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Stantec
<br /> L & M OPERABLE UNIT- FOURTH QUARTER AND ANNUAL 2010 SITE STATUS,
<br /> REMEDIAL SUMMARY, AND GROUNDWATER MONITORING REPORT
<br /> Introduction
<br /> January 31, 2011
<br /> approximately 45 hours; simultaneously on wells DPE-4 and DPE-6 for approximately 28 hours;
<br /> and simultaneously on wells DPE-1, DPE-3, and DPE-7 for approximately 26 hours. Results of
<br /> DPE feasibility testing indicated the following: (1) a calculated radius of influence of 31 ft west of
<br /> well 2AMW-14, and lower estimated radii of influence to the south and east due to the presence
<br /> of low permeability clays and lower induced vacuum readings in wells DPE-3, DPE-4, and
<br /> DPE-7; and (2) the removal of an estimated 196.38 pounds of total petroleum hydrocarbons in
<br /> gasoline range organics (TPHg) from soil and groundwater, 97.02 pounds of total petroleum
<br /> hydrocarbons in diesel range organics (TPHd) from groundwater, and 9.57 pounds of total
<br /> petroleum hydrocarbons in motor oil range organics (TPHo) from groundwater. Results are
<br /> summarized in SECOR's report entitled Well Installation and DPE Feasibility Report, dated
<br /> January 24, 2003.
<br /> An additional DPE test was performed at the Site from March 3 through 7, 2003, using a
<br /> 25-horsepower (hp) liquid ring vacuum pump connected to a thermal oxidizer unit for abatement
<br /> of the extracted soil vapor prior to discharge to the atmosphere. DPE tests were performed
<br /> separately on wells DPE-4 and 2AMW-14 simultaneously for approximately 21.5 hours and
<br /> wells DPE-4, DPE-6, and 2AMW-14 simultaneously for approximately 72.5 hours. The DPE unit
<br /> ran for a total of approximately 97 hours during the test. Groundwater and soil vapor were
<br /> removed simultaneously from the test wells by applying a high vacuum to a drop tube that was
<br /> lowered below the water table within each test well. Results of DPE feasibility testing indicated
<br /> the following: (1) an effective radius of influence of at least 36 ft to the west of 2AMW-14; and
<br /> (2) the removal of an estimated 212.3 pounds (34.2 gallons) of TPHg from soil vapor, and
<br /> approximately 0.29 pounds (0.05 gallons) of TPHg, 17.56 pounds (2.46 gallons) of TPHd, and
<br /> 8.29 pounds (1.13 gallons) of TPHo from groundwater. Results are summarized in SECOR's
<br /> report entitled Results of Additional DPE Feasibility Testing, dated May 23, 2003.
<br /> From March 10 through April 9, 2003, 12 shallow zone groundwater monitoring wells (MW-18
<br /> through MW-23, MW-25, MW-28, MW-30, MW-31, MW-33, and MW-34), eight deep zone
<br /> groundwater monitoring wells (MW-16, MW-17, MW-24, MW-26, MW-27, MW-29, MW-32, and
<br /> MW-35) were installed, and seven soil borings (SB-1 through SB-6 and MW-16A) were
<br /> advanced at the Site. Results are summarized in SECOR's report entitled Additional
<br /> Assessment Report, dated May 30, 2003.
<br /> From October through December 2003, five additional DPE wells (DPE-8 through DPE-12) were
<br /> installed and a DPE remediation system was installed at the Site. The DPE system is
<br /> connected to wells DPE-1 through DPE-12. Additionally, a Non-aqueous Extraction Technique
<br /> (NETTIM) SPH removal system was installed at well 2AMW-14. System installation activities are
<br /> summarized in SECOR's report entitled DPE Well and System Installation Report, dated
<br /> December 5, 2003.
<br /> On December 17, 18, and 22, 2003, exploratory excavations were conducted at the Site to
<br /> locate underground utilities including former product pipelines. Steel pipelines were discovered
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