PULP MILLS (JUDGMENT) 86 “ADCP”) — to record water flow velocities for a range of depths for about a year. The three-dimensional system generated a large number of data later introduced in a numerical hydrodynamic model. On the other hand, Botnia based its environmental impact assessment on a bidimensional modelling — the RMA2. The EcoMetrix CIS implemented both three-dimensional and bi-dimensional models. However, it is not mentioned whether an ADCP sonar was used at different depths. 213. The Court sees no need to go into a detailed examination of the scientific and technical validity of the different kinds of modelling, calibration and validation undertaken by the Parties to characterize the rate and direction of flow of the waters of the river in the relevant area. The Court notes however that both Parties agree that reverse flows occur frequently and that phenomena of low flow and stagnation may be observed in the concerned area, but that they disagree on the implications of this for the discharges from the Orion (Botnia) mill into this area of the river. 214. The Court considers that in establishing its water quality standards in accordance with Articles 36 and 56 of the 1975 Statute, CARU must have taken into account the receiving capacity and sensitivity of the waters of the river, including in the areas of the river adjacent to Fray Bentos. Consequently, in so far as it is not established that the discharges of effluent of the Orion (Botnia) mill have exceeded the limits set by those standards, in terms of the level of concentrations, the Court finds itself unable to conclude that Uruguay has violated its obligations under the 1975 Statute. Moreover, neither of the Parties has argued before the Court that the water quality standards established by CARU have not adequately taken into consideration the geomorphological and hydrological characteristics of the river and the capacity of its waters to disperse and dilute different types of discharges. The Court is of the opinion that, should such inadequacy be detected, particularly with respect to certain areas of the river such as at Fray Bentos, the Parties should initiate a review of the water quality standards set by CARU and ensure that such standards clearly reflect the characteristics of the river and are capable of protecting its waters and its ecosystem. (ii) Consultation of the affected populations 215. The Parties disagree on the extent to which the populations likely to be affected by the construction of the Orion (Botnia) mill, particularly on the Argentine side of the river, were consulted in the course of the environmental impact assessment. While both Parties agree that consultation of the affected populations should form part of an environmental impact assessment, Argentina asserts that international law imposes specific obligations on States in this regard. In support of this argument, Argentina points to Articles 2.6 and 3.8 of 76

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