Free Product Removal and Recovery

The goal of free product removal and recovery is to capture as much of the contaminants as possible.

With significantly more screen per well and the flexibility to be installed in hard-to-reach places, horizontal remediation wells provide maximum efficiency in NAPL recovery.

The more contaminated sites tend to have the presence of non-aqueous phase liquids (NAPL) and require free product removal and recovery. When activating a capture well, whether for free product collection or groundwater control, we’re more than likely looking to capture as much volume as possible. Through their orientation and increased screen footage per well, horizontal remediation wells offer the opportunity to capture significantly more volume compared to traditional vertical alternatives.

NAPL, or free product, exists as a separate phase from the groundwater it is interacting with. Less dense NAPL, or LNAPL, rises to the top of the groundwater interface and creates a thick barrier between the vadose zone and the saturated zone. Denser NAPL, or DNAPL, will sink through the groundwater and pool on top of the next impermeable layer. Gravity is then the primary force that drives migration of the DNAPL, meaning it can travel in the opposite direction of the groundwater flow if the lithologic layers are oriented in a conflicting direction. Either way, NAPL plumes tend to be more laterally extensive than vertically thick.