Effects of Gas Well Effluent On Forest Soil Chemical Properties.

As energy demand continues to grow in the United States, development of many energy resources will expand.  Relatively little research has examined the impacts of natural gas development in the eastern United States, where natural gas in shale formations is now considered an important and relatively easily accessible resource.  A natural gas well was developed on the USDA Forest Service’s Fernow Experimental  Forest  in West Virginia, a  hardwood forest landscape dedicated to long-term research and monitoring.  Fluids used during the drilling and hydrofracturing process were land-applied to an area of slightly less than 0.5 acres of forested area, resulting in mortality of the overstory and understory vegetation.  Soil samples were collected from within the fluid application area, and from a nearby area where no fluids were applied in July and October of  2008, and  in May and October  of 2009.  Chloride, sodium and calcium concentrations in the upper 10 cm of the soil were significantly elevated  in July 2008 within the fluid application area relative to the adjacent reference area.  In October of 2009, soil levels of chloride and sodium were still significantly greater within the fluid application area, relative to the reference area, but had declined by about 75%.  Mortality of overstory trees was nearly 100% within the fluid application area, and the pattern of mortality suggests that salts were responsible for the mortality, both through contact with the foliage of understory trees and through uptake by roots of overstory trees.