ARCHIVED REPORTS XR0010485 - Laserfiche WebLink

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Since it was decided that further excavation, was not feasible, the removed spoil was remediated on site by aeration over a period of weeks. Laboratory analysis of the soil after treatment showed it to be clean, and the EHD authorized returning it to the excavation Refer to EXHIBIT G for a copy of that correspon- dence. October 4 & 5, 1990 - Five (5) auger holes were placed in an attempt to further define the plume. Four were located on Normac property, and one was located to the west of the tank site on property owned by Hammertown Partners. The locations of those 5 holes are shown on PLATE VI . Details are given in EXHIBIT C. April - 8 & 9, 1992 - Because the previous work had not determined the vertical & lateral extent of the contamination, six (6) additional auger holes were placed as shown on PLATES VI & VIII . The limits were defined except in a southerly direction on the Hammertown property. EXHIBIT D gives more details of the work performed. August 13 1992 - Three additional soil borings were located on Hammertown Partners property as shown on PLATE VI . EXHIBIT E discusses the results of that work, which revealed that Toluene was detected in all three holes at 40' bgl, which was the approx- mate water table level in the Spring of 1986. As a result of the above work, the County EHD staff had required that monitoring wells be installed to determine if the ground- water had been impacted by the leaking UST. During a recent meeting with members of the EHD staff, it was agreed that add- itional soil & water sampling might be sufficient to determine if the remaining residual contamination will pose a threat to the groundwater. The following workplan is designed to accomplish that task. WORKPLAN_FOR _ADVANCING_TWO (_2) SOIL BORINGS TO WITHIN 10-15 FEET OF THE WATER TABLE TAKING APPROPRIATE SAMPLES- AND DRIVING A WATER SAMPLING DEVICE INTO THE WATER -TABLE -IN ORDER TO OBTAIN A CLEAN UNCONTAMINATED WATER SAMPLE FOR ANALYSIS: 1. The approximate locations of the two (2) soil borings are shown on PLATES VII & VIII; the actual locations may vary slightly from those indicated. 2. Osterberg & Stewart drilling equipment will be used IL will be equipped with sufficient clean 5-foot lengths of 8 1/4" OD auger flights to allow the advancing and completing of each well • without stopping to clean flights. If necessary, flights will be 3