Centralized Water Supply Research Articles

Current Trends in Sanitary Microbiology within Implementation of Sanitary and Epidemiological Surveillance of Safety of Water Bodies

Introduction: The epidemic situation in the territory of the Russian Federation is noted for an increase in waterborne diseases and registration of up to 70 % of cases of acute intestinal infections of unknown etiology on certain territories. Numerous cases of gastrointestinal diseases of bacterial and viral etiology associated with the use of water that complies with regulatory requirements validate the importance of improving criteria for pathogen control in water bodies. Objective: To substantiate the expediency to expand the list of key microbiological indicators and standards for an objective assessment of safety of various water bodies. Material and methods: We summarized the results of microbiological testing of water quality and safety in water bodies (potable water, reservoirs, waste water) and substantiated water safety standards proposed by research institutes and centers for hygiene and epidemiology of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor) for 2010–2020. Sanitary and microbiological indicators of potable water and water bodies in places of water use of the population were analyzed based on data of Annual Report Form No. 18 for 2017–2021. Results: Introduction of new indicators and standards for all coliform bacteria, Escherichia coli, and enterococci to control water safety will ensure the absence of waterborne pathogenic and potentially pathogenic bacteria causing gastrointestinal infections. Noncompliance with regulatory requirements for Escherichia coli and enterococci is a strong evidence of recent fecal pollution and the potential epidemic danger of the aquatic environment. Introduction of the Legionella pneumophila indicator to control safety of hot water of centralized water supply, swimming pools and water parks is aimed at preventing Legionella infections in the population. Discussion: Harmonization of key indicators for all types of water enables determination of the epidemiological significance of a particular water body in transmission of pathogens of intestinal infectious diseases and prediction of the epidemic situation. Conclusions: The adequacy of the detected key indicators of water safety determines health outcomes. Their excess indicates the extent of contamination and related risks for population health and necessitates prompt managerial decisions and appropriate preventive measures to eliminate adverse health effects of microbiological agents.

Hygienic assessment of manganese content in household and drinking water supply sources of the Vladimir region

Introduction. One of the most important tasks to ensure the sanitary and epidemiological well-being of the population of the Vladimir region is to provide it with high-quality drinking water. Due to the territory of the region to be partially associated with known hydrogeochemical anomalies of excess manganese content in groundwater, a hygienic assessment of the water of economic and drinking sources was carried out according to the content of this element. Materials and methods. The paper presents the data of own research of the Department of Biology and Ecology of the Vladimir State University named after A.G. and N.G. Stoletov for 2021. During this period, the authors of the work examined about 110 samples of water from the household and drinking centralized and non-centralized water supply of the Vladimir region. Water samples were taken in the largest settlements (these are district centers, regional cities and large district settlements) and from drinking water sources of individual farms located in the territory of the region in various districts. The manganese content in water was determined on the analyzer “Fluorat-02-5M” according to HDPE F 14.1:2:4.188-02. Results. The drinking water of the centralized water supply of the Vladimir region in terms of manganese content was established to meet regulatory requirements and be safe for the health of the resident population. In all samples of drinking water, the concentration of manganese is below 0.1 mg/dm3. At the same time, water from underground sources of non-centralized water supply has in some cases an excess of manganese (from 2 to 7 MPC), which is primarily due to the specifics of the geochemical composition of the water-bearing rocks of these territories. Conclusion in order to provide the population of territories using underground water with a high content of manganese, it is necessary to build local modular water treatment plants using modern methods of non-reactive de-ironing and demanganation and using effective modern equipment and filtering materials.

