The Colorado River is threatened by rising levels of pollution. Most pressingly, the Grand Canyon is threatened by mercury pollution and other toxic chemicals as revealed by a study conducted by the United States Geological Survey (USGS). In a statement released by the team after the study, “concentrations of mercury and selenium in Colorado River food webs of the Grand Canyon National Park regularly exceeded risk thresholds for fish and wildlife" (EcoWatch). This poses a massive risk to the entire local ecosystems. Even though this habitat is isolated, it has been contaminated by toxins that have flowed down the river and bioaccumulation of contaminants. One of the issues that arises with river pollution is that it is extremely difficult to locate where the toxins are coming from as the water flows down stream could be polluted, however, the irrigation in selenium rich soils upriver is a culprit (EcoWatch).
In 2015, the Environmental Protection Agency released a large quantity of toxic wastewater from the Gold King Mine in Silverton, CO, in an attempt to add a tap to the mine's tailing pond (the place where you keep all the wastewater from mining operations). Ironically, the EPA had to add the tap because the local government refused to request Superfund cleanup money from the federal government on the mine's behalf. The spill put heavy metals like lead and cadmium into the Animas River. This was especially bad for members of the Navajo Nation, who relied almost entirely on the Animas for irrigation. It is estimated that the total financial loss to the Navajo is around $335 million, but that figure could rise in conjunction with new reports asserting the EPA took nearly 24 hours after the spill before it notified Navajo leadership of the spill (Bryan).
In 2015, the Environmental Protection Agency released a large quantity of toxic wastewater from the Gold King Mine in Silverton, CO, in an attempt to add a tap to the mine's tailing pond (the place where you keep all the wastewater from mining operations). Ironically, the EPA had to add the tap because the local government refused to request Superfund cleanup money from the federal government on the mine's behalf. The spill put heavy metals like lead and cadmium into the Animas River. This was especially bad for members of the Navajo Nation, who relied almost entirely on the Animas for irrigation. It is estimated that the total financial loss to the Navajo is around $335 million, but that figure could rise in conjunction with new reports asserting the EPA took nearly 24 hours after the spill before it notified Navajo leadership of the spill (Bryan).
![Picture](/uploads/8/8/8/9/88892218/animasbeforeafter_orig.png)
This is a before and after picture of the Animas River after a massive spill of chemicals while the aforementioned spill. As the toxins wash down the river, they kill plants, animals, and pollute the water so that it can no longer be used for domestic or agricultural purposes. The toxins remain deep in the soil long after it has left the water, and so water percolating in the surrounding areas do not allow the toxins to be fully washed away. Because the Animas River is a tributary to the Colorado, these toxins washed down into the main Colorado River Basin.
http://www.durangoherald.com/article/20150807/NEWS01/150809708/-1/animasriver/EPA-takes-blame-for-Animas-River-contamination&template=AnimasRiverart