4.2 Water pollution
4.2 Water pollution
Within the Russian part of the Lake Baikal basin, surface water pollution is monitored at 41 established monitoring stations in 34 locations covering 24 rivers and one lake. The hydrochemical monitoring network covers the major tributaries of Lake Baikal, i.e. the rivers Selenga, Upper Angara, Barguzin and Turka, and the smaller rivers Tyya, Maksimikha, Kika, Davsha and Bolshaya Rechka (4.2.1).
Pic. 4.2.1 The quality of surface water of Baikal basin [3]
In 2013, concentrations of the following pollutants in Lake Baikal water occasionally exceeded water quality standards:
- chloride ions (up to 1.2 MPC in March and August);
- suspended matter (up to 1.1 MPC in January);
- volatile phenols (2-3 MPC continuously during the period from January to September).
In 2013, pollution by non-sulfate sulfur in Lake Baikal water declined significantly compared with 2012 – the maximum concentration was 0.23 mg/l (observed in January), while the maximum concentration in 2012 was 0.53 mg/l (observed in February). As compared with 2012, the pollutant concentrations were lower and the number of MPC exceedances was less during 2013. Volatile phenols were an exception with 5 times more MPC exceedances in 2013 than in 2012. In 2013, thus the quality of Lake Baikal water was found to have improved compared with 2012.
In 2013, the input of easily oxidizable substances and oxidation-resistant substances into the lake decreased compared with 2012, concurrently with decreases in water levels on large rivers. The input of volatile phenols, synthetic surfactants and copper into the lake decreased significantly. The input of dissolved mineral substances, suspended matter and petrochemicals increased by 12 %, 24 % and 31%, respectively [1].
An expedition of Limnological Institute SB RAS to the northern part of Lake Baikal in 2013 discovered an excessive proliferation of filamentous macroalgae of the genus Spirogyra unusual to Lake Baikal [5]. Waves hitting the shores threw out black-green mass of dead algae, which formed long foul-smelling heaps stretching for hundreds of meters (pic. 4.2.2).
Pic. 4.2.2 Filamentous macroalgae of the genus Spirogyra deposited on the shore of northern Lake Baikal (photo by V. Korotkoruchko)
An expedition conducted in September 2014 discovered water blooming along the entire perimeter of Lake Baikal. At some places, the weight of the decaying algae deposited on the shore reached 100 kg/m2. The large algae clusters were accompanied by «cemeteries» of thousands of gastropod shells (pic. 4.2.3). Incidents of epidemics and mass mortality of Baikal sponges – unique water-filtering organisms – have been recorded previously.
Pic. 4.2.3 Dead gastropods on the shore of northern Lake Baikal.
(photo by V. Korotkoruchko)
This phenomenon was observed throughout Lake Baikal. It was found that the sponges were infected by cyanobacteria of the genus Formidium that infects weak organisms.
Scientists established that the reason for the algae proliferation was the long-term discharge of untreated or inadequately treated sewage rich in nitrogen and phosphorus into the lake. The sources of sewage discharge are the sewage treatment facilities of the coastal settlements, many of which were built during the Soviet times. Furthermore, in many of the locations where tourism-related infrastructure has been or is being built, sewage treatment facilities are non-existent. Other sources of sewage are the numerous ships cruising Lake Baikal [5].
The results of water quality monitoring in 2013 are described below.
Rivers of the Baikal-Amur Mainline Area. In 2012, water in the rivers was slightly alkaline with pH ranging between 7.52 and 7.79. Dissolved oxygen content in the rivers was satisfactory during all phases of the hydrological regime. The minimum recorded oxygen saturation was 75%. During the year, water in the rivers had a low salinity in winter and very a low salinity in summer, satisfactory oxygen content, and slightly alkaline pH. The rivers Tyya and Upper Angara showed the highest salinity with the amount of ions ranging from 42.7 to 142 mg/dm3 depending on the season, while the Goudzhekit river had the lowest salinity (10.2-24.6 mg/dm3). Organochlorine pesticides were not detected. Synthetic surfactants and petrochemicals were detected at concentrations not exceeding the MPCs. Nutrient content was low. MPC exceedances were recorded for copper, zinc, iron, and phenols. No cases of high pollution or extremely high pollution were recorded. Discharges of wastewater into the rivers Tyya and Upper Angara were taking place in the towns of Severobaikalsk and Uoyan, respectively [1].
