In water treatment, Abdel-Shafy, H.I et al. (2014) examined the different hybrid treatment process for handling greywater for reuse. This study proves the reduction of TSS, COD, and BOD with the addition of EM. Furthermore, it states that “Addition of effective micro-organisms (EM) to the raw greywater enhance the settling and aeration process effectively” and “increasing the EM dose to 1.5ml/L and settling time up to 4.5 h followed by aeration for 90 min could improve the final effluent up to the permissible level”. This final effluent meets the ‘Egyptian Guideline’ for unrestricted water reuse.