REMOVAL_2020 - Laserfiche WebLink

Home Browse Search

Broadbent & Associates, Inc. OWS System Decommissioning Report Chico, California Pilot Flying J Travel Center #618, Ripon, California March 11, 2020 Page 4 8 . 0 DISCUSSION An oil water separator OWS system composed of a 4, 000-gallon 3 -stage concrete unit with attached 1, 000-gallon UST was decommissioned by JCGI in January 2020 . The 4, 000-gallon concrete 3 - stage separator was filled with cement slurry and abandoned in - place . The UST was exhumed and transported for off-Site disposal . Two ( 2 ) compliance soil samples were collected from beneath the UST and analyzed per SJCEHD permit requirements . Comparison of analyte detections to San Francisco Bay Regional Water Quality Control Board ' s Environmental Screening Levels ( ESLs ) indicate that soil detections are below commercial ESLs for analyzed constituents . Two ( 2 ) soil samples were collected from the approximately 50- cubic yards of overburden pea gravel excavated from above and around the system and were analyzed per SJCEHD permit requirements . Stockpile samples were found to contain low to moderately low concentrations of DRO and ORO and an assortment of metals at concentrations typical of background levels for soils in California . The stockpiled tank overburden was subsequently transported for off-Site disposal . The former tank excavation was backfilled with imported clean fill and compacted to 95 percent relative compaction from grade to three ( 3 ) feet bgs and 90 percent relative compaction from to the total depth of excavation . Review of laboratory analytical results for tank closure assessment samples T1 and T2 did not indicate the presence of residual hydrocarbon mass associated with decommissioning the OWS or the UST at PFJ # 618 . Based on this information and that the primary source area ( OWS System ) has been removed , no further action is recommended at this time . 9 . 0 LIMITATIONS This document has been prepared for the exclusive use of Pilot Travel Centers, LLC . The findings presented in this report are based upon the observations of Broadbent field personnel , points of investigation and results of laboratory tests performed by Alpha Analytical of Sparks, Nevada . Services were performed in accordance with the generally accepted standard of practice at the time this report was written . No warranty, expressed or implied, is intended . It is possible that variations in the soil or groundwater conditions could exist beyond the points explored in this investigation . Also, changes in site conditions could occur at some time in the future due to variations in rainfall , temperature, regional water usage or other factors .