Sewers are the pipelines that carry sewage and wastewater from the locations they are collected to treatment facilities. Wastewater lines are often separate from sanitary sewer systems. Sanitary sewers are connected to houses and industries, and carry sewage to locations where it can be treated and purified for reuse. Sewage is wastewater comprised of water, faeces and urine. It is a type of wastewater, but is treated differently due to its nature. Sanitary sewers must be carefully constructed to minimise the potential of leaking sewage. If drinking water supplies are contaminated by sewage, it can cause illness or even death in those who are supplied by that particular pipeline.
Many countries have very basic sewerage systems, or sometimes no system at all. In the past, sewage was deposited on the street, to be washed away by rainfall. This was extremely unsanitary, and caused a huge number of deaths. Some cultures cannot afford the treatment facilities we have in the United Kingdom, and sewage is deposited directly into rivers or the sea. This is also potentially very harmful to both humans and the environment.
Sewer systems in the United Kingdom carry their contents to treatment facilities that use chemicals and bacteria to breakdown the elements of the sewage that can be removed. The water that is salvaged can be purified and reused as drinking water, and the elements that cannot be treated are disposed of safely. Shafts are created in the pipelines that allow workers access to the sewers. They are covered by manholes, and are essential for sewer maintenance. It is important that the conditions of the sewers are carefully monitored to prevent any leakage. The sewerage system is an extremely important aspect of society, and marked a huge step in modern society when it was first introduced. It hugely decreased the amount of illness in any given area, and significantly improved public sanitation.
The first sewers were found in Ancient Rome, and have been developed to create the standard sewerage systems we find today. The sewers are carefully designed, and rely on various means to transport the sewage to treatment facilities. Pumps can be used to promote the flow of sewage. Many developing countries rely on simplified sewers, which cost a fraction of the price and can be installed with relative ease. Sewers are of great importance, so it is extremely useful that these simplified sewerage systems are available to benefit poorer nations.