Tommy Giertz, Stockholm vatten och avfall, gave a presentation on overflows in relation to combined or duplicate systems, infiltration and inflow and precipitation. He also linked the problem of infiltration, inflow and overflow to leaks in the drinking water network and the importance of keeping track of non-normal operation of pump stations. Erika Lundström, Luleå Miljöresurs, told about the wastewater treatment they built to take care of wastewater along a long transmission line from places in the southwestern part of the municipality. Especially during snowmelt and rainy periods, it can melt. The purification process is an initial mechanical purification system followed by a chemical mixture and after that a pond. Previous bioponds have been used for these precipitation ponds. Anders Eriksson, Karlskoga Energi & Miljö, told about the Actiflow system they have installed to take care of overflow water. Up to 3.5% of the total flow can be purified in total with this system. An addition of PIX microsand is made to flocculate particles which are then separated.
The next network meeting is planned for the month of November-December. Keep an eye out for the next newsletter. Feel free to join the LinkedIn group ”Nätverket tillskottsvatten och bräddning” to take part in presentations from the network meetings, stay updated on the next seminar and where you can always ask questions and discuss infiltration, inflow and overflow with others in the group.