The quality of water is determined by its physical, chemical and biological characteristics, which determine the suitability of water for a particular type of use. Chemical pollution of natural waters, first of all, depends on the amount and composition of wastewater from industrial enterprises and municipal services discharged into water bodies. A significant part of pollutants enters water bodies also as a result of their washing away by melt and rain waters from the territories of settlements, industrial sites, agricultural fields, livestock farms. Poor water quality can also be caused by natural factors (geological conditions, rivers fed by waters with a high content of organic matter, etc.).
Of all the types of pollutants entering water bodies, only registered wastewater discharges can be quantified. The background on the map shows the annual discharge of dissolved pollutants in wastewater (in conditional tons) per 1 sq. km. km of the territory of the corresponding water management area, which is most often the catchment area of a medium-sized river or separate parts of the basin of a large river, sometimes the catchment area of a lake. Relative tons are determined taking into account the harmfulness (danger) of individual pollutants by introducing a weighting coefficient for each substance, which is numerically equal to the reciprocal of the maximum allowable concentration of this substance. The most common pollutants with large weight coefficients (100–1000) are phenols, nitrites, etc. Chlorides and sulfates, which, along with organic matter, form the bulk of the substances contained in wastewater, are characterized by the lowest weight coefficients (0.3–0, five).
The largest influx of the mass of dissolved substances in the composition of wastewater is characterized by water management areas, within which there are several cities with a significant volume of wastewater. A similar result is obtained with a relatively small volume of wastewater, but with pollutants that differ in large weight coefficients. The low intensity of pollutants entering water bodies in the composition of wastewater is mainly characteristic of the north of Siberia and the Far East, with the exception of the area within which the city of Norilsk is located.
The main criterion for the quality of water in rivers and reservoirs is the averaged frequency of exceeding the maximum permissible concentration of the main pollutants by their actual content in water, determined on the State Observation Network by the hydrometeorology and environmental monitoring departments of Roshydromet.
At water bodies that do not have stations for stationary monitoring of water quality, it is determined by analogy with water bodies where such observations are carried out, or on the basis of an expert assessment of the impact on water quality of a complex of factors, primarily the presence of sources of pollution of natural waters, as well as dilution capacity of water bodies.
“Extremely dirty” waters are observed mainly in small rivers with low dilution capacity. When even a relatively small volume of wastewater is discharged into them, the average annual concentration of individual pollutants can exceed the maximum permissible concentration by 30-50, and sometimes more than 100 times. This class is inherent in some medium-sized rivers (for example, Chusovaya), into which wastewater with a high content of the most dangerous pollutants is discharged.
The “dirty” class includes water bodies with average annual concentrations of individual pollutants up to 10–25 times the maximum allowable concentration. This situation can be observed both on small and large rivers or their separate sections. Pollution of some large rivers (for example, the Irtysh) is associated with navigation.
"Significantly polluted" water bodies are characterized by average annual concentrations of pollutants up to 7–10 times the maximum allowable concentration. They are typical for many water bodies located in the most economically developed regions of the European part of Russia and the Urals. Pollution of rivers is mainly associated with mining, rivers - with the gold mining industry, rivers and the Lower Tunguska - with the washout of pollutants from the territories of coastal economic facilities. A source of pollution of rivers flowing in a forested area can be timber rafting, especially molar.
In “slightly polluted” water bodies, the average annual concentrations of individual pollutants are 2–6 times higher than the maximum permissible concentration, and in “conditionally clean” water bodies, this can be observed only in short periods of time.
Water bodies of “slightly polluted” and “conditionally clean” rivers prevail in the north of the European part of Russia and the Far East.
Despite the fact that the volume of polluted wastewater discharges in Russia as a whole in the 2000s, compared with the early 1990s, decreased by 20–25%, there is no improvement in water quality, and often even its deterioration is noted. . This is due to a number of reasons, including a significant accumulation of pollutants in the bottom sediments of rivers and, as well as in the soils and soils of their basins, a decrease in the efficiency of treatment facilities, and more frequent cases of accidental pollution of natural waters. Part of the deterioration in water quality indicators is due to the tightening of the maximum allowable concentration for some substances (for example, iron).
Among the pollutants contained in surface waters, most often (in 50-80% of samples) the maximum allowable concentration exceeds the content of copper (Cu) and iron (Fe), as well as the value of biological oxygen demand, which characterizes the content of easily soluble organic substances. A 10-fold excess of the maximum permissible concentration in more than 10% of samples was noted for the same substances. Certain regions of Russia are characterized by the presence of specific pollutants in water bodies: lignin, lignosulfonates, sulfides, hydrogen sulfide, organochlorines, methanol, and mercury compounds. Some pollutants pass from the aquatic environment to bottom sediments and can serve as a source of secondary water pollution.
10. Novikov Yu.V., Plitman S.I., Lastochkina K.S. Evaluation of water quality according to complex indicators // Hygiene and Sanit. 1987. No. 10. S. 7-11.
11. Guidance on methods of hydrobiological analysis of surface waters and bottom sediments, Ed. V.A. Abakumov. L.: Gidrometeoizdat, 1983. 239 p.
12. Shlychkov A.P., Zhdanova G.N., Yakovleva O.G. Using the pollutant runoff coefficient to assess the state of rivers // Monitoring. 1996. No. 2.
Received 03.05.05.
The survey of methods of a complex estimation of the quality of surface waters
The survey of methods of a complex estimation of the quality of surface waters is the result. The opportunity of use of some of them for an estimation of the quality of water objects of Udmurtiya is considered.
Gagarina Olga Vyacheslavovna Udmurt State University 426034, Russia, Izhevsk, st. Universitetskaya, 1 (building 4)
Email: [email protected] en
As a source of drinking water supply, characterized by a low-flow regime and subject to eutrophication processes, it is necessary to assess the quality of water, combining hydrochemical, bacteriological and hydrobiological indicators. In this case, we prefer the methods of the first group.
Among other things, the assessment of surface water quality also depends on the objectives of the study. If we want to get an approximate picture of the chemical pollution of natural waters, then it is really enough for us to assess the quality of water using the WPI. If we are faced with the goal of characterizing a water body as an ecosystem, then hydrochemical characteristics alone are not enough, hydrobiological indicators must also be introduced.
In conclusion, it is worth noting that the use of any selected integrated assessment of water quality in each specific case requires additional research for a more complete development of a practical and universal system for assessing the quality of natural waters.
BIBLIOGRAPHY
1. Belogurov V.P., Lozansky V.R., Pesina S.A. The use of generalized indicators for assessing the pollution of water bodies // Comprehensive assessments of the quality of surface waters. L., 1984. S. 33-43.
2. Bylinkina A.A., Drachev S.M., Itskova A.I. On the methods of graphic representation of analytical data on the state of water bodies // Proceedings of the 16th hydrochem. meeting Novocherkassk, 1962. S. 8 - 15.
3. Temporary guidelines for a comprehensive assessment of the quality of surface and sea waters. Approved USSR State Committee for Hydrometeorology on September 22, 1986
4. No. 250-1163. M., 1986. 5 p.
5. Gurariy V.I., Shain A.S. Comprehensive assessment of water quality // Problems of water protection. Kharkov, 1975. Issue 6. pp. 143-150.
6. Drachev S.M. Fighting pollution of rivers, lakes, reservoirs by industrial and domestic wastewater. M.; L.: Nauka, 1964. 274 p.
7. Emelyanova V.P., Danilova G.N., Kolesnikova T.Kh. Evaluation of the quality of surface waters of land by hydrochemical indicators // Hydrochemical materials. L.: Gidrometeoizdat, 1983. T.88. pp. 119-129.
8. Zhukinsky V.N., Oksiyuk O.P., Oleinik G.N., Kosheleva S.I. Criteria for a comprehensive assessment of the quality of surface fresh waters // Self-purification and bioindication of polluted waters. M.: Nauka, 1980. S. 57 - 63.
9. Methodological bases for assessing the anthropogenic impact on the quality of surface waters, Ed. A.V. Karaushev. L.: Gidrometeoizdat, 1981. 175 p.
Depending on the values of complex estimates of W, the authors propose 4 levels of water pollution (see Table 4).
Table 4
The degree of pollution of water bodies depending on the values of complex indicators W, calculated according to the limiting signs of harmfulness
Pollution level Pollution criterion according to the values of integrated assessments
Organoleptic W) Sanitary regime of TO Sanitary and toxicological Wst) Epidemiological TO
Valid 1 1 1 1
Moderate 1.0 - 1.5 1.0 - 3.0 1.0 - 3.0 1.0 - 10.0
High.0 2, 1.5 3.0 - 6.0 3.0 - 10.0 10.0 - 100.0
Extremely high > 2.0 > 6.0 > 10.0 > 100.0
The advantage of this technique is not only a more complete account of hydrochemical indicators of water quality, but also the fact that, in contrast to the above indicators of WPI and KIZ, in this case, bacteriological indicators are also taken into account. This is especially important for drinking and recreational reservoirs. However, when assessing water quality using this method, two points attract attention: firstly, there is no clear definition of priority indicators of microbial contamination. Most likely, for reservoirs that are sources of drinking water supply, such as the Izhevsk pond, the following can be suggested as such: the number of thermotolerant coliform bacteria, the number of coliphages, and the presence of intestinal infection pathogens. Each of these indicators individually can act as an epidemiological criterion. Secondly, the authors offer only 4 gradations of the level of pollution, which is not always sufficient when working with water bodies (or their sections) that differ in different levels of anthropogenic load.
In conclusion, I would like to emphasize that when developing complex indicators of water quality, it is necessary to proceed from the characteristics of the hydrological regime, climatic and soil conditions of the watershed, as well as the type of water use. So, for the Izhevsk reservoir, which is
water quality class. Thus, an incomprehensible situation arises - either we enter into the calculation all the hydrochemical indicators for which water analyzes are available, or only 5-6 especially "sore" ones for a given reservoir.
