37
Construction of installations for providing and/or treating and/or distributing of electricity, gas, in particular natural gas, heating, in particular long-distance heating, and water; construction of installations for recycling and/or processing of waste, refuse or industrial waste; construction of installations for waste water removal and/or waste water purifying; construction of pipelines for transporting gases, liquids and solids; repair and maintenance of the aforesaid installations and pipelines
39
Transport and distribution of electricity, gas, heating and water, in particular distribution of electric current, natural gas and long-distance heating; transport of gases, liquids and solids by pipeline; Supplying of energy
40
Recycling of waste and refuse, processing of refuse using physical and/or chemical and/or biological processes; treatment of materials, waste water purifying