Failure of two collectors discharging sewage from the left-bank Warsaw to the "Czajka" sewage treatment plant on the right bank took place at the end of August. As a result, all the waste was discharged into the Vistula. On 14 September, the discharge of sewage was suspended, all sewage disposed of goes to the treatment plant.
The discharge of untreated municipal sewage to the Vistula, in connection with the failure of the sewage transmission system to the "Czajka" sewage treatment plant was the cause of the occurrence of local stagnation of pollutants and foam on the water surface observed on the one-hundred-kilometer section of the Vistula. By taking immediate action: the construction of a pontoon bridge and an installation for emergency sewage transfer to the "Czajka" sewage treatment plant, a few days after the failure was able to reduce the amount of sewage discharged into the Vistula, and thanks to the installation of new, high-efficiency pumps from Saturday (14 September) has been suspended.
In addition to coordinating work on the construction of a temporary sewage transfer plant to the "Czajka" sewage treatment plant, employees of the Water Supervision and Technical Support Teams of Polish Waters conduct continuous monitoring of the Vistula River on a section of the river over a hundred km from the Maria Skłodowska-Curie Bridge in Warsaw to Płock. Patrols are conducted from the boat as well as from the shore.
From 28 August to 9 September, employees of Wody Polskie observed foam locations and stagnation. Due to the improvement of hydrological and meteorological conditions: an increase in the state of the water on the Central Vistula, an increased flow in the river, an increase in wind strength and water waves and a decrease in air temperature, from 6 to 11 September the number and extent of reservoirs and foam locations decreased.
Due to changing hydrological and meteorological conditions, the observed phenomena are variable in time, sometimes after a few hours there is no trace of the phenomenon. The Voivodship Crisis Management Center (Mazowieckie), VIEP in Warsaw, MPWIK and relevant cells of Wody Polskie are informed about the results of monitoring conducted by Wody Polskie.
The effect of discharge of wastewater into the Vistula will be a persistent increased level of nutrients, mainly mineral forms of nitrogen and phosphorus, which contribute to eutrophication of waters. The influence of biogens on the condition of Vistula will be especially felt by aquatic organisms. Almost all mussels found in Poland are sensitive to pollution and oxygen deficiency in water. The effects of delivering the nutrient load to Vistula and the Baltic Sea will be felt for many months.
The state of municipal wastewater treatment in the member states of the European Union is constantly monitored by HELCOM - Baltic Marine Environment Protection Commission. Everything that goes into the rivers ultimately determines the quality of the waters in the Baltic.
Poland is also implementing the provisions of the Directive on urban waste water treatment 91/271 /EEC. The Warsaw agglomeration has always been an important point on the map for creating pollution of flowing waters.
In the 1990s, high-risk communal points were designated in the Warsaw agglomeration - HELCOM Baltic Hotspots, which included sewage treatment plants designed in the 1990s in Warsaw due to failure to meet the appropriate level of municipal wastewater treatment. The construction and modernization of existing wastewater treatment plants - "Czajki" and "Południe", as well as the organization of sewage management in the Warsaw agglomeration allowed them to be removed from the list of hotspots in 2015.
The "Czajka" sewage treatment plant is the largest treatment plant not only in Poland, but even throughout Eastern Europe. At the time of its construction in the 90s of the last century, it was an outdated building that did not meet the standards of the time - the construction was carried out on the basis of a project that was created in the 1970s. of the 20th century. The extension and modernization of "Czajki" was the most important investment in terms of impact on environmental protection and the condition of Vistula. Meanwhile, after the failure of the sewer transmission collectors from the left-bank Warsaw, we went back to the early 90s, when the wastewater was not treated.
Before the accident during the week 0.6 tons of phosphorus and 10.8 tons of nitrogen went to the Vistula. During the accident, Vistula may receive 10.8 tons of phosphorus and 101 tons of nitrogen per week. These are 18 and 9 times higher, respectively. This means that every week of failure, Warsaw dumped as much phosphorus - the most harmful element in terms of eutrophication - from its left bank to the Vistula - as it would normally shed for four months, which is why it was so important to eliminate the failure and find an alternative, temporary solution to stop discharge of untreated sewage directly to the Vistula. Currently, the installation has obtained 100% efficiency and all discharged sewage goes to the treatment plant.
Department of Social Communication
PGW Wody Polskie