[Class : 7] Machines, Spares And Accessories For Supply And Construction Of Industrial Wastewater Treatment Plants, Sewerage And Sewage Treatment Plants, Water Conveyance And Water Treatment Plants, Hazardous And Solid Waste Collection, Treatment And Disposal, Bio Medical Waste Collection, Treatment And Disposal, Bio Gas Plants And Bio Gas Utilisation Systems Such As Captive Power Generation Units, Pollution Control Equipment, Water Retaining Structures, Civil Engineering Structures.