Practical experience shows that such a subjective factor as the amount of ingredients used to evaluate water quality can affect the result. For water bodies experiencing a significant anthropogenic impact, with the introduction of a larger number of ingredients into the calculation of the QIP, the water quality class deteriorates.
In our opinion, a more correct approach to assessing water quality, which would allow avoiding subjectivity, comes down to methods where mandatory indicators are included in the calculations, combined into groups according to the limiting hazard indicator (LHI). One of these is the method of assessing water quality by Yu.V. Novikov et al., who propose to calculate a comprehensive assessment of the level of pollution for each limiting sign of harmfulness. In this case, four criteria of harmfulness are used, for each of which a certain group of substances and specific indicators of water quality is formed:
Sanitary regime criterion (Wc), when dissolved oxygen, BOD5, COD and specific contaminants are taken into account, normalized by the impact on the sanitary regime;
The criterion of organoleptic properties (^f), when taking into account the smell, suspended solids, COD and specific contaminants, normalized according to the organoleptic sign of harmfulness;
Hazard criterion of sanitary and toxicological pollution (Wcm): take into account COD and specific pollution, standardized on a sanitary and toxicological basis;
Epidemiological criterion (W,), taking into account the risk of microbial contamination.
The same indicators can be included in several groups at the same time. The complex assessment is calculated separately for each limiting sign of harmfulness (LH) Wc, W,/,. Wcm and W, according to the formula
W= 1 + ^-------
where W is a comprehensive assessment of the level of water pollution for a given DP, n is the number of indicators used in the calculation; N is the standard value of a single indicator (most often N = MPCg). If 6 i< 1, то есть концентрация менее нормативной, то принимается 6 i = 1.
Table 3
Classification of water quality in watercourses according to the value of the combinatorial pollution index
Quality class Grade of the quality class Characteristics of the state of pollution Value of the combinatorial pollution index (CPI)
without taking into account the number of limiting pollution indicators (LPI) taking into account the number of limiting pollution indicators
1 LPZ (k=0.9) 2 LPZ (k=0.8) 3 LPZ (k=0.7) 4 LPZ (k=0.6) 5 LPZ (k=0.5)
I lightly polluted
II - contaminated (1n; 2n] (0.9n; 1.Bn] (0.Bn; 1.6n] (0.7n; 1.4n] (0.6n; 1.2n] (0.5n; 1.0n]
III dirty (2p; 4p] (1,Bn; 3.6n] (1.6n; 3.2n (1.4n; 2.Bn] (1.2n; 2.4n] (1.0n; 1.5n ]
III a dirty (2n; 3n] (1,Bn; 2.7n] (1.6n; 2.4n] (1.4n; 2.1n] (1.2n; 1.Bn] (1.0n; 1 ,5n]
III b dirty (3p; 4p] (2.7n; 3.6n] (2.4n; 3.2n] (2.1n; 2.Bn] (1.Bn; 2.4n] (1.5n; 2 ,0n]
IV very dirty (4n; 11n] (3.6n; 9.9n] (3.2n; B,Bn] (2.Bn; 7.7n] (2.4n; 6.6n] (2.0n; 5 ,5n]
IV a very dirty (4n; 6n] (3.6n; 5.4n] (3.2n; 4.Bn] (2.Bn; 4.2n] (2.4n; 3.6n] (2.0n; 3.0n]
IV b very dirty (6p; 8p] (5.4n; 7.2n] (4.Bn; 6.4n] (4.2n; 5.6n] (3.6n; 4.Bn] (3.0n; 4.0n]
IV c very dirty (8p; 10p] (7.2n; 9.0n] (6.4n; B.0n] (5.6n; 7.0n] (4.8n; 6.0n] (4.0n; 5.0n]
IV d very dirty (10p; 11p] (9.0n; 9.9n] (B.0n; B,Bn] (7.0n; 7.7n] (6.0n; 6.6n] (5.0n; 5.5n]
Further, the summation of the generalized assessment points of all pollutants determined in the alignment is carried out. Since this takes into account various combinations of pollutant concentrations in the conditions of their simultaneous presence, V.P. Emelyanova and co-authors called this complex indicator the combinatorial pollution index.
According to the value of the combinatorial pollution index and the number of water quality ingredients taken into account in the assessment, water is assigned to one or another quality class. There are four classes of water quality: slightly polluted, polluted, dirty, very dirty. Since the third and fourth classes of water quality are characterized by wider ranges of fluctuations of the QIP value than the first and second ones, and significantly different water pollution is assessed in the same way, falling into the same class, the authors introduce quality categories into these classes (Table 3).
Ingredients for which the value of the total evaluation score is greater than or equal to 11 are distinguished as limiting indicators of contamination (LPI).
In cases where the water is very heavily polluted with one or more substances, but has satisfactory characteristics for the rest, when obtaining QIZ, high values of some indicators are smoothed out due to low values for other indicators. To eliminate this, a safety factor k is introduced in the quality gradation, which deliberately underestimates the quantitative expressions of quality gradations depending on the number of limiting contamination indicators and decreases with an increase in the number of the latter (from 1 in the absence of LPZ to 0.5 with 5 LPZ). Thus, if there are limiting indicators of pollution in the water of a water body, the water quality class is determined taking into account the safety factor. If there are more than five LPZs in the water, or if the QIP value is more than 11 p, the water is characterized as “unacceptably dirty” and is considered outside the proposed classification.
So, when calculating the KIZ in comparison with the WPI, in addition to the multiplicity of exceeding the MPC, the frequency of exceeding the MPC is also taken into account. This is a very important addition, although it complicates the assessment of water quality (since the calculations are simple, significant processing of the material is required), but it makes the idea of the contamination of a water body logically complete.
However, as mentioned above, the authors of this method do not limit the number of ingredients involved in the calculation of the QIP. Although, as practical experience shows, when assessing the water quality of water bodies subject to high anthropogenic load (rivers and reservoirs within the city), the more ingredients involved in the calculation of the QIP, the worse
the following method for assessing water quality using a combinatorial pollution index (hereinafter - CPI), proposed by V.P. Emelyanova et al.
The definition of KIZ is carried out according to the following formula:
where Ch, is a generalized evaluation score.
The calculation of the QIS is carried out in several stages. First, a measure of pollution stability is established (according to the frequency of cases of exceeding the MPC):
where H is the frequency of cases of exceeding the MPC for the 1st ingredient; NPdK is the number of analysis results in which the content of the 1st ingredient exceeds its maximum permissible concentration; N is the total number of analysis results for the i-th ingredient.
On the basis of repeatability, one can single out the qualitative characteristics of contamination, which are then awarded quantitative expressions in points.
The second stage of establishing the level of pollution is based on the determination of the indicator of the multiplicity of exceeding the MPC
where K is the multiplicity of exceeding the MPC for the i-th ingredient; C, - concentration of the i-th ingredient in the water of the water body, mg/l; SPdK - maximum allowable concentration of the i-th ingredient, mg/l.
When analyzing the water pollution of water bodies in terms of the multiplicity of exceeding the standards by an individual pollutant, qualitative characteristics of pollution are distinguished, which are assigned quantitative expressions of gradations in points.
Combining the first and second stages of water classification for each of the ingredients taken into account, we obtain generalized pollution characteristics that conditionally correspond to the degree of their influence on water quality over a certain period of time. Qualitative generalized characteristics were assigned generalized evaluation scores B, obtained as a product of estimates for individual characteristics.
table 2
Water quality classes depending on the value of the pollution index
Waters WPI values Water quality classes
Very pure up to 0.2 I
Pure 0.2-1.0 II
Moderately polluted 1.0-2.0 III
Contaminated 2.0-4.0 IV
Dirty 4.0-6.0V
Very dirty 6.0-10.0 VI
Extremely dirty >10.0 VII
Regarding the last condition, I would like to note the following. In the mid 90s. A.P. Shlychkov et al. proposed a WPI taking into account water content (hereinafter referred to as WPI*). WPI* is calculated using the following formula:
A X "™4 * X-" fact
WPI * = WPI K = - £
The numerator in this expression is the observed runoff of the ingredients that make the main contribution to pollution, and the denominator is its maximum allowable runoff in an average water year. And if the pollution of regulated river systems (for example, the Izh River) can be characterized using the WPI, then on rivers characterized by a constant determination of discharges, the calculation of the degree of pollution of a water body for the year should be corrected for the water content in this year. Observations show that on rivers that fall under the main influence of unorganized pollution sources located in the catchment area, in high-water years and seasons of the year (spring), WPI * exceeds just WPI. A different picture is typical for rivers receiving organized wastewater discharges or polluted tributaries (for which, again, the main source of pollution is organized wastewater discharge). In this case, the WPI* in wet years, on the contrary, is lower than the WPI. This is explained by the better dilution of pollutants entering the riverbeds in an organized manner from permanent sources of pollution.
A clear advantage of WPI is the speed of calculations, which made this indicator one of the most common. However, based only on hydrochemical indicators, it can be used for an approximate assessment of the current state of a water body, as well as
However, in the current version of SanPiN 2.1.5.980-00, such a hygienic classification is no longer available.
The second group of methods for assessing water quality consists of methods based on the use of generalized numerical characteristics - complex indices of water quality. One of the most commonly used in the system for assessing the quality of surface waters is the hydrochemical water pollution index (WPI), established by the USSR State Hydrometeorological Committee. This index represents the average share of exceeding the MPC for a strictly limited number of individual ingredients (as a rule, there are 6 of them):
where C is the concentration of the component (in some cases, the value of the physicochemical parameter); n is the number of indicators used to calculate the index, n = 6; MPC - the established value of the standard for
corresponding type of water body.
