Laserfiche WebLink
LV'Y' E T g <br /> 0 <br /> A S S O C I A T E S I N C <br /> Summary Report of <br />' Additional Subsurface Investigation <br /> Ripon Unified School District <br />' 304 North Acacia Avenue <br /> Ripon, California <br /> ATC Project No 13099 0001 <br />' 1.4 INTRODUCTION <br />' ATC Associates Inc has prepared this letter report, on behalf of Ripon Unified School District to <br /> summanze findings of the subsurface investigation performed at the above referenced site (Figure <br /> 1) The purpose of the subsurface Investigation was to evaluate the horizontal extent of residual <br />' Impacted soil and groundwater This work was done at the request of San Joaquin County Public <br /> Health Services, Environmental Health Division (PHS/EI D) The findings of the subsurface <br /> Investigative study are summarized in the following paragraphs <br /> 1.1 Site Location <br />' The site is located on the east side of North Acacia Avenue and the north side of Pine Street, <br /> Ripon, California, as shown on Figure 1 The location is a residential and commercial area The <br /> site Is currently occupied by Ripon Unified School District <br />' 1.2 Background <br />' In February, 1991, one 50�allon underground storage tank (UST) of unknown fuel was <br /> removed, in August, 1991,one 550-gallon unleaded gasoline UST was removed, in October, <br /> 1991, 47 feet of single wall piping was removed, and, in December, 1991, one 7,500-gallon <br /> unleaded gasoline UST was removed Laboratory analysis of soil samples collected from beneath <br /> the former USTs and piping locations indicated the presence of detectable concentrations of total <br /> petroleum hydrocarbons Discoloration of soil and a petroleum hydrocarbon odor were noted in <br /> ' the field After the tanks were removed, the areas of the former tanks were backfilled with the <br /> stockpiled material <br /> ' On April 23, 1998, a geologist from ATC Associates supervised the advancement of six soil <br /> bonngs to 21 feet below ground surface (bgs) A site plan showing soil boring locations Is <br /> ' Included as Figure 2 Soil samples were collected at five-foot intervals and grab groundwater <br /> samples were collected from each boring Samples were analyzed for petroleum hydrocarbons <br /> and elevated concentrations of petroleum hydrocarbons were detected in soil and groundwater <br /> samples <br /> w I13099Wportslsum2 doc <br /> 1 <br />