УРОВНИ ИНДИВИДУАЛЬНЫХ РИСКОВ ЗДОРОВЬЮ НАСЕЛЕНИЯ ГОРНОРУДНОЙ ТЕРРИТОРИИ ВОСТОЧНОГО ЗАБАЙКАЛЬЯ

The formation of geochemical anomalies in Zabaikalsky Krai is associated with the activities of mining enterprises. Over a long period of mining operations in Eastern Zabaikalsky Krai, a significant number of objects of accumulated environmental risk have formed, many of which are located in the vicinity of settlements. Mining wastes pose a potential hazard to the soil, underground and surface water sources, and atmospheric air pollution by a wide range of chemical elements. Arsenic, lead, zinc, cadmium, bismuth and tin are the most common chemical elements exceeding hygienic standards. As a result of a study of the water quality of surface water bodies, drinking water of centralized and non-centralized water supply systems, and the state of the soil cover in the territory of Klichka settlement (Priargunsky District), it was established that in the water of noncentralized and centralized drinking water supply sources the excess of hygienic standards for arsenic and chromium was 2.0 – 5.8 TLV and 1.2 TLV, respectively. The maximum excess of the normative values for arsenic, lead, cadmium and zinc was detected in technosol, which are 200.5, 47.2, 14.0 and 5.5 times, respectively. An assessment of children’s health risk from chemical pollution of drinking water shows that the coefficient of non-carcinogenic hazard for most of the studied chemicals does not exceed the allowable value (HQ = 1.0) the exception is the hazard ratio associated with exposure to arsenic (HQ = 2.50). When calculating the total hazard index for the simultaneous ingestion of chemicals, it was found that for the child population the HQ was 4.12, with arsenic making the greatest contribution to the value of the index. The results obtained indicate the need for further study of environmental factors and in-depth biomedical research.

Review of drinking water quality in the northern regions of the Moscow region based on data from Rospotrebnadzor and private laboratories

The problem of drinking water quality affects many aspects of our lives. The use of water that does not comply with the established safety standards can provoke various adverse consequences for humans. This article reviews the quality of drinking water in water intake wells, public wells, springs, and centralized water supply points in apartment buildings in the Taldom and Dmitrov town districts of the Moscow region. As a result of the analysis of the indicators of 76 sources in these areas, it was found that drinking water that fully complies with the Sanitary Regulations and Norms 2.1.4.1074-01 is observed only in 3 sources. Which advises 3.9% of the total. In 96.1% of the sources, the water is not suitable for drinking and requires additional cleaning measures (up to sanitary and hygienic regulatory requirements for disinfection).

Regional features of the quality of the centralized water supply

The paper studies the results of social and hygienic monitoring of drinking water from centralized water supply systems carried out in the Primorsky Krai, in comparison with Russian indicators according to state reports. Attention is paid to the state of sanitary protection zones, a comparative characteristic of underground and surface sources of drinking water is given in terms of sanitary and epidemiological well-being. There is a decrease in the proportion of samples in the Primorsky Krai that are unsatisfactory in sanitary and epidemiological terms, due to the elimination of water sources that do not have sanitary protection zones along the region. In terms of sanitary and chemical indicators, the proportion of detected unsatisfactory samples taken from underground sources is higher than that of samples taken from surface sources. There is a lag in the provision of high-quality drinking water to the rural population compared to the urban population, and this gap is predicted to increase due to migration outflow to the urban environment and the postponement of the reconstruction of water supply systems. The leading role of surface sources in providing water supply to the largest number of the population of Primorsky Krai, the laboriousness of water treatment and transportation of water against the background of a reduction in the number of sources and centralization of water supply around more productive water sources are noted. The frequency of non-standard samples of drinking water in terms of microbiological indicators is included in the list of primary factors affecting the sanitary and epidemiological well-being of the region. In the Primorsky Krai, hydrogeochemical provinces were identified according to the increased content of manganese in the water and the physiological inferiority of drinking water. The importance of assessing the quality of drinking water, which has a significant impact on the formation of public health, is emphasized.

INVESTMENT DOMINANTS OF THE IMPLEMENTATION OF THE INNOVATIVE MODEL OF SUSTAINABLE USE OF FRESHWATER RESOURCES AT THE NATIONAL AND REGIONAL LEVELS

