Gulf of Finland
There are three capital cities located on the coast of the Gulf of Finland: St. Petersburg, Tallinn and Helsinki. St. Petersburg is the most populous. Several other cities located in the Baltic Sea catchment area face problems similar to St. Petersburg and Tallinn.
Together with its suburbs, the city of St. Petersburg is the largest municipal emission source in this area. It has about five million inhabitants and more than 2 000 large industrial enterprises (metal, electrical, chemical, textile, paper and construction) discharging untreated wastewater into municipal sewers. Due to extensive water consumption, municipal sewage treatment plants are overloaded and unable to adequately treat the wastewater. The poor condition of the sewer network andthe inevitable leakages add to the problem. St. Petersburg is responsible for about 40 percent of the total BOD point-source load and about 50 percent of the total phosphorus point-source load discharged to the Gulf. In 1990, the city discharged 51 500 tons of BOD, 20 000 tons of tot-N, and 3 300 tons of tot-P. Three biological treatment plants are under construction. The biggest problems related to wastewater management in St. Petersburg are insufficient pre-treatment of industrial wastewater, discharge of untreated sewage from about two million city inhabitants, and insufficient nutrient removal rates at the central and suburban wastewater treatment plants. The discharge of untreated sewage is partly due to the lack of treatment facilities (about 40 percent) and partly to insufficient treatment capacity and frequent by-passes (about 60 percent).
Municipal and industrial wastes (including hazardous and toxic substances), as well as wastewater sludge, are of great concern. In the city of St. Petersburg alone. over 70 percent of municipal wastes are taken to landfill sites. At Krasnyj Bor, about 1 million cu m3 of hazardous wastes have been deposited during the past 20 years, and the area will be filled within two to three years. The surface water from Krasnyj Bor drains to the tributaries of the Neva and ultimately reaches the Gulf. Sewage sludge from the city wastewater treatment plants is stored in an earth basin area. Leakage is considerable. The city of St. Petersburg is responsible for about 90 percent of all copper and chromium discharges to the Gulf of Finland (108 tons/year and 69 tons/year respectively). This load is generated primarily by about 300 plating industry plants located in the city.
The main part of the SO2 emissions generated in the city of St. Petersburg and the surrounding region originates in thermal electric power plants. In recent years, about 70 percent of the city plants have been converted to natural gas, and the same tendency is observed in the St. Petersburg region. In spite of these measures, in the late 198Os, SO2 and dust emissions in St. Petersburg and region amounted to 184 600 tons/year and 16 100 tons/year, respectively.
The city of Tallinn has some 500 000 inhabitants (about one third of the total population of Estonia). All industrial enterprises in the city are connected to the sewer system. In 1990, effluents from the wastewater treatment plant (mechanical and chemical treatment; first phase of biological treatment to be completed in 1992) contained 12 300 tons of BOD7, 3 600 tons of tot-N, and 255 tons of tot-P. In other cities of Estonia, poor conditions of the sewer systems and pumping stations cause frequent sewage bypasses. These unsatisfactory conditions occasionally cause bacteriological pollution of the coastal waters of Estonia.
The Helsinki region has a population of about 800 000, and in 1990 the effluent from its six wastewater treatment plants equalled some 2 040 tons of BOD7,4 050 tons of tot-N and 96 tons of tot-P. Within the whole sub-region, there are 39 Finnish municipalities generating sewage loads of more than 10 000 p.e. each. Ten of these plants are on the coast.
There are 17 pulp and paper plants in the Russian part of the sub-region. Outside of the factories located in the city of St. Petersburg, the largest are the Volkhov aluminium and chemical plant in the St. Petersburg region and the Nadvoitsy aluminium plant in Karelia.
These industrial enterprises pollute both the water and the atmosphere. Their atmospheric emissions, combined with those of traffic, have many detrimental effects on human health. The major Russian sources of atmospheric emissions are pulp and paper plants and the mining industry located in Karelia. By the end of the 198Os, the emissions totalled 141 800 tons/year of SO2 and 31 000 tons/year of dust. Almost 40 percent of the total SO2 emissions originated at the Kostamuksha mining combinate. The Nadvoitsy aluminium plant as well as the Pitkyaranta, Segezha, and Kondopoga pulp and paper plants are the other sources of primary importance.
