impact of point sources on water quality in the Camalote River, Oaxaca, Mexico Point sources of pollution in the Camalote river

Abstract

Objective: This study evaluates the water quality of domestic discharges into the Camalote River, Oaxaca, Mexico, and identifies their environmental impact, with the aim of using the results in the establishment of preventive and mitigation measures, for the benefit of both the environment and the communities that depend on this resource.

Design/methodology/approach: Seven domestic wastewater discharges to the river were analyzed using the methodology of NOM-001-ECOL-1996 for the collection and analysis of water samples.

Results: The results reveal that the discharges exceed the maximum   permissible limits established by NOM-001-SEMARNAT-2021, in total   suspended solids (256.67 mg L-1) and biochemical oxygen demand (392.22 mg L-1) in discharge 4; as well as in total coliforms (27,333,333.33 NMP/100 mL) and fecal coliforms (10,000,000.00 NMP/100 mL) in discharge 6.

Limitations on study/implications: The results indicate risk to both public health and aquatic ecosystems, therefore constant monitoring of the river is recommended, especially in the drought period, when the dilution capacity of the river decreases, pollutant and organic matter concentrations increase, and anaerobic conditions affecting aquatic biodiversity.

Findings/conclusions: The study highlights the need to implement     preventive and mitigation measures, such as wastewater treatment and   revegetation of strategic areas, to reduce pollution and preserve water quality for the benefit of both the environment and the local communities that depend on this resource.