Plumbing Services means the design, installation, construction, replacement, service, repair, alteration, or modification of pipes, fixtures, and other apparatus used for bringing the water supply into a building and removing liquid and water-carried wastes from a building. The three main types of plumbing systems installed in residential and commercial buildings are potable, sanitary, and stormwater systems. Each one has a unique function and purpose required to keep water flowing smoothly. There are five main types of plumbing pipe materials that are still in use today: copper, galvanized steel, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), and cross-linked polyethylene (PEX).