Fracking will once again be the topic of discussion today in Richmond. An advisory panel is scheduled to begin its review of Virginia rules on so-called fracking for natural gas. The Department of Mines, Mines and Energy has assembled the review panel amid the growing interest by energy companies wishing to drill for the estimated 1 billion cubic feet of natural gas in eastern Virginia. The industry says the drilling technique is not harmful to the environment. Critics counter that it is a threat to air quality and water supplies.