In-situ treatment has been defined by the industry in a number of ways. Usually, in-situ treatment refers to the use of reactive or adsorptive materials in small amounts on the sediment surface for the reduction in contaminant concentrations in the biologically active zone (BAZ).
Reduction in contminants is evaluated by pore water measurements; considered the most bioavailable contaminant ___? Materials on the sediment surface are thought to mix naturally into the BAZ, resulting in desired reduction.
AquaGate®+ materials have been applied successfully in both pilot and full-scale implementation of In-situ treatment. Most applications involve the use of powder activated carbon (PAC) placed in very thin lifts (1-2 inches).
An example of results from a similar project are shown below. In the pilot study, PCB pore water concentrations were reduced over 90% following application of a 2-inch layer of AquaGate+PAC. This resulted in a loading of approx. 5% activated carbon within the upper 6-inches of sediment.