In developing countries, it still suffers from endless problems regarding wastewater treatment and the problem of choosing the appropriate treatment system due to lack of proper technology and weak economy. This study highlights the maturity oxidation pond (stabilization) of small communities as an effective, low-cost and simple post-treatment technique for treating wastewater before discharging into an aquatic ecosystem. The Rashid plant was cited as a treatment plant in the city of Rashid-ElBeheira Governorate - Egypt as a model plant for applying this technology in treatment of wastewater. This work also includes the studying of the relationship between climatic conditions, physicochemical parameters and biomass of microorganisms to evaluate the efficiency of its performance.