Laserfiche WebLink
0.0 <br /> V <br /> V <br /> 1.0 INTRODUCTION <br /> On behalf of the San Joaquin County Facilities Management Department (responsible party and <br /> property owner), Ramage Environmental, Inc. has prepared this Work Plan, Vapor Intrusion <br /> "~ Assessment for submittal to the San Joaquin County Environmental Health Division (EHD) and to <br /> the Central Valley Regional Water Quality Control Board (RWQCB). This document also includes <br /> the results of quarterly groundwater monitoring, sampling and analysis for the first quarter of 2007. <br /> 1.1 Site Location and Description <br /> The site is a government vehicle parking area on the east side of the county courthouse, located <br /> at 222 E. Weber Avenue in Stockton, California (Figure 1). The parking area site is approximately <br /> 12 feet below street grade, and is accessed by a ramp on the west side of San Joaquin Street, <br /> approximately 150 south of East Weber Avenue. A former 10,000-gallon gasoline underground <br /> storage tank (UST) and a single former gasoline dispenser existed at the site (Figure 2). <br /> 1.2 Previous Work <br /> 1.2.1 UST System Removal <br /> On August 30, 1996, Fisch Environmental removed the UST system. According to the EHD <br /> inspection notes, the tank appeared to be in good condition, but the underground piping was <br /> pitted, rusted, and disintegrating at the joints. EHD noted gasoline odor in the excavation. <br /> Fisch Environmental collected two soil samples from beneath the north end and one soil sample <br /> from beneath the south end of the former UST, two soil samples from beneath the former <br /> underground piping (P1 and P2), and a single soil sample from beneath the former dispenser <br /> (P3). The soil sample locations are shown on Figure 2. <br /> Total Petroleum Hydrocarbons (TPH)-as-gasoline, toluene, ethylbenzene, and xylenes were <br /> detected in the soil sample collected from beneath a disintegrating joint in the underground piping <br /> (P1), and all three soil samples collected from beneath the former UST. Benzene was only <br /> detected in the soil sample collected at 13 feet from beneath the north end of the former UST, and <br /> methyl tertiary butyl ether(MTBE) was only detected in the soil sample collected at P1. The other <br /> soil samples did not contain detectable concentrations of gasoline compounds. The soil sample <br /> analytical results are summarized in Table 1. <br /> 4 <br />