Already one year ago the biology of the ARA Unteres Pustertal has tilted. Since then, there have been repeated minor disturbances, which, however, remained within limits.
On Saturday, March 20, 2021, an unknown disturbing substance reached the plant, which strongly inhibited the bacteria.
Due to the damaged microorganisms, the wastewater of the entire Lower Puster Valley can now no longer be sufficiently purified. The effluent from the treatment plant exceeds the limit values and now pollutes the Rienz River with harmful substances. This condition now continues until the bacteria in the plant have recovered and resume their purifying work.
The only possible supportive measure now is inoculation sludge transports. This involves transporting healthy bacteria from Tobl to the plant in Mühlbach. This inoculation sludge is intended to accelerate the rebuilding of the bacterial mass so that the purification performance will soon be achieved again.
Update as of 01.04.2021:
Since March 30, the limits have been met again, the wastewater treatment plant is fully operational again.