Wastewater treatment plant is a basic infrastructure in modern society to purify wastewater created by homes and businesses. Its operation is 24 hours a day and wastewater treatment comprises multiple processes to remove solids, organic compounds and other matters. Such a complex work flow needs a careful management and it is insufficient only being supervised by plant personnel. Besides, the source water quality can be changed in an instant and any negligence or mistake may lead to improper treatment or cause environmental pollution. Therefore, the treated effluent to meet the environmental regulations and government criteria before discharging into the sewer or river.