Article - Physicochemical Evaluation of Surface Water in the Caplina River Basin, Tacna, Peru, during October 2024: Assessment against Environmental Quality Standards

This study assesses the physicochemical quality of surface water in the Caplina River Basin, Tacna, Peru, during October 2024, comparing the results with the Peruvian Ministry of the Environment’s Environmental Quality Standards for Water (ECA-Agua). In situ measurements of temperature, pH, electrical conductivity (EC), and dissolved oxygen (DO) were conducted at 20 stations distributed along the main river channel and its tributaries, complemented by laboratory analyses following the APHA Standard Methods. The results revealed persistently high EC values (5,085–5,796 µS/cm), far exceeding the reference threshold for irrigation of moderately sensitive crops (1,500 µS/cm), indicating a generalized salinization process. DO levels were critical (<5 mg/L) at 40% of the stations, particularly between P02 and P08, suggesting stress conditions for aquatic biota. pH remained stable (7.39–7.98) within the regulatory range, with no episodes of extreme acidification or alkalinization. The persistence of high salinity and DO deficits, combined with altitudinal gradients and anthropogenic inputs, poses significant challenges for water management in arid–coastal basins. Recommendations include implementing continuous monitoring, optimizing irrigation practices, improving wastewater treatment, and strengthening community engagement in water conservation. These findings provide a technical baseline for the development of adaptive management strategies in response to climate variability and increasing pressure on water resources in the region.