Thus, the WPI is calculated as the average of 6 indices: O2, BOD5 and four pollutants most often exceeding MPC. This is due to the fact that pollution of a water body may be due to the excess of MPC by one or two substances, while the content of others is insignificant compared to them, and as a result of averaging, we can obtain underestimated WPI values. To eliminate this shortcoming, it is necessary to take into account the priority pollutants of water bodies. For water bodies of Udmurtia, they are represented by the content of organic matter, total iron, ammonium nitrogen, oil products, copper, zinc. One of the constant indexes in WPI calculation is the content of dissolved oxygen. It is normalized exactly the opposite: the reciprocal value is substituted for the C/MPCg- ratio. Depending on the value of the WPI, sections of water bodies are divided into classes (Table 2).
At the same time, a requirement is established that water pollution indices be compared for water bodies of the same biogeochemical province and a similar type, for the same watercourse (along the flow, in time, etc.), and also taking into account the actual water content of the current year.
Phytoplankton biomass - structural hydrobiological indicator; at values of 5.0 g/m3, phytoplankton contributes to water self-purification; higher values are typical for the mass development of phytoplankton (“blooming” of water), the consequences of which are the deterioration of the sanitary-biological state and water quality.
The phytomass of filamentous algae gives an idea of the real and potential deterioration of water quality, since the decomposition of the phytomass of filamentous algae is the cause of water pollution with organic substances, an increase in the number of bacteria. It is estimated by values for the entire area on which these algae develop.
Self-cleaning / self-pollution index (L/I). The ratio of gross production to the total destruction of plankton per day is a functional hydrobiological indicator. Low values of the index (less than 1) indicate an excess of oxygen consumption over its production, as a result of which an oxygen regime unfavorable for the processing of pollution is created. Values above unity characterize intensive processes of organic matter oxidation. At the same time, with a regular excess of production over destruction (L/R>1), biological contamination occurs due to the primary produced residual organic matter.
To identify the impact on water quality of reservoirs of industrial and domestic wastewater in a comprehensive assessment, V.N. Zhukinsky et al. included the scheme of the biotic index for assessing water quality, adopted in England. "Big
the advantages of the latter are: combined accounting of species
diversity of organisms, transformation of qualitative characteristics into quantitative ones (scores or indices), sensitivity to contaminants of unknown origin and ease of use; the disadvantage is the limitation of taxa-indicators... In this regard, the column ''Indicator taxa'' is not filled in the proposed system. When using this assessment of water quality in relation to the Izhevsk Pond, it is necessary to select taxa-indicators specific for this reservoir, which, however, is the field of activity of hydrobiologists and requires special consideration.
A rather successful attempt to classify water according to the degree of pollution for drinking and recreational water bodies was also made at the level of regulatory documents. Thus, SanPiN 4630-88 provides a hygienic classification of water bodies.
complex assessment of water quality of reservoirs, and supplementing them, thereby expanding the scope of water quality assessment. One of the most successful in this area is the development of a comprehensive assessment of the quality of surface fresh water (an early version), proposed by V.N. Zhukinsky with co-authors. It assesses the degree of pollution of the reservoir, taking into account the eutrophication of reservoirs, which is relevant for the Izhevsk reservoir. In this classification, along with hydrochemical indicators of water quality (pH, ammonium nitrogen, nitrate nitrogen, phosphates, percentage of water saturation with dissolved oxygen, permanganate and bichromate oxidizability, BOD5), bacteriological indicators are also used: biomass
phytoplankton and filamentous algae, self-purification index. Let us dwell on the characteristics of these important indicators.
Table 1
The system of coefficients for deriving the total value of the indicator
Indicator name Pollution degree
Very clean Clean Moderately polluted Polluted Dirty Very dirty
Ammonium nitrogen 0 i 3 6 12 15
BOD5 and toxic substances 0 5 8 12 15
Radioactivity total 0 i 3 5 15 25
Escherichia coli titer 0 2 4 10 15 30
Smell 0 and 2 8 10 20
Appearance 0 i 2 6 8 10
Average total pollution factor 0-1 2 3-4 5-7 8-10 >10
some heavy metals (manganese, chromium), petroleum products, ammonium nitrogen, phosphates, BOD5, coli index, water smell.
Thus, the authors of the above classification of water quality have identified those indicators that, in their opinion, should be most often used in the study of water bodies. These indicators are very necessary (one might even say urgent) to characterize the sanitary condition of water bodies in Udmurtia, especially those located in rural areas, where the main sources of pollution are either unorganized sources - surface runoff from livestock facilities and from the village, or organized - disposal of untreated household wastewater into water bodies.
A very important indicator of the sanitary state of water bodies is the content of toxic substances. "As an indicator of the degree of pollution of water bodies in terms of the content of toxic substances, one can take the ratio of the amount of toxic substances found analytically to permissible concentrations, in accordance with existing standards."
Unfortunately, S.M. Drachev does not specify which toxic substances can act as indicative, most likely, those for which more frequent excesses of sanitary and hygienic standards are noted. Regarding the water bodies of our republic, such may be the content of total iron, copper, zinc, chromium.
The authors of this method give each of the indicators a priority - a numerical value corresponding to the importance and significance of this factor. If the classification of a reservoir is ambiguous according to various indicators (the same state of water can be assigned to different quality classes according to different indicators, which is a disadvantage of these methods), then it is necessary to calculate the total pollution indicator by averaging the numerical values of the conditional priorities. The coefficients for calculating the total indicator and the grouping of water bodies according to the sum of signs are given in Table. one.
Despite the fact that with the help of this classification an attempt was made to assess the sanitary state of water in reservoirs (so far we are not talking about a comprehensive assessment of water quality), we cannot but recognize the choice of priority indicators as successful: the titer of Escherichia coli, smell, BOD5, ammonium nitrogen and the appearance of the reservoir at the sampling site (according to the degree of oil pollution). Naturally, in almost half a century that has passed since the appearance of this classification, both knowledge in this area and technical means for monitoring water quality have expanded. Therefore, all of the above indicators can only be taken as a basis for the development
adopted in the international drinking water quality standard (1958). The latter indicator is the ratio of the number of unicellular organisms that do not contain chlorophyll (B) to the total number of organisms, including those containing chlorophyll (A), expressed as a percentage: BPZ \u003d 100 * B / (A + B); organoleptic indicators (transparency, suspended matter content, smell of water, appearance of the water surface).
the total ^-activity can be taken as an indicator, since in relation to this definition there is the largest number of analytical materials” .
As the main indicators of A.A. Bylinkina and co-authors recommended the following five indicators: Escherichia coli titer, smell, BOD5, ammonium nitrogen, and the appearance of the reservoir at the sampling site (according to the degree of oil pollution).
Subsequently, many proposals appeared in the literature on the choice of main indicators for assessing water quality. Some authors suggested using all indicators for which MPCs were established. Others used a limited number of indicators in their calculations (9-16 on average).
The ideal option would be to use all indicators, but this is not feasible in real conditions. It is necessary to select indicators for obligatory observation. Almost all authors, with slight variations, agree on the following group: suspended solids, dissolved
oxygen, biochemical oxygen demand (BOD), pH, coli-index, Na+, NO^, chlorides, sulfates.
Proposals for a comprehensive assessment of water quality based on such a reduction in the list (or any of its extended options) are based on the use of the representativeness principle, according to which pollutants are divided into two groups: representative and background. The first group is determined systematically, and the second - relatively rarely. Among the representative pollutants are specially selected, the concentrations of which, based on local conditions, can significantly exceed the MPC. Substances of the obligatory group are considered as the background (there may be 15-20 of them). For example, for the Izhevsk reservoir, located within the city and receiving industrial and domestic wastewater, as well as surface runoff from the city, the number of representative compounds should include
UDC 504.4.054 O.V. Gagarin
REVIEW OF METHODS FOR INTEGRATED ASSESSMENT OF SURFACE WATER QUALITY
An overview of methods for a comprehensive assessment of the quality of surface waters is given. The possibility of using some of them to assess the quality of water bodies in Udmurtia is being considered.
Key words: water quality, water quality assessment, water quality indicators, water quality classes.
The currently existing methods for a comprehensive assessment of surface water pollution are fundamentally divided into two groups: the first includes methods that allow assessing water quality by a combination of hydrochemical, hydrophysical, hydrobiological, microbiological indicators; to the second group - methods related to the calculation of complex indices of water pollution.
In the first case, water quality is divided into classes with different degrees of pollution. This method in assessing the state of water bodies has a long history. Back in 1912, in England, a similar classification was proposed by the Royal Commission on sewage. True, then mainly chemical indicators were used. According to the external signs of pollution, the reservoirs were divided into six groups: very clean, clean, fairly clean, relatively clean, questionable and bad. BOD5, oxidizability, ammonium, albuminoid and nitrate nitrogen, suspended solids, chlorine ion and dissolved oxygen were then taken as indicators. In addition, the smell, turbidity of water, the presence or absence of fish, and the nature of aquatic vegetation were taken into account. The greatest importance was attached to the value of BOD.
In 1962, in the USSR, A. A. Bylinkina and co-authors proposed a classification of water bodies according to chemical, bacteriological and hydrobiological characteristics and physical properties. It was the first most advanced development in this direction, which laid the foundations for the widespread six-point scale for classifying water bodies. Water quality is assessed using chemical indicators (dissolved oxygen content, pH, BOD5, oxidizability, ammonium nitrogen, content of toxic substances); bacteriological and hydrobiological indicators (coli-titer, coli-index, number of saprophytic organisms, number of helminth eggs, saprobity and biological indicator of pollution, or Khorasawa index,
General characteristics of surface water quality
The characterization of the quality of the rivers of the Vologda Oblast was made on the basis of materials obtained as a result of hydrochemical monitoring at 50 points, which are controlled by the Vologda TsGMS, and 1 point of production control (JSC Severstal) at water bodies of the Vologda Oblast:
29 rivers, Kubenskoye Lake, Rybinsk and Sheksninskoe (including Lake Beloe) reservoirs.
