The article describes visually detectable anomalies in the structure of the crucian carpet, which make it possible to consider them as a reliable tool for operative ecological monitoring of aquatic ecosystems under the conditions of the anthropic press. The results of the conducted studies were tested in the course of the research "The Post-Mercury Control of Mercury Pollution in the Territory of the Former PO" Khimprom", and also appear to be important in assessing the environmental risk from groundwater pollution and adjacent water bodies in the northern industrial zone of Pavlodar.

Main problem: The article analyzes water quality assurance as the main goal of preserving human health. The study of chemical and microbiological parameters of wastewater and drinking water was carried out using generally accepted standards. The number of deaths associated with the use of contaminated drinking water, according to WHO, tripled in 2021 and reached almost 19 thousand against 6 thousand in 2020. In addition, the number of neoplasms, diseases of the genitourinary system, digestive organs and skin increased by 2 %, to 1.486 million. The reasons for the increase in the level of harmful chemicals and microbiological pollutants in the water are outdated sewage treatment plants, old pipes and disinfection with chlorine. Purpose: Study of the quality of wastewater and drinking water in Pavlodar, study of the quality of wastewater and drinking water in Pavlodar. Methods: Sampling of wastewater, chemical and bacteriological analysis of wastewater and drinking water, statistical method, correlation analysis of experimentally obtained results and calculated characteristics, etc. Results and their significance: In the field of public health risk, pollution of reservoirs that are sources of household drinking water supply and recreational water use, the continuing necessary high deterioration of water supply networks, their accident rate, as a result of low level of operation, failures in the operation of treatment facilities. Hygienic assessment of reservoirs according to complex indicators indicates the continuing high degree of water pollution in places of water use. The water quality indicators of the surface reservoirs of the region remain low in terms of sanitary and chemical (primarily organoleptic and general sanitary), as well as microbiological indicators. According to toxicological indicators, the level of water pollution in places of water use is estimated as moderate. The main pollutants of the Irtysh River in Pavlodar are industrial enterprises and housing and communal facilities that discharge untreated or insufficiently treated wastewater into reservoirs. A complex of causes of drinking water pollution has been identified: high deterioration of water supply networks, their accident rate, because of a low level of operation, failures in the operation of treatment facilities, unfair treatment of industrial wastewater by industrial enterprises of Pavlodar, etc. Priority preventive directions for improving the quality of water as a source of life are the implementation of long-term targeted planning of measures for the modernization of water supply and sewerage networks and facilities in Pavlodar. The state of water supply necessary and measures to improve it should be constantly monitored and considered at meetings of sanitary and anti-epidemic commissions.