A groundbreaking plan to eradicate millions of tiny but destructive zebra mussels from a popular diving quarry in Prince William County appears to be working, according to local divers.
The pesky dime-sized mollusk first was discovered in 2002 at the Millbrook Quarry in the eastern portion of the county, just a stone’s throw away from a major tributary that feeds into the metro area’s main water supply. Regional leaders estimated that if the mussels — which clog water intakes and attach themselves to anything solid — were allowed to spread, they could in just a few years slow industry, stunt tourism and potentially create billions of dollars in damage. A 5-foot water intake pipe can be completely blocked by the mollusks in just a few years’ time, officials said.
Biologists in the Great Lakes region — which spent an estimated $120 million in cleanup costs in one five-year period following the zebra mussel invasion in 1988 — said damage estimates in the area have now reached as high as $5 billion annually.
After nearly four years of study and beleaguered fundraising efforts, a contractor hired by the state began pumping potassium chloride into the 12-acre quarry in February in hopes of killing off the invaders.
The nearly $400,000 effort, which has never been tried in such a large body of water, appears to be working.
“We’ve seen evidence that they’ve been dying off,” said David “Doc” Korte, an instructor at Manassas-based Virginia Scuba. “They are simply sinking to the bottom.”
Several other dive shops reported seeing similar results at quarry, which was opened for diving courses this weekend for the first time since the treatment.
Pat Charlebois, nonindigenous specialist with the National Oceanic and Atmospheric Association, said biologists across the country are watching the results of the “experiment” very closely.
Virginia officials, who could not be reached for comment for this story, are expected to release a report on the results sometime this summer. If successful, it will be the first total eradication of the mussels from a large, open-water population in history.
