The recovery of contaminated groundwater from tight formations can be accelerated by the use of recovery trenches. One cost effective method RECON utilizes to construct groundwater recovery trenches is the biopolymer trench technique.
Biopolymer trenches are typically used as an extraction or inceptor trench for the collection and/or removal of groundwater or as dewatering devices. They are installed using similar construction techniques as slurry trench/cut off walls, except, once excavated, biopolymer trenches are backfilled with permeable materials, such as sands or well graded gravels.
Instead of supporting the trench with a bentonite slurry, the trench is supported with a biodegradable slurry. This type of slurry exerts hydraulic pressure against the trench walls and acts as shoring to prevent collapse. The biopolymer slurry is biodegradable and does not reduce the final permeability of the in situ soil or backfill materials.
Biopolymer drains have proven to be a cost effective way to construct deep collection drain trenches. The biopolymer trench drain techniques eliminate the difficulties and costs associated with temporary shoring and all the dewatering associated with conventional construction.