Small-scale gold suction dredging occurs for only 3-4 months each year.

Actually this photo shows that the sediment cloud is quickly clearing and as it leaves the right side of the photograph. The photograph below was provided by the Karuk Tribe and was intended to illustrate how bad turbidity is to the environment. She reasoned that, “If one takes a ladle of soup from a pot, lifts it above the pot, and pours the soup back into the pot, one has not ‘added’ anything else to the pot.” What is turbidity? It is a cloud of fine sediment that develops behind the sluice box with the falling rocks, sand and gravel. The Chief Justice likened a water system to a pot of soup. tends to support the miner’s position that turbidity is not a pollutant added to a waterway. Supreme Court Justice Sandra Day O’Connor’s majority opinion rendered in the South Florida Water Management District v. Because the miners and prospectors are in the river channel, they can’t add anything that isn’t already there. Suction dredging within the normal high water mark of a river channel does not add a pollutant to the water system. Small-scale gold suction dredging is the most environmentally friendly best management practice for removing gold and wastes found in rivers and streams. This material is passed over a sluice box which captures all the heavy materials while allowing the lighter material to pass through and return to the river a few feet downstream of the dredge.

A suction dredge is a vacuum cleaner that sucks gravel, sand and sediment (less than 4-inches in diameter) from the river bottom.

Building a small scale dredge