Air emissions at large municipal wastewater treatment plants in Finland for national E-PRTR reporting register

EC regulation (166/2006) obligates all urban waste water treatment plants above 100.000 PE in European Union area to report their water and air emissions by PRTR protocol from year 2007. There were no general rules or correlations determined to calculate or measure air emissions of municipal wastewater plant. Due to fact that major part of the treatment plants is uncovered, individual air emission study was demanding to implement. In Finland a group of large wastewater treatment plants studied PRTR air emissions based on the samples of Viikinmäki WWTP (780.000 PE), the largest wastewater treatment plant in Finland. Since Viikinmäki WWTP is completely covered, underground plant, ventilation air analyses were possible to implement in full scale. Based on this study, air emissions of Viikinmäki WWTP has been determined and reported to fulfil the PRTR protocol demands. Air emission model was accepted by Finnish Environmental Authorities and the air emission model of Viikinmäki WWTP was used by other, large Finnish WWTPs.