We monitor our impact on water systems closely, and have identified a total of 135 major river systems that are affected by our operations. A sample of these rivers are tested annually with 41, 65 and 29 tested in 2014, 2015 and 2016 respectively. The data from these tests has shown no significant deterioration of the water quality in these systems. Future assessments of stream water quality will be conducted based on the need for such analysis.
Our monitoring processes cover the water discharged from our mills, which cannot be returned back into the environment in its raw state. On average, palm oil mills generate about 2.5 MT of POME for every MT of CPO. While organic, raw POME is highly acidic and has a high Biological Oxygen Demand (BOD) due to its rich nutrient content. To ensure that the water discharged from our mills do not pollute our water systems, the discharged water undergoes a number of treatment processes to ensure that the concentration of BOD falls within safe levels.
Our average BOD data for 2016, 2015 and 2014 are 75 parts per million (ppm), 63ppm and 47ppm respectively, which is well below the discharge limit. Despite stringent requirements, there are occasions when the concentration of BOD exceeds regulatory limits, especially during high crop seasons when mills process FFB beyond their stipulated capacity. We are aware that this may occur at some of our mills and we are looking at ways to ensure that our discharge limits are always well within safe levels.
Water is essential for irrigating our oil palms and the production of CPO (approximately 5-7.5 MT of water is needed to process 1.0 MT of CPO from FFB). The sustainable harvest and return of water to our river systems are critical for both our operations and our surrounding ecosystem as the interruption of a clean water cycle could cripple our operations and damage the surrounding ecosystem beyond repair. Our ultimate aim is to reduce our water usage to 1.0 MT of water for each MT of FFB processed. In 2016, we used 1.34 MT of water on average to process 1.0 MT of FFB on average.