What is Sewer?
[[Image:Orfice.jpg|thumb|A sewer]] '''Sewers''' are underground [[Pipe (material)|pipes]] that take away dirty water and [[human]] [[waste]] from homes, offices and many other places. [[Sanitary sewer]]<nowiki/>s lead to [[sewage treatment]] plants that remove the harmful and unwanted parts, returning clean water to the [[environment]]. Many rules and regulations exist for how clean the final discharge (effluent) must be. [[Storm drain|Storm sewers]] are usually simpler. Houses that do not have a connection to city sewer will have a [[septic tank]]. Cleaning crews use special trucks and tools to help keep the sewers clear of grease, tree roots, and other blockages. More rural areas may have septic systems where sewers do not yet exist. In many urban areas, street [[gutter]]s to carry rainwater are combined with sewers. {{Sewerage}} {{Plumbing}} {{stub}} {{Commonscat|Sewers}} [[Category:waste]] <!-- interwiki --> [[Category:Drainage]]