product recovery and containment operations consist of two
types of pumping systems:
Dual-pump product recovery
Vacuum-enhanced pneumatic total fluids pumping
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
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 of the active product recovery systems consists of daily
and weekly checks, performance adjustments and preventive maintenance.