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Site History
<br /> T4� p oP rty N10 04-449'CA
<br /> A capy of SECOR's "(quarterly Monitoring Report� September 1997"dated Oct
<br /> to the appropriate regulatory agencies on October 16, 1997
<br /> ober i 3, 1997, was forwarded
<br /> rth
<br /> ples w
<br /> October 13, 1997, samere collected from each of the groundwater m
<br /> MW-1 p} at the subject site by a representative of SEGOR Prior to groundwater
<br /> , the
<br /> was measured to evaluate elevation, flow direction, and gradient Groundwater
<br /> wells (MW 1 through
<br /> in the center of the site was encountered in the wells at depths of 66 40 fee depth to water in each well
<br /> surface Fr which appeared to converge
<br /> Free product was not encountered in any of the wells t to 87 89 feet below ground
<br /> Since the July 1997 sampling event, groundwater elevation decreased in MW-1
<br /> 0 34 feet to 1 14 feet, and groundwater elevation increased in MW-2, MW-3 M _
<br /> 0 25 feet, 0 42 feet,
<br /> and 0 03 feet, respectively and MW-4 through Ml++V 9 by
<br /> Y These changes resulted in an overall average decrease I groundwater elevation
<br /> Of 0 42 feet across the site Groundwater flow direction has
<br /> typically been to the southwest on the subject
<br /> site, however, a convergence in groundwater flow was indicated in the October sampling event Chang
<br /> flow direction and gradient are most likely a result of seasonal variation
<br /> Analyses identified elevated concentrations of hydrocarbons in the samples toile
<br /> cted Ppb gasoline, 921 ppb benzene, 8,49p
<br /> 1675 ppb gasoline, 91 4 ppb benzene, 6 6 toluene, 1,400 Ppb ethylbenzene, and 820 from
<br /> MW-1 (35,500
<br /> (2,820 ppb gasoline, 246 ppb benzene, 72 ppb toluene, 907 ppb ethYibenzene and 150 pp xylenes}, MVy 2
<br /> ppb xylenes), MW_3
<br />. (2,090 ppb gasoline, 138 ppb benzene, 229 ppb ethylbenzene, and 933
<br /> MW-6 (247 ppb gasoline, 26 ppb benzene. 3 4b toluene, 28 4 ppb ethylbenzene, and 291 ppb xylenes}, MW-5
<br /> Lower concentrations of hydrocarbons were foundbm the samples collected from ppb xylenes), and
<br /> ppb ethylbenzene, and 46 1
<br /> 3 7 ppb benzene, and 0 8ppb xylenes)
<br /> benzene), and MW-9 103 ppb xylenes), MW-7 (73 ppb gasoline MWS (225 ppb gasoline,
<br /> samples collected from ppb gasoline and 2 5 ppb benzene } MW$ (52 ppb gasoline and i ppb
<br /> -10
<br /> however, rt was not detect n any of the other samples in the benzene)
<br /> le rocarctedbons were not detected in the
<br /> p collected from MW-4 at 10 g ppb
<br /> The highest concentrations of hydrocarbons appear to remain onsite in the vicinity o
<br /> 9 and MW-3) When compared to the July 1997 sampling event, groundwater con
<br /> MW-1 and MW-W5hen
<br /> they remained relatively unchanged in the remainder o ty f the pump islands ed(MW-
<br /> groundwater decreased in
<br /> A copy of SECOR's " f the wells
<br /> to thea Quarterly Monitoring Report_ December 1997"dated January 28, 1998, was forward
<br /> appropriate regulatory agencies an February 2, 1998
<br /> ed
<br /> Fir a r 998
<br /> Can January 27, 1998, samples were clollected from each of the groundwater
<br /> 4a wary 199
<br /> MW 10) at the subject site by a representative of SECOR Prior to Purging, the
<br /> endepth wells water
<br /> in a through
<br /> was measured to evaluate elevation, flow direction, and gradient Groundwater with a s
<br /> direction at a hydraulic gradient of 0 02 ft/ft was encountered to the wells at d depth to water in each well
<br /> feet below ground surface Free product was not encountered in any of the wells southeasterly flow
<br /> depths of 67 88 feet to 82 18
<br /> Since the October 1997 sampling event, groundwater elevation increased in MW-2
<br /> and 5 26 feet, respectively, while groundwater elevation decreased in MW-1, MVV-3
<br /> through MW-10 by 0 27 feet to 154 feet Changes in groundwater depth, flaw direction,and MW 5 by 0 g6 leaf
<br /> most itkely a result of seasonal variation , MW-4, and MW-5
<br /> and gradient are
<br /> is
<br />
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