Pump
and Treat
http://en.wikipedia.org/wiki/Groundwater_remediation
http://www.epa.gov/tio/download/citizens/a_citizens_guide_to_pump_and_treat.pdf
Pump and treat is one of the most widely used ground water
remediation technologies. In this process ground water is pumped to the surface
and is coupled with either biological or chemical treatments to remove the
impurities.
What Is Pump And Treat?
Pump and treat is a common method for cleaning
up groundwater contaminated with dissolved chemicals, including industrial
solvents, metals, and fuel oil. Groundwater is pumped from wells to an
above-ground treatment system that removes the contaminants. Pump and treat
systems also are used to contain the contaminant plume. Containment of the
plume keeps it from spreading by pumping contaminated water toward the wells.
This pumping helps keep contaminants from reaching drinking water wells,
wetlands, streams, and other natural resources.
How Does It Work?
Pump and treat methods may involve installing
one or more wells to extract the contaminated groundwater. Groundwater is
pumped from these extraction wells to the ground surface, either directly
into a treatment system or into a holding tank until treatment can begin. The
treatment system may consist of a single cleanup method, such as activated
carbon or air stripping, to clean the water.
Is Pump And Treat Safe?
Pump and treat is a safe way to both clean up
contaminated groundwater and keep it from moving
to other areas where it may affect drinking
water supplies, wildlife habitats, or recreational rivers and
lakes. Although pumping brings contamination to
the ground surface, it does not expose people to that
contamination. A pump and treat system is
monitored to ensure the extraction wells and treatment units
operate as designed. Also, the groundwater is
sampled to ensure the plume is decreasing in concentration and is not
spreading.
How Long Will It Take?
Pump and treat may last from a few years to
several decades. The actual cleanup time will depend on several factors, which
vary from site to site. For example, it may take longer where:
Contaminant concentrations are high, or the
contamination source has not been completely
removed.
The contaminant plume is large.
Groundwater flow is slow, or the flow path is
complex.
How Might It Affect Me?
People living or working near the site may see
increased truck traffic while the system is being built
as drill rigs and construction supplies arrive
at the site. or construct the treatment system. Treatment systems usually are
designed to minimize noise while operating. Because pump and treat cleanups can
take a long time, systems can be designed so that other site activities may
continue during cleanup. For example, the treatment system may be constructed
in a location as far as possible from an office building or parking lot. It
also may be enclosed by a fence or a shed so that it is less obvious.
Why Use Pump And Treat?
Pump and treat is used to remove a wide range of
contaminants that are dissolved in groundwater. Pump and treat typically is
used once the source of groundwater contamination, such as leaking drums and
contaminated soil, has been treated or removed from the site. It also is used
to contain plumes so that they do not move offsite or toward lakes, streams,
and water supplies. Pump and treat is the most common cleanup method for
groundwater. It has been selected or is being used at over 800 Superfund sites
across the country