A sewerage or sewer system collects waste water. Sanitary sewers were designed and built to carry waste water from domestic, industrial and commercial sources. ( EPA 2004) Gravity is used to convey the waste water wherever possible. Thus, it is not surprising that natural storm water drainage is usually used. experts in Insight Home Inspections will inspect your homes sewerage system to let you know if there is any fault which is to be fixed before your shifting.