Wastewater treatment

Treatment of wastewater

We provide the service of wastewater discharge to almost 1/3 of the Estonian population. In order to ensure compliance with environmental requirements and purity of the Baltic Sea and the Gulf of Finland, Paljassaare Wastewater Treatment Plant removes more and more pollutants from wastewater each year. The wastewater treatment plant uses environmentally friendly and modern technologies to treat wastewater collected from Tallinn and its surrounding areas.

As a result of investments made in Paljassaare Wastewater Treatment Plant, Tallinn was removed from the list of hotspots (environmentally hazardous cities) determined by the environmental agreement of the Baltic Marine Environment Protection Commission (HELCOM). In 2014, our wastewater treatment parameters were in compliance with the requirements established by HELCOM as well as with those arising from the legislation. Thanks to our good day-to-day operation, efficient dosing of chemicals and additional treatment stage launched in 2011, bio filter, the quality of effluent discharged from the wastewater treatment plant achieved the full compliance with legislative requirements in all four quarters of 2014. We continue to invest in the assets of the wastewater treatment plant in order to improve the quality of effluent that has gone through the treatment process and is discharged to the Gulf of Finland.

Cleaner living environment

Our focus continues to lie on prevention and reduction of risks related to potential floodings and pollution. The number of blockages is the main indicator for the condition of the sewerage network. Blockages are mainly caused by sediment, which accumulates in sewage pipes. Water consumption has been continually decreasing during the past years, as a result of which the flow volumes and speed have decreased as well. This, in turn, increases the risk of blockages. Furthermore, the general number of blockages is also influenced by the continuous extension of the sewerage network.

We perform various preventive actions, such as flushing the sewerage pipelines, to reduce the number of blockages. In order to carry out jet washing, high-speed water flow is generated in the network, which washes all the accumulated sediment out into the nearest cesspool. After that, the sediment is collected into jet washing vehicles and transported to Paljassaare Wastewater Treatment Plant. Flushing of pipelines is carried out by our subsidiary company OÜ Watercom whose jet washing vehicles with re-use cycle enable to re-utilise the water necessary for flushing.

Reconstruction and extension of sewerage network

Investments in the replacement of depreciated sewerage pipelines, as well as in the construction of new pipelines have enabled us to continuously improve the provision of environmentally friendly services. In 2014, we reconstructed a total of 5 km of sewerage network.

More information on the Company’s water and wastewater treatment is available electronically in the 2014 Environment Report.