Compared with the preceding five-year period, in 2012-2013 an unfavorable trend of increasing concentrations of mineral nitrogen, phosphate phosphors and total phosphorus was noted for the Tyya river (a small tributary of the lake) at a monitoring station 1 km downstream of the town of Severobaikalsk. In 2013, the input of total phosphorus increased to 0.05 thousand tons, while before the average annual input was 0.022 thousand tons. The input of mineral nitrogen increased to 0.26 thousand tons (the average annual input was 0.12 thousand tons). The estimates provide evidence of the increased load of mineral nitrogen, phosphate and total phosphorus into the ecosystem of the Tyya river downstream of the town of Severobaikalsk in 2013 [1].
Monitoring of the Upper Angara River covered its stretch between the settlements Uoyan and Upper Zaimka. Salinity of the river water varied during the year from 45.9 mg/dm3 to 125.0 mg/dm3. The maximum salinity was recorded near Upper Zaimka. MPC exceedances were observed for 5 monitored pollutants. Based on frequency of MPC exceedances, the river pollution by total iron, copper and zinc was defined as «characteristic», while pollution by oxidation-resistant organic substances and phenols was defined as «unstable». The highest concentrations of several pollutants were recorded near Upper Zaimka, i.e. total iron concentration reached 4.6 MPC (May 23), copper concentration reached 6.0 MPC (Oct. 26), zinc concentration reached 1.6 MPC (Oct. 26), and concentration of oxidation-resistant organic substances reached 1.2 MPC (May 23).
Water quality monitoring of the Barguzine River was done at three monitoring sites, covering the section of the river between village of Mogoyto (background site) and the river mouth in the village of Ust-Barguzin. Water in the river had satisfactory oxygen content throughout the monitoring period. pH values varied from neutral to slightly alkaline. Salinity of water varied from low to medium during different phases of hydrological regime. Overall, MPC exceedances were recorded for total iron, copper, zinc, oxidation-resistant organic substances, phenols, and petrochemicals in 100%, 90.0%, 59.1%, 36.4%, 18.2%, and 13.6% of samples, respectively. Based on integrated pollution indicators, pollution by total iron, copper and zinc was defined as «characteristic», pollution by oxidation-resistant organic substances was defined as «persistent», and pollution by phenols and petrochemicals was defined as «unstable». The maximum concentrations of total iron (10.5 MPC) and copper (4.6 MPC) were registered in Mogoyto on May 31st, during the period of spring flooding., maximum In samples taken at the monitoring site in Barguzin, the maximum concentrations exceeding MPCs were recorded for petrochemicals (1.4 MPC on Sep. 14) and oxidation-resistant organic substances (2.3 MPC on May 28). Near the village of Ust-Barguzin the maximum concentration of phenols (3 MPC) was recorded on June 30. Wastewater was not discharged into the river in any of the locations [1].
The rivers Turka, Maksimikha and Kika are tributaries of Lake Baikal. Throughout the monitoring period, the rivers had satisfactory oxygen content and low salinity levels. During the year, pH varied from neutral to slightly alkaline. Among the rivers, Maksimikha had the highest salinity (pic. 4.2.4). For the river, MPC exceedances were observed for 5 out of 13 monitored pollutants. Based on integrated pollution indicators, the pollution by total iron, copper, zinc and oxidation-resistant organic substances was defined as «characteristic», while pollution by phenols as «unstable». High concentrations exceeding MPCs were recorded for zinc (1.5 MPC on Oct. 29), total iron (8.1 MPC on Jul. 30), phenols (2 MPC on May 29), copper (6.7 MPC on Oct. 29), and oxidation-resistant organic substances (3 MPC on May 29).
