Bio-Polymer Slurry Trench
Air Injection Trench
Camp Lejune, North Carolina

Project included the construction of a 100 linear foot air sparging trench. The trench was excavated utilizing the Bio-Polymer Slurry Drainage Trench Method. The Bio-Polymer slurry is a bio-degradeable fluid which is a usable trenching slurry but degrades to water and a minute amount of carbohydrate. The trench was excavated with a hydraulic excavator to a maximum depth of 44 feet.

As soon as the excavation was completed and the trench filled with slurry, the air sparging piping and wells were installed. The piping system, which consists of a horizontal air injection well screen and three risers, was assembled on the surface next to the trench and weighted with concrete weights to overcome buoyancy. Using a crane, the piping system was lowered in the trench to the proper design depth.

At the beginning of the backfilling procedure, the stone was gently placed at the end of the trench with the excavator until the slope of the backfill emerged at the surface. Once the initial angle of repose was developed at the beginning of the trench, the remaining aggregate was placed on the surface of the topped out existing backfill by using a loader bucket, allowing the stone to slide down the slope of the backfill.

Upon the completion of the trench, the slurry was degraded with additives and circulated throughout the trench by pumping from temporary PVC extraction wells.

• Start: 1/21/98
• Completion: 2/13/98