Long-range atmospheric transport is directed towards Finland. Up to 30 percent of total sulphur deposition in southern and eastern Finland originates in Estonia and the Russian part of the Gulf catchment area. Nitrogen emissions from Russia account for 10 to 30 percent of the total NOx and 20 to 50 percent of the total reduced nitrogen deposition in Finland.
In Estonia there are two pulp and paper mills, a small sulphite mill in the center of Tallinn (present production reduced to about 20 000 tons due to wood shortage) and a sulphate mill at Kehra (production about 40 000 tons/year). Both Estonian mills have an adverse impact on water quality in the Gulf. The Kohtla-Jarve industrial complex, including oil shale burning power plants, is of special significance. The total annual waterborne load generated by this complex amounts to 525 t/year of tot-N, 15 t/year of tot-P, 950 t/year of phenols, and 5 500 tons/year of BOD5. The Estonian Phosphorates located in the eastern part of Tallinn annually discharge 240 tons of tot-N, 50 tons of tot-P, and 320 tons of BOD5.
The critical sources of atmospheric emissions in Estonia are two large oil-shale burning power plants located near the city of Narva. The SO2 emissions from these plants equal about 75 percent of the Estonian total which, by the end of the 1980s. amounted to an estimated 288 000 t/year.
There are 29 Finnish pulp and
paper mills in the sub-region, several of
which are located on inland lakes. Five
mills are on the coast and eight on the
banks of rivers that directly affect the
coastal waters. Two of these mills (Sunila
Oy at Kotka and Kymin Paperiteollisuus
Oy at Kuusankoski) produce bleached
kraft (1990 production 660 000 tons).
The rest of the mills produce mainly
wood-containing paper (production in
1990 of 2 250 000 tons). Both in pulp
and paper mills various internal and
external measures have been taken to
reduce discharges of organic substances
and nutrients. Atmospheric emissions
from the Finnish coastal pulp and paper
industry do not affect the Baltic Sea
because of the prevailing westerly winds
and air pollution control measures.
In the St. Petersburg region there are several large-scale livestock farms with about 500 000 hogs, 30 000 head of cattle, and 11 000 000 fowls. Of the 5 million m3 wastewater generated annually by hog farms, over half is not treated at all or treated insufficiently. This wastewater is stored in huge open reservoirs built between earth dams. The ultimate leakage to the Gulf is considerable. Arable land in the Russian part of the sub-region occupies some I 930 000 ha (St. Petersburg region - 4 15 000 ha, Novogrodsky region - 504 000 ha, Pskovsky region - 934 000 ha and Karelia - 77 000 ha). The fertilizer (NPK) application rates in 1990, were on the order of 270 kg/ha in St. Petersburg and Karelia regions. In the Novogrodsky and Pskovsky regions they are lower than the above rates by about 100 kg/ha.
In Estonia, large-scale livestock production is also dominant, with large farms of more than 400 cows or 5 000 hogs (the largest hog farm situated near Viljandi has 35 000 to 40 000 head). Arable land occupies about I .O million ha. In the 195Os, the usage of mineral fertilizers (NPK) was on the order of 40 kg/ha while in the late 1980s it reached the very high level of 290 kg/ha. Last year mineral fertilizer and pesticide use decreased because of price increases.
In Finland, arable land occupies about 1. I million ha. Forested area is equal to about 6 million ha. Agriculture contributes to a considerable nutrient load, due to a high application rate of N/P fertilizers. To reduce the load, the following measures, among others, have been taken: protective zones; introduction of fertilization taxation, based on the N and P contents of fertilizers; fertilizer usage according to yield expectation; and improved storage and spreading of manure.
Municipal sewage and industrial wastewater flowing to the Gulf of Finland from Russia and Estonia are the principal causes of water quality problems in the Gulf. Large-scale livestock operations as well as municipal and industrial hazardous and toxic wastes contribute to the problem significantly. In addition, discharges from non-point sources are substantial. Large-scale pulp and paper industries, mainly located at inland lakes, discharge considerable amounts of organic substances and nutrients.
Source: The Baltic Sea Joint Comprehensive Environmental Action Programme. Helsinki, 1993. (Balt. Sea Environ. Proc. No. 48), pp. 3-3 - 3-6