This paper is designed to get better performance and higher capacity of the old wastewater treatment plant in Benha City. Characterization of the wastewater has been investigated and based on these results, Advanced Primary Treatment (APT) was chosen. From conditioned Jar testes, alum in a dose of 95 mg/L and 0.3 mg/L of an anionic polymer produce an effluent with a BOD < 60 mg/L, which reduce the load of pollution in the plant and neighboring communities and allows its disposal in the drain. However because faecal coliform content is high, an additional disinfection process is necessary.