Of course, in addition to an effective system of control and administration of water resources, essential factors in the implementation of an innovative model of sustainable use of freshwater resources in the regions are the introduction of new technologies aimed at cleaning freshwater water bodies and promoting the rational use of water resources. The activation of such works requires sufficient funding and the attraction of additional investments in the industry. The article aims to research investment dominants in implementing an innovative model of sustainable use of freshwater resources at the national and regional levels. An analysis of investment support for developing the freshwater resource management system in Ukraine was carried out. The analysis showed that over the past ten years, the number of investments increased by 115%, which positively affected the state of water bodies and contributed to the reduction of water consumption in the economy. However, given the high level of wear and tear of the water management infrastructure, which according to the State Statistics Service, is an average of 63% of the available investments, it is not enough for the transition of water management to an innovative model of sustainable development. In addition, the conducted studies showed that more than 98% of investments are directed primarily to eliminating current problems in water management, reorganizing the industry, and partial modernization of water treatment facilities and centralized water supply systems. Almost no funds are invested in developing innovative activities in this area. The main areas of improvement of the system of investment support for innovative development of water management systems in the region are outlined, including improvement of regulatory and legal support and development of public-private partnership, in particular in the form of ESCO contracts; the use of freshwater resources for aquaculture production, which will increase the economic efficiency of the use of surface water bodies, will contribute to the attraction of investments in the industry and strengthening of food security; creation of conditions for attracting foreign investments, in particular in the construction and modernization of infrastructure; intensification of work in the direction of attracting international finances: grants, participation in international programs for the protection and restoration of water resources, etc.

Developing a softening technology for confined groundwater used for the potable water supply in Kondratovo, the Perm Krai

The problem of providing water of drinking quality to small settlements today does not lose its relevance. This article discusses the existing methods of preparing water from a borehole water intake, surveyed part of the centralized system of the settlement, the intended purpose of the extracted groundwater is the household and drinking water supply of the village of Kondratovo, and based on the results of a survey of the technical condition of the centralized water supply system of the village and the water quality of the existing underground source, a technology has been developed for softening water from artesian wells, which ensures that the quality of drinking water complies with the centralized water supply system. Water quality studies were carried out in an accredited testing laboratory center of the Western branch of the FBUZ “Center for Hygiene and Epidemiology in the Perm Territory”. The results of this work increase the reliability of supplying consumers with drinking-quality water and can be applied in assessing investments in engineering infrastructure facilities and developing an investment program.

IMPROVEMENT OF THE MAIN WATER NETWORK FOR MIDDLE CITY

In systems of centralized water supply, the givining-distribution complex (GDC) has the highest cost, including pumping stations, water pipes and water supply networks: main, street, intra-quarter. The economic efficiency of the operation of this complex directly depends on the technical condition of the facilities and equipment. But over time, the technical characteristics of both pumping units and pipelines deteriorate due to wear. Therefore, it is necessary to periodically check their technical characteristics, as well as evaluate the topological characteristics of the water network in the process of its development. This requires regulatory documents and research by specialists in this field of technical sciences. This paper presents an example of such an approach for the givining-distribution complex of the water supply system the medium-sized city Borispol (65 thousand inhabitants) of the Kiev region. To set the throughput of the main water network, hydraulic calculations were performed on a computer using the HIDRO program. It has been established that the main water network has sufficient capacity, as evidenced by the constructed piezometric maps. It has been established that the topological structure of the water network is imperfect. To improve the structure, it is proposed to loop the network by introducing an additional section. This section is introduced in parallel to two existing dead-ends. This improvement made it possible to reduce the pressure at pumping stations by 2.4 m and obtain an annual energy saving of 19.57 thousand kWh. Due to the commissioning of an additional section, a new network ring was formed and the reliability of water supply to a number water consumers increased more than 5.6 times. The indicated increase in the reliability of water supply is due to the fact that this section is introduced in parallel with 2 existing dead-end sections.

