ARCHIVED REPORTS XR0000869 - Laserfiche WebLink

Home Browse Search

' Dichloroethene in low concentrations BTEX was not found in this new soil bore or water samples CPT-1&2 were installed 10/21/05 in order to further delineate the 1,2-DCA plume to the North and ' to the East Monitoring well MW#I D was installed to 85' with a 5' screen on 11/29/05 MW#1 S was mstalled ' to 55'with a 15' screen and MW#1 was over drilled to 71' and destroyed 11/30/05 MW#6D was installed to 80' with a 5' screen on 12/l/05 and MW#6S was installed to 50' with a 15' screen on 1212/05. The most recent monitoring event is the first quarter of 2006 and was performed 1/5/06 ' WATER TABLE ELEVATIONS AND GRADIENT First water table is currently 42 5' below ground surface (bgs) The water table has been in a drought condition and has fallen 8 5'smce 1999 The groundwater is characterized by two different water bearing sand layers The shallow sand layer is at 45' bgs with primary direction of flow beanng S 76° E. with a gradient of s=0006 The deep sand layer is at 70' bgs with primary direction of flow bearing N 86' E with a gradient of s=0 004 The groundwater soundings for shallow and deep wells show that the deep wells hold a static elevation slightly higher than the shallow wells SOIL BORING SAMPLE ANALYSIS FINDINGS The soil samples from the monitoring well borings indicate the contaminated soil is limited to the . soil under the existing building. The borings under the two tanks 03H-1, and MW-1) show contamination clinging to the soil particles BH#1 showed TPHg from 1,000 to 6,800ppm the whole length,75'at 50°from horizontal (57 45'vertical) BTEX compounds were spotty for BH#1 Benzene,and Toluene are limited to the sand Iense at the 35'vertical depth with concentrations of 0 351 and 177ppm, respectively Ethyl Benzene appears at the top and at the bottom with concentrations ranging from ND to 32.5ppm Total Xylene was present the length of the bore with concentrations ranging from 10 to 572ppm The bore for MW-1 shows TPHg and BTEX only in the top 30' Benzene at 1 8ppm, Toluene at 261ppm, Ethyl Benzene at 22 8ppm, Total Xylene at 1,540ppm, and TPHg at 12,300ppm The soil samples from MW-2, MW-3, MW-4, and MW-5 came back clean ' The soil samples from CPT#1 and CPT#2 came back clean MW-1 (depth 70') was replaced with MW-1S (depth 55') and MW-1D (depth 85'), all in separate boreholes MW-11) was simply a well replacement and soil samples were not taken every 5' because there was not an apparent need to replicate data Therefore soil samples were only taken at 20',45', 70',75',80',and 85' The 20'soil sample at MW-11)shows much less TPHg than the 20' sample from the original MW-1 boring, 2ppm versus 6,930ppm The soil samples from MW-6D came back clean A summary of results for soil samples is attached, . Exhibit D 2