Author(s): Reema, Anchal Sharma and Neelma Kunwar

Abstract:
The standard sanitation technology in urban areas is the collection of wastewater in sewers, its treatment in wastewater treatment plants for reuse or disposal in rivers, lakes or the sea. Sewers are either combined with storm drains or separated from them as sanitary sewers. Combined sewers are usually found in the central older parts or urban areas. Heavy rainfall and inadequate maintenance can lead to combined sewer overflows or sanitary sewer overflows, i.e more or less diluted raw sewage being discharged into the environment. Industrial often discharge wastewater into municipal sewers, which can complicated wastewater treatment unless industries pre-treat their discharges. The high investment cost of conventional wastewater collection systems are difficult to afford for many developing countries. Some countries have therefore promoted alternative wastewater collection systems such as condominium sewerage, which uses pipes with smaller diameters at lower depth with different network layouts from conventional sewerage.