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Monitoring wells were vented and purged by normal methods per standards of the industry (see Groundwater Field Report by Del-Tech Geotechnical Services attached) Purge pump rates were +/-0 5 gallons per minute in all monitoring wells Groundwater samples were extracted from each IS monitoring wells using the check valve in tube technique Samples were transported on ice for delivery under chain of custody to Sherwood Labs for analysis WATER TABLE ELEVATIONS AND GRADIENT Soundings on the monitoring wells showed the groundwater elevation has lowered+/-4'feet from the last soundings on 6111/02 The hydraulic gradient of the water table is bearing to the northeast at S=0 003 WATER SAMPLE ANALYSIS FINDINGS In general, monitoring well samples taken on 03/20/03 were very similar to the previous sample events when analyzed for BTEX and TPHg MW-3S continues to be the only monitoring well with BTEX compounds and TPHg as determined by EPA Method5030/8015(M) TPHg in this well was analyzed at 1260 ug/L The purgeable Halocarbon, 1,2-Dichloroethane, continues to be present in all of the wells with the exception of MW-4S and MW4D MW-4S and MW-4D continue to produced only a positive results for Chloroform and no other analyte For this event, monitoring well MW-5D had the highest recorded values of the compound 1,2- D;chloroethane, at 47 ug/L, sense the starts of this investigation(see recap of data attached) CONCLUSIONS BTEX compounds in the monitoring well MW-3S remain in the same range as the past events This morntonng well is receiving the highest impact of all the wells due to TANK#1 (the Stoddard Solvent tank), which is usually up gradient and Southwest of MW#3S A case narrative from Entech Analytical Labs states that the detectable hydrocarbons found in MW-3S were more in line with gasoline than Stoddard solvent Low concentrations of 1,2-dichoroethane remain in monitoring wells MVV-I, MW-2S, MW-2D, MW-3S, MW-3D and MW-5S and MW-5D RECOMMENDATIONS The author requests that all monitoring wells continue to be sampled in semiannual events to conserve financial resources WORK IN PROGRESS A receptor survey to indicate possible groundwater extraction within 2000' of the site is in the planning stages Please contact this office at 2091368-9381 if any questions anse from tills report Respectfully submitted, avvPFEss��, ��y�� Foothill ne ng RIF 4� 9c E n fen cc Mrs Helen Higgins, 5815 Mo rg O #16, Stockton CA 95219 2