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LEEDSHILL•HERKENNOFF, INC. <br /> corrosion and holes along the bottom of the drain line. If water containing <br /> PCE and/or TCE entered this drain line, the contaminants could have leaked <br /> from the holes into the soil beneath the foundation. <br /> ' Samples were collected from the other two dry-cleaners by core drilling a <br /> three-inch diameter hole through the existing foundation near several sus- <br /> pect- floor drains. These drains were chosen based on owner interviews <br /> regarding past operations of the facility, facility inspection, and access. <br /> A schematic of the dry-cleaning facilities and sampling locations are shown <br /> ' in Figures 3. 1 and 3.2. After a hole had been cored in the concrete slab, a <br /> three-foot-long by one and a half-inch-diameter hollow steel barrel lined <br /> with six one-inch diameter brass tubes was mechanically driven into the <br /> ' soil . The barrel was then removed, opened, and the brass tubes recovered. <br /> The uppermost tube, corresponding to approximately the top six inches <br /> directly under the slab, and the lowermost tube, corresponding to a depth of <br /> approximately 2; ' to 3 foot below the slab, were collected and sent to an <br /> approved DOHS hazardous waste analytical laboratory for analysis. <br /> ' The previous investigation implied that leakage through the sewer might be a <br /> possible contamination source. Previous sewage water samples collected at <br /> ' several on-site manholes contained high levels of PCE. Air pressure testing <br /> of the sewer system showed several leaking joints which required pressure <br /> grouting to seal . To determine if some of the sewer water containing <br /> ' PCE/TCE had leaked into the permeable backfill material below it, soil <br /> samples were collected from beneath the various sewer lines. Five locations <br /> ' were chosen to be sampled, three laterals, each of which extended to a dry- <br /> cleaning establishment, a line combining two of the laterals and a line <br /> combining all flow from Lincoln Village Center and closest to LVMD well #1. <br /> ' A schematic of the soil sampling locations is shown on Figure 3.3. A one <br /> and one half-inch diameter stainless steel barrel was driven underneath the <br /> sewer using a mechanically powered hammer. The barrel was offset two to <br /> three feet from the sewer and angled such that a sample was collected <br /> approximately two feet below the invert of the sewer line. Three samples <br /> ' were collected at varying depths under the sewer line closest to LVMD #1 . <br /> It should be noted that soil samples collected beneath the sewer lines which <br /> had not been pressure grouted, were noticably moist, compared to samples <br /> ' collected beneath pressure grouted lines, such as between manhole #4 and <br /> Gettysburg Place, which was dry. <br /> ' 3-2 <br />