Plumbing systems in public buildings such as restaurants, schools, office towers, and stores are the focus of commercial plumbing. These systems might handle 10- to 100- times more wastewater than a lowly residential toilet, so they are far more complex and require far more skill to work on and to design. In a public building, the plumbing system must do what it’s supposed to do without being noticeable or offensive, day and night. That’s public plumbing at its best.Conversely, plumbing that is used in industrial contexts is geared toward manufacturing plants, factories, and any entity involved in production processes. These types of plumbing systems usually must accommodate the transportation of chemicals, gases, and other substances found in industrial settings. It often must also deal with large-scale, labor-intensive plumbing solutions, such as those needed in wastewater treatment plants, which are required to manage both dirty water and the hazardous industrial materials usually found in it—up to 80% of which is highly toxic—with the assurance that none of it will escape into any of the waterways for which the human population has any foreseeable use.