Active product recovery and containment operations consist of two types of pumping systems:

1. Dual-pump product recovery
2. Vacuum-enhanced pneumatic total fluids pumping

Dual-Pump Product Recovery:
In dual-pump product recovery, free-phase diluent and groundwater is pumped from the wells located near the leading edge of the free-phase diluent plumes. Free-phase diluent is recovered from these wells using pneumatically-operated, product-only bladder pumps. Groundwater levels are lowered in the wells using electrically powered submersible pumps. Diluent is then skimmed off the water surface in the well using a specific gravity-based product intake. Up to 70 to 100 gallons of diluent can be recovered per day. Groundwater removed from the wells is transferred to the existing re-injection system or utilized to maintain Land Treatment Unit (LTU) soil moisture levels.

Vacuum-Enhanced Pneumatic Pumping:
Vacuum-enhanced pneumatic pumps withdraw both groundwater and diluent from eight existing wells. A high vacuum is placed on the pneumatic pump exhaust to improve the pump performance. In addition, a medium vacuum is placed on the well to enhance diluent recovery and provide air changeouts that have been shown to improve biodegradational processes. Air exhaust from vacuum blowers is routed through carbon filters to control emissions. Recovered diluent is separated and stored in a product tank for periodic removal by a vacuum truck. Recovered groundwater is transferred to the injection system or utilized to maintain LTU soil moisture levels.

Monitoring:
Monitoring of the active product recovery systems consists of daily and weekly checks, performance adjustments and preventive maintenance.