Laserfiche WebLink
REMEDIATION TESTING AND DESIGN May 28, 1993 <br /> the site . They will be pneumatically installed to a depth of, but <br /> not more than, approximately twenty feet below ground surface . The <br /> installed depths of the probes will be determined in the field by <br /> the registered geologist from RTD and by a representative of <br /> Ultramar, Inc . (Ultramar) . <br /> RTD and Ultramar have extensively discussed the limitations and <br /> potential dangers associated with driving temporary probes . Given <br /> these limitations, Ultramar, as our client and site owner/operator, <br /> is entirely responsible for selecting probe locations . All probes <br /> driven by RTD will be at the direction of Ultramar . RTD reserves <br /> the right to refuse to drive any probes at its sole discretion. <br /> Following installation, a pump induced vacuum will be applied to <br /> each probe to purge resident soil gas . Sample purge rates and <br /> vacuums will be monitored and recorded for each probe . Soil gases <br /> from the probes will be analyzed for total volatile hydrocarbons <br /> (TVH) using a Beckman Model 400 Total Hydrocarbon Analyzer Equipped <br /> with a Flame Ionization Detector (FID) . In addition, RTD will <br /> collect soil gas samples into 1-liter Tedlar air bags from up to <br /> five probes to be sent to a certified laboratory for analysis of <br /> total petroleum hydrocarbons as gasoline (TPHg) and benzene, <br /> toluene, ethylbenzene and total xylenes (BTEX) . The soil gas TVH <br /> data will be mapped on a scaled site plan to aid in the evaluation <br /> of hydrocarbon impacted areas and possible migration pathways . Upon <br /> completion of the SGS, the probes will be used for the VEFT. Once <br /> the VEFT is completed, the probes will be removed and the probe <br /> -= holes sealed with portland cement slurry. <br /> Vacuum Extraction Feasibility Testing <br /> A VEFT using the temporary vapor probes will be conducted to <br /> determine the effectiveness of using vacuum extraction technologies <br /> for remediation of impacted soils, if present . <br /> Vacuum extraction will be conducted with a Sutorbilt Model 3ML <br /> positive displacement blower capable of extracting 100 standard <br /> cubic feet per minute (scfm) under a vacuum load of 15 inches of <br /> mercury. Extracted vapors will be routed through a 55-gallon water <br /> accumulator to remove any vaporized water. Prior to discharge to <br /> the atmosphere, the extracted vapors will pass through two granular <br /> activated carbon (GAC) cannisters in series, each containing 175- <br /> pounds of vapor phase GAC. <br /> The duration for each test will be determined in the field based on <br /> initial flow and vacuum levels . Based on these flow and vacuum <br /> level characteristics of the probes as predetermined in the SGS, two <br /> or three will be used as extraction points for a full day of <br /> testing. The VEFT will be conducted in two to three segments . Each <br /> segment will consist of applying an extraction vacuum to the top of <br /> the probe and recording the vacuum gradient in neighboring probes . <br /> The actual testing scheme will be determined in the field by RTD in <br /> conjunction with Ultramar based on the results of initial testing. <br /> 2 <br />