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i <br /> north-northwest direction at about 26 ' /mile Althought there is <br /> insufficient data to determine if the current water table and <br /> gradient agrees with historical trends, the fact that the highest <br /> levels of somal contamination were measured in the downgradient <br /> MW-1 & SB-2, indicates this has been the regional gradient at <br /> this location <br /> Maps showing lines of equal concentration of benzene, ethyl- <br /> benzene, toluene, xylene & TPH as gasoline were constructed, <br /> (PLATES XIV through XVIII, ) which show that the levels of all <br /> components increase to the northwest, in the downgradient <br /> direction These maps were constructed using both the hydropunch <br /> samples taken from the soil borings on 8/3/95, and the water <br /> samples taken from the monitoring wells on 8/9/95 Although the <br /> two samplings were taken 6 days apart by slightly different <br /> methods, the levels of components measured appear to correlate <br /> well with each other Constructing maps using only the data from <br /> the three monitoring wells produces a similar picture, but with <br /> the increase in contamination to the west, towards MW-1 <br /> CONCLUSIONS <br /> • Based upon all of the data obtained to date, the following <br /> conclusions appear to be reasonable <br /> 1 The limits of soil contamination have only been defined to <br /> the southwest (SB-3, ) and the southeast (SB-2 , ) it has not been <br /> located to the south, west, north, and northeast - (PLATE XIX ) <br /> 2 The limits of groundwater contamination have not been defined <br /> in any direction; the lowest overall levels were measured in <br /> SB-3, indicating that the plume does not extend much farther to <br /> the south <br /> 3 The groundwater gradient was determined to be to the <br /> northwest based on the 8/9/1995 sampling event Although there <br /> is insufficient data to verify that this is the historical <br /> direction, the results of soil and groundwater contamination <br /> encountered show a consistent increase in all measured compounds <br /> in a northerly direction as shown on PLATES XIV through XVIII <br /> RECOMMENDATIONS <br /> 1 Put the three monitoring wells on a quarterly sampling <br /> schedule <br /> 2 After analyzing the results of at least two (2) additional <br /> • quarterly monitoring events, additional site investigative work <br /> 10 <br />