A comparison of soil and plant characteristics between abandoned natural gas drill pads and adjacent areas, Barksdale Air Force Base, Bossier City, Louisiana.

摘要

Soil and plant characteristics were investigated on abandoned natural gas drill pads located within pine, pine-hardwood, and bottomland-hardwood forest vegetation types on Barksdale Air Force Base (BAFB), in northwest Louisiana. Drill sites ranged from three to seventy-seven years since date of plug and abandonment. Soil and vegetation were sampled and compared between on-pad and the adjacent off-pad area. Variables sampled for both soil and vegetation were found to be different between on-pad and off-pad locations as a result of natural gas drilling regardless of time since plug and abandonment. Pad material (fill material on pad) was coarser in texture, mainly sandy loam and loamy sand, while the adjacent off-pad soils were mainly silt loam texture. Pad material was found to generally have higher bulk densities, soil strength, pH, and calcium and magnesium concentrations compared to adjacent off-pad soils. On-pad sites were generally vegetationally dissimilar and less diverse when compared to the adjacent off pad locations. Site quality described by site index (base age 25 and 50) for loblolly pine (Pinus taeda L. ) alone was found to be 15 points lower on-pad.;Historical aerial photos and current satellite imagery were used to determine the total surface land area impacted by gas drilling operation since 1966 on BAFB. Beginning in 1966, the total land area in drilling pads alone has increased by over 300%. As of February 2, 2007 the cumulative surface land area used for natural gas production on BAFB is 387 hectares. This represents about 8 percent of the forested eastern portion of the base. Nearly one half of the land area used for natural gas production operations was gas drill pad surface while the remainder was in pipelines, access roads, and collection lines. Because the demand for natural gas is predicted to rise it can be assumed the land area used for drilling will continue to rise. More stringent remediation plans may need to be employed to lessen the difference between plugged and abandoned natural gas pads and the adjacent areas.