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CPT-#1&#2 were installed 10/21/05 in order to furdier delineate the 1,2-DCA plume to the North <br /> and to the East. <br /> Monitoring well MW#1D was installed to 85'with a 5'screen on 11/29/05. MW#1 S was installed <br /> to 55' with a 15' screen and MW#1 was over drilled to 7l' and destroyed 11130/05. MW46D was <br /> installed to 80' with a 5' screen on 12/1105 and M #6S was installed to 50' with a 15' screen on <br /> 12/2/05. <br /> CPT#5 was sampled 8/17106, and CPT'#3 and#4 were sampled 8/18/06. <br /> WORK PLAN FOR MW-7 &D AND MW-8S&D <br /> PURPOSE <br /> The purpose of MW-7 shallow and deep, and MW-81 shallow and deep is to monitor ground water <br /> conditions South East of the site. <br /> CHARACTERIZATION OF SITE . <br /> The site was affected by a leaking underground leaded gasoline storage tank, and a leaking <br /> underground Stoddard Solvent storage tank. The lithology below ground surface is characterized <br /> by two layers of sand. The first sand layer starts at about 45'+/-below ground surface and is about <br /> 10'thick. The second sand layer starts at about 70'+.(-below ground surface and is about 15'thick. <br /> The direction of ground water flow is Easterly. The depth to the ground water is currently about <br /> 40'. <br /> The contamination plume seems to be characterized by two modes of migration,BTEX and TPHg <br /> compounds have not migrated across California St eet and have stayed in the upper sand layer. <br /> 1,2-DCA is a lead scavenger in leaded gasoline. It has impacted both the shallow and the deep sand <br /> layers. It has also moved across California Street and the most Easterly monitoring wells,MW-5S, <br /> and MW-513 have the highest concentrations. Frorr CPT#3,#4,and 95,the 1,2-DCA migration is <br /> limited vertically to depths of 75-85' and horizonta ly to 100'North and 100' East of MW-5. <br /> SCOPE OF WORK <br /> The scope of work involved is to place shallow and deep monitoring wells in separate bore holes <br /> along the East and West shoulder of North Califo is Street on the North side of East Pine Street. <br /> 2" PVC casings and screens will be placed in 8" diameter bore holes. The shallow and deep wells <br /> will be 5' apart. Shallow wells will be drilled to a t p of 55' with a 20' screen. Deep wells will be <br /> drilled to a tip of 85' with a 5' screen. These dep hs correspond to the two sand layers in other <br /> borings. Depths may be adjusted in the field with the goal of finding the bottom of each sand layer, <br /> if possible. The deep well will be drilled first in order to obtain lithology. Soil samples will be <br /> taken at 5' intervals in order to confirm the lithology. <br /> TARGET DEPTHS AND TESTING <br /> The target depths of 55' and 85' were selected based on the lithology from the other borings and <br /> CPT logs. One of the purposes of CPT #3, #4, and 95 was to collect water samples below the <br /> 2 <br />