Evaluación de las condiciones de calidad del agua de caño grande localizado en el municipio de Villavicencio.

Abstract

In this project the water quality of the Caño Grande micro-watershed, located in the municipality of Villavicencio-Meta, was evaluated, which shows alterations in the resource due to the discharge of domestic wastewater, through the application of the National Foundation index. of Sanitation (ÍNSF). Initially, field visits were made to collect primary information and identify the discharges of domestic wastewater over a four-kilometer section of the tributary, where a total of 81 discharges were obtained. Later, four sampling points were established along the studied section of Caño Grande, where punctual and composite samples were taken in different periods of time (October and December) taking into account that the month of October was characterized by a high rainfall while the month of December was low precipitation; in order to evaluate in situ and in laboratory, nine physicochemical and microbiological parameters of wáter (Dissolved Oxygen, pH, Biochemical Oxygen Demand, Nitrates, Phosphates, Temperature, Turbidity, Dissolved Solids and Fecal Coliforms) required to apply the NSF index. The result of these parameters, allowed to identify before the application of the index, that the pipe is being altered by the vertimientos, especially by the high presence of fecal Coliforms with values higher than 24000 CFU in 100ml of water, considering that this is an indicator of fecal contamination. Another of the parameters evaluated is the contamination with turbidity, with values of up to 19 NTU, which hinder the processes of photosynthesis in water. With respect to the other parameters, these values are presented within the standards established in decree 1594 of 1984. After obtaining the NSF index of the different sampling points in the two climatic seasons (High rainfall and Low rainfall), where it was determined that the water quality of the tributary is good at all points, except at sampling point 4 in low rainfall season that presented an average quality; an analysis was made to the results by means of an ANOVA and designs of complete blocks at random, identifying the high influence of the climatic seasons at the time of sampling with a p - CONDICIONES DE LA CALIDAD DEL AGUA DE CAÑO GRANDE 16 Value = 0.000 <α = 0.05 and the location of them with a p - Value = 0.018 <α = 0.05. Finally, a double-entry matrix was used to identify the level of impact at the four sampling points, taking into account criteria such as the ICA-NSF, the number of upstream discharges, the sewerage service and the number of dwellings established within the water round, where all the points are in a moderate situation. This in order to determine proposals focused on improving the water quality of Caño Grande according to the affectation in the points, taking into account that the main cause of the degradation of this, are the constant discharges of domestic wastewater.