|DNR Westmoreland State Park|
During the early Mesozoic Era about 227 million years ago several shale basins formed along the east coast of the United States and Canada. The basins filled with a variety of sediments including boulder beds, coarse-grained sandstones, red siltstones, mudstones, gray and black shale and coal. the U.S. Geological Survey (USGS) estimates a potential mean undiscovered natural gas supply of 3,860 billion cubic feet and natural gas liquids of 135 million barrels within five of the East Coast Mesozoic basins: Deep River, Dan River-Danville, Richmond basins, which are within the Piedmont Province of North Carolina and Virginia; the Taylorsville basin, which is almost entirely within the Atlantic Coastal Plain Province of Virginia and Maryland; and the southern part of the Newark basin. The Taylorsville basin is estimated to have a mean gas potential of 1,064 billion barrels.
Our ability to recover natural gas buried in shale deposits beneath the earth has increased. Advances in horizontal drilling which allows a vertically drilled well to turn and run thousands of feet laterally through the earth combined with advances in hydraulic fracturing (fracking), the pumping of millions of gallons of water and laced with thousands of gallons of chemicals into shale at high pressure have increased our ability to recover natural gas from shale. Long ignored shale gas is potentially valuable. Until recently there was no economically feasible way to extract this gas. The Taylorsville basin has not been explored using newer fracking techniques so it is not known if we have the technology to exploit these deposits, yet. Nonetheless, according to Ruby Brabo, Shore Exploration and Production Corp. has obtained mineral leases on 84,000 acres of land in Virginia.
Though fracking has been widely used for decades without problems, hydraulic fracturing or hydro fracking has changed in the past 15 years. The oldest type of hydraulic fracturing is coal bed formation fracturing that has been used for more than 65 years. The volume of water needed for hydraulic fracturing varies by site and type of formation. Fifty thousand to 350,000 gallons of water may be required to fracture one well in a coal bed formation while two to five million gallons of water injected at much higher pressure may be necessary to fracture one horizontal well in a shale formation. Virginia currently only has gas well in the coal rich Appalachian Plateau. The existing wells are vertical wells that were nitrogen fracked. This is a completely different technology than contemplated for the Taylorsville shale deposit, but apparently the Department of Mines, Minerals and Energy is granting permits for these areas seemingly untroubled that the techniques to safely drill and frack this geology has not been demonstrated.
There are other problems and risks with fracking that should be addressed before hydro fracking takes place within the Commonwealth of Virginia. Water used for fracking fluids is acquired from surface water or groundwater in the local area. The Northern Neck of Virginia has only a single source of drinking water the aquifer in the coastal plain. The sediment deposits in the coastal plain is a geology that has never been fracked. Though chemicals typically represent less than 0.5% of the volume of the fracking water, that 0.5% amounts to 15,000 gallons of chemicals in the waste water recovered from the typical hydro fracking job. The chemicals serve to increases the viscosity of the water to a gel-like consistency so that it can carry the propping agent (typically sand) into the fractures to hold them open so that the gas can flow. The flow back, the recovered fracking fluid mus be properly and safely disposed of.
Determining the proper methods for the safe disposal of the large quantities of this fracking fluid that may also contain contaminants from the geological formation including brines, heavy metals, radionuclides and organic contaminants and monitoring the impact from this disposal must also be addressed before fracking is allowed in Virginia. Several of the techniques That have been utilized in other parts of the country to dispose of fracking fluid have proven unsafe and the others may not be viable or safe in Virginia. Techniques that have been tried have included deep well injection, discharged to surface waters after treatment in an waste water treatment plant designed to remove contaminants of concern, or applied to land surfaces where it can seep into the water table which is the sole source of drinking water in the Northern Neck communities. Deep well injection disposal has been associated with earthquakes, but in Virginia may simply sever as a path for contamination of the groundwater. There are no appropriate waste water treatment plants to treat the likely contaminants in Virginia, and surface application of contaminated water may be too direct a route to the aquifer in the coastal plain.
Geologists and engineers believe that in hydraulic fracturing the intervening layers of rock prevent a fissure from extending into the water table. The problems seen in drinking water wells near hydro fracking jobs typically occur when fracking fluid seeps into drinking water wells through improperly sealed or abandoned drilling wells. However, there has been no testing of proper well construction in shoreline sediment deposits. Proper well construction and abandonment standards to protect the watershed needs to be developed and enforced. Virginia does not yet have a regulatory structure to ensure proper well construction and protection of drinking water supplies. In addition, the water that is absorbed into rock formations may change the formations and the hydraulic balance in ways we do not understand and drawing large quantities of water in a short period of time may impact the groundwater whose level has been falling for decades from over pumping.
Finally, care must be taken to avoid degradation of watersheds and streams from the industry itself as large quantities of heavy equipment and supplies are moved on rural roads, recreational trails and residential roads and placed on concrete pads. The picture below from the U.S. Geological Survey, USGS, shows the amount of equipment involved in a hydro frack. The watersheds must be monitored. Sampling should take place before fracking and at regular intervals after a hydro frack job. We need to proceed slowly to make sure that we are doing it right and protecting our water resources and communities. While landowners have every right to lease their land and obtain gas royalties, We have only a small margin for error our water resources and the regional ecology. The gas will still be there if we take the time to understand fracking adequately to be able to release the gas from the shale formations without significant damage to our water resources and communities.