|ISBN (pdf):||978-952-11-4240-6|| |
|Julkaisusarja ja numero:||Reports of the Finnish Environment Institute 36/2013|| |
|Kustantaja:||Finnish Environment Institute|| |
|Saatavuus (pdf):||http://hdl.handle.net/10138/42300|| |
|Tekijät:||Janne Ropponen; Hanna Arola; Petri Kiuru; Timo Huttula
The City of Lappeenranta is considering options for its wastewater discharge sites in the future. One possibility is to release the treated wastewater into River Vuoksi, flowing through the City of Imatra, approximately 35 kilometres northeast from Lappeenranta. This report contains results from nutrient and fecal bacteria water quality modelling along River Vuoksi. The model endeavours to answer how the possible changes in wastewater discharge amounts and locations affect the river water quality near the freshwater intake at Svetogorsk, Russia. The river model was built using a river modelling system SOBEK from Deltares Systems. Calibration was done using data from the year 2010 and actual scenario simulations used 2011 data. According to the simulations there are no major water quality deviations compared to the current situation in normal operating scenarios, but there is some risk of water quality deterioration in certain catastrophic scenarios. The location of the discharge site might have some effect on the water quality due to the time required for the effluent to fully mix with the river water. Additionally a 3D research model of the southern Lake Saimaa was built to study passive tracer transport from two different sites near the City of Lappeenranta. The open source modelling software COHERENS was used to simulate scenarios during the open water period in years 2010 and 2011.