C - Hanford Site

WHC-SD-EN-TI-136, Rev. 0
1.0 INTRODUCTION
This report describes the removal/characterization actions concerning
underground storage tanks (UST) at the 100-N Area (Figure 1). Included are
105-N-LFT, 182-N-1-DT, 182-N-2-DT, 182-N-3-DT, 100-N-SS-27, and 100-N-SS-28.
The text of this report gives a summary of remedial activities. In addition,
correspondence relating to UST closures can be found in Appendix B. Appendix
C contains copies of Unusual Occurrence Reports, and validated sampling data
results comprise Appendix D.
2.0 HISTORY
Tanks 105-N-LFT, 182-N-1-DT, 182-N-2-DT, 182-N-3-DT, and 100-N-SS-27 are
located in the 100-N Area and were temporarily taken out of service in August
1990. Tank 100-N-SS-28 was removed on July 17, 1991. The single-shell tanks
were constructed of carbon steel and varied in size from 11,356 to 56,781 L
(3,000 to 15,000 gal). All tanks contained diesel fuel with the exception of
Tank 100-N-SS-27, which contained unleaded gasoline. The tanks varied in age
from 11 to 30 years at time of removal (Table 1).
Advance notification for closure of UST 105-N-LFT, 182-N-1-DT,
182-N-2-DT, 182-N-3-DT, and 100-N-SS-27 was given in accordance with Chapter
40 Code of Federal Regulations (CFR) 280/281. This 30-day advance
notification was given to the State of Washington Department of Ecology
(Ecology) on September 20, 1990 (Correspondence No. 9004172). Advance
notification for Tank 100-N-SS-28 was given to Ecology on June 13, 1991
(Correspondence No. 9102476) in accordance with Washington Administrative Code
(WAC) 173-360-385.
Notice of Permanent Closure for UST 105-N-LFT, 182-N-1-DT, 182-N-2-DT,
182-N-3-DT, and 100-N-SS-27 was given to Ecology on July 16, 1991
(Correspondence No. 9103422), and Notice of Permanent Closure for
UST 100-N-SS-28 was given on June 13, 1991 (Correspondence No. 9102476) (See
Appendix B).
3.0 182-N-1-DT, 182-N-2-DT, AND 182-N-3-DT
Tanks 182-N-1-DT, 182-N-2-DT, and 182-N-3-DT were removed on November
30, 1990. It was noted in the field log book (WHC 1992a) that these tanks
were in excellent condition with no significant rust or dents. A slight
diesel odor, however, was noticed in the tank excavation area. Further
investigation by the site safety officer (SSO) and the field team leader (FTL)
revealed no levels of organic vapor above background detected with HNU meter
(a tradename of HNU Systems, Inc.). It was suggested that the odor was
probably coming from the valve caissons still in place. Samples were
collected for each respective tank and sent offsite for laboratory analysis
(Figure 2). The results of these samples were below detection levels.
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