The water quality was assessed in accordance with the RD 52.24.643-2002 developed by the Hydrochemical Institute and put into effect in 2002 "Methodological guidelines. A method for a comprehensive assessment of the degree of pollution of surface waters by hydrochemical indicators, using the software package "UKIZV - network".
Based on the analysis of samples taken in 2010, it can be concluded that the surface waters of the region mainly belong to class 3 (the "polluted" category) - 60% of observation points, to class 4 (the "dirty" category) - 36% , to class 5 (category "extremely dirty") - 2% of points, which is explained by the natural origin and background nature of the increased content of iron, copper and zinc in the surface waters of the region, as well as chemical oxygen demand (COD), which mainly determine the value UKIZV. At the same time, the anthropogenic component of pollution is clearly seen only in watercourses, the natural flow of which is much less than the volume of wastewater entering them (the Pelshma, Koshta, Vologda, Sodema, and Shogrash rivers). Class 2 (the category “weakly polluted” includes 2% of points (Figure 1.2. and Table 1.2.).
Compared to 2009, there has been a decrease in the number of water bodies classified as quality class 3 (“polluted” category), while the number of objects classified as class 4 (“dirty” category) has simultaneously increased.
An analysis of possible causes showed:
In 2010, compared to 2009, the volume of polluted wastewater decreased by 2.3 million m3, the mass of pollutants decreased by 0.6 thousand tons;
The deterioration of water quality has affected in most cases water bodies, the anthropogenic impact on which is insignificant or completely absent.
Thus, it can be concluded that the deterioration of water quality in the water bodies of the region is associated with an abnormally high temperature and a shortage of precipitation during the summer low water period of 2010, which led to an increase in oxidative processes and an increase in the share of groundwater in the formation of runoff. As a result, there was an increase in the content of nitrogen group substances in water, as well as substances characteristic of water-bearing soils (copper, zinc, aluminum, manganese).
Table 1.2.
Comparison of surface water quality in the oblast based on the 2009 and 2010 UKWIS Composite Indicator.
| year 2009 | 2010 | ||||
| UKWIS | UKWIS | class, category (category) of water quality | |||
| White Sea basin | |||||
| lake Kubenskoye - village Korobovo | 2,32 | 3A (contaminated) | 3,17 | 3B (very polluted) | Cu (3.6 MAC), COD (2.6 MAC), Fe (1.3 MAC), BOD5 (1.7 MAC) |
| R. Uftyuga - village Bogorodskoe | 4,68 | 4A (dirty) | 3,68 | 3B (very polluted) | Fe (1.9 MAC), Cu (2.0 MAC), COD (1.3 MAC), BOD5 (2.5 MAC), SO4 (1.2 MAC) |
| R. Bolshaya Elma - d. Filyutino | 2,72 | 3A (contaminated) | 3,60 | 3B (very polluted) | Cu (5.1 MAC), Fe (1.4 MAC), COD (2.1 MAC), BOD5 (1.5 MAC), SO4 (1.2 MAC) |
| R. Syamzhena - with. Syamzha | 3,50 | 3B (very polluted) | 4,66 | 4A (dirty) | Fe (4.9 MAC), Cu (11.0 MAC), COD (3.6 MAC), Zn (2.2 MAC), petroleum products (1.9 MAC), NO2 (1.1 MAC) |
| R. Kubena - village Savinskaya | 3,13 | 3B (very polluted) | 4,86 | 4B (dirty) | Cu (28.3 MAC), Fe (2.9 MAC), COD (2.2 MAC), Zn (6.9 MAC), NH4 (1.0 MAC), petroleum products (1.0 MAC) |
| R. Kubena - village TroitseEnalskoe | 3,34 | 3B (very polluted) | 2,26 | 3A (contaminated) | Fe (2.7 MAC), Cu (3.0 MAC), COD (1.5 MAC) |
| R. Sukhona - 1 km above Sokola | 3,62 | 3B (very polluted) | 3,57 | 3B (very polluted) | Cu (4.9 MAC), COD (2.5 MAC), Fe (1.1 MAC), BOD5 (1.3 MAC), phenols (1.8 MAC), Ni (1.4 MAC), Mn ( 1.0 MPC) |
| R. Sukhona - 2 km below Sokola | 4,00 | 3B (very polluted) | 4,34 | 4A (dirty) | Cu (5.3 MAC), COD (2.5 MAC), Fe (1.7 MAC), BOD5 (1.3 MAC), phenols (1.8 MAC), Ni (1.4 MAC), Mn ( 1.0 MPC) |
| R. Toshnya - d. Svetilki | 3,36 | 3B (very polluted) | COD (2.4 MAC), BOD5 (1.6 MAC) | ||
| R. Toshnya - Vologda, water intake PZ | 4,39 | 4A (dirty) | 4,48 | 4A (dirty) | Cu (4.8 MAC), COD (1.8 MAC), BOD5 (1.7 MAC), NH4 (1.1 MAC), NO2 (1.3 MAC) |
| R. Vologda - 1 km above the city of Vologda | 4,54 | 4A (dirty) | 4,32 | 4A (dirty) | Cu (8.0 MAC), COD (2.3 MAC), Fe (1.9 MAC), BOD5 (1.4 MAC), Ni (1.3 MAC), Mn (1.5 MAC), phenols ( 1.2 MPC) |
| R. Sodema - Vologda | 7,43 | 4B (very dirty) | 7,64 | 4B (very dirty) | BOD5 (2.8 MAC), NO2 (3.8 MAC), COD (2.7 MAC), NH4 (2.2 MAC), petroleum products (4.3 MAC), phenols (2.5 MAC) |
| R. Shogrash - Vologda | 8,40 | 4B (very dirty) | 7,45 | 4G (very dirty) | NH4 (4.5 MAC), BOD5 (2.5 MAC), COD (2.2 MAC), NO2 (3.6 MAC), petroleum products (1.2 MAC), phenols (2.5 MAC) |
| R. Vologda - 2 km below Vologda | 5,54 | 4B (dirty) | 6,02 | 4B (very dirty) | NO2 (4.2 MAC), NH4 (4.1 MAC), Cu (4.4 MAC), BOD5 (3.3 MAC), COD (2.7 MAC), Fe (2.3 MAC), phenols (1.4 MAC), Ni (1.5 MPC), Mn (1.5 MPC) |
| R. Lying - v. Zimnyak | 3,26 | 3B (very polluted) | 2,92 | 3A (contaminated) | Cu (5.4 MAC), Fe (2.6 MAC), BOD5 (1.5 MAC), COD (2.4 MAC) |
| R. Sukhona - 1 km above the mouth of the river. Pelshmy | 2,70 | 3A (contaminated) | 2,68 | 3A (contaminated) | COD (2.2 MAC), Fe (1.2 MAC), Ni (1.5 MAC), NO2 (1.7 MAC) |
| Water body - settlement | year 2009 | 2010 | |||
| UKWIS | class, category (category) of water quality | UKWIS | class, category (category) of water quality | indicators exceeding the MPC (Cav / MPC) | |
| R. Pelshma | 7,29 | 5 (extremely dirty) | 7,89 | 5 (extremely dirty) | Fe (4.3 MAC), BOD5 (20.5 MAC), lignosulfonates (14.6 MAC), phenols (15.3 MAC), COD (11.9 MAC), NH4 (2.4 MAC), NO2 ( 1.2 MPC), oxygen (1.0 MPC) |
| R. Sukhona - 1 km below the mouth of the river. Pelshmy | 2,70 | 3A (contaminated) | 2,81 | 3A (contaminated) | COD (2.2 MAC), Fe (1.2 MAC), phenols (1.1 MAC), Ni (1.4 MAC) |
| R. Sukhona - s. Narems | 3,06 | 3B (very polluted) | 3,76 | 3B (very polluted) | COD (3.0 MAC), Cu (6.1 MAC), Fe (2.5 MAC), BOD5 (1.9 MAC), Mn (1.0 MAC), Ni (1.2 MAC) |
| R. Dvinitsa - the village of Kotlaksa | 3,17 | 3B (very polluted) | 3,68 | 3B (very polluted) | Fe (3.5 MAC), Cu (6.4 MAC), petroleum products (1.1 MAC), COD (2.9 MAC), BOD5 (1.0 MAC), NH4 (1.0 MAC) |
| R. Sukhona - above the city of Totma | 2,74 | 3A (contaminated) | 3,06 | 3B very (polluted) | Fe (3.4 MAC), COD (2.9 MAC), Cu (3.8 MAC) |
| R. Sukhona - below the city of Totma | 3,98 | 3B (very polluted) | 3,33 | 3B (very polluted) | Fe (2.9 MAC), COD (2.9 MAC), Cu (3.6 MAC), NO2 (1.5 MAC) |
| R. Ledenga - d. Yurmanga | 4,01 | 4A (dirty) | 5,06 | 4A (dirty) | Cl (1.1 MAC), Fe (2.2 MAC), COD (2.7 MAC), SO4 (3.4 MAC), Cu (3.5 MAC), BOD5 (1.4 MAC) |
