Biopolymer Collection Trenches
Biopolymer collection trenches are narrow trenches that intercept and collect groundwater for construction dewatering and/or treatment, facilitate aeration or injection of reagents for in-situ treatment of groundwater contaminants, and general slope stabilization. These trenches are excavated through slurry trenching methods using degradable biopolymer slurry mixes. The trenches are then backfilled with permeable materials such as clean gravel to collect the groundwater. Collection or injection wells can be installed during trench backfilling operations to minimize additional construction costs. Customized walls for groundwater collection and extraction often require construction of an HDPE liner on the down gradient face of the trench to function as an impermeable barrier to facilitate capture of flowing ground water. At project completion, the biopolymer slurry is either chemically degraded to the viscosity of water using a small amount of carbohydrate through the addition of chemicals (e.g. enzyme breakers, chlorine, hydrogen peroxide) or allowed to degrade naturally.