Pic. 4.2.4 Estuary of the Maksimikha River
For the Turka River, PMC exceedances were recorded for 6 (for 7 in 2011) monitored pollutants (pic. 4.2.5). Concentrations exceeding MPCs were recorded for total iron, copper, phenols, zinc and oxidation-resistant organic substances in 100%, 66.7%, 44.4%, 33.3%, and 11% of the samples, respectively. The maximum concentrations recorded were 1.4 MPC for easily oxidizable organic matter (Apr. 24), 2.1 MPC for oxidation-resistant organic substances (Apr. 24), 5.7 MPC for total iron (Jun. 6), 7.0 MPC for copper (Jun. 6), 1.4 MPC for zinc (Dec. 19) and 3 MPC for phenols (Jul. 10).
Pic. 4.2.5 Estuary of the Turka River
In water samples from the Kika River, total iron, copper, phenols, easily oxidizable organic substances and oxidation-resistant organic substances were detected in concentrations exceeding the MPCs. Exceedances of MPCs were recorded for 5 out of 13 monitored pollutants. The maximum concentrations recorded were the following: 1.4 MPC for oxidation-resistant organic substances (May 15), 2.5 MPC for total iron (May 15), 3.8 MPC for copper (May 15), 1.1 MPC for easily oxidizable organic substances (Oct. 3), and 2 MPC for phenols (Mar. 26, May 15, Jul. 10) [1].
The Selenga River. Monitoring of water quality of the Selenga River, the main tributary of Lake Baikal, was conducted at 9 monitoring stations located between the village of Naushki, which is on the border with Mongolia, and the village of Murzino in the river delta (pic. 4.2.6). Throughout the monitoring period, the river water had satisfactory oxygen regime. Oxygen saturation varied in the range of 45-106%. The minimum oxygen saturation was noted at Kabansk monitoring station (0.5 km downstream of the village of Kabansk). Water pH varied from neutral to alkaline during the year.
Pic. 4.2.6 Delta of the Selenga river (Landsat)
At the Naushki monitoring station, MPC exceedances were recorded for 9 out of 17 monitored pollutants. In addition, fluorides, aluminum, manganese and nickel were also detected. MPC exceedances were observed for manganese in 100% of the collected samples, while levels of copper, total iron, and zinc exceeded the PMCs in 77.8%, 71.4% and of 55.6% of the samples, respectively. For these pollutants, water pollution was defined as «characteristic». Contamination by oxidation-resistant substances was defined as “stable”, while contamination by nickel, aluminum, phenols and petrochemicals as “unstable”. The maximum concentrations recorded were the following: 21.38 MPC for total iron (Jul. 24), 4.0 MPC for copper (Sep. 23), 1.3 MPC for zinc (Dec. 4), 1.5 MPC for nickel (May 17), 9.1 MPC for manganese (Dec. 4), 1.7 MPC for oxidation-resistant organic substances (Aug. 20), 2.0 MPC for phenols (Sep. 23), 1.2 MPC for petrochemicals (Feb. 20, Jun. 20). Compared with the last year, there was an increase in maximum concentrations of total iron, zinc and nickel. Concentrations of oxidation-resistant organic substances, copper, aluminum, manganese, and petrochemicals have reduced.
At a monitoring station near the village of Novoselenginsk, MPC exceedances were observed for 6 (7 in 2011) pollutants out of 13 monitored. Based on the frequency of MPC exceedances, the water pollution by total iron and copper was defined as «characteristic», the pollution by zinc and oxidation-resistant organic substances was defined as “stable”, and the pollution by easily oxidizable organic substances and phenols as «unstable». The maximum concentrations recorded were the following: 1.5 MPC for zinc (Dec. 6), 23.5 MPC for total iron (Jun. 27), 2 MPC for phenols (Apr. 26, May 22), 7.0 MPC for copper (Jul. 25), 1.9 MPC for oxidation-resistant organic substances (Jul. 25), and 1.3 MPC for easily oxidizable organic substances (May 22) [1].
