Abstract: The quality control is one of the sciences which has gained a passion for many researchers and writers in economic and administrative sciences, so look for a new mechanism to achieve the requirements of the costumer and please him in terms of the quality of goods and services, whether in price or the extent of their availability, and because of customer satisfaction would increase the profitability of the enterprise and enhance the competitive position and to ensure the survival and continuity in the local market as well as create a competitive advantage in the international market. quality control has evolved rapidly and then using statistical quality control chart, the concept of six Sigma from the latest statistical concepts in the science of quality control, but in the case of non-symmetric data were introduced skewness correction to obtain a more accurate charts, those charts were applied on the data extracted from the East Mansoura station to purify drinking water. This paper found some of the following recommendations: the need to use skewness correction control chart in the case of non-symmetric data which gives more accurate results for the adjustment of the boundaries of statistical quality control chart over production. So we need to develop the water treatment plants and using the modern methods of purification like ozone and ultraviolet rays.