By John Crane
Published: May 12, 2009
Drilling is expected to take place at Coles Hill today if weather permits, but it won’t be for uranium.
Virginia Tech graduate student J.P. Gannon is studying how groundwater moves through the rock there. Two new agricultural cattle wells will be drilled for Gannon to study and further understand how water moves through fractured bedrock, said Patrick Wales, a geologist and spokesman for Virginia Uranium Inc., which owns the land and seeks to mine and mill a 119-million pound uranium ore deposit there.
The drill holes will not be in VUI’s uranium-exploration area, Wales said. Pittsylvania County farmer Hank Maxey leases land from VUI and grazes cattle where the holes will be drilled.
“The wells will be used to provide an alternative drinking water source for the cattle that graze nearby, and I look forward to using them soon,” Maxey said in a statement.
Wales said drilling should be finished a few days. Coles Hill is about six miles northeast of Chatham.
Gannon, working toward his master’s degree in hydrogeology at Virginia Tech’s geosciences department, will write his thesis on his findings. He has been studying the Coles Hill area since last summer and has conducted a geophysical survey of the subsurface to locate and identify networks of fractured rock underground.
During an interview Tuesday, Gannon contrasted water-flow patterns on Virginia’s coastal plain with those at Coles Hill. Flatter, more expansive aquifers characterize the coastal terrain, but impermeable flat rock is found at Coles Hill, Gannon said. Water can’t flow through it, but moves through networks of cracks and fracture patterns, Gannon said.
Gannon believes the fault at Coles Hill broke up a lot of rock there.
“Are fractures still there or have they healed up?” he said.
Gannon wants to know where fractures are located and where the water is flowing. Gannon also hopes to find out if the fractures fill up when rain falls or whether there is a connection allowing faster flows.
The holes will be 400 feet deep and 6 inches wide, through broken-up bedrock and down into more solid bedrock, Gannon said. Well locations were picked that would be mutually beneficial for agricultural use and hydrological research. To locate water-rich areas, Gannon set up a computerized electrical survey system, driving stakes into the ground at different locations and measuring electricity flows in each stake. The less resistivity — more electricity flow — the more water.
With his academic advisor there today, Gannon will date the groundwater, taking samples from different depths.
One way he’ll determine the water’s age is by the presence of environmental tracers. Water high in industrial-era chlorofluorocarbons would be relatively young, Gannon said, adding that he would try to date it at a specific year. However, “as it gets older, it’s more difficult to pin it down,” he said.
Gannon’s research is expected to last through the summer.