Laserfiche WebLink
L04%Tc <br /> A S S O C I A T E S I N C <br /> I,. <br /> Summary Report of <br /> L. Groundwater Monitoring Well,Installations <br /> _ g <br /> Fire Station No.3 <br /> 1116.First.Street <br /> Stockton,:California <br /> ATC Project No. 62574.0005 <br /> L, 1.0 INTRODUCTION <br /> ATC Associates Inc. has prepared this letter report on behalf of the City of Stockton Public <br /> L Works Department to summarize the installation of groundwater monitoring wells at the City of <br /> Stockton Fire Station No. 3 (Figure 1).. The, purpose of the groundwater monitoring well <br /> 1i installations was to evaluate the vertical and horizontal extent.of impacted soil and groundwater <br /> in the vicinity.of the former underground storage tank (UST) and evaluate the groundwater <br /> gradient at the site. This work .was done at the request of San Joaquin.County Public_Health <br /> Services, Environmental Health Division (PHS/EHD). The findings_ of the subsurface <br /> investigative stud are summarized in the following report. <br /> g Y g P <br /> 1.1 Site Location <br /> The site is located on the south side of First Street and the east side of Union Street in Stockton, <br /> California, as shown on Figure 1. The location is primarily-a commercial and residential area. <br /> The site is currently occupied by the City of Stockton Fire Station No. 3. - <br /> 1.2 Background <br /> One gasoline-UST of unknown size, and all associated piping"and dispensing equipment were <br /> removed and transported from the site. Laboratory analysis of soil samples collected from. <br /> beneath the former UST location indicated the presence of detectable concentrations of total <br /> petroleum hydrocarbons. After the tank was.removed,the area of the former tank was backfilled. <br /> Following tank removal activities, four soil borings:(SP-1 through SP-4) were advanced in the <br /> immediate vicinity of the former UST. Analytical results indicated that. soil impacted with <br /> petroleum hydrocarbons extended to approximately 28 feet below ground surface (bgs). The <br /> approximate locations of the former,UST and soil borings are shown on Figure 2. <br /> On July 20, 1998, Advanced GeoEnvironmeintal Inc. (AGE) supervised,the advancement of one <br /> soil boring-(MW-1) through the former.UST excavation to a depth of 65 feet bgs. The boring <br /> was completed as a two-inch diameter monitoring well screened from 45 to 65 feet bgs. <br /> ' Analytical results of soil samples_indicated the presence of petroleum hydrocarbons at 20 feet <br /> wA16393Veportslsumi.doc 1 <br />