| R. Old Totma - village Demyanovsky Pogost | 3,71 | 3B (very polluted) | 3,05 | 3B (very polluted) | COD (1.6 MAC), Fe (1.5 MAC), Cu (2.1 MAC), BOD5 (1.2 MAC), SO4 (1.5 MAC) |
| R. Upper Erga - village Pikhtovo | 3,67 | 3B (very polluted) | 3,29 | 3B (very polluted) | Fe (2.6 MAC), Cu (4.2 MAC), COD (1.8 MAC) |
| R. Sukhona - 3 km above Veliky Ustyug | 3,01 | 3B (very polluted) | 3,51 | 3B (very polluted) | Cu (5.4 MAC), COD (2.2 MAC), Fe (2.6 MAC), Ni (1.4 MAC), Mn (1.2 MAC) |
| R. Kichmenga - village Zakharovo | 2,74 | 3A (contaminated) | 3,61 | 3B (very polluted) | Fe (2.0 MAC), COD (1.8 MAC), Cu (3.6 MAC) |
| R. South - d. Permas | 3,03 | 3B (very polluted) | 1,98 | 2 (lightly polluted) | COD (1.8 MAC), Fe (3.6 MAC), Cu (2.9 MAC) |
| R. South - d. Strelka | 3,36 | 3B (very polluted) | 3,24 | 3B (very polluted) | Fe (4.7 MAC), COD (1.7 MAC), Cu (5.4 MAC), Zn (1.0 MAC) |
| R. M. Northern Dvina - below the city of Veliky Ustyug (Kuzino) | 3,39 | 3B (very polluted) | 3,78 | 3B (very polluted) | Fe (4.3 MAC), Cu (7.1 MAC), COD (2.0 MAC), Ni (1.4 MAC), Zn (1.1 MAC), Mn (1.2 MAC) |
| R. M. Northern Dvina - 1 km above the town of Krasavino (Medvedki) | 3,75 | 3B (very polluted) | 3,43 | 3B (very polluted) | Fe (3.3 MAC), Cu (5.8 MAC), COD (2.1 MAC), Zn (1.2 MAC), BOD5 (1.0 MAC) |
| R. M. Northern Dvina - 3.5 km below the town of Krasavino | 3,41 | 3B (very polluted) | 4,02 | 4A (dirty) | Fe (3.2 MAC), COD (2.4 MAC), Cu (6.3 MAC), Zn (1.1 MAC), Ni (1.7 MAC), BOD5 (1.0 MAC), Mn ( 1.5 MPC) |
| R. Vaga - village Gluboretskaya | 3,53 | 3B (very polluted) | 4,36 | 4A (dirty) | Cu (3.5 MAC), Fe (3.3 MAC), COD (2.6 MAC), BOD5 (1.1 MAC), petroleum products (1.6 MAC) |
| R. Vaga - below with. Verkhovazhye | 4,72 | 4A (dirty) | 3,66 | 3B (very polluted) | COD (1.6 MAC), Fe (1.8 MAC), Cu (3.2 MAC), SO4 (1.3 MAC), NO2 (1.5 MAC), BOD5 (1.4 MAC) |
| Caspian basin | |||||
| R. Kema - village Popovka | 2,49 | 3A (contaminated) | 3,08 | 3B (very polluted) | Fe (3.9 MAC), COD (1.6 MAC), Cu (2.0 MAC), NH4 (1.0 MAC) |
| R. Kunost - d. Rostani | 2,77 | 3A (contaminated) | 2,97 | 3A (contaminated) | Fe (2.2 MAC), Cu (4.1 MAC), COD (2.1 MAC) |
| lake Beloe - d. Kisnema | 2,77 | 3A (contaminated) | 3,04 | 3B (contaminated) | Fe (5.8 MAC), Cu (2.9 MAC), COD (2.9 MAC), NH4 (1.1 MAC) |
| lake Beloe - Belozersk | 3,35 | 3B (very polluted) | 3,07 | 3B (very polluted) | Fe (4.5 MAC), COD (2.8 MAC), Cu (2.7 MAC) |
| Sheksna reservoir. - village Krokhino | 2,58 | 3A (contaminated) | 2,11 | 3A (contaminated) | Fe (5.7 MAC), Cu (5.0 MAC), COD (2.6 MAC) |
| Sheksna reservoir. - from. Ivanov Bor | 3,23 | 3B (contaminated) | 4,28 | 4A (dirty) | Fe (6.2 MAC), Cu (3.7 MAC), COD (2.5 MAC), petroleum products (1.0 MAC), NO2 (1.7 MAC) |
| R. Yagorba - d. Mostovaya | 4,93 | 4A (dirty) | 5,00 | 4A (dirty) | Fe (1.1 MAC), COD (1.8 MAC), BOD5 (2.0 MAC), SO4 (4.3 MAC), Cu (2.3 MAC), Ni (1.4 MAC), petroleum products (1, 6 MAC), NH4 (1.1 MAC), NO2 (1.5 MAC), Mn (1.0 MAC) |
| R. Yagorba - Cherepovets, 0.5 km above the mouth | 3,75 | 3B (very polluted) | 4,41 | 4A (dirty) | Cu (3.6 MAC), Fe (2.2 MAC), COD (2.7 MAC), Ni (1.7 MAC), BOD5 (1.4 MAC), Mn (1.3 MAC) |
| R. Costa - Cherepovets | 6,29 | 4B (dirty) | 6,11 | 4B (dirty) | NO2 (5.7 MAC), Cu (6.6 MAC), Zn (2.8 MAC), SO4 (1.9 MAC), Ni (1.7 MAC), COD (2.7 MAC), BOD5 (2.0 MAC), Fe (2.0 MAC), Mn (1.8 MAC), NH4 (3.6 MAC) |
| R. Andoga - village Nikolskoye | 3,67 | 3B (very polluted) | 3,33 | 3B (very polluted) | Fe (4.2 MAC), Cu (3.7 MAC), COD (3.1 MAC), petroleum products (1.9 MAC) |
| R. Ships - village BorisovoSudskoe | 4,29 | 4A (dirty) | 4,54 | 4A (dirty) | Fe (3.8 MAC), Cu (9.0 MAC), COD (1.3 MAC), Zn (1.5 MAC), BOD5 (1.6 MAC), NH4 (1.1 MAC), NO2 ( 1.3 MPC) |
| R. Chagodoshcha - village Megrino | 2,72 | 3A (contaminated) | 2,69 | 3A (contaminated) | Fe (4.6 MAC), Cu (2.8 MAC), COD (1.8 MAC) |
| R. Mologa - above the city of Ustyuzhna | 2,89 | 3A (contaminated) | 3,15 | 3B (very polluted) | Fe (3.2 MAC), COD (1.8 MAC), Cu (3.1 MAC), BOD5 (1.1 MAC) |
| R. Mologa - below the city of Ustyuzhna | 2,71 | 3A (contaminated) | 3,53 | 3B (contaminated) | Fe (3.0 MAC), COD (1.8 MAC), Cu (4.3 MAC), Zn (1.0 MAC), BOD5 (1.2 MAC) |
| Rybinsk reservoir – 2 km above the city of Cherepovets | 3,16 | 3B (very polluted) | 3,85 | 3B (very polluted) | Cu (4.1 MAC), COD (2.2 MAC), Fe (1.9 MAC), Ni (1.0 MAC), BOD5 (1.0 MAC) |
| Rybinsk reservoir - 0.2 km below the city of Cherepovets | 3,31 | 3B (very polluted) | 4,26 | 4A (dirty) | Cu (3.5 MAC), COD (2.6 MAC), Fe (2.3 MAC), Ni (1.6 MAC), NO2 (1.0 MAC), BOD5 (1.3 MAC), Mn ( 1.3 MPC) |
| Rybinsk reservoir - from. Myaksa | 3,74 | 3B (very polluted) | 3,24 | 3B (very polluted) | Cu (3.8 MAC), COD (2.4 MAC), Fe (2.6 MAC), NH4 (1.1 MAC) |
| Baltic basin | |||||
| R. Andoma - village Rubtsovo | 3,67 | 3B (very polluted) | 3,27 | 3B (very polluted) | Fe (7.5 MAC), COD (2.3 MAC), Cu (2.9 MAC), NH4 (1.0 MAC) |
Figure 1.2
Figure 1.3.
Changes in water quality along the length of Kubenskoye Lake - Sukhona River -
r.Malaya Northern Dvina in 2009-2010
Figure 1.4
Changes in water quality along the length of Beloe Lake - Sheksninskoye Reservoir. -
Rybinsk reservoir in 2009-2010
R. Pelshma
River water quality Pelshma for 2010 (Figure 1.5.) deteriorated within the category 5 "extremely dirty" - UKWHI = 7.89 (in 2009 UKWHI = 7.29).
The main pollutant ingredients are lignosulfonates and phenols, the average content of which was 14.6 MPC and 15.3 MPC, respectively. The maximum values of biochemical oxygen demand (BOD5) were observed in summer and amounted to 83.0 MPC. The maximum content of phenols and lignosulfonates was also observed in winter and amounted to 22.3 and 21.06 MPC, respectively.
Figure 1.5.
River water quality Pelshma in 2003 - 2010
R. Sukhona near the town of Sokol and the mouth of the river. Pelshmy
River water quality The Sukhona upstream of the city of Sokol improved in comparison with 2009 within the category 3B "very polluted" (IWPI is 3.57), below the city of Sokol it worsened with the transition from category 3B "very polluted" to category 4A "dirty" ( UKWEE equals 4.34) (Figure 1.6.).
Figure 1.6.
River water quality Sukhonas in the area of Sokola in 2003 - 2010
Above the mouth of the river Pelshma river water quality The sukhona remained within category 3A "contaminated": UKIZV2010 = 2.68, UKIZV2009 = 2.70.
Below the mouth of the river Pelshma river water quality The sukhona also remained within category 3A "contaminated" (UKPIW2010 = 2.70, UKPIW2009 = 2.81) (Figure 1.7.).
Figure 1.7.
River water quality Sukhona near the mouth of the river. Pelshma and s. Narems in 2003 - 2010
R. Vologda. The water in the river upstream of the city (Figure 1.8.) compared to the previous year in 2010 remained in category 4A "dirty" (UKWEE2010 = 4.32, UKWEE2009 = 4.54).
