For the purposes of the approval process of the plan for the energy recovery of dried sewage sludge from the Olomouc wastewater treatment plant at the Olomouc heating plant, the Czech Association of Circular Economy has issued the opinion below.
The company Veolia Energie ČR, a.s. asked the ČAObH for an opinion on the administrative process of the EIA notification and zoning proceedings - Energy recovery of dried sewage sludge at the Olomouc Heating Plant. The inquiry is directed to the possible classification of dried sewage sludge as hazardous waste in terms of possible necessary measures during transport, storage, etc.
Here we refer to the currently valid Act No. 541/2020 Coll., which regulates in Section 67 the definitions and obligations for the management of sewage sludge. Under Section 67(1)(b), treated sludge is sludge that has been subjected to biological, chemical or thermal treatment or any other suitable process so as to significantly reduce the content of pathogenic organisms in the sludge and thus the health risk associated with its application. According to information from the publicly available Notice of Intent 'Supplementation of the sludge management of the Olomouc WWTP' under Act No 100/2001 Coll., the implementation of the project will result in the production of dried sludge with a dry matter content of over 90 % (from the original average dry matter content of 27 %). The proposed drying process is one of the most effective ways of achieving the necessary treatment in accordance with the requirements of Section 67 of the Act. The removal of water from the sludge matrix at a drying temperature close to 100 °C is the most effective way to achieve this. This is because it is a physical method of treating the waste, which ensures hygienisation in accordance with Annex 6, point D9, of Act No 541/2020 Coll. (physico-chemical treatment not specified elsewhere in this Annex, the end product of which is compounds or mixtures that are removed by one of the methods listed under D1 to D12 (e.g. evaporation, drying, calcination)). The implementation of the project will thus result in the treatment of the waste and the complete elimination of a potentially dangerous property of the waste - infectivity. A significant secondary effect of the treatment of sewage sludge by drying is also the reduction of the sludge volume and odour emissions to a minimum.
For the above reasons, it is possible to classify dried sludge as treated in the other category without the need to take additional measures in subsequent transport or energy recovery.
Sincerely,
RNDr. Miloš Kužvart
Executive Director, ČAObH
