Over recent hot days, such canals in Da Nang as Do Xu, Phan Lang, Da Co, Hong Thai - Tan Trao and Khe Can have faced the threat of serious pollution, adversely affecting the daily lives of nearby residents. Besides, the negative changes in the water quality of many lakes might cause mass fish deaths and other related incidents.

An automatic water environment monitoring station is anchored and floats on the water’s surface to monitor the water quality

Many families living nearby these pollution hotspots have expressed their annoyance about the unpleasant odor emitted from these canals during the current dry season.

According to the indexes released from automatic water environment monitoring stations, managed by the Da Nang Centre of Integrated Circuits (CENTIC), many lakes are experiencing poor water quality in different parameters.

The parameters include pH, ORP, electricity conductivity, turbidity, chlorine, temperature and suspended solids content, even the chemical oxygen demand, and the amount of dissolved ammonium.

The concentration of total ammonia nitrogen (TAN) as NH4 + in the Cam Le District- located Do Xu Lake has increased to 8.35 mg/L, 10 times higher than the allowed limits. The level of dissolved oxygen has decreased to only 1 mg/L whilst the safe threshold is over 2 mg/L.

The water quality of the 29 March Lake is also suffering from the same problem. The poor level of dissolved oxygen there will result in the possible incident of mass fish deaths unless radical solutions are taken to deal with this issue of deep concern.

In recent sunny days, the water of the Da Co canal in Lien Chieu District’s Hoa Khanh Nam Ward has turned black as the result of a large amount of domestic effluent discharged from families nearby, and a volume of leachate from the landfill areas inside the Khanh Son Waste Dump. People who passed by had to put up with a sickening stench wafting off the canal.

In an attempt to resolve the environmental pollution at lakes and canals, many effective measures have been taken by relevant local agencies.

The focus has been on dredging the thick sludge out of these sites, treating the solid waste, installing drain grates, and upgrading all the sluice gates.

In addition, many patches of floating aquatic creatures have been grown in lakes in order to give it a higher aesthetic value, alleviate the bad smells, and create an airy space.

In a bid to reduce the discharge of leachate into the polluted Da Co canal, a new leachate treatment plant at the Khanh Son Waste Dump is expected to be put into use in the 4^th quarter of this year.

Utilising a leachate treatment model developed by Ha Noi’s SEEN Technologies Corporation, the plants aim is to make the daily minimum and maximum levels of leachate treatment at the waste dump 500m³ and 700 m³ respectively.

In a similar vein, the development of a wastewater collection system surrounding the Phan Lang canal and the Bau Trang lake is scheduled to be completed in the 2^nd quarter of this year.

Also, the dredging of 112,800 m³ of thick sludge out of the 29 March lake will be conducted in the coming  time in a bid to improve the water quality here.