Thoroughly handle the shortcomings of the wastewater reservoir of Nghi Yen Solid Waste Treatment Area

Current situation

In early December 2024, Nghe An Newspaper reporters received a petition from the Provincial Fatherland Front Committee of voters in Nghi Yen commune (Nghi Loc) with the following content: "Voters of Nghi Yen commune, Nghi Loc district proposed to organize a specific assessment of the cause of the large amount of untreated wastewater from the solid waste treatment area flowing into the environment on the evening of September 23, 2024 and request the Vinh City Urban Environment Company to take measures to reinforce the dam, ensuring that untreated wastewater does not flow into the environment...".

Verifying information from the People's Committee of Nghi Loc district, the incident of untreated wastewater from the solid waste treatment area flowing into the environment on the evening of September 23, 2024 is real. Specifically, at 8:00 p.m. on September 23, 2024, there was a prolonged heavy rain, the water level in the reservoir rose so high that the embankment in the southeast corner broke; water from the reservoir flowed through the canal to Khe Rieng bridge. Nghe An Urban Environment and Construction Joint Stock Company then reinforced the broken embankment so that by 9:00 p.m., there was no more wastewater flowing out.

Nghi Loc District People's Committee determined that there was no basis to determine that Nghe An Urban Environment and Construction Joint Stock Company discharged wastewater into the environment; however, it required the organization to operate the wastewater treatment plant in accordance with regulations, and to treat wastewater to meet standards before discharging it into the environment; absolutely not to discharge untreated wastewater into the environment; and required to implement measures to renovate and reinforce the earthen embankments around the leachate reservoir, ensuring that no incidents occur.

Actual observations of the wastewater reservoir of Nghi Yen Solid Waste Treatment Complex show that the water level in the reservoir has risen to approximately the top of the embankment. Meanwhile, the embankment is just an earthen dike with a length of more than 500m.

Because the reservoir’s reserve capacity is no longer available, there is a risk of overflow or landslides when there is heavy rain. Therefore, the concerns of Nghi Yen residents are well-founded.

Talking with the Director of Nghi Yen Solid Waste Treatment Complex, Mr. Truong Duc Son, it was informed that previously, leachate from landfills was treated according to European technology; the water was collected and treated through 8 biological lakes, 1 regulating lake, then flowed out into the environment. However, due to the unsuitability of climate conditions and waste properties in Vietnam, the quality of the wastewater discharged into the environment was not guaranteed.

Therefore, in 2019, the Provincial People's Committee invested in a Leachate Treatment Plant with a design capacity of 200m3/day and night; by October 2022, the Leachate Treatment Plant was put into operation, replacing the natural sedimentation treatment technology through biological ponds. However, complex weather often has prolonged heavy rains, leading to surface rainwater flowing into the reservoir, causing the water level to rise. To prevent the water in the reservoir from overflowing, in early 2023, the company had to fill in soil to create a dike around the reservoir.

Up to now, the water level in the reservoir is up to about 500 thousand m³, while the dike was built with soil, when it rained heavily, in some locations the weak ground led to landslides like on the night of September 23, 2024... so Nghe An Urban Environment and Construction Joint Stock Company organized a review and re-evaluation of environmental protection work at the complex, consulted experts to recently have a comprehensive report on environmental protection work to the Provincial People's Committee, Vinh City People's Committee and related functional branches.

On September 25, 2024, Nghi Loc District People's Committee issued Document sNo. 2701/UBND-TNMT reportProvincial People's CommitteeInspection at Nghi Yen Solid Waste Treatment Complex, recommending the Provincial People's Committee to direct relevant departments and branches to organize inspection and supervision of environmental protection work as well as directing Nghe An Urban Environment and Construction Joint Stock Company to have a plan to reinforce the embankments of the leachate reservoir, operate the treatment station in accordance with the approved environmental license to minimize the amount of water in the reservoir and avoid incidents.

Focus on fixing problems so they don't happen again

It is known that on December 3, 2024, Nghe An Urban Environment and Construction Joint Stock Company issued Document No. 143/MTDT-KLH requesting the Provincial People's Committee to issue many recommendations related to handling existing problems at Nghi Yen Solid Waste Treatment Complex.

In particular, it is proposed to allow the company to research and invest in building a dike system to contain leachate using stone embankments or solid concrete; invest in increasing the capacity of the leachate treatment plant to 500m³day/night to handle the volume of leachate remaining; invest in covering the entire surface of the current landfill cells with HDPE tarpaulin to separate all surface rainwater from flowing into the reservoir and into existing landfills, reducing the risk of rising water levels, ensuring the safety of the reservoir during heavy rains.

In addition, it is allowed to invest in planting trees on the land area around the complex that has been recovered by the Provincial People's Committee but has no plan for use, to create a buffer zone thereby minimizing odor emissions and increasing the environmental landscape.

Considering the proposal of Nghe An Urban Environment and Construction Joint Stock Company, on December 10, 2024, the Provincial People's Committee issued Official Dispatch No. 11017/UBND-CN assigning the Southeast Economic Zone Management Board to preside over and coordinate with the Department of Natural Resources and Environment, Vinh City People's Committee, Nghi Loc District and relevant agencies to consider the proposal of Nghe An Urban Environment and Construction Joint Stock Company in the above Official Dispatch; report and advise the Provincial People's Committee in accordance with regulations.

On January 7, 2025, Vinh City People's Committee organized a working session to remove difficulties and obstacles and resolve recommendations from Nghe An Urban Environment and Construction Joint Stock Company. After that, Notice No. 20/TB-UBND dated January 17, 2025 assigned Nghe An Urban Environment and Construction Joint Stock Company to continue operating Nghi Yen Solid Waste Treatment Complex in accordance with approved procedures, focusing on reinforcing the embankment, and preventing incidents from occurring.

Vinh City People's Committee agreed to organize tree planting on the land that the Provincial People's Committee had reclaimed around the Nghi Yen Solid Waste Treatment Complex. Regarding the proposal to build a system of embankments, surface drainage systems for landfills and surrounding areas, and upgrade the leachate treatment plant to 500m3/day and night at the Nghi Yen Solid Waste Treatment Complex, Vinh City People's Committee requested Nghe An Urban Environment and Construction Joint Stock Company to urgently hire a capable consulting unit to comprehensively assess the operation of the Nghi Yen Solid Waste Treatment Complex to prepare an investment project and submit it to the competent authority for consideration and decision.

According to Mr. Nguyen Huu Thang - Head of the Administrative Organization Department of Nghe An Urban Environment and Construction Joint Stock Company, implementing the direction of Vinh City People's Committee in Notice No. 20/TB-UBND dated January 17, 2025, the Company has hired a consulting unit to comprehensively evaluate the operations of Nghi Yen Solid Waste Treatment Complex to prepare an investment project; has contacted and invited reputable experts to research solutions to separate all surface rainwater from flowing into the reservoir.

To minimize the risk of landslides in the wastewater reservoir, the company has organized the construction of soil to reinforce the dike; at the same time, in preparation for work, the Nghi Loc District People's Committee has developed a plan to plant trees on the land surrounding the Nghi Yen Solid Waste Treatment Complex to minimize odor emissions and improve the environmental landscape...

Mr. Nguyen Huu Thang added: "Along with the earth filling, the company will soon organize the installation of bamboo piles at the foot of the dike and plant bamboo, covering the entire body of the dike to prevent landslides.

These are possible measures to prevent landslides in wastewater reservoirs when the embankment cannot be reinforced with concrete...".