Laserfiche WebLink
Metadata
Document management portal powered by Laserfiche WebLink 9 © 1998-2015 Laserfiche. All rights reserved.
UPDATE 30 11-11-94 <br /> Fecal Coliform. <br /> From December, 1991 through February, 1992, monthly fecal <br /> coliform samples were collected from monitor wells MW3 , MW4 , MW5 <br /> and MW6 . Samples were again collected in June, 1992, from <br /> monitoring wells MW3 , MW4 and MW6 During the September 11, 1992 <br /> sampling, MW3 and MW6 were dry, no fecal coliform samples were <br /> obtained Table 2 shows the results of these samples The only <br /> wells that have tested positive for fecal coliform are MW4 and <br /> MW5 As of June, 1992 all these wells are below detection <br /> limits, <2 2 MPN, for fecal coliform <br /> VAPOR EXTRACTION <br /> Vapor Recovery Summary <br /> The VES was turned off on December 30 , 1993 for evaluation of <br /> site closure <br /> Confirmation soil sample borings were performed on February 2 , <br /> 1994 Field screening of the samples obtained from these borings <br /> indicated that some petroleum range hydrocarbons stall existed in <br /> the soil beneath the site Subsequently these borings were <br /> converted into vapor recovery wells VSB13 , VSB14 and VSB15 The <br /> VES was not turned on again until after completion of quarterly <br /> ground water sampling on February 16 , 1994 At that time MW5 , <br /> VSB13 , VSB14 and VSB15 were connected to the VES manifold and the <br /> system was restarted Samples from the VES obtained on February <br /> 21, 1994 indicated that only 1 65 pounds of hydrocarbons were <br /> being removed by the VES per day From February 16 thru March <br /> 23 , 1994 an estimated 33 pounds of gasoline range hydrocarbons <br /> had been removed for a 0 9 pounds per day removal rate, and from <br /> March 23 -July 21, 1994 an estimated 97 pounds was removed for a <br /> 0 8 pound per day removal rate (97 lbs/120 days) Presently, <br /> July 21, - November 7, 1994 , an estimated 117 pounds have been <br /> removed for approximately one pound per day removal rate (117 <br /> lbs/109 days) Total gasoline range hydrocarbons removed <br /> through November 7, 1994 by vapor extraction are 18 , 439 pounds or <br /> 2950 gallons , see Table 3 and Vapor Recovery Summary Charts - <br /> Figures 5, 5A, 5B and 5C <br /> Vacuum Influence <br /> Vapor recovery has removed the lighter fractions of gasoline <br /> range (through ethylbenzene and most of the Xylenes) petroleum <br /> hydrocarbons from the soil and has greatly reduced the petroleum <br /> hydrocarbons dissolved in the ground water beneath this site <br /> Figure 3A represents the vacuum influence generated from the <br /> vapor recovery system, as measured on October 12 , 1994 <br /> System Operation: <br /> Prior to turning the system off on December 30 , 1993 a flow rate <br /> of 51 cubic feet per minute was maintained by the two blowers <br /> that are placed in series, that exhaust through 2 (in series) 110 <br /> page4 <br />