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Introduction--Aluminum is incorporated into water naturally and/or anthropically, health risk levels above 0,2 mg/l according to Colombian regulations. It can arise as an emerging contaminant when aluminum salt coagulants are used improperly in the clarification of drinking water. Objective--To evaluate air pollution for human consumption in the central region of Colombia, determine its potential origin and compliance with current regulations. Methodology--Exploratory research, analysis of the presence of aluminum in raw water and treated during the period 2008-2018, by means of samples and laboratory tests, as well as the hydraulic evaluation and the operation of water treatment plants, in municipalities of Los departments of Tolima and Cundinamarca, central region of Colombia. Results--In more than 30% of the municipalities evaluated, the presence of aluminum in the water for human consumption was evidenced, above the maximum allowed by the current regulations. In several cases it was due to deficiencies in the treatment process where aluminum salts are used for coagulation, without adequate dosage as occurred in the municipality of Melgar, or due to high concentrations present in the water supply sources, such as the case of Magdalena river in the central region of Colombia. Conclusions--Aluminum in water for human consumption is due to its presence in water sources and the product of hydraulic and operational deficiencies in the clarification process of treatment plants where aluminum sulfate is used as a coagulant, due to inadequate application of optimal doses, poor intensity of agitation and speed gradients in fast mixing and flocculation, flocculation and sedimentation times outside the optimal range. [ABSTRACT FROM AUTHOR]

Introduction: aluminum is incorporated into water naturally and/or anthropically, health risk levels above 0,2 mg/l according to Colombian regulations. It can arise as an emerging contaminant when aluminum salt coagulants are used improperly in the clarification of drinking water. Objective: to evaluate air pollution for human consumption in the central region of Colombia, determine its potential origin and compliance with current regulations. Methodology: exploratory research, analysis of the presence of aluminum in raw water and treated during the period 2008-2018, by means of samples and laboratory tests, as well as the hydraulic evaluation and the operation of water treatment plants, in municipalities of Los departments of Tolima and Cundinamarca, central region of Colombia. Results: in more than 30% of the municipalities evaluated, the presence of aluminum in the water for human consumption was evidenced, above the maximum allowed by the current regulations. In several cases it was due to deficiencies in the treatment process where aluminum salts are used for coagulation, without adequate dosage as occurred in the municipality of Melgar, or due to high concentrations present in the water supply sources, such as the case of Magdalena river in the central region of Colombia. Conclusions: aluminum in water for human consumption is due to its presence in water sources and the product of hydraulic and operational deficiencies in the clarification process of treatment plants where aluminum sulfate is used as a coagulant, due to inadequate application of optimal doses, poor intensity of agitation and speed gradients in fast mixing and flocculation, flocculation and sedimentation times outside the optimal range. [ABSTRACT FROM AUTHOR]

New zircon and apatite fission-track analyses and aluminium in hornblende thermobarometric data are presented from Cretaceous and Triassic plutons situated along an east-west transect across the Central Cordillera, the Cauca Romeral Fault System and the eastern slopes of the Western Cordillera in the Colombian Andes. The results are combined with published apatite (U–Th)/He ages revealing three episodes of increased cooling during the Late Cretaceous (~110 - 90 Ma), the Eocene (~55-40 Ma) and the Miocene (23-20 Ma). The latter two phases correlate well with the Pre-Andean and Proto-Andean periods previously identified on the basis of stratigraphic unconformities and thermochronology studies in the region. A fourth event, at ~10 Ma, is tentatively recognized in modelled data sets, but not by absolute age values. The thermochronology data imply a total of uplift-driven exhumation (i.e., crustal unroofing) in the study area of up to 10 kms since ~50 Ma at rates of ~0.1 km/Myr and 4 kms since ~23 Ma initially at 0.2 km/Myr. From 10 Ma the rates changed to 0.3–0.33 km/Myr with estimated geothermal gradients of 25–30 °C/km. Thermobarometry data suggest that the crystallization of the Cretaceous intrusions, now at the surface, took place at depths of 8–13 km confirming the amount of exhumation revealed by low-temperature thermochronology. • New thermochronology ages for Northern Andes combining apatite and zircon FT. • Thermochronology/thermobarometry dataset in the Northern Andes of Colombia. • Vertical profile shows pulses of uplift exhumation at ~110–90, 45–50 and 23 Ma. • Orogenic events involving erosional cooling and crustal unroofing from ~8 to 13 km. • Orogenic events are coeval with pulses in the Caribbean, Southern-Central Andes. [ABSTRACT FROM AUTHOR]