ARCHIVED REPORTS_XR0011735 - Laserfiche WebLink

Home Browse Search

Phase II Environmental Site Assessment Multi-Modal Station Stockton,San Joaquin County,California Page 26 6.2.1 808 E. Miner Avenue A gas station was listed in the 1940 Polk City Directory for Stockton at 802 E Miner Avenue (histone address for 808 E Miner Avenue) Based on this listing, a GPR study was conducted at the property on May 28 and 29, 2002 to evaluate the possible presence of a UST A total of 73 GPR lines traversed the property No further information regarding the gas station or possible UST removal was found An approximately three-foot by three-foot circular depression was noted at the property and an adjacent area was investigated None of the radargrams collected in the vicinity of the depression contained features of interest 6 2.2 730 E Channel Street EHD records indicated ten USTs were present at the former Stockton Metropolitan Transit District facility at 145 N Grant Street (current address 730 E Channel Street) in 1985 Two USTs were reportedly removed in 1987, but no additional information regarding the remaining eight USTs was observed in the EHD records The property was investigated on August 27 and 28, 2002, by a total of 117 GPR lines Radargrams of the property's subsurface suggest that there was some past disturbance of the soil The northwestern exterior corner of the property appeared to previously have been a bus washing area and possible bus yard A large concrete patch and four existing vent pipes suggested that this portion of the property may be the current and/or former location of one or more USTs Data collected from the large concrete patch area near the center of this portion of the property includes several possible current or • former UST locations Three additional possible USTs beyond the limits of the large concrete patch were also identified during the GPR investigation Further details regarding the results are presented in Appendix C 6.3 DIRECT PUSH BORINGS 6 3 1 Right-of--Way Laboratory analytical results indicated that only chloroform and the CAM 5 Metals were detected in soil samples collected from the right-of-way The CAM 5 Metals were all detected at concentrations below the applicable United States Environmental Protection Agency (EPA) Region IX Preliminary Remediation Goals (PRGs) and are representative of naturally occurring background concentrations Thirty-one groundwater samples were collected from borings advanced in the roadway right-of-ways at the site Low concentrations of VOCs were detected in the 26 of the 31 groundwater samples The VOCs detected in the right-of-way groundwater samples include acetone, 1,1-dichloroethene(1,1-DCE), cis-1,2- dichloroethene (cis-1,2-DCE), chloroform, 1,2-dichloroethane (1,2-DCA), tnchloroethene (TCE), toluene, tetrachloroethene (PCE), and m,p-xylene The presence of acetone and chloroform in the groundwater samples is suspect, as these constituents are common laboratory contaminants It is possible that chloroform is present in groundwater below the site, resulting as a decay product of chlorinated municipal water applied to the ground surface such as grass lawns and allowed to infiltrate to the water table over time The concentrations of VOCs detected in the groundwater samples collected in the roadway right-of-ways are below applicable California Maximum Contaminant Levels (MCLs) for drinking water, except for PCE PCE was detected above the MCL of 5 0 µg/L in two samples from N Aurora Street, immediately east of 843 E Weber Avenue These PCE detections appear to be related to a groundwater plume possibly originating at 843 E Weber Avenue(Figure 20,Appendix A) r 1 lit CONDOR