Laserfiche WebLink
,1. <br /> Ms. Vicky McCartney <br /> ' Page 2 of 4 <br /> In 1965, Wilbur-Ellis Company installed a 1,000-gallon underground gasoline storage tank (UST) <br /> at the site. In 1987, the UST and associated piping were removed. Reportedly, low levels of total <br /> petroleum hydrocarbons as gasoline (TPHg) were detected in-Esoil samples collected at the time of <br /> removal. Affected soil was reportedly excavated and aerated.1 The former UST pit was backfilled. <br /> The approximate location of the former UST system is shown'on Figure 2. <br /> r <br /> In 1993, Wilbur-Ellis sold the property to H & H Engineering and Construction, Inc. A soil <br /> assessment conducted in January and February 1998 found! low levels of TPHg and benzene, <br /> toluene, ethylbenzene and xylenes (BTEX compounds) in the;soil. Petroleum hydrocarbons were <br /> found in discrete groundwater samples collected in March 1998. Additional soil and groundwater <br /> sampling, including the installation of three groundwater monitoring wells, was conducted from <br /> August through November 1998 and in June 2000. Periodic igroundwater sampling has continued <br /> since that time. In addition to analysis for TPHg and BTEX; water samples from the monitoring <br /> wells were analyzed for methyl tert butyl ether (MTBE) on five occasions between October 1998 <br /> and December 1999 and for the complete suite of gasoline oxygenate additives on two occasions. <br /> None of the target oxygenate compounds was detected. In March 2000, EHD approved a request <br /> by Wilbur-Ellis to reduce the groundwater sampling frequency to semi-annual and to discontinue <br /> sampling for fuel oxygenates and alcohols. 1;. <br /> =1 <br /> Nature and Extent of Contamination <br /> The nature and distribution of identified soil contamination appears to be consistent with a release <br /> of gasoline from the former UST system. Detectable concentrations of TPHg and BTEX were <br /> located in general proximity to the former UST system and the ratio of benzene to TPHG ranged <br /> from less than 1% to approximately 12%. ,a. <br /> In groundwater, however, benzene is the primary detectable contaminant. Toluene, ethylbenzene <br /> and xylenes have only rarely been detected in samples from the monitoring wells and "TPHg" <br /> appears to be comprised primarily of benzene. No gasoline oxygenates have been detected in <br /> groundwater. Data from the monitoring wells along with discrete samples collected from a number <br /> of borings have defined the lateral extent of groundwater contamination except to the southwest <br /> (upgradient) and the northeast (downgradient) of the release area. <br /> Soil and discrete groundwater sample analytical data are summarized in Tables 2 and 3, <br /> respectively. Historical groundwater analytical data from `the three site monitoring wells are <br /> summarized in Table 4. <br /> PROPOSED SCOPE OF WORK <br /> k� <br /> In order to further define the lateral extent of groundwater contamination, particularly upgradient of <br /> the former UST and downgradient of monitoring well MW3; Ground Zero proposes to drill and <br /> sample seven soil borings at the approximate locations shown on Figure 2. Based upon the data <br /> obtained, additional groundwater monitoring wells may be proposed. <br /> 7; <br /> q: <br /> 11GZA FSWOL 1IDATA%GROUNDZEIW-EIREPORTSIhydpuWKPLAN.doe <br /> =iE <br />