United States           Solid Waste and          EPA 510-F-93-030
Environmental Protection     Emergency Response       October 1993
Agency              5403W

Groundwater
Remediation  For
UST Sites

Pump And Treat
   Pump and treat is a technique that brings contaminated
   groundwater above the ground through the use of
extraction wells. The water is then treated, normally
using one of three processes: granulated activated
carbon, air stripping, or bioremediation.

This technique is most effective in permeable aquifers. It
also can be used with in situ vapor extraction (SVE) to
enhance removal of volatile contaminants from the zone
of water table fluctuation.

A limitation of pump and treat is that it can take a long
time to achieve complete remediation, sometimes as long
as seven years even for an ideal site. In addition, this
method is subject to fluctuations of the water table that
can smear contaminants and complicate cleanups.
   Petroleum Types And Constituents

   • Dissolved gasoline and diesel, jet fad, and
    kerosene

   • Dissolved constituents such as benzene, toluene,
    ethylbenzene, and xylene (BTEX)

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Pump And Treat
Advantages
Limitations
System
Components
Wastestream
Treatment
Parameters to
Monitor1
Cleanup Levels
and Timing2
Costs5
• Controls contaminant plume migration and reduces
plume concentration
• Not very effective in aquifers with low permeability
• Can require expensive and lengthy long-term pumping
and treating
• High iron content/hardness can affect water treatment
• Requires control of water table fluctuation to minimize
smearing contaminants
• Might require off-site discharge permits
• Vertical or horizontal extraction wells
• Trenches
• Water pumps
• Aboveground water handling and/or treatment systems
• Wastestream treatment options:
• Air stripping
• Granulated activated carbon
• Bioreactors
• Constituent concentrations in groundwater
• Influent and effluent concentrations from water
treatment system
• Water discharge rate
• Water levels
• Might not meet cleanup standards or maximum
contaminant levels (MCLs)
• For an ideal site3, 3 to 7 years
• For an average site4, 3 to 10 years or longer
• For an ideal site3, $150,000 to $200,000
• For an average site4, $250,000 to $300,000
'"Parameters to monitor* are for performance purposes only; compliance monitoring parameters vary by state.
3An 'ideal site" assumes no delays in corrective action and a relatively homogenous, permeable subsurface.
4An "average site" assunes minimal delays in corrective action and a nxxiejately heterogeneous are) penrieable subsurface.
5Costs include equipment, and operation and maintenance.

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