What type of traffic will there be at the plant after its completion?
The treatment plant will have 30–40 employees, many of whom will drive to and from work in their own cars because there are no proper public transport connections to Blominmäki. During regular working hours on weekdays, some heavy vehicles will drive to and from the treatment plant. A reception point for sludge from septic tanks will also be built in the Blominmäki bedrock facility in conjunction with the treatment plant, where a few sewage pumping trucks per hour are expected. The volume of traffic related to sewage tunnels will be very low, being only related to tunnel maintenance.
How can you ensure that there will be no odour nuisances in the immediate vicinity when the treatment plant is in operation?
All odorous air conducted from the bedrock treatment plant will be collected and extracted to the air through a tall chimney. The odours will dissipate in the air so that only temporary (for less than an hour at any one time) mild odours may be sensed on the ground surface. We have utilised the experiences obtained from the Viikinmäki treatment plant in the design of Blominmäki. Exhaust units in the supply sewer tunnel will be installed in places where they do not cause any nuisances to residents. If odour nuisances are larger than expected, we are able to take a number of corrective actions.
Will hazardous substances be transported to the treatment plant on lorries?
Methanol (a flammable fluid) and fuel oil are the most hazardous substances to be used at the treatment plant. Iron sulphate and lime are not as hazardous. Smaller volumes of other chemicals will also be needed, but they are not particularly hazardous.