ARCHIVED REPORTS XR0000857 - Laserfiche WebLink

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time the soil bore was made The cable layout was marked in error by Williams'cable locator,Miller . Technical Services Before placing the soil bore,the drill crew hand augured to a depth of 6 5 feet to check for any utilities None were encountered to a depth of 6 5 feet A new permit was obtained from the City of Stockton to place the soil bore in the parking lane of north bound California Street Originally the city would not allow drilling in the parking lane and required that the soil bore be located in the sidewalk The second attempt to install the soil bore for MW-5A&B was made on 11/7/2001 Monitoring wells MW-5A&B were completed on 11/8/2001 without further complications REPORT OF FINDING FROM THE MW-5A&B SOIL BORE INSTALLATION PROCEDURE A ten-inch soil bore was made to a depth of 75' Soil sample extraction was done from 25 to 75' of depth at five foot intervals The samples were extracted with a 2" split spoon sampler Each sample was transported in a brass sample tube that was capped with Teflon tape and a plastic cap Each sample was stored on ice for transportation to Sherwood Labs under a chain of custody WELL DEVELOPMENT & SAMPLING Del-Tech Geotechnical Services developed the wells and extracted a water sample from both monitoring wells on 11/15/2001 A field log for this work is attached and is a part of this report • SAMPLE ANALYSIS Soil Analysis All soil samples were analyzed by EPA method 8020/8015 for BTEX and TPHg Each soil sample was also analyzed by EPA method 8260B The results ofthis analysis are listed in both recap form and lab report form, and are a part of this report. Water Sample Analysis Water samples were analyzed by EPA methods 8020 and E624 Results of this analysis are listed in recap form and the original lab report form FINDINGS The soil samples from soil bore MW-5 were non detect for all analytes It should also be noted that there was a laboratory contamination error in all the soil samples that indicated Methylene Chloride It is noted on the lab report that the test method blanks also indicated a hit for Methylene Chloride Methylene Chloride is a common compound used in laboratories Sample MW5@70' indicated a positive reaction to 1,1-Dichlorethane at 29 ppb Water samples analysis for both MW-5A and MW-513 produced a positive reaction to 1,2- Dichloroethane,cis-1,2-Dichloroethene,and Tetrachloroethene(see recap of results attached) BTEX compounds were not present in any of the soil or water samples • CONCLUSIONS Compounds of Chloroethene have been present in low concentrations in monitoring wells east ofthe cleaning fluid UST This condition has been common for the three years that this site has been monitored The plume has migratea to the east across California Street The highly permeable sand 2