Below the city of Vologda, in 2010, the water quality deteriorated compared to 2009 with the transition from category 4B “dirty” to 4C “very dirty” (UKWEE2010 = 6.02, UKWEE2009 = 5.54).
Figure 1.8.
Change in the quality of river. Vologda in the region of Vologda in 2003 - 2010
To a limited number of indicators that determine the water pollution of the river. Vologda downstream of the city and the conditions of the UKIZV include ammonium nitrogen (4.1 MPC) and nitrite nitrogen (4.2 MPC), BOD5 (3.3 MPC), phenols (1.4 MPC), copper ions (4.4 MPC), nickel (1.5 MPC), iron (2.3 MPC), manganese (1.5 MPC).
Rybinsk reservoir
The water quality of the Rybinsk Reservoir. according to the indicator of the UKWAP above the city of Cherepovets, it worsened within the category 3B “very polluted” (WHIW = 3.85) (Figure 1.9.).
The quality of water downstream of Cherepovets (village Yakunino) deteriorated with the transition from category 3B “very polluted” to category 4A “dirty”: UKWHI2009 = 3.31, UKWHIW2010 = 4.26.
In the area with Myaksa water quality has improved within category 3B “very polluted”: UKWHI2009 = 3.74, UKWHI2010 = 3.24.
The main substances that determine the value of the Rybinsk Reservoir IWQW are copper, iron, and COD ions, which are of natural origin and background character. In the area with Ammonium nitrogen (1.1 MPC), Yakunino village BOD5 (1.3 MPC), June manganese (1.3 MPC) were noted in Myaksa.
Figure 1.9.
Changes in the quality of the Rybinsk Reservoir. in the area of Cherepovets in 2003 - 2010
R. Costa
In 2010, the water quality in the river. Koshte (Figure 1.10.), compared with 2009, remained within the category 4B “dirty water” at the UKWAT 6.11 (in 2009 the UKWHI = 6.29).
The main substances polluting the water of the river. Koshta, were COD (2.7 MPC), nitrite nitrogen (5.7 MPC) and ammonium (3.6 MPC), sulfates (1.9 MPC), BOD5 (2.0 MPC), nickel ions (1.7 MPC), zinc (2.8 MPC), copper (6.6 MPC), iron (2.0 MPC) and manganese (1.8 MPC).
Figure 1.10.
River water quality Koshty near the city of Cherepovets in 2003 - 2010
R. Yagorba
River water Yagorby (Figure 1.11.) in 2009, upstream of the city of Cherepovets (village Mostovaya), belonged to category 4A "dirty" (UKPIW = 5.00), which is slightly higher than the level of 2009 (UKPIW = 4.93). Within the city of Cherepovets, the water quality deteriorated with the transition from category 3B "very polluted" to category 4A "dirty": UKWEE2009 = 3.75, UKWEE2010 = 4.41.
Among the main ingredients polluting the water of the river. Yagorbs include: nickel ions (1.4 - 1.7 MPC), copper (2.3 - 3.6 MPC), iron (1.1 - 2.2 MPC), manganese (1.0 - 1.3 MPC ), BOD5 (1.4 - 2.0 MAC), COD (1.8 - 2.7), ammonium nitrogen ((1.1 MAC) and nitrite (1.5 MAC), sulfates (4.3 MAC) and oil products (1.6 MPC).
Figure 1.11
River water quality Yagorba in 2003 - 2010
In order to assess and identify the impact of economic activity on the quality of surface waters, the calculation of the water pollution index (WPI) was also carried out, in which the concentrations of substances with increased natural values were not taken into account.
Assessment of the quality of surface waters according to the complex indicator "Water Pollution Index (WPI)" showed that in 60% of observation points in 2010 the water was classified as "clean", in 34% - "moderately polluted", in 4% (r. Koshta - 3 km above the mouth, the Vologda River - below the city of Vologda) - polluted, in 2% (Pelshma River) - "extremely dirty" (Table 1.3.).
The greatest anthropogenic load in the region is experienced by the Pelshma, Koshta, Vologda rivers below the city of Vologda, Sodema, Shogrash.
The cleanest water bodies of the region are the rivers Yug, Kubena, Chagoda, Lezha, Kunost, Mologa, Kema, Staraya Totma, B. Elma, Syamzhena, Ledenga, V. Erga, Andoga, Andoma, lake. Beloe, oz. Kubenskoe, Sheksna reservoir.
Table 1.3. Comparison of surface water quality in the region for 2009 and 2010.
| Water | Locality | year 2009 | 2010 | ||
| WPI | water quality | WPI | water quality | ||
| White Sea basin | |||||
| lake Kubenskoe | village Korobovo | 0,51 | pure | 0,75 | pure |
| R. Uftyuga | village Bogorodskoe | 1,11 | moderately polluted | 1,04 | moderately polluted |
| R. B. Elma | village Filyutino | 0,64 | pure | 0,76 | pure |
| R. Syamzhena | in line with Syamzha | 0,57 | pure | 0,86 | pure |
| R. Cubana | village Savinskaya | 0,54 | pure | 0,69 | pure |
| R. Cubana | Troitse-Enalskoye village | 0,56 | pure | 0,46 | pure |
| R. Suhona | 1 km above Sokola | 1,28 | moderately polluted | 1,01 | moderately polluted |
| R. Suhona | 2 km below Sokola | 1,21 | moderately polluted | 1,07 | moderately polluted |
| R. vomiting | 1 km above the mouth | 1,02 | moderately polluted | 0,90 | pure |
| R. Vologda | 1 km above the city of Vologda, 1 km above the confluence of the river. vomiting | 1,23 | moderately polluted | 1,19 | moderately polluted |
| R. Vologda | 2 km below the city of Vologda, 2 km below the wastewater discharge from MUE Housing and Public Utilities "Vologdagorvodokanal" | 4,15 | dirty | 3,5 | polluted |
| R. Lying | v. Zimnyak | 0,68 | pure | 0,74 | pure |
| R. Suhona | above the confluence of the Pelshma | 0,88 | pure | 1,21 | moderately polluted |
| R. Pelshma | 5 km east of the town of Sokol, near the road bridge on the village of Kadnikov, 37 km upstream of the mouth, 1 km downstream of the wastewater discharge of the Sokolsky OOSK | 15,98 | extremely dirty | 12,26 | extremely dirty |
| R. Suhona | 1 km below the confluence of the river. Pelshmy | 1,34 | moderately polluted | 1,12 | moderately polluted |
| R. Suhona | from. Narems | 0,94 | pure | 1,14 | moderately polluted |
| R. Dvinitsa | village of Kotlaksa | 0,59 | pure | 0,72 | pure |
| R. Suhona | 1 km above the city of Totma | 0,57 | pure | 0,60 | pure |
| R. Suhona | 1 km below Totma | 0,78 | pure | 0,78 | pure |
| R. Ledenga | v. Yurmanga | 0,99 | pure | 1,49 | moderately polluted |
| R. Old Totma | village Demyanovsky Pogost | 0,92 | pure | 0,74 | pure |
| R. Upper Erga | village Pikhtovo | 0,68 | pure | 0,56 | pure |
| R. Kichmenga | v. Zakharovo | 0,85 | pure | 1,08 | moderately polluted |
| R. Suhona | 3 km above the city of Veliky Ustyug, 0.5 km below the confluence of the river. Vozdvizhenki | 0,88 | pure | 1,06 | moderately polluted |
| R. South | d. Permas | 0,55 | pure | 0,39 | pure |
| R. South | d. Strelka | 0,57 | pure | 0,49 | pure |
| R. M. Sev. Dvina | 0.1 km below the city of Veliky Ustyug, 1.5 km below the confluence of the Sukhona and Yug rivers, 0.5 km below the wastewater discharge of the shipyard | 0,83 | pure | 1,05 | moderately polluted |
| R. M. Sev. Dvina | 1 km above the town of Krasavino, within the boundaries of the village of Medvedki; 1 km above the confluence of the river. Lapinka | 0,62 | pure | 1,03 | moderately polluted |
| R. M. Sev. Dvina | 3.5 km downstream of the city of Krasavino, 9 km downstream of the confluence of the Lapinka River, 1 km downstream of the wastewater discharge of the flax mill | 0,79 | pure | 1,16 | moderately polluted |
| R. vaga | above with. Verkhovazhye | 0,93 | pure | ||
| Water | Locality | year 2009 | 2010 | ||
| WPI | water quality | WPI | water quality | ||
| R. vaga | village Gluboretskaya | 0,76 | pure | 0,88 | pure |
| R. vaga | below p. Verkhovazhye | 1,05 | moderately polluted | 1,04 | moderately polluted |
| Caspian basin | |||||
| R. Kema | village Popovka | 0,49 | pure | 0,58 | pure |
| R. Kuness | d. Rostani | 0,61 | pure | 0,57 | pure |
| lake White | village of Kisnema | 0,53 | pure | 0,54 | pure |
| lake White | Belozersk | 0,64 | pure | 0,53 | pure |
| Sheksna reservoir. | village Krokhino | 0,50 | pure | 0,40 | pure |
| Sheksna reservoir. | village Ivanov Bor | 0,66 | pure | 0,89 | pure |
| R. Yagorba | d. Mostovaya | 1,65 | moderately polluted | 2,13 | moderately polluted |
| R. Yagorba | within the city of Cherepovets | 0,93 | pure | 1,18 | moderately polluted |
| R. Costa | within the city of Cherepovets, 3 km above the mouth | 3,02 | polluted | 2,58 | polluted |
| R. Andoga | d. Nikolskoe | 0,66 | pure | 0,73 | pure |
| R. ships | d. Borisovo-Sudskoe | 0,69 | pure | 0,97 | pure |
| R. Mologa | 1 km above Ustyuzhna | 0,53 | pure | 0,57 | pure |
| R. Mologa | 1 km below Ustyuzhna | 0,56 | pure | 0,59 | pure |
| Rybinsk reservoir | 2 km above the city of Cherepovets, within the village of Yakunino | 0,70 | pure | 0,85 | pure |
| Rybinsk reservoir | 0.5 km below the wastewater discharge from the treatment facilities of Cherepovets | 0,85 | pure | - | - |
| Rybinsk reservoir | 0.2 km below the city of Cherepovets, 1 km below the confluence of the river Koshta | 0,89 | pure | 0,96 | pure |
| Rybinsk reservoir | b/o Torovo | 0,84 | pure | 1,21 | moderately polluted |
| Rybinsk reservoir | Myaksa village | 0,96 | pure | 0,64 | pure |
| Baltic basin | |||||
| R. Andoma | village Rubtsovo | 0,68 | pure | 0,67 | pure |
The paper reflects the main results of the assessment of the quality of the waters of the Upper Volga reservoir for the period 2011–2014. The analysis of hydrochemical data of reservoir waters was carried out. Priority pollutants have been identified, which include manganese, common iron, color, ammonium ion, and petroleum products. The results of calculation of integral indicators of water quality are presented: indices WPI (Water Pollution Index), GPI (General Sanitary Water Quality Index) and UKWPI (Specific Combinatorial Water Pollution Index). An assessment of the quality of the waters of the Upper Volga reservoir was carried out. In general, the quality of the waters of the Upper Volga Reservoir, according to the value of integral hydrochemical indices, was assessed as “dirty” water (according to the WPI index), moderately polluted (according to the IQI index), and very polluted water (according to the ICIW index).
