PULP MILLS (JUDGMENT) 93 river are : dissolved oxygen ; total phosphorus (and the related matter of eutrophication due to phosphate) ; phenolic substances ; nonylphenols and nonylphenolethoxylates ; and dioxins and furans. The Court now turns to the assessment of the evidence presented to it by the Parties with respect to these parameters and substances. (i) Dissolved oxygen 238. Argentina raised for the first time during the oral proceedings the alleged negative impact of the Orion (Botnia) mill on dissolved oxygen in the river referring to data contained in the report of the Uruguayan OSE. According to Argentina, since dissolved oxygen is environmentally beneficial and there is a CARU standard which sets a minimum level of dissolved oxygen for the river waters (5.6 mg/L), the introduction by the Orion (Botnia) mill into the aquatic environment of substances or energy which caused the dissolved oxygen level to fall below that minimum constitutes a breach of the obligation to prevent pollution and to preserve the aquatic environment. Uruguay argues that Argentina’s figures taken from the measurements of the OSE were for “oxidabilidad”, which refers to the “demand for oxygen” and not for “oxígeno disuelto” — i.e., dissolved oxygen. Uruguay also claims that a drop in the level of demand for oxygen shows an improvement in the quality of the water, since the level of demand should be kept as low as possible. 239. The Court observes that a post-operational average value of 3.8 mg/L for dissolved oxygen would indeed, if proven, constitute a violation of CARU standards, since it is below the minimum value of 5.6 mg of dissolved oxygen per litre required according to the CARU Digest (E3, Title 2, Chapter 4, Section 2). However, the Court finds that the allegation made by Argentina remains unproven. First, the figures on which Argentina bases itself do not correspond to the ones for dissolved oxygen that appear in the EcoMetrix Third Monitoring Report, where the samples taken between February and October 2008 were all above the CARU minimum standard for dissolved oxygen. Secondly, DINAMA’s Surface Water and Sediment Quality Data Report of July 2009 (Six Month Report : January-June) (hereinafter “DINAMA’s Water Quality Report”) (see p. 7, fig. 4.5 : average of 9.4 mg/L) displays concentrations of dissolved oxygen that are well above the minimum level required under the CARU Digest. Thirdly, Argentina’s 30 June 2009 report says in its summary that the records of water quality parameters over the period were “normal for the river with typical seasonal patterns of temperature and associated dissolved oxygen”. The hundreds of measurements presented in the figures in that chapter of the “Colombo Report” support that conclusion even taking account of some slightly lower figures. Fourthly, the figures relating to dissolved oxygen contained in DINAMA’s Water Quality Report have essentially the same characteristics as those gathered by Argentina — they 83