Next Media - A legal challenge to a ban on a riverbed mining technique known as suction dredge mining is making waves in California.
The ban has been in place for four years, but recreational miners say it amounts to an infringement on personal liberties as the practice presents little or no harm to the environment.
Environmental groups such as the Sierra Fund, however, say dredge mining unsettles and disperses toxins such as mercury which can be absorbed by fish, posing a threat to humans.
Authorities concede the practice introduces hazards back into the environment but say they are unsure how to best regulate it.
This animation explains the technique and possible environmental hazard.
The New 49’ers