Plumbing work refers to the laying, installation, alteration, repair, or replacement of water pipes, tanks, taps, and fittings in the drinking water supply system for the conveyance of water supplied by PUB. This includes the yearly water tank cleaning that the PUB requires.

Sanitary work involves installing, replacing, or moving toilet bowls and sanitary piping systems that transport used water from a building or premises to the used water system. This covers grease trap maintenance, CCTV drain inspection, and electro-mechanical obstruction clearance and cleaning of sewer lines.