WASTEWATER RECLAIMING AND RECYCLING: ESSENCE AND DIRECTIONS FOR IMPLEMENTATION

Topicality. The topicality of the research results from the fact that according to the data of the United Nations (UN), 36% of the world's population lives in water-scarce regions, in particular Ukraine is ranked 125th among 179 countries on the indicator of total internal renewable water resources per capita, which states that Ukraine is poorly supplied with freshwater. In recent years, special attention of international communities have been paid to the wastewater reclaiming and recycling as a possible alternative to traditional water supply and solution of water scarcity problem. In the UN World Water Development Report 2017, it is noted the need to use wastewater as a resource since fresh water has become increasingly scarce. Aim and tasks. The purpose of the article is to determine the essence, features and directions for wastewater reclaiming and recycling implementation to ensure sustainable water resources management in Ukraine. Research results. The results indicate that climate change, rapid urbanization and population growth affect the state of water resources and the population's access to fresh water. In order to find ways to overcome the natural water shortage, it was proposed to use alternative sources of water supply, in particular, wastewater reclaiming and recycling. Based on the analysis of national and foreign regulatory legislation, the modern semantic content of the concepts of "wastewater reclaiming" and "wastewater recycling" has been clarified, and a scheme for introducing the wastewater reclaiming and recycling into the water cycle has been developed. Statistical data on providing the population of Ukraine with centralized water supply and drainage systems and the amount of volumes of untreated wastewater discharged into the environment have been analyzed. The analysis was carried out and the main areas of recycling of wastewater reclaiming components were determined. Conclusion. Considering the importance of ensuring sustainable water resources management, the authors of the article determined the place and role in the introduction of wastewater reclaiming and recycling. The study demonstrated that 97% of Ukraine's wastewater is not recycled, and more than a quarter of the discharged wastewater in the Odessa region is discharged without proper treatment, which has extremely detrimental consequences for the environment and human health. The stages of technological processes of centralized water supply and sanitation services are considered and the introduction of wastewater reclaiming into the water use cycle, in particular in the energy, manufacturing, agricultural sectors and for municipal and domestic needs, is proposed. It is argued that the introduction of wastewater reclaiming and recycling contributes to the development of a circular economy and provides certain socio-economic-environmental benefits, including reducing environmental impact, avoiding overexploitation of water resources and increasing water availability in arid regions of Ukraine.

Umbrella evaporator for continuous solar vapor generation and salt harvesting from seawater

Solar vapor generation, which uses photothermal materials to desalinate seawater by evaporation, is a promising technology to mitigate the water scarcity problem, but its performance is hindered by large heat leak and salt accumulation problems. Here we report an umbrella evaporator that achieves efficient vapor generation and salt harvesting concurrently via double-sided evaporation and reveal the salt nucleation, growth, and falling mechanism. The evaporator reaches an evaporation rate of 1.25 kg m −2 ·h −1 under ambient conditions, and its continuous operation for vapor and salt production from seawater is demonstrated. The salt mobility on the evaporation surface determines whether the salt could accumulate at the edge, which is influenced by water supply, solar intensity, salinity, and Mg 2+ and Ca 2+ contents.A simple salt creeping test on a glass slide is developed to determine whether and to what extent seawater needs to be pre-treated for continuous operation. • Umbrella evaporator achieves a high efficiency via double-sided evaporation • Central water supply results in salt accumulation at edges • Salt grows from the front by wicking water through its porous structures • Salt creeping behaviors indicate if Ca 2+ and Mg 2+ content is below the lower limit Solar evaporation could mitigate water stress problems, but challenges remain in structural improvement of devices, salt accumulation, and salt harvesting mechanisms. Ma et al. show an umbrella evaporator that achieves efficient vapor generation and salt harvesting concurrently via double-sided evaporation and reveal the salt nucleation, growth, and falling mechanism of salt harvesting.

Water Quality from the Sources of Non-Centralized Water Supply within the Rural Settlements of Zhytomyr Region

Abstract The research was conducted within the territories of rural settlements of Zhytomyr region. A total of 72 sources of non-centralized water supply were surveyed. Water quality was assessed by physical and chemical (pH, iron total, total water hardness) and toxicological (nitrites, nitrates, and ammonium) indicators, the content of which was compared with the norms given in the State Sanitary Regulations and Standards 2.2.4-171-10 “Hygienic Requirements for Drinking Water Intended for Human Consumption.” The assessment of drinking water quality was carried out in accordance with DSTU (National Standards of Ukraine) 4808:2007 and with the water quality index (WQI). It was found that the largest deviations from the norm among toxicological indicators were observed for nitrates – 63.9%. In terms of water quality classes according to DSTU 4808:2007, drinking water from sources of non-centralized water supply of villages showed the following distribution: 2.8% of the samples belonged to class 1 (excellent water quality), 72.2% to class 2, and 25% to class 3. According to WQI, 16.7% of the examined sources of non-centralized water supply had excellent water, 63.9% had good water, and 19.4% had poor water. Despite the fact that the water from the investigated sources of non-centralized water supply was of acceptable quality, it is impotable due to the excessive nitrate content. The results obtained show that there is a need for monitoring of drinking water quality from the sources of non-centralized water supply, especially in rural settlements that are not provided with centralized water supply.

