Remedial Investigation/recommended action-1995

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� Sailors World, Inc. Summit Project No..922030 � October 5, 1995 Page 7 � recorded onto a water level form. The completed forms included the following information: the probe number; the time of the measurement; the date of the measurement; the depth to the � groundwater surface; the type of ineasuring device used; the initials of the individual collecting the data; the Summit project number; and the location of the site. The groundwater levels were measured from a surveyed point at each location: These surveyed points depicted relative � elevations and were referenced to an on-site concrete slab with an assumed elevation of 100.00 feet. t� Groundwater elevation data is included in Table 4. These data suggest movement of ` groundwater toward the southeast as exhibited on the groundwater contour map (Figure 3). Based on the inferred groundwater contours generated, the average horizontal gradient was � estimated to be approximately 0.01. Hydraulic conductivity of the soil (probable fill) is expected h to vary widely with respect to transport of groundwater and dissolved petroleum constituents. � According to Mr. De Santis, the level of Lake Minnetonka was very high in June 1995, " approximately 6 inches below flood stage. Because the lake level was relatively high and groundwater elevation data indicated movement toward the lake, groundwater movement away ,� from the Lake does not appear likely. A hydrogeologic setting and groundwater contamination worksheet are included in Appendix V. . � 3.6 Receptor Survey - The purpose of the receptor survey was to identify potential receptors and provide an estimate of -� the relative risks of adverse impacts to these potential receptors. This assessment evaluated the following potential receptors: surface water bodies, water wells, utility trenches, and buildings. � The site is located adjacent to a large surface water body, namely Smith Bay of Lake Minnetonka. Other surface water bodies within approximately '/z mile of the site include other � bays to the northeast and southwest and wetlands to the north and west(Figure 1). Water well records were obtained from the Minnesota Geological Survey as a part of this � assessment. The well records for the water supply well on the site was not located. The closest identified wells to the site are Unique Well Numbers 100169 and 205621, located approximately 500 to 1,000 feet west of the site. Both of these wells are used for domestic putposes. Well '� 100169 is cased to 117 feet below grade and is equipped with a nine foot screen with the bottom of the screen set at 126 feet below ground surface. Unique Well'Number 205621 has a five-foot screen set from 215 to 220 feet below grade. Both well logs indicate that at least the upper 125 � feet of soil consists predominantly of clay. A location map for the wells and copies of the well logs are contained in Appendix VI. � A vapor survey was performed at accessible sewer manholes, a storm sewer catch basin, and two residential basements located west of the Sailors World Marina in June 1995..Elevated PID or � . � ,