Around Ulan-Ude city, the Selenga river water quality was monitored at 3 monitoring stations: 1) 2 km upstream of the city (background site); 2) 1 km downstream of the city (control site); and 3) near Mostovay railway station. Wastewater discharges were carried out by the municipal sewage treatment plant «Vodokanal», namely by its treatment facilities located on both banks of the river. The discharged wastewater was graded as «insufficiently treated». The effect of sewage on the quality of the Selenga river water was indicated by concentrations of suspended solids, sulfates, nutrients and some metals. Out of 17 monitored pollutants, guideline threshold exceedances were observed for 8 pollutants at the background site, 10 pollutants at the control site and 9 pollutants at Mostovaya monitoring station. Water pollution by total iron, copper, zinc, and manganese was defined as «characteristic», while pollution by aluminum, phenols, oxidation-resistant and easily oxidizable organic substances was defined as «unstable». The maximum concentration of easily oxidizable organic substances (1.4 MPC) was detected at a monitoring station upstream of the city on November 20. The maximum concentrations of nitrite nitrogen (2.2 MPC on Feb. 20), manganese (10 MPC on Feb. 20), copper (5.6 MPC on Dec. 20), aluminum (1.7 MPC on Jul. 19), and petrochemicals (1.6 MPC on May 21) were detected downstream of Ulan-Ude city. At the monitoring station near Mostovaya railway station, the maximum concentrations of total iron (9.5 MPC) and oxidation-resistant organic substances (2.2 MPC) were detected on May 22, during a spring flooding, while maximum zinc concentrations (2.4 MPC) were recorded on April 20 [1].
Near the village of Kabansk, monitoring was done at three monitoring stations: 1) 23.5 km upstream of the village (background site); 2) 19.7 km upstream of the village (control site); and 3) 0.5 km downstream of the village (river gauge). Sewage was discharged into the river by a local utilities department. MPC exceedances were recorded for 6 out of 13 monitored pollutants at the background site, for 7 pollutants at the control site, and 9 pollutants at the monitoring station near the river gauge. Based on frequency of MPC exceedances, the water pollution by oxidation-resistant organic substances, total iron, zinc, copper and manganese was defined as «characteristic», pollution by easily-oxidizable organic substances as «resistant», and by nickel, aluminum and phenol – «unstable».
The Selenga River remained the major supplier of controlled substances into the lake. In 2013, the river brought 87.6% of suspended solids, and 78.0% each of dissolved minerals, oxidation-resistant and easily oxidizable organic substances [1].
The Dzhida River was surveyed at two sites near the villages of Khamney and Dzhida. Water hardness varied from soft to moderately hard, while salinity varied from low to medium [1]. The maximum salinity was observed in winter near Khamney (pic. 4.2.7). pH was slightly alkaline, and oxygen regime was satisfactory throughout. Based on MPC exceedance frequency, pollution by copper was graded as «characteristic», by iron and zinc as «stable», by easily oxidizable and oxidation resistant organic substances and petrochemicals as «unstable». The maximum concentrations of oxidation-resistant organic substances (1.2 MPC on Aug. 24), easily oxidizable organic substances (1.1 MPC on Aug. 24), total iron (1.9 MPC on Dec.21), zinc (1.3 MPC Dec. 21), and petrochemicals (2.6 MPC on Mar. 21) were recorded near Dzhida village. The highest copper concentration (3.6 MPC) was recorded near Khamney on June 17.
Fig. 4.2.7 The middle reaches of the Dzhida river
The Chikoy River was surveyed at two sites within Buryatia, near the villages of Chikoy and Povorot (pic. 4.2.8). Oxygen regime was satisfactory, the river water had a low salinity [1]. The maximum salinity was observed in the winter period near Chikoy. At both the monitoring sites, MPC exceedances were observed for 6 pollutants out of 13 monitored. MPC exceedances were observed for total iron, zinc, copper, phenols, easily oxidizable organic substances, petrochemicals, and oxidation-resistant organic substances. Based on frequency of MPC exceedances, pollution by iron, copper and oxidation-resistant organic substances was defined as «characteristic», by zinc and phenols as «stable», and by easily oxidizable organic substances as «unstable». The maximum concentrations of zinc (1.6 MPC on Oct. 28) and petrochemicals (1.4 MPC on Sep. 20) were recorded near Chikoy village. The maximum concentrations of oxidation-resistant organic substances (2.6 MPC on May 22), total iron (15.4 MPC on May 22), easily oxidizable organic substances (1.4 MPC on Oct. 22), copper (7.4 MPC on Jul. 25), and phenols (3 MPC on Apr. 27, May 22) were recorded near Povorot [1].
