About the 2015 events in La Pasión river
Based on the two fish mortality events on the La Pasion River that transpired on April 29 and June 6, 2015, REPSA commissioned the CBM-Colegio de Biólogos de México, A.C. (Http://www.colegiodebiologosdemexico.org/), to carry out a specific study with the objective of determining the environmental conditions of the affected ecosystem and the probable causes of both events. The CBM, a non-profit organization founded in 1961, brings together the best professionals in the biological sciences of Mexico and is a reference for ethics, quality, objectivity and application of scientific knowledge. Here is a summary of the main findings and conclusions of the independent study.
The study, which was done in August 2015, found that both events are clearly distinct in magnitude, since the first was limited to a narrow section of 3 kilometers and the second was reported to have occurred in a section of the river of more than 100 kilometers in length, according to official reports.
As for the first event, the CBM study revealed the fact that during the evening of the 28th and early morning of the 29th April, extreme torrential rain ensued. According to INSIVUMEH, the Guatemalan meteorological agency, more than 170 mm of rainfall were reported in less than 12 hours, which is equivalent to 10% of the total rainfall that the area receives in one year. The weather conditions were clearly unusual and extraordinary. And given that there were no rains in previous months, the intensity of the climatic phenomenon provoked massive soil erosion and sediment to accumulate in the river channels, as well as vegetative organic matter and debris, in addition to human wastes from neighboring communities. Heavy rainfall also affected REPSA infrastructure by provoking an overflow of the last POME treatment pond in mill number 2, as was immediately reported by the company to the respective government authorities. It is very important to note that the excess volume of POME that overflowed was insignificant in comparison to the total amount of water captured by the Chapayal-San Ignacio river basin. It is also key to note that the overflow occurred 11 kilometers upstream of the mouth of the La Pasión river.
The study concluded that this first event occurred after several months of a pronounced low water level period of the rivers in the Petén area. Therefore, the climatic event caused a violent displacement of naturally accumulated materials (soil and sediments) in the many tributaries of the La Pasión River. This caused sediment and debris saturation in the rivers and consequently an unfavorable condition at the confluence of the Chapayal-San Ignacio River with the La Pasión River. The hydrological and physical peculiarities of the mouth of this tributary, in particular because it enters La Pasión in an opposite direction to its main current, were determinant in the occurrence of the event. The intensity of the rains caused temporary impacts associated with the saturation of sediments, which generated low oxygen availability that induced the fish mortality. Once again, the POME and water overflow contribution to the event was appraised and it was determined that it was not significant given that it represents a minor percentage of all the water that was captured in the basin of the Chapayal-San Ignacio river. The study also confirms that the April 29th event is comparable to other recurrent events in different parts of the world, such as the one that occurred in Cusco, Peru in September 2013, among others. Finally, the study did not identify residual environmental impacts derived from the extreme climatic event that might have permanently altered the equilibrium of the La Pasión river ecosystem.
Now, regarding the second circumstantial event of June 6, 2015, the study gathers some acknowledged facts: 1) The climatic and environmental conditions were normal, that is to say there were no unusual meteorological events. 2) The starting point of the fish mortality was located more than 12 kilometers downstream from where the fish mortality of the first event occurred, well outside the REPSA zone of influence. 3) The event had an impact of catastrophic dimensions causing high mortality of aquatic biodiversity, such as crustaceans, amphibians and some reptiles, and not solely fish, according to CONAP. 4) The impact of the catastrophe was prolonged for 6 days, with mortality of fauna along approximately the 140 kilometers where its effects were identified. 5) The June 6 catastrophe occurred 38 days after the extreme weather event on April 28.
Some of the study conclusions related to the second circumstantial event are as follows: The catastrophic effect and the respective death of fauna can only be attributed to a highly toxic substance discharged into the river in amounts that can cause the known results in the species that were affected. The persistence of the toxic effects in 140 kilometers of the river indicates that a toxic contaminant difficult to dilute in water and in high concentrations, was spilled into the river on purpose. There is also NO substance, material or product at any stage within the palm oil production process of REPSA with the characteristics of toxicity that could have caused the effects that occurred in the river that started on June 6. Finally, there is no relationship between the event of April 29 and that of June 6.—-