Relevant issues of determining total organic carbon in water

Introduction. Total organic carbon (TOC) is a generalized indicator characterizing the pollution of water bodies with organic substances. In accordance with SanPiN 2.1.3864-21 for drinking water, the standard value of TOC content is set equal to 5 mg/dm3. Currently, total carbon analyzers are widely used to determine TOC. Despite its undoubted advantages, the determination of TOC on analyzers has many bottlenecks. Purpose of the study. Analysis of the TOC values of water samples of various origins, obtained using different methods and measurement conditions. Materials and methods. Determination of TOC was carried out with a total carbon analyzer TOC-VCHP (Shimadzu) in accordance with the operation manual of the difference measurement method (TOC) and non-blown organic carbon (NPOC). The objects of study were the water of natural sources, the centralized water supply system of various districts of Moscow, standard solutions of organic compounds. Results. It has been established that during the operation of the analyzer in the analysis of natural and drinking water, incomplete disclosure of humic and fulvic compounds is observed, which cannot be established by standard tests provided for carbon analyzers. The lack of standardized procedures for degassing sparkling water can lead to TOC errors of thousands of percent. Limitation. The limit of determined TOC values was 0.5 mg/dm3. Conclusion. To control the correctness of the determination of TOC in drinking, natural and waste waters, standard samples of humic compounds are required that are characteristic of a particular area with a certified TOC value. It is required to develop and implement a standard procedure for degassing gaseous samples when determining TOC, since the lack of control of this stage of analysis can lead to unacceptable errors in the determination.

Water facilities of Ternopil: hydrography, ecological condition and water supply

The most sensitive to anthropogenic pressure in the city are water resources: surface and groundwater, water sources, etc. Therefore, the analysis of hydrographic features and ecological status of water bodies of the city of Ternopil is an urgent and important scientific and practical task. Purpose. Analysis of hydrographic features and ecological condition of water bodies of the Ternopil city, coverage of problems of pollution of the reservoir, quality of water in the Seret River and the main water intakes of the city Methods. Generalization and systematization, descriptive, SWOT-analysis, cartographic, geoinformation, geochemical assessment of the ecological status of water bodies of the city. Results. Generalization and systematization of data on the hydrographic network of the Ternopil city, allows us to state the fact that the main water bodies of the city is the Seret River – 242 km long (within the city 1.8 km) and the basin area 3900 km2; reservoir – an area of 300 hectares, nameless right tributary and canalized left tributary of the Seret River – the Rudka. The ecological condition of the Seret River within the city of Ternopil can be assessed as unsatisfactory. The main geoecological problems of the river are construction within the the coastal protection zone, water pollution by solid waste, exceeding the maximum allowable concentrations of suspended solids, sulfates, chlorides, nitrates and petroleum products. Environmental problems of the Ternopil reservoir are water pollution by chemical compounds of ammonium nitrogen, petroleum products, suspended solids and total iron; high siltation and pollution of the bottom sediments of the reservoir with heavy metals and mobile forms of biogenic elements. Water supply in the Ternopi cityl is carried out from two water intakes - Biletsky and Verkhnyo-Ivachivsky. Verkhno-Ivachivsky water intake is located at a distance of 3 km from the city landfill in the village of Malashivtsi. In the last few years, the process of drilling and using private artesian wells with a depth of more than 50 m has become widespread in the city. According to the results of the analysis, installed compliance with sanitary requirements of water samples in these wells, pH in all samples within normal limits (6,5-8,5). Conclusions. Current trends in climate change and the growth of anthropogenic pressure on water bodies, increases the risks of degradation and changes in some components of the hydrographic network of the city. In Ternopil, it is necessary to modernize the centralized water supply system, reconstruct rainwater collectors and strengthen control over unauthorized discharges into surface water bodies. It is also worth designing another water intake for the city in environmentally secure conditions.

