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h� KLEINEELDER ( 1 INTRODUCTION AND FIELD ACTIVITIES 1.1 INTRODUCTION From October 16 to October 21, 2002 Kleinfelder completed an air sparging pilot test at the Del Monte Disco Site at 110 Filbert Street (see Plates 1 & 2). The pilot test was completed using a recently constructed test well cluster comprising a 2" vapor extraction well screened from 15-35 ' feet below grade surface (bgs) and two 1" sparge wells screened from 87 to 90 feet bgs and 137- 140 feet bgs (see Plate 3). Sparge testing was completed by injecting air into the sparge wells with a portable compressor and monitoring the effect in nearby wells. Vent well testing was completed by purging the vent well with a small pump and drawing a vapor sample representative of the formation. The objective of the test was to evaluate the radius of influence of the two sparge wells and i quantify the vapor contamination that would be anticipated in the soil in the vicinity of the source area. The pilot test results will be used to evaluate design parameters for a full-scale implementation of the technology at the site in a forthcoming Corrective Action Plan. 1.2 PILOT TEST FIELD ACTIVITIES On October 16, the shallow sparge well was run initially for two hours and the effect in nearby wells MW-1, NP-1 and NP-2 were recorded (see Plate 2). Due to the size of the compressor, the shallow sparge well was run independently of the deep well during testing. The sparge well was operated at a wellhead pressure of 39 psi and a flow of 5 standard cubic feet per minute of air j (scfm). Air was noted exiting from MW-1 indicating that sparge air was intercepting the screened interval of the well. Air was not noted exiting NP-1 or NP-2 likely indicating the i sparge path had not reached the wells or the screen interval of 1 foot was too small in these wells f to intercept a detectable amount of sparge air. To quantify the interception point of the sparge air reaching MW-1 a bubble flux test was implemented in the well described in Section 3.1. On October 21, the deep sparge well was operated for 4 hours and the effect on oxygen concentrations in SVE-S and SVE-N was monitored. The well was operated at a wellhead { pressure of 49 psi and a flow of 5 scfin. Air was not noted exiting any of the nearby monitoring 122801SAC2R566 Page 1 of 9 November 25,2002 Copyright 2002 Kleinfelder,Inc. i