Pic. 4.2.8 The Chikoy river near the village of Povorot
The Khilok River was surveyed within the Republic of Buryatia in its mouth area near the village of Haylastuy. The river water had a low salinity. Threshold exceedances were observed for 6 pollutants (7 in 2011). Pollution by total iron, oxidation-resistant organic substances, copper and phenols was «characteristic». Moreover, total iron concentrations exceeded the MPC in 100% of the samples. Pollution by easily oxidizable organic substances and zinc was graded as «stable». The maximum recorded concentrations of pollutants were the following: 3.3 MPC for oxidation-resistant organic substances (May 24), 1.5 MPC for easily oxidizable organic substances (Sep. 13), 16.6 MPC for total iron (May 24), 4.9 MPC for copper (Jul. 26), 1.5 MPC for zinc (Sep. 13), and 2 MPC for phenols (Feb. 15, May 24, Jun. 28, Sep. 13) [1].
The Uda River water quality monitoring was carried out at two sites around Ulan-Ude city: 1 km upstream of the city (background site) and 1.5 km upstream of the river mouth (control site). The river receives wastewater discharges from the wastewater treatment facility of Ulan-Ude Central Heating Plant (pic. 4.2.9). The river had satisfactory oxygen regime throughout the observation period. pH varied from neutral to slightly alkaline. Water salinity was moderate during all phases of the hydrological regime, the maximum salinity values were observed in winter. Cases of high or extremely high water pollution were not registered.
Pic. 4.2.9 The wastewater treatment facility of Ulan-Ude Central Heating Plant
MPC exceedances were observed for 11 pollutants (7 in 2011). The water quality was generally better at the background site than at another site located downstream. Similar to the previous year, concentrations of iron and manganese consistently exceeded the MPCs in 100% of samples. Water pollution by total iron, manganese, copper and zinc was defined as «characteristic». The maximum concentrations recorded were: 6.6 MPC for total iron (Apr. 20), 4.1 MPC for copper (Sep. 20), 2.3 MPC for zinc (Apr. 20), 2.4 MPC for oxidation-resistant organic substances (May 21), 1.5 MPC for nickel (Oct. 19), 1.3 MPC for aluminum (Apr. 20), 8.7 MPC for manganese (Apr. 20), 1.2 MPC for petrochemicals (Mar. 21). Downstream of the city, water pollution by copper, zinc, iron and manganese was «characteristic», by phenols – «stable», by easily oxidizable and oxidation-resistant organic substances, nickel, aluminum and fluoride – «unstable». The maximum concentrations recorded were: 5.8 MPC for iron (May 21), 4.1 MPC for copper (Aug. 21), 2.3 MPC for zinc (Apr. 20), 2.5 MPC for oxidation-resistant organic substances (May 21), 1 4 MPC for nickel (Oct. 19), 1.1 MPC for aluminum (Jul. 19), 7.7 MPC for manganese (Apr. 20), 1.8 MPC for petrochemicals (Mar. 21), and 1.3 MPC for fluoride (Feb. 20).
Lake Gusinoe. Observations were made near the railway station Gusinoe Ozero. The lake water salinity was average during the year, with the highest values recorded during winter [1]. The total hardness of water varied from soft to moderately hard. The lake had satisfactory oxygen regime throughout the observation period. pH was slightly alkaline. MPC exceedances were observed for total iron and easily oxidizable organic substances. Water pollution by the pollutants was defined as «characteristic». The maximum concentrations recorded were: 2.1 MPC for oxidation-resistant organic substances (Mar. 19), 1.5 MPC for easily oxidizable organic substances (Jun. 14), 1.6 MPC for total iron (Jun 14), 4.0 MPC for copper (Dec. 20), 1.3 MPC for zinc (Oct. 10), 2.0 MPC for phenols (Jun. 14, Oct. 10), and 3.2 MPC for petrochemicals (Mar. 19).
