FACTORS AFFECTING EROSION ON A NATURAL GAS PIPELINE IN THE CENTRAL APPALACHIANS

Author

Dan Holz, Southern Illinois University CarbondaleFollow

Date of Award

1-1-2009

Degree Name

Master of Science

Department

Forestry

First Advisor

Williard, Karl

Abstract

High fuel prices have created an economic climate in which oil and gas development is increasingly profitable, and consequently, is increasing rapidly in the United States. The development includes drilling new wells and expanding the pipeline network to deliver gas and oil. This is especially true in the northern Appalachian region where the relatively undeveloped Marcellus shale formation is located. The Marcellus formation has been called a "super giant" gas reservoir possibly containing 50 trillion cubic feet of recoverable natural gas (Harper, 2008). In Pennsylvania alone, over 375 wells targeting the Marcellus shale formation have been approved between 2003 and the end of 2007. However, environmental impacts from well pads and pipelines are relatively unknown. Sediment concentrations and yields were measured from four sections of an in-road pipeline in the Monongahela National Forest in Tucker County, West Virginia during summer and fall 2007 and spring 2008. The objectives of this study were to determine the influence of vegetation cover and precipitation characteristics on sediment concentrations in runoff and sediment yields from the in-road pipeline, and to compare sediment yields to forest roads. Poorly vegetated pipeline sections produced 30.92 kg of sediment throughout the study compared to 13.49 kg for the well vegetated sections. Despite this, percent vegetative ground cover had no statistically significantly effect on sediment concentrations or yields except during very intense storms. Several precipitation characteristics, especially intensity, played a significant role in explaining sediment yields and concentrations. Precipitation patterns changed with seasons, and therefore, sediment concentrations and yields varied significantly by season. The most intense storms occurred during the summer months, which is when most soil loss also occurred. Erosion rates from the pipeline were greater than from undisturbed or well-managed forest plots, but were less than rates reported for logging and skid roads when normalized for rainfall. The reduced erosion rates suggest that routing new pipelines along closed roads may be a good method to reduce erosion compared to clearing new pipeline rights-of-ways. To further reduce erosion potential, steps in the installation process that expose mineral soil should be timed to avoid periods of intense rainfall.