Why Was Hydraulic Mining So Damaging to the Environment

Why was hydraulic mining so damaging to the environment?

A) It used up what little water resources existed in the West and put a stop to western migration.
B) It entailed the removal of entire mountain ranges, which killed wildlife and changed the climate.
C) It caused tons of dirt and debris to clog rivers, kill fish, and pollute downstream farmland.
D) It caused the migration of wildlife like raccoons, bears, and deer into nearby big cities.
E) It relied on sifting gold dust and nuggets out of riverbeds by means of "placer" mining, or "panning."