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� <br />� <br />3.o r►r�.n rx��i3ORA7'IONS <br />� 3.1 13orings <br />_., �.',.,;:'_�i`:�:�,:.;�i' S�'.�.I`�':. <br />� Thc ficid c�plorations for this study includcd drilling fiftccn borings, dcsignatcd B-7 through I3- <br />12, B-12A, B-13 through B-16, B-IGA, B-1GB, B-l7, and B-1S. Thc borings wcrc drilled <br />� bchvccn Pcbrunry 19 and Junc 21, 2002. Thc borings wcrc advanccd to depths ranging bchvccn <br />15.3 and l00.4 fcet, which corresponds to approximatc bottom clevations of 127.7 to 55.6 fcct. <br />At the adjacent Justice Center site, borings B-I through B-6 ���ere drilled concuirently ���ith the <br />, initial drilling for thc Administration Building and Garagc sitc. <br />� Pollowing thc discovcry of soil with clevatcd lcvcls of pctrolcum h}'drocarbons in borings B-13, <br />8-13, and B-16, thc borings wcrc tcnninated bcfore reaching thc proposcd driil depth. Borings <br />� B-12A, B-IGA, and II-1GI3 ���crc latcr complctcd to depth bctween May 6 and l0, 2002, using an <br />cnvironmcntal driller. Boring B-13 �vas not completed to proposed drill depth aftcr detenninin� <br />that subsurfacc data in ncarUy borings ���cre sufficicnt. Borings B-l7 and B-IS wcrc drillcd to <br />� install l�eo additional monitoring wclls anJ perfonn h��draulic conductivi[y ficld [csts. <br />� Onc cnvironmcntal soil samplc cach was collccted from borings B-12, B-13, B-16, and B-lGA <br />for petroleum hydrocarbon and leud analyses. Suspect contaminated soil �vas also obser��ed <br />during drilling of boring B-IS, so two soil samples �ecre collected for petroleum hydrocarbon <br />' analyscs. Soil anal�'UCiII 1'CSl1Il5 :II'C (IISCUSSC(� Iatcr in this rcport. <br />1 Thc appro�imate locations of thc suhsurfacc cxplorations are sho�� n on l�i�,urc'_. The locations <br />of thc ncw cxplorations ���crc cstablishcd by taping from existing sitc fc:itures sho��m on thc sitc <br />, map. 'l�hc loc:uions of all thc horings should hc considcrcd :ippro�imatc. Appendiz A. Picld <br />Gxplorations, discusscs �rillim, :in�l sampling tcchniyucs and prescnts dct:iilcd boring logs for <br />subsurfacc csplorations. <br />3.2 Obser��alion 1Vclls <br />� r-�,-� 0�,5���,�:,�;o„ „��us „��� +�„�allcd arross thc Administration 13uildin� and Garagc project sitc. <br />\1'clls ���cre installed in borings B-9, B-1 I, and [3-14 anJ scrcened ncar the bottom of thc <br />� originally proposcd excavation to evaluatc where groundwatcr may be cncountcred during <br />construction. �Vclls were also installed in boiings B-17 and B-18 and scrcencd ���ithin thc <br />�iotential aater-bcaring zone to complete in-place penneability testin��. <br />_ i � i -u����,..ix�t. r. i.,,,, �u,i <br />i <br />2l - I -096�1-1-OOi <br />