PROGNOSTIC VALUE OF EXPRESS ANALYSIS OF DRINKING WATER IN RELATION TO THE INCIDENCE OF COVID-19 IN BOYS AND GIRLS AGED 21-22 YEARS

Annotation: To date, the problem of drinking water quality and its impact on human health has been widely covered. Thus, in 2020-2021, 600 samples were examined in 5 districts of Khabarovsk by conducting an express analysis of drinking water of centralized water supply for qualitative and semi-quantitative determination of рН, NO2─, NO3─, Cl─, GH as factors in the formation of COVID-19 morbidity in boys and girls aged 21-22. Such indicators as рН, NO2─, NO3─ and GH correspond to the standard in all districts and all seasons of 2020-2021. The characteristics of Cl─ in drinking water deviate from the standard to a greater or lesser extent, depending on the district of Khabarovsk and the 2020 season. While, in 2021, the Cl─ indicators correspond to the norm. The incidence of COVID-19 of students participating in the study living in different districts of Khabarovsk was also analyzed and the interdependence of the incidence of COVID-19 of boys and girls with some characteristics of drinking water indicators of centralized water supply was determined.

Water footprint of drinking water: The consumptive and degradative use

Centralized water supply systems provide an essential service for society, although they generate direct and indirect environmental burdens to water resources. Quantifying the environmental aspects and impacts is paramount to improving the sustainability of water supply systems, especially in regions affected by water scarcity. In this context, this study aimed to assess the water footprint (WF) of drinking water production. In the aspect dimension, the water footprint assessment (WFA) was used to account for the direct and indirect consumptive (WFBLUE) and degradative (WFGREY) uses of freshwater in m3FW, summed in a WFCOMBINED indicator. Additionally, in the impact dimension, the water scarcity footprint (WSFBLUE) was used to assess the consumptive use of freshwater equivalent in m3 world-eq. The functional unit was 1.0 m3 of drinking water produced in a water treatment plant (WTP) located in northeastern Brazil. Primary data from the water utility company was used in the foreground inventory. The system boundary covered the WF flows for water extraction from the reservoir, net difference of evaporation-to-precipitation on the reservoir surface, supply of chemicals and electricity, WTP infrastructure, transport, WTP sludge management, and water incorporation in the final product (i.e. water content in drinking water). Aside from the Base scenario, where the raw sludge is discharged into the surface water body without treatment, four proposed scenarios for sludge management were evaluated. The WFA results showed that the WFCOMBINED was 67.7 m3FW per m3 of drinking water in the Base scenario, in which direct WFGREY (97.4 %) was the major contributor due to the aluminum assimilation from the sludge discharge, followed by direct and indirect WFBLUE (1.7 %), mainly due to the water incorporation into the final product, and indirect WFGREY (0.9 %). The direct WFGREY in the Base scenario was highly sensitive to the coagulant dosage. The sludge management measures in the proposed scenarios were landfill disposal (Scenario 1), landfill cell sealing material (Scenario 2), recycling in the production of ceramic goods (Scenario 3), and treatment for coagulant recovery (Scenario 4), which reduced the WFCOMBINED by at least 97 %. The coagulant recovery scenario presented the smallest WFCOMBINED and the highest level of compliance with the current environmental standard and policy. The WSFBLUE was obtained using the Available WAter REmaining (AWARE) method considering different method versions and spatiotemporal coverages. The WSFBLUE was highly sensitive to the characterization factor used, which led to different impact rankings when comparing with other regions of the world from the consulted literature. Multiple WF indicators were used herein to represent water consumption, water degradation, and water scarcity, showing how they support more robust decision-making in water resources planning, management, and security.

