ARCHIVED REPORTS XR0001427 - Laserfiche WebLink

Home Browse Search

July 15, 1998 Page 2 were removed during demolition The site is currently an asphalt -paved parking lot owned by and servicing the Wells Fargo Bank located immediately to the south A Iimited subsurface investigation was conducted by L M Swift for Wells Fargo and is detailed in a Phase 1 Report, Addendum 1, dated March 29, 1994 The investigation included an underground electronic survey of the parking lot to determine if any abandoned USTs existed beneath the site, and exploratory borings to collect soil and groundwater samples The underground survey detected no large metal anomalies, and concluded that there were no USTs beneath the site However, hydrocarbon -impacted groundwater was detected in the northern portion of the site A Phase I Environmental Site Assessment, dated December 16, 1994, was prepared by Enviros Inc , for Unocal The site assessment concluded that twelve sites, in the vicinity of the Unocal site, have been identified as having impacted soil and groundwater However, none of these sites were identified in the immediate upgradient direction from the Unocal site Additionally, the report concluded that two former service stations were located across from the Unocal site, a former Shell Oil service station at the northwest corner of 111h Street and Central Avenue during the period of approximately 1949 to 1962, and a former service station (possibly Chevron) at the northeast corner of 11th and Central Avenue during the period of approximately 1913 to at least 1962 _ . In May 1995 nine exploratory soil borings were drilled and three groundwater monitoring wells were installed by PEG at the site Exploratory test pitting was performed and two abandoned UST's were encountered at the northern property boundary, beneath the 11 th Street sidewalk A report documenting the soil and groundwater investigation was submitted to Unocal and San Joaquin County in December 1995 On September 6, 1996, Unocal submitted a corrective action plan to address hydrocarbon -impacted soils that maybe encountered during removal of the USTs Two abandoned 550 -gallon USTs were removed in November 1996 A third UST was encountered during the removal activities and was properly abandoned in place by grout infection One groundwater monitoring well was installed in December 1996 in the location of the removed USTs to evaluate soil and groundwater quality Based on recent quarterly groundwater monitoring data collected by Gettler-Ryan from the site, depth to water is between 8 and 10 feet below ground surface (bgs) PROPOSED SCOPE OF WORK The scope of work proposed for this investigation will include the installation of two groundwater monitoring wells and one continuous core soil boring with a discrete water sample to delineate the lateral and vertical extent of hydrocarbons and solvents in the soil and groundwater A continuous core will be collected from the soil boring to investigate geological conditions on site 910-017 1 A/WPLAN