Life Life

07/11/2019 - 08:22

To keep the water constantly clean

Natural disasters, epidemics, and even human activities have been posing threats to water resources and water security.

Renovation of the sedimentation tank at Quang Te 1 water treatment plant

HueWACO's statistics show that 2019 is the year of the highest demand for water use ever. Production water output reached a record level of 201,505 m3/day-night, exceeding 22,011 m3/day-night (11.15%) compared to the peak days of 2018. Currently, the company's plants have been operating beyond their capacity, including temporary capacity.

Meanwhile, according to the plan, in 2020, HueWACO will have to return the premise of Da Vien plant to the province as part of tourist areas planning. Also, Quang Te, Phu Bai, and Hoa Binh Chuong plants have ceased their operation in order to ensure water quality.

Mr. Truong Cong Nam, Chairman of HueWACO's Board of Directors explained, besides the limitation of treatment capacity, the insufficient capacity of the storage tanks also carries potential risks to the city and surrounding areas. Currently, the secure capacity of the storage tank at the 4 plants, including Quang Te 1, Quang Te 2, Tu Ha, and Phu Bai is only 17,300m3, addressing the water supply demand for just about 2.5 hours. As a result, water insecurity has always been a constant threat.

Plants’ workers are trained in operation management skills

According to Mr. Mai Xuan Tan, Deputy Head of HueWACO’s Water Quality Management Department, this constant risk is well perceived by the company. Hence, the company has deployed many solutions. The most important of which is to suspend the operation of the plants in the downstream areas of the rivers to minimize the impacts of domestic wastewater and production, business, and other human-related activities.

Monitoring stations have been installed in every river basin to enable relevant water quality tests on a monthly basis. So far, 24 monitoring stations have been set up in the basins for the sake of source water quality. Therefore, in the event of changes in the quality of the water source, the company could act correspondingly.

Monitoring the quality of the input water source is also taken seriously through the installation of oil fencing buoys and breeding of fishes that are sensitive to changes of water quality right in the reservoir where source water is contained before being piped to sedimentation and filter tanks.

Once the quality of the input water source is not secure, these fishes will become lethargic or dead. Following these signs, necessary actions will be taken.

Output water quality, on the other hand, is monitored on an online system and water quality parameters are updated constantly. Each stage of water sedimentation and filtering is strictly supervised using monitoring devices. Every week, all the plants must collect water samples and take them to the Water Quality Management Department for analyses.

As Mr. Tan said, each plant has developed a safe water supply strategy with studied risks and proposed solutions. Every worker and every plant is provided with a water treatment operation manual where they can find detailed instructions to handle emergencies immediately to minimize hazards.

HueWACO’s is the first water plant that successfully deploys the tap-drinking water model. Photo: HOANG HAI

To cope with the deterioration of water quality, technological solutions such as installing smart sedimentation tanks to treat inorganic polluting sources, introducing biological contactor settling tanks to treat organic polluting sources, establishing facilities to tackle manganese iron or preparing Javen electrolytic salt, etc. are also applied.

Measures to collect groundwater in the rainy season to reuse in hot weather periods have also helped to ease the water scarcity, preventing water insecurity to happen in cases of prolonged droughts.

Thanks to that, the water quality has always been safeguarded with turbidity decreased by 8.5 times (0.02/0.19 NTU) compared to 2007, which is 100 times lower than that regulated in the Decision of Ministry of Health (MOH) (0.02/2 NTU); Iron concentration decreased by 4 times (0.010/0.040 mg/l) compared to 2007, 30 times lower than that regulated in the Decision of MOH (0.01/0.3 mg/l); Manganese concentration decreased by 3 times (0.001/0.003 mg/l) compared to 2007, 300 times lower than that regulated in the Decision of MOH (0.001/0.3 mg/l).

According to Truong Cong Nam, improving the water quality and increasing the number of clean water users are the most important targets to ensure water security. This is why the company decided to implement the ADB project (with loans from the Asian Development Bank). The project has introduced intelligent, synchronous, sustainable, and efficient water supply technical infrastructure and has assured the supply of safe water, ensuring clean water security for over 90% of the province’s population by 2020 (equivalent to more than 1.05 million people).

Implementing the water supply plan, the company has been investing in executing phase 1 of Van Nien Plant project with a treatment capacity of 120,000 m3/day, a 40,000m3 storage tank and a 60,000m3 pressure tank in Quang Te 3 hill. This has lifted the total secure and sustainable storage capacity of Hue area to 117,300m3, increasing water storage time from 2.5 hours to 18.5 hours, enhancing water safety and security to ensure water supply for Hue city and the surrounding areas.

Story and photos: HOANG LOAN