I grew up in the anthracite coal country of Northeastern Pennsylvania (I left there at age 25 back in 1978) and saw hundreds of miles of rivers and streams be devoid of any life because of acid mine drainage from the coal mines and coal processing plants called coal breakers. I also spent a lot of time exploring small streams in Montana during the 12 years I lived there from 1979 to 1981 and saw a lot of mine tailings problems in the now ghost town mining towns, not to mention to huge problem in the Clark Fork River from the copper mining and smelting in Butte and Anaconda Montana area.
I witnessed a huge fish kill after a short, intense cloudburst on the Upper Clark Fork in 1989 because it washed heavy metals, cyanide, and arsenic from the "slickens" along the river into it. I also witnessed what happened to the Blackfoot River in the early summer of 1990 when the old 7-Up Pete mine tailings pond located upstream of the town of Lincoln, MT broke and dumped heavy metals, cyanide, and arsenic into the big Blackfoot and killed fish all the way to Milltown dam some 90 miles downstream. This "event" took a long time for the river to recover from this and only recently has become a decent fishery again.
These things have made me very aware of the dangers of development such as mining in upstream areas. That is why I mentioned the Mining Act of 1872. It allows individuals or mining companies to stake a claim for the metals or minerals found, patent the mine site (meaning it becomes their propery), and then mine it if they get permission to do so while not even having to pay royalties on the metals or minerals extracted. That is something only Congress can change.