The Nelson Tunnel/Commodore Waste Rock sites are located near willow creek in Mineral County, Colorado and was founded in the late 1800s and is a suprfund site. The Commodore Waste Rock site was a waste rock dumpsite that took in material from near by mining sites that produced large amounts of minerals and metals such as lead, gold, aluminium, zinc, and silver. Over time the surrounding area including Willow Creek and the Rio Grande River, Willow Creek was a tributary, became contamiated with cadium, zinc, and lead. The Nelson Tunnel, built aoround the same time, discharges high consetrations of different metals into the Willow Creek adding to contaminated water quality. The wast rock site also heavily contaminated the surrounding soil and atmosphere, which also leads to the high conamnation of the creek, bringing a lot of health concerns to not only humans but also to the surrounding wildlife.
Some of the health conserns to humans are high lead expourse, metallic contaminaton in blood caused by repiratory injestion of airbone lead dust, consumption of contaminated meat from the wildlife that have been exposed to these mineral contaminants, and in rare cases has caused cancer. Overall, iron and lead are the highest contanimants in the surrounding area and watershead with lead causing the most consern for health. In 1999 a commitee, the Willow Creek Reclamation Committee, was formed to investigate the extent of the contamination. In 2010, the EPA began grading the large waste rock piles in order to stabilize its slope to reduce as much camination runnoff as possible. A 2,000 foot long reinforcing channel was also built around the creek to prevent further soil induced contamination. Begining in 2019 land rehabilitaion efforts began and a low level damn was built to manage the water levels from the Upper Mine Pool located around the waste rock sites. As of 2/19/2021 inspections are contuning to happen in order to figure out where more land rehabilitation efforts are needed.
Sources
https://cumulis.epa.gov/supercpad/SiteProfiles/index.cfm?fuseaction=second.Cleanup&id=0802630#bkground
https://www.colorado.gov/pacific/sites/default/files/HHW_CSA_Nelson-Tunnel-Followup-Surface-Soil-HC_6.12.2012.pdf
https://cumulis.epa.gov/supercpad/SiteProfiles/index.cfm?fuseaction=second.Cleanup&id=0802630#Done
https://www.outtherecolorado.com/news/mine-in-colorado-discharging-388-800-gallons-of-contaminated-water-daily/article_830cd633-9dc3-5687-818b-88217c2bfcfd.html