water quality
Upper Volga reservoir
integral quality indices
1. Upper Volga reservoir // Great Soviet Encyclopedia. - M.: Soviet encyclopedia, 1969-1978. URL: www./enc-dic.com/enc_sovet/Verhnevolzhskoe_vodohranilische-3512.html (date of access: 07/17/15).
2. Hydrochemical indicators of the state of the environment: reference materials / ed. T.V. Guseva. – M.: Forum: INFRA-M, 2007. – 192 p.
3. Lazareva G.A., Klenova A.V. Assessment of the ecological state of the Upper Volga reservoir by hydrochemical indicators // Proceedings of the VII International Scientific Conference of Young Scientists and Talented Students "Water Resources, Ecology and Hydrological Safety" (Moscow, IVP RAS, Russian Academy of Natural Sciences, December 11–13, 2013) . - M., 2014. - C.173-176.
4. RD 52.24.643-2002 Method for a comprehensive assessment of the degree of pollution of surface waters by hydrochemical indicators - Roshydromet, 2002. - 21 p.
5. Shitikov V.K., Rozenberg G.S., Zinchenko T.D. Quantitative hydroecology: methods of system identification. - Tolyatti: IEVB RAS, 2003. - 463 p.
The water quality of water bodies is formed under the influence of both natural and anthropogenic factors. As a result of human activity, many pollutants of varying degrees of toxicity can enter water bodies. Water bodies are polluted by effluents from agricultural and industrial enterprises, wastewater from settlements. In modern conditions, the problem of providing the population with clean water is becoming increasingly important, and the study of the state of water bodies is one of the most important tasks.
The purpose of this work is the assessment of the quality of the waters of the Upper Volga reservoir using integral quality indicators.
Objects and methods of research
The Upper Volga Reservoir was created in 1843 (reconstructed in 1944-47) and consists of interconnected lakes Sterzh, Vselug, Peno and Volgo. The reservoir is located in the north-west of the Tver region on the territory of the Ostashkovsky, Selizharovsky and Penovsky districts. The surface area of the reservoir is 183 km2, the volume is 0.52 km3, the length is 85 km, and the maximum width is 6 km. The length of the coastline is 225 km. At a high water level close to the normal retaining level (206.5 m), the reservoir is a single body of water, and in low water, with strong drawdown, it is divided into lakes that are poorly connected to each other. The water resources of the Upper Volga Reservoir are used during the summer low-water period to regulate levels in the upper reaches of the Volga, as well as for industrial purposes, communal needs, agriculture and animal husbandry. The reservoir is of great importance for recreation, tourism and fishing.
During the research, 3 sections of the Upper Volga reservoir were studied (section of Lake Volgo, Peno village; section of Lake Volgo, Devichye village; section of the Upper Volga Beishlot) (Fig. 1) according to hydrochemical indicators for the period from 2011 to 2014.
Figure 1. Map-scheme of sampling stations of the Upper Volga Reservoir: 1 - alignment of the lake. Volgo, Peno village, 2 - alignment of the lake. Volgo, d. Devichye, 3 - alignment Upper Volga Beishlot
The data provided by the Dubna Ecoanalytical Laboratory (DEAL) of the FGVU "Tsentrregionvodkhoz" were used in the work, on such hydrochemical indicators as: hydrogen index, color, ammonium ion, nitrate ion, nitrite ion, phosphate ion, total iron, chloride ion , sulfate ion, manganese, magnesium, biochemical oxygen demand, copper, zinc, lead, petroleum products, dissolved oxygen, nickel.
Research results
The analysis of hydrochemical data showed that all the studied sections of the Verkhnevolzhsky reservoir are characterized by a high content of manganese, total iron and ammonium ion in the water, the concentrations of which always exceeded the MPCw, in some periods the excess of the MPCw for oil products was noted. The concentrations of these substances changed insignificantly during the study period.
To assess the quality of the waters of the Upper Volga reservoir for 2011-2014. integrated indicators of water quality were calculated: WPI (Water Pollution Index), GPI (General Sanitary Water Quality Index) and UKWPI (Specific Combinatorial Water Pollution Index). The results obtained are presented in table 1.
Table 1
The value of the WPI, IKV, UKVZ indices, water quality class, qualitative and ecological state of water in the sections of the Upper Volga reservoir
|
Meaning of indices by alignment |
||||
|
The gate of the lake Volgo, Peno village |
||||
|
Water quality class Quality state |
very dirty |
|||
|
Water quality class Quality state |
moderately polluted |
moderately polluted |
moderately polluted |
|
|
Class and rank Quality state |
very polluted |
very polluted |
polluted |
|
|
The gate of the lake Volgo, d. Devichye |
||||
|
Water quality class Quality state |
||||
|
Water quality class Quality state |
moderately polluted |
moderately polluted |
moderately polluted |
|
|
Range Upper Volga Beyshlot |
||||
|
Water quality class Quality state |
very dirty |
|||
Continuation of Table 1
|
Meaning of indices by alignment |
||||
|
Water quality class Quality state |
moderately polluted |
moderately polluted |
moderately polluted |
moderately polluted |
|
Class and rank Quality state |
very polluted |
very polluted |
very polluted |
very polluted |
The Hydrochemical Water Pollution Index (WPI) was used as the main comprehensive indicator of water quality until 2002. The classification of water quality according to WPI values makes it possible to divide surface waters into 7 classes depending on the degree of their pollution. The calculation of the WPI is carried out for six ingredients: mandatory - dissolved oxygen and BOD5, and 4 substances that had the highest relative concentrations (Ci / MPCi) . The main disadvantage of this method for assessing water quality is that it takes into account a small range of pollutants.
The maximum values of the WPI index in all sections are observed in the winter-spring period, and the minimum values - in the autumn period. According to the value of the WPI index in 2011-2013, in all sections, the water quality is assessed as "dirty" (water quality class - 5). In 2014, in the Verkhnevolzhsky Beishlot (No. 3) site, the water quality deteriorated to the 6th quality class - “very dirty”, while in the sites of the lake. Volgo, Peno village (No. 1) and lake. Volgo village Devichye (No. 2), the water quality has not changed (Fig. 2).
Figure 2. Change in the values of the WPI index in the sections of the reservoir for 2011-2014
To determine the general sanitary water quality index (WQI), a scoring is carried out (from 1 to 5 points). Points are assigned to each indicator used for calculation, the weight of the indicator is also taken into account, after which the value of IQV is determined.
In general, according to the values of the RQI index during the period under review (2011-2014), in all water sections throughout almost the entire period of study, with a few exceptions, they are characterized as “moderately polluted” (3rd class of water quality) (Fig. 3).
Figure 3. Change in the values of the ICR index in the reservoir sections for 2011-2014
The specific combinatorial index of water pollution (SCWPI) today becomes a priority in assessing water quality. Classification of water quality according to the values of UKWIS allows to divide surface waters into 5 classes depending on the degree of their contamination. In contrast to the WPI, this approach to calculation determines not only the multiplicity of exceeding the MPC, but also determines the frequency of cases of exceeding the standard values. The data from the calculation of the UKWIS index allow a more accurate reflection of the quality of surface waters.
According to the value of the index of the ECWPI, the water of the Upper Volga reservoir during the observed period (2011-2014) in all sections is assessed as “very polluted” (class 3, category “B”), with the exception of the section in the section of the lake. Volgo village of Peno in 2014, where the degree of water pollution is characterized as “polluted” (class 3, category “A”) (Fig. 4).
Figure 4. Change in the values of the ECWHI index in the reservoir sections for 2011-2014
An increase in the values of the IQHIW index was noted in the gauges located downstream of the reservoir, and although they do not go beyond the values of one quality class and category, this indicates a slight deterioration in water quality. In the sections near the village of Devechye and the Upper Volga Beishlot, the index value in 2013 is slightly higher than in the other years of the study period.
conclusions
Thus, as a result of the work carried out, priority pollutants and indicators of the waters of the Upper Volga reservoir were identified, which include manganese, total iron, color, ammonium ion and oil products. The quality of the waters of the Upper Volga Reservoir was assessed as "dirty" (class 5) by the WPI index, as "moderately polluted" (class 3) by the IQI index, and "very polluted" (class 3, category "B"). The use of the UKWIS index provides more accurate information about the class of state of surface waters, since when calculating it, all hydrochemical indicators determined in the sample are used.
