United States
Environmental Protection
Agency	
Region 5
77 West Jackson Blvd.
Chicago, Illinois 60604
Illinois, Indiana
Michigan, Minnesota
Ohio, Wisconsin
      4>EPA    Before  You  Dig -  Radioactive
                       Thorium and  Construction  Activities
                       in the  Streeterville Area
Chicago, Illinois
                                    November 2006
INTRODUCTION

The purpose of this update is to provide basic
background information on the history of
thorium within the Streeterville area and basic
procedures when uncovering or intruding into
subsurface soils within the potentially
contaminated area.

BACKGROUND

In the 1990's, U.S. EPA became involved in
Streeterville due to the discovery and
excavation of approximately 40,000 tons of
radioactive thorium-contaminated soils that
were located during  property development
and utilities installation and maintenance.
Additional subsurface thorium contamination
has been found in other Streeterville
locations.  This radioactively contaminated
material must be managed in accordance with
State and Federal environmental
requirements.  U.S. EPA believes that
radioactive thorium waste from the Lindsay
Light and Chemical Company (Lindsay Light)
was disposed of in the Streeterville area, but
there are no historic records describing where
Lindsay Light disposed of its waste.

Our historical research indicate that beginning
in about 1904 and continuing through the mid
1930's, Lindsay Light manufactured  thorium
mantles impregnated with thorium in the City
of Chicago. The Lindsay Light operation
reportedly originated at 22 W. Hubbard and
later moved to 161 E. Grand and 316 E.
Illinois in Chicago, Illinois. Thorium-containing
ore apparently was processed at 316 E.
Illinois into liquid thorium nitrate which was
           used to make gas light mantles at 161 E.
           Grand. Details regarding Lindsay Light
           operations at 22 W. Hubbard are sketchy.
           From the early 1900s until the early 1920s,
           Lindsay Light occupied the five-story building
           at 22 W. Hubbard, however, it is not known
           which operations took place at this location.
           Lindsay Light moved to the City of West
           Chicago, Illinois and closed its Streeterville
           operations by about 1936.  The Lindsay Light
           operations in West Chicago resulted in four
           Superfund sites including over 670 residential
           properties which were cleaned up pursuant to
           U.S. EPA orders.

           PROCEDURES

           If subsurface thorium wastes are uncovered
           without proper environmental controls, workers
           and the public  may be exposed to elevated
           radiation levels. Also, if not managed properly,
           the radioactive materials may be spread to
           other locations. The City of Chicago has
           prepared a generic health and safety work plan
           for the Streeterville area that is available at the
           City's Department of Environment.  If your
           work involves removing the asphalt, concrete
           or other materials covering subsurface soils or
           tunneling, digging or otherwise intruding into
           subsurface soils, the following radiation survey
           testing procedures performed by a qualified
           person under the direction of a radiation health
           physicist must  be followed. The results should
           be presented in a written report sent to U.S.
           EPA.  This report should be detailed enough
           that someone not present would be able to
           determine that these radiation surveillance
           procedures were followed.  Please call U.S.
           EPA 48 hours prior to performing a walkover
           survey so that we may observe.  This report

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should be given to U.S. EPA prior to breaking
ground in Streeterville.

Taking Radiation Measurements

•     Determine the site radiation level.
      Hold a gamma-ray survey probe
      (sodium iodide detector) about 6 inches
      off the ground and walk the entire area
      along parallel lines about 3 - 4 feet
      apart. The site background  level is
      determined by looking at the  lowest
      count rate  readings and  looking for
      spots and regions of elevated radiation
      levels. If background readings appear
      to be elevated over expectations, U.S.
      EPA may ask for an off-site
      determination of background for the
      area.

•     Quantify exposure environment.
      Take readings of 30 second counts, on
      contact with the ground,  at intervals of
      10 feet along parallel lines five feet
      apart to quantify the exposure
      environment (these include background
      levels). Next, take readings at selected
      spots where initial readings were over
      twice the background level.

•     Assess an anomaly.
      If readings indicate anomalies, then
      subsurface gamma-ray  count rate
      readings and soil samples will need to
      be collected. These samples will need
      to be analyzed for radionuclide
      identification and quantification.
      However, gathering samples may
      generate hazardous waste and  may
      contaminate workers and equipment,
      so this phase should not be done
      without a U.S. EPA reviewed health
      and safety plan and a means of
      disposing of contaminated soil,
      protective clothing, etc.
FOR ADDITIONAL INFORMATION

If you have questions about these procedures,
equipment specifications, or thorium
contamination in Streeterville, please contact:

Verneta Simon
On-Scene Coordinator
Superfund Division (SE-5J)
(312)886-3601
simon.verneta@epa.gov

Eugene Jablonowski
Senior Health Physicist
Superfund Division (SMF-4J)
(312)886-4591
jablonowski.eugene@epa.gov
        24-hour response number
              (312)353-2318

Lindsay Light site-related information is
available at the following location:

     Harold Washington Public Library
             400 South State
             Chicago, Illinois

Monday: 9:00 a.m. to 7:00 p.m.
Tues. and Thurs.: 11:00 a.m. to 7:00 p.m.
Wed., Fri., and Sat.: 9:00 a.m. to 5:00 p.m.

WEB SITE

This and additional  updates can be found at
the following web site:

        www.epa.gov.regionS/sites/

Scroll down through the list to find the Lindsay
Light II/RV3 North Columbus Drive site.

Additional information about thorium is
available at:
www.epa.gov.superfund/resources/
radiation/pdf/thorium.pdf

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