|
f
<br /> ATC Associates Inc.
<br /> • `�/�V 1117 Lone Palm Avenue, Suite B Modesto,Ca209-57 -2221
<br /> 209-579-2221
<br /> Fax: 209-579-2225
<br /> In June and July 2000, WHF supervised the advancement of ten soil borings at the site and
<br /> completed five of the borings as groundwater monitoring wells MW5, MW6, MW8, MW9, and
<br /> MW10, and three of the borings as vapor extraction wells VEl, VE2, and VE3. Groundwater
<br /> monitoring well MW7 was replaced by vapor extraction well VE3. Soil samples collected from
<br /> borings B101, B103, B104, VE3, and VEl contained detectable concentrations of TPHg and
<br /> BTEX. A summary of the soil sample analytical results are presented in Table 1.
<br /> On September 18 and 29, 2003, ATC performed a short-term vapor extraction test and a long-
<br /> term vapor extraction test, respectively. On the first day, a short-term vapor extraction test was
<br /> performed by ATC using vapor well VE2 as the vapor extraction point while monitoring vacuum
<br /> response in surrounding wells VEl, VE3, MWI, MW2, MW3, MW4, MW5, MW6, MW8, and
<br /> MW9 (Figure 2). The test was approximately 3 hours and 45 minutes in length. Flow rates,
<br /> applied vacuums, influent and effluent VOC concentrations, and temperatures were also
<br /> monitored during the test.
<br /> On the second day, a long-term vapor extraction test was performed by ATC using vapor well
<br /> VE3 as the vapor extraction point while monitoring vacuum response in surrounding wells VEl,
<br /> . VE2, MWl, MW2, MW3, MW4, MW5, MW6, MW8, and MW9 (Figure 2). The test was
<br /> approximately 5 hours in length. Flow rates, applied vacuums, influent and effluent VOC
<br /> concentrations, and temperatures were also monitored during the test. Vapors were extracted
<br /> using a 3 HP Rotron Blower equipped with a moisture knockout chamber and three granular
<br /> activated carbon (GAC) canisters. Two influent vapor samples were collected during the test,
<br /> one after 15 minutes of operation, and one after 5 hours of operation. An effluent vapor sample
<br /> was collected after 20 minutes of operation.
<br /> ATC performs all quarterly groundwater monitoring activities including sampling, depth to
<br /> water, dissolved oxygen, turbidity and electrical conductivity. During quarterly monitoring
<br /> events, remediation system parameters are also monitored.
<br /> Vapor Extraction System Components
<br /> The vapor extraction system consists of four vapor wells (VEI-VE4) that are connected by
<br /> subsurface piping to an electric catalytic thermal oxidizer (Figure 3). The thermal oxidizer is a
<br /> 250 ECAT manufactured by Solleco. The remediation system is optimized to run at least 600°
<br /> Fahrenheit (F) and total flow of 235 cubic feet per minute (cfm). The system is safeguarded to
<br /> shut down if it reaches a temperature below 600° F in order to meet the requirements made by
<br /> SJVAPCD. The remediation system also has a safeguard from overheating, exceeding a
<br /> temperature of 1200° F. The system can open a dilution valve and reduce the intake of petroleum
<br /> • hydrocarbon vapors, decreasing the amount of combustion in the oxidizer.
<br /> S:\Enviromenml\25291\reports\sunup.doc 3
<br />
|