Hygienic assessment of the risk of development of metabolic disorders associated with pollution of drinking water with organic chlorinous compounds

Introduction. High morbidity rates of diseases of the endocrine system and the existing features of drinking water pollution with organochlorine compounds (OCCs) make it necessary to study the mechanisms of the influence of low doses of organochlorine pesticides on public health. The purpose of the study is to study the features of the formation of non-carcinogenic risk in the population associated with exposure to OCCs in drinking water and endocrine disorders, using the example of 2,4-dichlorophenoxyacetic acid (2,4-D) under conditions of chronic oral exposure in small doses in the experiment. Materials and methods. According to the results of a comparative hygienic assessment of more than 10 thousand samples of drinking water from centralized water supply in 41 municipalities of the Orenburg region, a rural area with the highest content of OCCs and 2,4-D was identified. There was executed an analysis of the incidence of diseases of the endocrine system, digestive system and metabolic disorders (E00-E90) in the population. The experimental part of the work was carried out on 2 groups of Wistar rats: the 1st group was control, the 2nd group consumed water containing 2,4-DA (ammonium salt of 2,4-dichlorophenoxyacetic acid) at a concentration of 0.015 mg/l (0 .5 MPC). In the blood serum of animals, an analysis was made of the level of hormones: triiodothyronine (T3) and thyroid hormone (T4), testosterone and insulin, with an assessment of body weight and epididymal fat. Results. The observation area was established to be characterized by a high level of contamination of drinking water with OCCs and mainly with 2,4-D. Non-carcinogenic risk for the endocrine system (0.005), corresponding to an acceptable level, is significantly higher by 2-4 times (p < 0.05) for adults and children than in the comparison area. The primary incidence of diseases of the endocrine system, digestive system and metabolic disorders (E00-E90) in the observation area (34.88±5.9) is by 2 times higher than the average regional value and 6 times in the comparison area, which indicates the manifestation of disruptive properties 2,4-D and OCCs. The experiment showed that in animals of the experimental group, body weight on day 135 is 10% higher than the control one. An increase in the level of insulin in animals of the experimental group by 70% on day 45 and by 25% on days 90 and 135 of the experiment was established. In the experimental group, on the 45th, 90th and 135th days, the concentrations of T3 decreased by 22%, 5% and 6%, and T4 - by 13%, 12% and 38%, respectively. By the end of the experiment, the testosterone content in the experimental group was lower by 36%. Limitations. The limitations of the study are related to the transfer of the results of experimental data to the studied exposed population and the assessment of only OCCs and 2,4-dichlorophenoxyacetic acid (2,4-D) in drinking water without taking into account other environmental factors. Conclusion. The conducted study testifies to the manifestation of the disruptive properties of 2,4-D in an animal experiment, which is expressed by a violation of the mechanisms of metabolism regulation. The results of the experiment showed the intake of small doses (0.5 MPC) of 2,4-D into the body to have an obesogenic effect, manifested in a gain in total body weight and epididymal fat, accompanied by a decrease in the level of testosterone and thyroid hormones in the blood serum.

Scientific assessment of negative changes in the state of karst groundwater

Centralized water supply in remote settlements is often difficult or impossible, so there is a need to use a non-centralized water supply. The article develops a method for an expert assessment of the negative change in the state of underground karst waters based on a paired analysis of complex indicators of the protection of the aquifer. To assess the vulnerability of non-centralized water supply sources, five factors are used, including the geological structure of the territory, the level of surface and underground runoff, the development of the karst network, precipitation regime electrical conductivity, and mineralization of groundwater. The test was performed using the method of inversely weighted distances (IDW). The vulnerability assessment of karst waters was carried out in the area of 10 key control points identified during the deployment of the hydrogeological control system in 2017. Based on various geological and hydrological indicators, the discrepancy between the vulnerability assessment of karst waters was no more than 15 %. The conditions under which it is advisable to use direct measurements or geoelectric methods to monitor karst groundwater's state are identified.

The third route: A techno-economic evaluation of extreme water and wastewater decentralization

