For a long time, residents of the Staszica housing estate have complained about the unpleasant smell. In the late evening, it is difficult to sit outside, while in the apartments it is better to keep the windows closed. Recently, the smell from the nearby wastewater-treatment plant has even been noticeable to residents of Małachowskiego Street. The cause is the outdated design of the digestion chambers, which are simply not covered by anything.
"In new wastewater-treatment plants, enclosed chambers with biogas recovery are built. Special filters are installed," explains Grażyna Koroluk, manager of the wastewater-treatment plant in Bolesławiec. "Unfortunately, here we have open chambers. That is how they were built," she adds.
During the fermentation of sludge collected in the chambers, gases including methane and hydrogen sulfide are released. Hydrogen sulfide is the most troublesome. The mixers operating in the chambers are responsible for spreading the smell. When they are running, a larger amount of the bothersome odor is released from the sludge. To limit this, the mixers are switched on only at night, when the effects of their operation on the smell are least bothersome.
Over the past few days, in addition to winds blowing southward, there have been sudden changes in atmospheric pressure, which also contribute to stronger smells being perceived. These several factors caused the odor from the wastewater-treatment plant to be noticeable over a larger area than usual.
The construction of enclosed digestion chambers will become possible after the Municipality receives money from the ISPA fund.