The document discusses the P.T.A.P water treatment plant, which cleans drinking water through reservoirs, filters, and PVC pipes of varying diameters. The plant brings water from its large-diameter intake to the town through 12- or 10-inch pipes, which then distribute the water throughout the town through smaller 8-, 7-, 4-, and 3-inch pipes. Valves control the flow of drinking water into the town from the plant.