Plumbing is a system that allows fluids to travel through pipes, tanks, valves, and other gadgets. Its origins date back to ancient civilizations, including Rome, Greece, and Persia, which used unique methods to transport water, remove wastewater, and irrigate crops. In modern times, plumbing is the main system for water transfer. The three primary systems of plumbing are: Sanitary drainage systems – Sanitary drainage systems ensure the removal of wastewater from within a building. The pipes used in these systems flush waste that comes from toilets, laundry, and cooking. Waste exits through pipes and enters a local sewer system. Stormwater drainage systems – Through the use of this plumbing system, rainwater is carried away from a building or structure and drained into either a sanitary drainage system (for older buildings) or a community storm sewer (for newer buildings). This system’s drains and pipes are found below the ground, while gutters are visible from the outside of a building. Public water systems – The public – or potable – water system is designed to bring drinkable water from a community source into a structure. The system has several pipes as well as a valve that can shut water off from its main supply. Public water systems typically contain meters that make it easy to gauge how much water is being used. Plumbers are responsible for managing plumbing systems. They install and repair pipes, plumbing fixtures that deliver and drain water (toilets, bathtubs, water heaters, dishwashers, etc.), valves, and much more. Plumbers troubleshoot to pinpoint a plumbing system malfunction, determine what equipment will be necessary to complete a job, then provide their clients with thorough cost estimates. Once their job starts, they might take on responsibilities that range from removing obstructions and cleaning drains to assisting in the overall maintenance of a septic system. Plumbers can also read blueprints to ensure building codes are being followed. Many plumbers work as contractors or are self-employed. Those who are contracted with businesses commonly work full-time, including nights and weekends. They may also be on-call to take care of emergencies. Self-employed plumbers often set their own schedule and may only work during standard business hours. While completion of high school is commonly sufficient education to begin a career as a plumber, individuals who enter this career often take courses at vocational schools, as well. Training might include a paid apprenticeship that lasts four or five years. During the apprenticeship, plumbers often learn how to read blueprints, utilize proper plumbing safety protocols, and follow plumbing regulations and codes for their area. In many states and localities, plumbers are required to be licensed. Generally, individuals can attain a license after accruing an average of two to five years of experience and passing the appropriate test. Individuals can expand their career opportunities in plumbing by entering the field of plumbing design or becoming master plumbers or project managers. Plumbers can commonly find work on projects that include the new construction of a building or maintenance of existing buildings.