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' Stantec
<br /> ' L & M OPERABLE UNIT-THIRD QUARTER 2010 SITE STATUS, REMEDIAL SUMMARY,
<br /> AND GROUNDWATER MONITORING REPORT
<br /> Introduction
<br /> October 27, 2010
<br /> 1
<br /> 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 /> tJanuary 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 /> tFrom 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 /> (NETTM) 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
<br /> at the Site at 14 locations. Results are summarized in SECOR's report entitled Revised
<br /> Underground Utility Search Report, dated March 5, 2004.
<br /> In January 2004, SECOR completed construction of the DPE system. Electrical power and
<br /> natural gas service were established by Pacific Gas and Electric (PG&E) on March 4, 2004.
<br /> Under the conditions of the initial air permit for the DPE system issued by the San Joaquin
<br /> tValley Air Pollution Control District (SJVAPCD) in April 2003, which covered the first six months
<br /> ' J:Mdewate� Stocton(Par l2A-0415)\Reports\OMR@01013Q1013C110oSSRQRSRQMRStoc n_FINALA.o 1.5
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