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The eastern part of West Virginia is underlain with karst or caves. Surface water enters groundwater systems rapidly as it passes through the fractured bedrock under thin layers of permeable soil. Groundwater in karst areas can travel as quickly as a few thousand feet to over a mile per day. If surface water is polluted, the groundwater, including wells and springs over several miles, also may become polluted, and sensitive habitats may no longer support sensitive cave species.  Those characteristics of karst ecosystems make the surface/groundwater environment fragile and highly susceptible to human disturbance.

Beautiful Cave

Caves contain significant resources related to biology, geology, hydrology, archeology, paleontology, recreation, and scenery. Cave environments, by their very nature, provide unique, closed systems that are valuable for scientific study and environmental education of underground resources and the interrelationship between surface and subsurface. Potential hazards to cave/karst resources and surrounding communities may result from the following natural gas activities:

    1. Contaminants such as lost drilling fluids as well as hydrocarbons from spills or leaks (including floods) from well casings, storage tanks, reserve pits, pipelines, and production facilities that may enter into the cave/karst systems;
    2. Cements escaping into voids which may restrict groundwater flow and introduce pollutants;
    3. Vented or escaped gases, collecting in sinkholes and caves. These gases can cause a die-off of plant and animal life that use the special habitat created by the microclimate of the cave entrances or sinkhole. Some cave systems in the Greenbrier Valley extend for miles under thousands of acres below homes, building and towns. An explosion touched off by cavers with carbide lamps or other source of ignition could result in major loss of life and property. There is not only a explosion hazard but also an aphyxiation hazard to the lucky homeowner, business owner, customer or caver;
    4. Increased soil erosion from gas development activities (i.e., well pads, roads, etc); and
    5. Corrosion of the casing strings.

Caves are "known" openings in the limestone that have a person sized connection to the surface so they can be entered and explored.  In karst areas, for every "known" cave there could be literally hundreds or thousands more - number, feet, miles - of "unknown" passage that has no connection to the surface or has not been discovered.  Water well drillers have hit as many as eight voids on their way through the karst. So when gas drilling companies say they will stay away from "known" caves they are whistling in the dark.

When asked about drilling through karst, gas drillers tend to respond like its the same as hitting an abandoned mine passage - they say they just keep drilling and then double case the void so it is sealed and then continue drilling below it.  In karst - and in WV - there are MANY cave passages that are over 50 ft in height - and MANY over 100 ft.......the largest underground continuous vertical drop in WV is 350 ft in a cave in Pendleton County.  So one question is how do you drill and case something over 30-40 ft in height?  Another is how do you drill and case through 8 successive voids.

Another difficulty in drilling through a karst void that increases the likelihood of problems with casing integrity is that the bottom of the cave often consists of large boulders making it extremely difficult to begin drilling in a spot that is directly under the hole entering the void, resulting in a casing that is not straight.

The integrity of the casing is vital in preventing leaks, and minor flaws may not become an issue until time has passed. Because natural gas has no odor until it is added, there would be no warning of a buildup of gas in a karst area. Some may argue the gas will stay fuel rich (non-flammable)underground due to lack of oxygen or displacement of air from the cave.  Caves have air the same as the surface - and they breath - suck in when high pressure weather system moves through the area and blow out when lower pressures weather system moves through the area.  High entrances tend to suck air and lower entrances blow air during summer due to bouyancy effects.  In summer, "cold" cave air is heavier and flows out lower entrances - causing a slight negative pressure in the cave which causes upper entrances to suck air in to replace that which flows out the lower entrances.   In winter the process reverses - now warm cave air is lighter than outside air and pours out upper entrances, the lower entrances then pull in surface air to replace.  So caves are always exchanging air with surface - bringing fresh air with oxygen to make flammable mixture.  Also any gas in the cave will be pulled out and to the surface with the cave air exchanged making it more likely to find an ignition source - a passing car, tractor, lightning........someone lighting a cigarette in their living room.


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