Chicago, Illinois

SITE LOCATION:

High rise, upscale apartment building near Lake Michigan waterfront in Chicago, Illinois.

CONTAMINATION:

Dissolved BTEX plume above Illinois EPA Tier 2 objectives emanating from former gasoline and heating oil tanks.  Approximate size of plume was 30 feet by 45 feet, located under a constrained and busy location near the entrance to a residential parking garage.

GEOLOGY:

Fine to coarse sand with some silt.

PLUME DESCRIPTION:

Groundwater at depths of 8 to 10 feet below ground surface.  Plume is fairly stationary and located approximately 300 feet from the shoreline of a harbor on Lake Michigan.

PRIOR REMEDIAL EFFORTS:

Three direct push injection events with RegenOx were conducted from May to November 2006.  6,400 gallons of RegenOx was injected at 40 DP locations during a total of 11 field days.  Groundwater total BTEX concentrations at a single source well increased after the injections (from 1.22 ppm in March 2006 to 10.72 ppm in January 2007)

EFR^® EFFECTIVENESS:

Four EFR^® events were conducted, two in June 2008 and two in August 2009.  A 4-inch recovery well was installed prior to the August 2009 events to provide better recovery from the source zone.  EFR^® achieved decreases in BTEX at a cost far  less than the DP/RegenOx injections.   Client is applying for site closure, crediting EFR^® for  having obtained cleanup levels.