PULP MILLS (JUDGMENT) 97 nutrients in the River Uruguay have been at high levels both before and after the bloom episode, and the fact that the bloom disappeared shortly after it had begun. The Parties also appear to agree on the interdependence between algae growth, higher temperatures, low and reverse flows, and presence of high levels of nutrients such as nitrogen and phosphorus in the river. It has not, however, been established to the satisfaction of the Court that the algal bloom episode of 4 February 2009 was caused by the nutrient discharges from the Orion (Botnia) mill. (iii) Phenolic substances 251. With regard to phenolic substances, Argentina contends that the Orion (Botnia) mill’s emission of pollutants have resulted in violations of the CARU standard for phenolic substances once the plant started operating, while, according to Argentina, pre-operational baseline data did not show that standard to have been exceeded. Uruguay on the other hand argues that there have been numerous violations of the standard, throughout the river, long before the plant went into operation. Uruguay substantiates its arguments by pointing to several studies including the EcoMetrix final Cumulative Impact Study, which had concluded that phenolic substances were found to have frequently exceeded the water quality standard of 0.001 mg/L fixed by CARU. 252. The Court also notes that Uruguayan data indicate that the water quality standard was being exceeded from long before the plant began operating. The Cumulative Impact Study prepared in September 2006 by EcoMetrix for the IFC states that phenolics were found frequently to exceed the standard, with the highest values on the Argentine side of the river. The standard is still exceeded in some of the measurements in the most recent report before the Court but most are below it (DINAMA July 2009 Water Quality Report, p. 21, para. 4.1.11.2 and App. 1, showing measurements from 0.0005 to 0.012 mg/L). 253. During the oral proceedings, counsel for Argentina claimed that the standard had not previously been exceeded and that the plant has caused the limit to be exceeded. The concentrations, he said, had increased on average by three times and the highest figure was 20 times higher. Uruguay contends that the data contained in the DINAMA 2009 Report shows that the post-operational levels of phenolic substances were lower than the baseline levels throughout the river including at the OSE water intake. 254. Based on the record, and the data presented by the Parties, the Court concludes that there is insufficient evidence to attribute the alleged 87