CPV code 45222100 designates Waste-treatment plant construction work in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
45222100 sits under 45222000 (Construction work for engineering works except bridges, tunnels, shafts and subways) and groups 1 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.