi Bac mine of the Company; during the implementation process, absolutely no wastewater that does not meet standards should be discharged into the environment. Report the results to the Department of Agriculture and Environment and the People's Committee of Chau Hong commune before November 30, 2025.” It requested Nghe Tinh Non-Ferrous Metals Joint Stock Company to proactively cooperate and create conditions for Ha An Tin Co., Ltd. to determine the cause and address the abnormal wastewater phenomenon in tunnel No. 1. At the same time, it requested the People's Committee of Chau Hong commune to continue monitoring the rectification of shortcomings and compliance with laws on mining and environmental activities of Ha An Tin Co., Ltd.
However, concerningly, stemming from the issue of "acidic water" in the tin mining area of Ha An Tin Company Limited, on August 21, 2024, the Provincial People's Committee sent Document No. 7451/UBND-NN to the Ministry of Natural Resources and Environment (now the Ministry of Agriculture and Environment). This document outlined the current state of mining operations by enterprises licensed by the former Ministry of Natural Resources and Environment to mine tin ore in the Suoi Bac area, Quy Hop district (formerly), along with past environmental incidents. Based on this, the Provincial People's Committee requested the Ministry to establish an inter-agency team to conduct a comprehensive inspection of compliance with laws in the field of natural resources and environment. Furthermore, on November 29, 2024, the former Department of Natural Resources and Environment had to send Document No. 8590/STNMT-BVMT to the former Ministry of Natural Resources and Environment. The document reiterates that the Provincial People's Committee had sent a letter to the former Ministry of Natural Resources and Environment, requesting the Ministry to establish an inter-agency team to inspect the compliance with the law by enterprises licensed to mine tin ore in the Suoi Bac area. However, despite two requests, the former Ministry of Natural Resources and Environment has still not established an inter-agency team to conduct the inspection.
On November 7, 2025, when writing about this issue, we contacted Mr. Cao The Bao, Chairman of the People's Committee of Chau Hong Commune, to get an update on the situation. He explained that due to continuous rain, "acid-contaminated" water from the mountain overflowed into the No. 1 mine entrance of Ha An Tin Company Limited in large quantities, reaching approximately 3,000 cubic meters.3/day. Therefore, Ha An Tin Company Limited continued to report and request guidance on emergency handling measures. Mr. Cao The Bao said: “The company reported that the water overflowing from the mine shafts has a large flow rate exceeding the processing capacity, while the settling tanks are full and do not have sufficient capacity, so it is very easy for an overflow to occur. The commune is very worried, but with the current conditions, we can only urge and remind the company to focus on handling the water, and request that they not discharge water that does not meet the standards into the environment, but we cannot offer any solutions...”.
.jpg)