Reviewers:
Zhmylev P.Yu., Doctor of Biological Sciences, Professor of the Department of Ecology and Earth Sciences, Faculty of Natural and Engineering Sciences, Dubna State University, Dubna.
Sudnitsin I.I., Doctor of Biological Sciences, Professor of the Department of Ecology and Earth Sciences, Faculty of Natural and Engineering Sciences, Dubna State University, Dubna.
Bibliographic link
Lazareva G.A., Klenova A.V. ASSESSMENT OF THE QUALITY OF SURFACE WATER BY INTEGRAL INDICATORS (BY THE EXAMPLE OF THE UPPER VOLGA RESERVOIR) // Modern problems of science and education. - 2015. - No. 6.;URL: http://science-education.ru/ru/article/view?id=23406 (date of access: 03/20/2020). We bring to your attention the journals published by the publishing house "Academy of Natural History"
Surface water quality
The hydrographic network of the Autonomous Okrug includes about 290,000 lakes and thirty thousand streams, most of which are small rivers. The main waterway is the Ob River, which receives large tributaries: the Irtysh, Vakh, Agan, Tromyogan, Bolshoy Yugan, Lyamin, Lyapin, Pim, Northern Sosva, Kazym. The total length of the hydro network is about 172 thousand km.
Most of the rivers belong to the flat type, have a slow flow, wide floodplains and a large number of channel lakes. Freezing begins in October, during the winter, small rivers and lakes freeze to the bottom. Ice drift runs from early May to early June.
The rivers are characterized by a strongly extended flood, a reduced draining role, which is one of the important factors of waterlogging and swamping of the territory. Watershed areas of rivers reach 50-70% or more. The influence of swamp waters largely determines the regional hydrochemical features of both river waters and groundwaters of surface aquifers.
The surface waters of the Autonomous Okrug are experiencing a powerful anthropogenic load associated with the active development in recent decades of the infrastructure of cities and the largest oil and gas complex in Russia.
In landscape geochemical studies, the hydrographic network is considered as the main block through which the flows of natural and technogenic substances pass. The dynamics of the chemical composition of surface waters is an indicator of the regional ecological situation. This determines the importance of hydrochemical studies, which constitute the most important section of the territorial system of ecological monitoring of Yugra.
The characteristics of surface water quality are presented based on the results of monitoring at 34 Roshydromet sites and 1,692 local points of the territorial observation network (Figure 1).
Observations at the posts of the state observation network (federal sites) are provided by Roshydromet (executor - Khanty-Mansiysk TsGMS) on 16 large watercourses (Ob with channels, Irtysh, Vakh, Agan, Trom-Yugan, Bolshoy Yugan, Konda, Kazym, Nazim, Pim, Amnya, Lyapin, Northern Sosva) near settlements. The annual volume of measurements is about 8000 pcs.
Figure 1. Surface water monitoring points in the territory
The functioning of local observation points of the territorial system is provided by subsoil user enterprises and the Government of the Autonomous Okrug (coordinator - Prirodnadzor of Yugra). Local monitoring stations cover 700 large and small watercourses within the boundaries of licensed subsoil plots, which are under the main load from the oil and gas complex. In 2018, 91,080 water quality measurements were made within the boundaries of 308 licensed subsoil plots.
The river waters of Yugra have a number of hydrochemical features. They are characterized by low mineralization, increased values of ammonium and metal ions, caused by the presence of a large amount of organic compounds in river and lake waters, intense coloration and low water transparency (Table 1).
Natural landscape and geochemical conditions caused almost universal excess of the maximum allowable concentrations (hereinafter - MPC) for iron (in 94-98% of samples), manganese (in 75-91% of samples), zinc (in 29-53% of samples) and copper ( in 60-73% of samples) (Figure 2).
The reasons for this are the geochemical features of the taiga swampy landscapes with their characteristic acidic soil reaction and the widespread reduction environment. Iron, manganese, zinc, and copper have a high migration capacity in acid gley landscapes; therefore, they intensively enter from soils into groundwater and then into rivers.
Table 1
Average content of pollutants and parameters
|
Indicator |
The ratio of the average in 2018 to the MPC |
|||||||
|
acidification |
||||||||
|
mgO 2 / dm 3 |
||||||||
|
hydrocarbons |
||||||||
|
sulfates |
||||||||
|
Manganese |
||||||||
Long-term observations show that the average concentrations of these substances are in the range:
iron - 1.35-1.86 mg / dm 3, or 13-18 MPC;
manganese - 0.09-0.18 mg / dm 3, or 9-18 MPC;
zinc - 0.01-0.02 mg / dm 3, or 1-2 MPC;
copper - 0.003 - 0.007 mg / dm 3, or 3-7 MPC.
Figure 2. Distribution of measurements of iron and manganese compounds
regarding the environmental standard
Significant seasonal fluctuations in hydrochemical composition are also a characteristic natural feature of the surface waters of the Autonomous Okrug. The maximum values of pollution indicators are reached during the winter low water period, when low flow rates and water temperature contribute to an increase in the concentrations of substances.
For the period 2010-2018, 159 cases of high (HH) and extremely high (HH) pollution of surface waters were recorded on 15 large watercourses (Table 2), of which 137 cases were observed during the closed channel period, when the rivers are fed only by groundwater, which leads to a violation of the oxygen regime and a slowdown in the rate of chemical reactions. The remaining 22 cases were recorded during the period of the beginning of the flood (flushing of pollutants from the adjacent territory) and before the freeze-up (decrease in water temperature). About 61% of the total number of cases of VZ + EVZ is accounted for by heavy metals, 37% by dissolved oxygen (Figure 3).
table 2
List of watercourses with cases of VZ and EVZ in 2010-2017
|
Number of cases |
Hydrochemical post |
|
|
Oktyabrskoye (33), Surgut (7), Sytomino (5), Nizhnevartovsk (6), Polnovat (1), Nefteyugansk (7), Belogorye (2) |
||
|
R. Sev. Sosva |
Berezovo (11), Sosva (4) |
|
|
Beloyarsky (7), Yuilsk (2) |
||
|
Khanty-Mansiysk (11), Gornopravdinsk (2) |
||
|
Roll-out (3), Uray (12), Bolchari (2) |
||
|
Novoagansk (3) |
||
|
R. Trom-Yugan, |
Russian (3) |
|
|
Bolshoy Yugan river |
||
|
Laryak (4), Bolshetarkhovo (3) |
||
|
Lyantor (2) |
||
|
Vykatnoy (1), Bolchary (3), Uray (10) |
||
|
Beloyarsky (7) |
||
|
Lombovozh |
||
|
|
The lack of dissolved oxygen is explained by the low water level during the period of the closed channel and partial freezing of the sections in the absence of the possibility of saturating the river waters with oxygen.
High concentrations of dissolved forms of heavy metals, in turn, are associated with a low oxygen content - under anaerobic conditions, the rate of oxidation of metal compounds slows down.
Of particular relevance for assessing the ecological situation in the region are the concentrations of oil products and chlorides in surface waters, which characterize the technogenic flows of pollutants in the areas of oil fields.
In accordance with the requirements approved by the Decree of the Government of the Autonomous Okrug dated December 23, 2011 No. 485-p, sampling of surface waters to determine oil products and chlorides as priority pollutants is carried out at local monitoring points on a monthly basis, taking into account the hydrological features of water bodies. The annual volume of measurements of oil products in surface waters on the territory of licensed areas is about 9,000 units.
According to the results of local monitoring, the share of samples contaminated with oil products tends to decrease from 11% in 2008 to 4.8% in 2018 of the total sample (Figure 4).
Figure 4. Distribution of measurements of oil products relative to MPC
In general, for 5 years at the oil fields of the district, the average content of oil products in surface waters varied at the level of 0.026-0.049 mg/dm3, not exceeding the established standard (table 1).
The content of chlorides in surface waters, as well as in oil products, reflects the degree of technogenic load and compliance with environmental management standards. Approximately 9,000 chloride measurements are performed annually in surface water at licensed subsoil areas. At the same time, excesses of the MPC for chlorides are rarely recorded, and the proportion of samples contaminated with chlorides has not exceeded 0.1-0.8% of the sample since 2008 (Figure 5).
Figure 5. Distribution of chloride measurements relative to MPC
Systematically elevated concentrations of oil products and chlorides at surface water monitoring points are observed locally, mainly within the boundaries of long-developed license areas with an increased accident rate: Samotlor (north) (18 points) and Samotlor (12 points), Mamontovsky (16 points), Yuzhno-Surgutsky (3 points), Pravdinsky (7 points), Yuzhno-Balyksky (4 points), Malo-Balyksky (4 points), Ust-Balyksky (2 points), Vakhsky (9 points) and Sovetsky (8 points).
In order to improve the environmental situation, under the control of the Natural Supervision of Yugra, the environmental protection measures of subsoil users on the territory of these licensed areas were adjusted, in terms of taking prompt measures to reduce accidents in pipeline systems; carrying out priority measures for the restoration of contaminated land plots and the submission of reclaimed land plots for examination in the current year.
Thus, the quality of water in the surface water bodies of the Autonomous Okrug is largely due to the natural origin and seasonal dynamics of compounds of iron, manganese, zinc, copper, as well as dissolved oxygen. Monitoring studies of recent years have shown that oil and salt pollution in the region as a whole has stabilized at a relatively low level.
The decrease in oil and salt pollution of surface waters on the territory of the Autonomous Okrug is also confirmed by the results of observations at the Roshydromet sites. In the main rivers (Ob and Irtysh), since 2008, there has been a steady downward trend in the average annual concentrations of oil products to a level not exceeding MPC; the content of chlorides is consistently tenths of MPC.
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