Water systems need to become more locally robust and sustainable in view of increased population demands and supply uncertainties. Decentralized treatment is often assumed to have the potential to improve the technical, environmental, and economic performance of current technologies. The techno-economic feasibility of implementing independent building-scale decentralized systems combining rainwater harvesting, potable water production, and wastewater treatment and recycling was assessed for six main types of buildings ranging from single-family dwellings to high-rise buildings. Five different treatment layouts were evaluated under five different climatic conditions for each type of building. The layouts considered varying levels of source separation (i.e., black, grey, yellow, brown, and combined wastewater) using the corresponding toilet types (vacuum, urine-diverting, and conventional) and the appropriate pipes and pumping requirements. Our results indicate that the proposed layouts could satisfy 100% of the water demand for the three smallest buildings in all but the aridest climate conditions. For the three larger buildings, rainwater would offset annual water needs by approximately 74 to 100%. A comprehensive economic analysis considering CapEx and OpEx indicated that the cost of installing on-site water harvesting and recycling systems would increase the overall construction cost of multi-family buildings by around 6% and single-family dwellings by about 12%, with relatively low space requirements. For buildings or combined water systems with more than 300 people, the estimated total price of on-site water provision (including harvesting, treatment, recycling, and monitoring) ranged from $1.5/m3 to $2.7/m,3 which is considerably less than the typical tariffs collected by utilities in the United States and Western Europe. Where buildings can avoid the need to connect to centralized supplies for potable water and sewage disposal, water costs could be even lower. Urine-diversion has the potential to yield the least expensive solution but is the least well developed and had higher uncertainty in the cost analysis. More mature layouts (e.g., membrane bioreactors) exhibited less cost uncertainty and were economically competitive. Our analysis indicates that existing technologies can be used to create economically viable systems that greatly reduce demands on centralized utilities and, under some conditions, eliminate the need for centralized water supply or sewage collection.

Groundwater sources in the West Siberian region: Chemical composition, analysis, and water treatment technologies

One-fifth of the Russian population does not have access to centralized water supply sources and consumes water without preliminary treatment. Moreover, the gas and oil extracting industries and facilities suffer without a centralized water supply. It requires an immediate solution to providing high-quality water that would meet human life needs. The West Siberian region is actively developing industrially. Despite the abundance of water bodies in Western Siberia, groundwater is the only available water source. It is because surface waters are environmentally unprotected from anthropogenic impact, and the use of groundwater is limited by both the density of humic compounds and the increased density of iron ions, which is typical for the West Siberian region. We analyzed more than three hundred groundwater chemical composition samples in Western Siberia, Russia. Analyzing the samples, we found out that the groundwater includes such compounds as ionic iron (hydro carbonate iron) and iron associated with organic elements (colloidal), color index, salinity, and hydro-carbons density, silicon ions, and organic components. Due to this research, we assessed the groundwater classification. The first type of groundwater classification contains hydro-carbonate iron; however, the second one contains colloidal iron compounds associated with organic elements. We determined that it would be incorrect to measure these two types of groundwater color index similarly. Therefore, the recommendation on measuring the groundwater color index of the second type is correctly revealed. It is essential to verify the groundwater impurities quantitative substance and its ratio, size, and charge of the dispersed phase. We also analyzed the current groundwater treatment procedures and approaches to remove iron from groundwater. The hydro-carbonate iron can be removed from the groundwater by applying the oxidation-filtration method so that the iron content in the form of colloidal iron compounds does not decrease to the maximum permissible concentration values. We determined for the second type, it is better to use membrane filtration, electric discharge, and sorption methods of purification in a particular sequence to ensure the efficacious deletion of iron, silicon, and organic components. This way, the groundwater will not lose other essential microelements. The proposed groundwater classification will instantly identify the problem, considering the water characteristics while analyzing indicators to obtain an accurate result and select further groundwater treatment stages.

Peculiarities of operation of drinking water supply systems in wartime

The military aggression of the Russian Federation and the illegal actions of the aggressor, aimed at the deliberate destruction of civilian infrastructure, proved the vulnerability of centralized water supply systems. Thus, in just a few days from the beginning of the war, consumers of the cities of Mariupol, Melitopol, Volnovakha, Chernihiv, Sumy, and others were completely or partially without water supply.
 In addition to the humanitarian catastrophe due to hostilities, the cessation of centralized water supply as a factor in the vulnerability of life support systems, was actively used by the occupiers in the information war to create panic among civilians, demoralize people, mental disorders and more.
 This article analyzes the main factors of vulnerability of centralized water supply systems in Ukraine, and proposes technical and organizational measures to reduce them, which can be implemented both in the short term and in the long run.
 The factor of sustainability of water supply systems in wartime should not be considered as the only direction of planning their development, but recent events show that it is certainly a priority. Therefore, the recommendations developed in this article can be applied by water supply companies both in operational activities and in strategic planning of the development of water supply systems in the future, in particular during the development of optimization schemes.