Hanoi: Plans mapped out for water quality improvement in Hoan Kiem Lake

NDO—Environmental experts and relevant authorities gathered at a workshop held by Hanoi Sewerage and Drainage Limited Company on February 15 to discuss measures to improve the water environment in Hoan Kiem Lake.

A corner of Hoan Kiem Lake in Hanoi. (Credit: Ha Hong/NDO)
A corner of Hoan Kiem Lake in Hanoi. (Credit: Ha Hong/NDO)

Hoan Kiem Lake covers around 12 hectares in the heart of Hoan Kiem District and within the protection zone of the special national relic site Hoan Kiem Lake and Ngoc Son Temple.

Not only does it serve as a rainwater reservoir and control climate condition for the area, but the lake is also a landmark of the capital city, being associated with the spiritual and cultural life of Hanoians, and a key tourist attraction.

However, its water environment is heavily polluted with high-density algae and a high pH, plus biochemical oxygen demand (BOD) and chemical oxygen demand (COD) at nearly two times higher than allowed. It has a sediment layer from 0.4-1.06m thick, containing heavy metals and toxic gases, affecting the habitat of creatures in the lake.

Therefore, experts said that the improvement of the lake’s environment is an essential task to improve the quality of its water and conserve its aquatic systems, while ensuring a green, clean and beautiful landscape.

As proposed by Hanoi Drainage Company, the unit will conduct dredging the lake in an area of over 97,000 m2 with the total volume of dredging needed at 57,400 m3 within 69 days.

After dredging and cleaning mud and waste beneath Hoan Kiem Lake, the company will carry out water treatment by spraying Redoxy-3C products on the lake, then recharging clean water into it and facilitating water circulation, thereby improving its water quality and aquatic ecosystem’s development.

At the seminar, most of the scientists and experts agreed with the plans proposed by Hanoi Drainage Company, adding that environmental improvement plans for Hoan Kiem Lake should be conducted prudently to redress its pollution while protecting its ecosystem and biodiversity.

Hanoi Drainage Company said that experts’ suggestions will be included to finalise its Hoan Kiem Lake environmental improvement plans to submit to the Hanoi’s authorities for approval in the shortest time possible.