Sustainable Reutilization of Excavated Trench Material

The Integrated Pipeline (IPL) project which involves a 147 mile pipe line is a joint effort between the Tarrant Regional Water District (TRWD) and Dallas Water Utilities (DWU) that will bring additional water supplies to the Dallas/Fort Worth metroplex. As a part of the pipeline layout and construction, large amounts of soil will be excavated during the pipeline installation process. Similarly, large amounts of soil need to be imported for bedding and backfilling of the trench. Both importing new fill material and exporting excavated trench material for landfilling will have serious implications on both the economic and environmental aspects of the construction project. As a result, a research study was initiated to identify insitu soil material that can be reused as either bedding, zone or backfill materials for the pipeline installation. For this purpose soil samples were collected along the pipeline alignment and comprehensive geotechnical characterization studies including estimation of expansive clay minerals are attempted. Based on these studies, the sampling materials are identified for potential reuse as backfill, bedding and zone materials. Cost and environmental benefits as well as emissions reductions of using insitu native material versus imported fill material are also discussed.