C - Hanford Site

INTRODUCTION
WC-SD-EN-TI-136, Rev. 0
FORTY-FIVE DAY REPORT
FOR UNDERGROUND STORAGE TANK IOON-SS-27
This report describes the site investigation and remediation plan for
the 100N-SS-27 fuel tank removal, located in the 100 N Reactor Area on the
Hanford site at the Fuel Station (Figure 1). The tank, approximately 23 years
old, has a 3,000 gallon capacity and was last used to store unleaded gasoline.
The tank was taken out of service on June 22, 1990, because of a failed
tightness test conducted the previous day. Twenty-four hour notification was
made to DOE-RL and Ecology per 40CFR280.61, and an Event Fact Sheet (#D&D/100-
10-90) was prepared as well.
TANK EXCAVATION
Tank excavation and tank removal were completed on December 18, 1990.
Approximately 25 feet of associated piping was removed from the ground along
with the tank. An inspection of the tank did not reveal any holes or cracks
and the overall condition of the tank was very good. The tank was taken to
the 190-C storage pad and will be cleaned and sold as scrap.
Immediately following the lifting of the tank, soil sampling was
conducted to test for the presence of contaminated soil . Samples were
collected for laboratory analyses of volatile and semi-volatile compounds to
assess potential petroleum hydrocarbon contamination. An organic vapor
monitor (OVM; HNU model PL 101) was used for the field investigation. The
field procedure consisted of collecting approximately 1/2 cup of soil, placing
it in a plastic bag, and sealing by twisting the top while including as much
air as possible. The plastic bag was then shaken for approximately 10 seconds
and the OVM probe was inserted in the bag for a reading. Photographs were
taken during and after tank excavation to document the condition of the tank
and surrounding soil.
INITIAL FIELD INVESTIGATION
The field sampling in the north 8 feet of the excavation (see Figure 2)
did not indicate a presence volatile organics. Samples taken at the south end
of the tank impression had readings in excess of 200 ppm. Additional field
samples were taken on the south end of the excavation between the IOON-SS-27
and -28 tank, approximately 9 feet apart, which showed vapor concentrations of
up to 350 ppm. Field sampling along the piping trench did not reveal the
presence of any volatile organics.
In addition to the field screening, additional samples were collected in
the same approximate locations, for laboratory analyses (Figure 2). These
were taken with new stainless steel spoons and deposited directly into clean
QA I-Chem bottles. The samples were packed in ice and sent to the K-25
Laboratory in Oak Ridge Tennessee for analysis. Chain of custody records will
be maintained.
B-11