Tuesday, January 31, 2006
In a first ever effort in the United States to eliminate the presence of Zebra mussels in a large body of water, the Virginia Department of Game and Inland Fisheries (VDGIF) announced on Monday that a private pond in Prince William County, Virginia is undergoing water treatment using a chemical potash of potassium chloride in concentrations high enough to kill invasive and native shellfish species.
The pond at the Millbrook Quarry will undergo treatment for three to four weeks in an effort to eliminate an infestation of zebra mussels, a condition of its waters that was confirmed by state environmental officials in 2002. The treatment is not expected to pose a threat to non-molluscan aquatic wildlife, vegetation, or land-dwelling creatures at the site. Officials expect the one-time treatment process will provide protection from the possibility of future infestation for 33 years.
The entire body of water will be treated with potassium chloride to a level of 90 ppm, well below the U.S. Environmental Protection Agency’s (EPA) standard of 250 ppm for potable water. There are no expected health risks for humans, or contamination of drinking water wells in the immediate vicinity.
The freshwater Zebra Mussel species is a threat to native mussels of the region because of their high reproduction rate and their ability to attach themselves in clusters to native mussels, which kills them since they are prevented from opening and closing their shells to feed or burrow. Bottom-dwelling marine species are often covered by the Zebra Mussel.
Measures to prevent the spread of zebra mussels vary by region where the species is present. In Maryland, boat owners who launch water craft on reservoirs that serve as sources of drinking water are required to register their boat for use only on those reservoirs, to reduce chances of the mussel being transferred from other waters. Drinking water treatment and power production facilities where the mussels are present must regularly treat their systems to keep them clear of decaying debris that fouls intake pipes.
Zebra mussels were first discovered in North America in 1988, in Lake Saint Clair, a lake between Lake Erie and Lake Huron. By 1990 they appeared in all of the Great Lakes. It is believed that the mussels were accidentally brought over from Europe on the hulls of ships.