Critical oxygen level and hydrogen sulfide: Kyiv residents urged to refrain from resting on Lake Nebrezh

Residents and guests of the capital are strongly urged to refrain from recreation on the water and swimming in Lake Nebrezh, located in Osokorky, due to unsatisfactory results of the water body's chemical analysis.

Фото: КП "Плесо"

10 July, 16:32

Laboratory studies have shown a significant excess of harmful substances and a critical drop in oxygen levels, making being in the water dangerous to health. Experts note that this lake is generally not intended for swimming, and the current ecological situation requires special control from ecologists and responsible behavior from citizens. This was reported by the communal enterprise "Pleso" citing the results of the analyses from the experimental chemical laboratory.

Chemical analysis results and threat to the ecosystem

Enterprise specialists conducted detailed sampling of water, as well as gray foam film that formed on the lake surface. The obtained data confirmed serious anthropogenic pollution, and the chemical indicators of the water body currently look like this:

samples do not meet standards for color, turbidity, and biochemical oxygen demand (BOD₅);
excessive content of ammonia (ammonium nitrogen), hydrogen sulfide, fats, and dangerous phenols has been recorded in the water;
the dissolved oxygen content in the water body has dropped to a critical limit due to a large amount of foreign substances.

Foam-film studies and microbiological analyses clearly recorded that toxic substances entered the lake through the runoff of coastal debris. In addition, the situation was significantly worsened by the regular discharge of untreated domestic wastewater from adjacent territories.

Slowed self-purification and ecologists' warnings

Currently, an excessive concentration of microalgae is observed in Lake Nebrezh, including green algae, filamentous algae, and cyanobacteria. Due to their active growth, a certain amount of oxygen is still released into the water, which initiates natural ecological processes.

However, specialists emphasize that the overall natural self-purification processes of the reservoir are currently significantly slowed down due to the large volume of dirt.

"We emphasize that Lake Nebrezh is generally not intended for swimming, and in connection with current water analyses, we strongly urge you to refrain from recreation on the water. We ask Kyiv residents to be responsible and heed the ecologists' warnings," state the municipal enterprise.