Operation of sewer systems
This sub-class includes: - operation of sewer systems and/or sewer treatment facilities - treatment of wastewater (e.g., human and/or industrial wastewater, water from swimming pools) by means of physical, chemical and/or biological processes like dilution, screening, filtering, sedimentation, etc. - maintenance and/or cleaning of sewers and/or drains, including sewer rodding - operation of wastewater treatment facilities, for the reuse of e.g., agricultural, industrial, road cleaning or collected rain water, or for artificial recharge or augmentation of groundwater bodies - freeze drying of sewage sludge by wastewater treatment plants - emptying and/or cleaning of cesspools and/or septic tanks, sinks and/or pits from sewage - servicing of chemical toilets