100% of inspected tin mining enterprises have violations

(Baonghean) - All 9 tin mining enterprises inspected were found to have violated regulations, showing that it is necessary to strictly monitor environmental protection at tin mines because wastewater and sludge after the tin selection process are harmful.

Check out the violations

After the dam burst of the Nghe Tinh Non-ferrous Metals Joint Stock Company, the Provincial People's Committee directed the inspection of all mineral mining enterprises in Quy Hop district. The 9 tin mining enterprises "were" inspected and audited, including: Ha An Tin Company Limited, Ha Cuong Company Limited, Tan Hoang Khang Company Limited, Hong Luong Company Limited, Duyen Hoang Company Limited, Trung Hai Minerals and Trading Joint Stock Company, Phu Son Investment and Construction Joint Stock Company, Hong Bao Ngoc Company Limited, Thanh Chau Nghe An Minerals Joint Stock Company.

To date, 6/9 of the above mentioned enterprises have been administratively fined with a total amount of 335 million VND. It is worth mentioning that through inspection, it was found that, like Nghe Tinh Non-ferrous Metals Joint Stock Company, all 9 enterprises did not comply with the commitments they stated in the environmental impact assessment (EIA) report approved by the competent authority.

These include the construction of dams and reservoirs to treat wastewater from ore selection activities and waste dumps that are not in accordance with the approved EIA report; environmental monitoring and supervision is not performed at a frequency sufficient to comply with the approved EIA report; the waste storage area is not in accordance with regulations; there is no certificate of completion of environmental protection works serving the operation phase.

The dike to block the settling pond of Hong Bao Ngoc Company Limited in Chau Thanh Commune (Quy Hop) built with waste mud is considered unsafe. Photo: Nhat Lan

For example, Ha An Tin Company Limited was licensed by the Ministry of Natural Resources and Environment to exploit tin minerals in the Suoi Bac area, Chau Hong commune. Through inspection, the authorities determined that the company had not ensured the progress of basic construction of the mine and mining activities; had not complied with the general principles of construction quality management. For mining site 1, 2 settling ponds with a total area of ​​about 500m2 were built, the lake banks were about 3m wide and were filled with waste rock and soil that could collapse during heavy rain; ditches were created to drain overflowing rainwater, however, this system was not completed; sludge from the ore selection process was dumped right next to the settling pits, a part of which was transferred to a waste dump with an area of ​​about 2,000m2, however, the location of the waste dump was not in accordance with the planning location and was currently dumped across the transport route.

Or like Hong Bao Ngoc Company Limited, licensed by the Ministry of Natural Resources and Environment to exploit minerals in the Suoi Mai area, Chau Thanh commune, has not ensured the progress of basic construction of the mine and exploitation activities; has not complied with the general principles of construction quality management. Wastewater produced from the ore selection process is collected and treated through 2 settling ponds, of which pond No. 1 has an area of ​​550m2 divided into 2 compartments, pond No. 2 has an area of ​​300m2, both ponds are lined with a dike on the bottom.

However, the dike built from waste sludge with a width of 5 - 7m is not safe, the construction of the dike and the area of ​​the settling ponds are not in accordance with the approved environmental impact assessment report; the overflowing rainwater is mainly allowed to flow by itself, only some areas have drainage ditches; production waste and waste rock are partly left at the quarry. The ore-processing sludge is dumped into the waste dump in the planning area, however, the dike for the waste dump is made from mud dredged from the settling pond with a dike surface of about 4m wide, which is not safe.

Must be closely monitored

In order to assess the level of heavy metal pollution from mineral exploitation activities, in 2013, the Department of Natural Resources and Environment conducted a specific and detailed investigation and assessment. Regarding tin minerals, the unit conducting the investigation was the North Central Technology and Environment Investment Joint Stock Company, which conducted a field survey in the communes of Chau Hong, Chau Thanh, Chau Tien, Chau Cuong, Lien Hop (Quy Hop), where there are enterprises licensed to exploit tin.

The general assessment is that many exploitation units have not thoroughly applied wastewater treatment measures, allowing the water to flow into Nam Ton and Nam Huong streams, causing the upstream water source to change to a turbid, dark color; reducing the function of irrigation works, affecting domestic water, and reducing the productivity of two-crop rice production of people in Ban Tham hamlets (Chau Cuong commune), Diem Bay, Tong Huong, Quang Huong (Chau Quang commune).

Sedimentation pond of Hong Bao Ngoc Company Limited. Photo: Nhat Lan

The investigation unit took water, soil and sediment samples from settling pits, wastewater drainage channels, mine areas, water reservoirs serving production, the beginning and end of drainage channels... of tin mining enterprises for analysis. Thereby, it was shown that many indicators exceeded the allowable limit. For example, at Thung Lin tin mine, Chau Hong commune (Tan Hoang Khang Joint Stock Company), surface water samples all had As, Pb, Fe content exceeding the allowable limit; soil had As content exceeding the allowable limit by 1.01 times; sediment had Cd content exceeding the allowable limit.

At the tin mine of Trung Hai Minerals and Trading Joint Stock Company in Chau Hong commune, surface water has a Pb content exceeding the permissible limit from 1.04 to 1.46 times; Cd exceeding the permissible limit from 1.5 to 6 times; Fe exceeding the permissible limit from 1.25 to 1.82 times; soil has a Cd content exceeding the permissible limit 1.26 times; sediment has a Cd content exceeding the permissible limit 3.07 times. Or at the tin mine of Nghe Tinh Nonferrous Metals Joint Stock Company in Chau Thanh commune, surface water has a Cd content exceeding the permissible limit from 8.8 to 15.1 times; soil has an As content exceeding the permissible limit 1.05 times, Cd content exceeding the permissible limit 1.29 times; sediment has a Cd content exceeding the permissible limit 1.09 times.

The North Central Technology and Environment Investment Joint Stock Company also took samples of surface water and sediments from streams and cultivated fields in affected areas. The results for Nam Huong stream showed that many surface water samples had As and Fe levels exceeding the permissible limits. Many sediment samples had As and Pb levels exceeding the permissible limits. At Nam Ton stream, out of 15 analyzed surface water samples, 8 had As levels exceeding the permissible limits; 3 of 15 sediment samples had Pb levels exceeding the permissible limits.

At Mai stream, 2 samples were analyzed, both samples had As and Fe contents exceeding the permissible limit; 2 sediment samples had As and Pb contents exceeding the limit. At Bac stream, in 2 analyzed water samples, both As contents exceeded the permissible limit by 1.5 - 1.94 times, 1 sample had Fe contents exceeding the limit by 1.47 times; 2 analyzed sediment samples both had Cd and Pb contents exceeding the threshold, 1 sample had As contents exceeding the threshold by 1.09 times. 5 samples were also taken from cultivated fields in Chau Quang commune for analysis; the results showed that all 5 samples had As contents exceeding the threshold by 1.11 - 1.47 times.

According to the information of the project to assess the level of heavy metal pollution in soil and water due to mineral exploitation activities, it shows that wastewater and waste after the mining and screening process of tin all contain substances that are harmful to the environment.

Along with the dam break incident of Nghe Tinh Non-ferrous Metals Joint Stock Company and the results of inspections of 9 tin mining enterprises, it can be completely affirmed that most tin mining enterprises do not seriously comply with environmental impact assessment commitments and environmental protection commitments; affirming that tin mining has had and is having a very negative impact on the environment.

Therefore, in addition to forcing businesses to strictly implement the contents pointed out through inspections, competent authorities need to do a good job of post-inspection and closely monitor the exploitation activities of these businesses./.

Nhat Lan