ABSTRACT

In an urban setup, a significant quantity of used water is disposed of from our showers, toilets, kitchens, laundry and other amenities. These used waters are called wastewater and are transported along with different types of wastes. Some wastewater is also generated from our garden irrigation, however, traditionally this wastewater is transported to our stormwater drainage system (if the stormwater drainage system is separate from the wastewater drainage system). As such, wastewater contains a higher level of contaminants, including human excreta, and, therefore, requires a higher level of cautions in regards to its collection, transport, treatment and disposal. Because of this sensitivity, wastewater collection pipes usually run deeper into the ground so that any accidental leakage/spillage does not easily reach the ground surface or come into contact with humans. In addition to potential hazards from contaminants, it also causes odour and nuisance to the residents. As such, this is an important component of urban water resources which needs to be dealt with very carefully as its failure may be catastrophic. Due to its higher levels of contaminations, it must not be disposed of in the environment without proper treatments.