Laserfiche WebLink
' Ms Mary MeaYs Page 2 <br /> September 11, 1997 <br /> As you recall, oxygen-regenerating compound (ORC) socks were previously <br />' installed within eight wells to enhance biodegradation of TPH and associated <br /> compounds (BTEX) These ORC socks were removed from each well prior to <br /> sampling The ORC socks were replaced with new socks during the May 1997 <br />' sampling"event <br />' GROUND WATER FLOW PATTERNS <br /> December 1996 <br /> Ground water elevation data for the December 1996 monitoring event are <br />' presented in Attachment A and on Figure 2A Comparison of these water levels <br /> to previous monitoring events indicates that these measured levels are somewhat <br /> anomalous These anomalous measurements may reflect impacts due to ORC <br />' sock removal During this event, the ORC socks were removed and certain wells <br /> were immediately purged and sampled during the first day Water level <br /> measurements were delayed until the following day to allow the water table to <br />' recover prior to measuring water levels, however,based on the measurements, <br /> we believe that an overnight recovery period was not sufficient <br /> May 1997 <br /> To lessen the impacts of ORC removal (e g to avoid anomalous water level <br />' measurements as above), the ORC socks were removed three days before <br /> collecting water level measurements Ground water elevation data for the <br /> May 1997 monitoring event are presented in Attachment A and contoured on <br />' Figure 2B As observed on this figure, the ground water flow direction is <br /> generally to the south, with a slight mounding in the immediate vicinity of <br /> Former Tank#2 Ground water and flow direction and water level fluctuations <br />' observed during this event are consistent with observations made during <br /> previous sampling events <br /> ANALYTICAL RESULTS <br />' Samples from all ten wells were analyzed for TPH(g) and TPH(d) by USEPA <br /> Method 8015 modified and for BTEX compounds using USEPA method 8260 <br /> ' Samples from all ten wells were also analyzed for a suite of ground water quality <br /> parameters to evaluate the effectiveness of the ORC process Samples from four <br /> wells (MW-4, MW-5, MW-1A, and MW-2A) were also analyzed for heterotrophic <br />' plate counts The water quality and plate count results were analyzed for <br /> comparison to the baseline conditions established during the third quarter 1996 <br /> monitoring event, they will not be included during every future monitoring <br /> event <br />