In 2013, no significant changes were observed in the underground hydrosphere of the Lake Baikal basin compared with 2012 [1]. In 2013, increased concentrations of petrochemicals were recorded within Ivolga-Uda basin and in the Selenga river valley. Significant sources of pollution continue to exist within the Ulan-Ude industrial hub, those that present a particularly high risk are the sedimentation reservoir of the locomotive and carriage repair plant (pic. 4.2.10), petroleum storage depots in Steklozavod neighborhood and facilities of aviation plant. Within the frameworks of the Federal Target Program «Lake Baikal protection and socio-economic development of Baikal Natural Territory during 2012-2020», the implementation of the activity no.8 «The elimination of subsoil accumulation of petrochemicals polluting the Selenga river in the vicinity of Steklozavod, Ulan-Ude city – remediation of the polluted lands, protection of the surface water and groundwater» began in 2013.
Pic. 4.2.10 The sedimentation reservoir of the locomotive and carriage repair plant (Google)
Within Irkutsk region, groundwater quality remained largely in its natural state. Within the impact zone of human settlements, groundwater might be contaminated by nitrogen compounds. Groundwater pollution, including pollution by petrochemicals, was observed at Kultuk petroleum storage depot, below its storehouse for light petroleum products. In 2013, concentrations of petrochemicals were the lowest during the entire observation period and did not exceed 0.08 mg/l (in 2012, the maximum concentration was 0.15 mg/l). Thermal and chemical pollution of groundwater by the facilities of the former Baikalsk Pulp and Paper Mill (production sites, manufacturing workshops, lignin landfills, etc.) remained significant.
Within the Khilok river basin in Zabaikalsky Krai, water quality in groundwater wells of the town of Petrovsk-Zabaikalsky remained unsatisfactory, with nitrate concentrations exceeding the MPC for water for drinking and household needs.
The Lake Baikal basin in Mongolia covers the most economically developed northern and central regions of the country. About 70% of the country’s population lives in within the Lake Baikal basin [2]. Furthermore, about 80% of industrial and 60% of agricultural output comes from the area. About 34% of all the entire livestock population (11 million heads) live and graze within the basin area.
Sources of water pollution within the Lake Baikal basin in Mongolia are waste waters from a number of enterprises belonging to the three large industrial hubs around the biggest settlements – Ulaanbaatar, Erdenet and Darkhan (pic. 4.2.1).
In recent years, the development of mining sector and livestock product processing sector lead to increased wastewater discharges by the industries (pic. 4.2.11). Untreated or inadequately treated sewage is another source of pollutants. Sewage treatment facilities of Ulaanbaatar (5 sewage treatment plants), Erdenet and Darkhan discharge treated sewage into the Selenga River. Over the last decades, the loads of pollutants have increased and for some pollutants the concentrations exceed the thresholds defined in the national water quality standard MNS 4586:1998 [6].
Pic. 4.2.11 Tail dumps and wastewater discharge point of a goldmining enterprise
(Zamaar soum, Tuv aimag)
Water pollution monitoring is routinely conducted by National Agency for Meteorology, Hydrology and Environmental Monitoring [2]. The monitoring results are published in annual reports on the state of the environment. Water pollution index is estimated based on measured concentrations of dissolved oxygen, easily oxidizable organic substances, mineral nitrogen, phosphorus, chromium and copper. In 2012, water pollution index was estimated for 85 rivers and 13 lakes based on monitoring data measured at 120 monitoring posts (Table 4.2.1 and 4.2.2)
Table 4.2.1 Surface water quality characteristics for the rivers within Lake Baikal basin in Mongolia
Table 4.2.2 Pollution of the rivers within Lake Baikal basin in Mongolia
In the country, there are more than 120 sewage treatment facilities operating. However, most of them have been in operation for several decades and use outdated equipment and technologies (pic. 4.2.12). The facilities produce inadequately treated effluents that are discharged into rivers. The national standard MNS 4943:2011 defines criteria for treated sewage discharged into the environment [6].
Pic. 4.2.12 Sedementation reservoirs of the enterprise “Erdenet”, Erdenet city
Garbage collection campaigns are organized around lakes, rivers and creeks during autumn and spring. In 2011, such campaigns were conducted in 21 aimags and involved 1409 water bodies and wells. In 2012, the number of water bodies was 1107. In 2013, the campaigns were organized in 10 aimag and 988 water bodies were covered in the activity (323 rivers, 31 lakes and ponds, 388 springs, 13 mineral water springs, 233 wells).
