Statistical Control of Water Quality in the Aracaju, Sergipe, Brazil

Abstract

In this work, we use statistical techniques for quality control, using the Control Attributes with the analysis of control chart C.The period of analysis was from 2009 to 2013 in order to perform microbiological analyzes of water quality. The parameter collected by DESO company was Total Coliforms, whichis evaluated through the variables Accepted Samples and Rejected Samples. Before the application of control charts C,we performedan exploratory analysis of variables and data normality. For normality,we used the Shapiro-Wilk Normality test and the Komogorov-Smirnov test. From the quantitative point of view, in relation to the water supply, we found that the analysis done by DESO in the Total Coliforms parameter, did not find a risk factor for human consumption and results indicated that the samples were free of coliforms. Based on the obtained data from DESO’s labsamples, the maximum allowable value (MAV) of total coliforms present in the water was 5%, in other words, the company is in accordance with the highest standard required by the regulations. Before the application of control charts C, we performed an exploratory analysis of the variables and we tested the normality of the data. We used STATISTICA 11 software to perform the tests, by means of these results, we could choose the best fit and the most significant and representative values for our work.