You worry that many of the activities you have seen during the expedition might have an impact on the quality of these water supplies. So far, you've seen land cleared for farming and grazing, trees cut for firewood and charcoal, and plants removed during resource mining. You've even seen the bare land that is left behind. Without vegetation, erosion must be taking place, washing soil into the rivers and degrading the water supply. Are people other than those in the Andes affected by the quality of this water? Are other species affected?