ARCHIVED REPORTS_ENVIRONMENTAL SITE ASSESSMENT ADDENDUM

Home Browse Search

SECTION V. CONCLUSIONS AND RECOMMENDATIONS Pinnacle Environmental, Inc. (PEI) was retained by the Industrial Drive Receivership Estate (Client), to expand the original scope of a Limited Phase II Environmental Site Assessment (Limited Phase II) of a property at 248 Industrial Avenue, Stockton, California 95206. The additional scope of work for this Limited Phase II was conducted in accordance with the July 31, 2012 proposal. The additional scope consisted of 8 soil borings of which 7 were converted to temporary groundwater monitoring wells. Thirty-one soil matrix and seven groundwater samples were collected and analyzed for VOCs and TPH-ccid. The RECs identified relevant to this report include whether the subsurface in limited areas at the subject property has been impacted by volatile organic compounds (VOCs) associated with previous activities at the Site. The findings are discussed below for each of the major areas evaluated: Septic System Area This Limited Phase II has found that concentrations of benzene and 1,2-dichloropropane (Table 1) exist above MCLs in groundwater samples associated with the septic system (borings SB-1001, -1002, -1003, and SB-1006, Figure 2). Therefore, PEI is of the opinion that the septic system represents a source area that continues to impact the subsurface. UST Graves Observations made during excavations of two UST graves (PEI, 2012a) are that the graves were impacted by petroleum hydrocarbons to depths of approximately 12 feet bgs. However, the current investigation found no compounds of concern detected in soil or groundwater beneath either of the two former UST locations. PEI is of the opinion that these areas require no further investigation or remedial action. Although, future excavation in the area may require worker safety precautions should areas of impact be encountered. Inside the Building Laboratory analyses of soil vapor samples collected during the investigation of the northernmost concrete patch inside the building showed TCE was present in soil vapor at a concentration of 0.13 ug/L, more than 10 times lower than the California Human Health Screening Level (CHHSL) for industrial/commercial land use. Further, the current investigation found no compounds of concern detected in soil samples from beneath this patch. Based upon these results, PEI is of the opinion that these areas require no further investigation or remedial action. Addendum to Limited Phase II Environmental Site Assessment Report Pinnacle Environmental,Inc. 248 Industrial Avenue,Stockton,CA 95206 Page 10