Environmental Indicators in the Pretreatment of Water Potabilization

Environmental indicators provide information that is both significant and comparable for process controls, such as drinking water quality. Therefore, the objective of this study was to determine the variability of the following parameters: turbidity, residual chlorine and pH, in the process of water pretreatment for potabilization and to propose corrective actions to ensure standards of water quality for human consumption are maintained. The methodology consisted in taking 45 simple samples of water to determine the aforementioned parameters in the water supply for the locality studied. Individual X-R control charts were elaborated to learn the central tendency and variability of the environmental indicators. These were compared to the control limits in the official Mexican standard NOM-127-SSA1-1994 “Environmental health, water for human use and consumption-permissible limits of quality and treatments to which water must be submitted for its potabilization”. The results showed that turbidity was under statistical control, whereas residual chlorine and pH were identified to be outside of the aforementioned control. Therefore it is suggested to improve training for operators and to establish a calibration program for the equipment used. This review of the environmental indicators also allowed us to conclude that this process is affected by water quality, which is variable. This is especially true in the rainy season where there is more turbidity due to the dragging of sediments towards the supply source, in addition to the existence of a relationship between the increase in turbidity of raw water and disinfectant dosage. Through the control of the water pretreatment process there will be gradual but significant advances to increase water quality, guaranteeing the satisfaction of the population