Evaluation of Microbial Quality of Drinking Water in Mianeh Rural Areas and Determination of Corrective Actions of Rural Health Workers and Technicians to Improve Water Quality

Abstract

Abstract Background: The purpose of this study was to evaluate the microbial quality of drinking water in rural regions of Mianeh County in the autumn of 2019. Also, the role of Rural Water and Wastewater Company (Abfar) in improving the microbial quality of drinking water was investigated. Material and methods: From the study population, 50 villages (25 villages covered and 25 villages not covered by Abfar) were randomly selected as statistical population based on proportional allocation. In this study, a total of 150 drinking water samples were taken over a period of 3 months (one sample from each selected village per month). The cultivation of the samples to evaluate the number of total coliforms and fecal coliforms was performed using the most probable number (MPN) technique and 9-tube method in two presumptive and confirmed phases. Finally, the statistical analysis of the results were performed by SPSS and Excel software. Results: The results showed that the desirability index for lack of total coliform bacteria test in drinking water in the villages covered by Abfar was 84%, 92% and 100%, in villages non-covered by Abfar was 64%, 84% and 48% and in all the surveyed villages was 74%, 88% and 74% in months October, November and December, respectively. Also, the desirability index for lack of heat-resistant E.coli bacteria test in drinking water in the villages covered by Abfar was 92%, 92% and 100%, in villages non-covered by Abfar was 64%, 84% and 60% and in all the surveyed villages was 78%, 88% and 78% in months October, November and December, respectively. Based on the results, the percentage of residual free chlorine in the covered, non-covered and total villages was 28.23, 12.02 and 20.57%, respectively In general, performance of health workers in the process of drinking water except in daily measurement of residual free chlorine (with 100% coverage) was less than expected. Also, the performance of Abfar in regular and daily chlorination of drinking water in the covered villages was much lower than expected. So that, out of 25 villages covered by Abfar, only drinking water in 9 villages (36%) have been chlorinated, and the average free residual chlorine in 6 to 7 villages (24-28%) was in the admissible limit of 0.5-0.8 mg/L. Conclusion: According to 2006 guidelines of WHO on evaluation of microbial quality of drinking water, the microbial quality of drinking water in covered villages was in excellent range (with the desirability index for lack of E.coli test 94.66%), in non-covered villages was in poor range (with the desirability index for lack of E.coli test 68%) and in all the surveyed villages was in good range (with the desirability index for lack of E.coli test 81.34%). In general, despite the poor performance of Abfar in chlorination of drinking water, the microbial quality of drinking water in covered villages by Abfatr was very favorable compared to non-covered villages. Therefore, the necessary measures should be taken in order to cover the villages by Abfar, as well as regular and continuous chlorination of drinking water in this villages. In addition, the performance of health workers in the process of controlling drinking water should be improved especially in villages with microbial contamination drinking water. Keywords: Mianeh County, Drinking Water, Microbial Quality, Rural Areas, Rural Water and Wastewater Company (Abfar