An unusual sight alarmed residents of the capital: the water in the Yesil River near one of the bridges turned a bright green hue. A video posted on the Instagram account Zhaloby__astana sparked heated discussion. In the footage, a woman says anxiously that the water looks as if it was deliberately painted, reports infohub.kz.
The authors of the post asked for an inspection into possible pollution of the river near the Tulpar bridge on the embankment. The appeal stated: "A dense layer of bright green mass is observed on the water surface, presumably due to a massive algal bloom or pollution of the water body. I request to determine the causes of this phenomenon, conduct necessary water quality tests, and, if environmental legislation is violated, take appropriate measures."
A correspondent sent a request to the press service of the city administration. They explained that in some sections of the water body, a seasonal phenomenon—water blooming—is observed. According to the administration, it is caused by intensive development of phytoplankton (cyanobacteria) under high air temperatures, low flow speed, and favorable hydrometeorological conditions.
"Such a phenomenon is typical for the summer period. Together with the Department of Ecology for Astana, an inspection of the site has been organized with water sampling for laboratory tests. Based on the results, an objective assessment of water quality will be given, and if necessary, appropriate measures will be taken within the framework of current legislation. Measures are being taken to mechanically remove algae from the water surface, and aeration works are being organized," the administration responded.
To reduce the intensity of blooming and improve the ecological state of the river, it is planned to apply a biological treatment method using a suspension of chlorella. This should restore the biological balance of the water body, suppress the development of blue-green algae, saturate the water with oxygen, and trigger natural self-purification.