ARCHIVED REPORTS_XR0007889 - Laserfiche WebLink

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Ms Mary Meays Page 7 March 2, 1994 structure Further soil excavation from these areas to remove impacted soils is impractical and would necessitate demolition of the buildings SOIL AERATION Approximately 1,900 cubic yards of soil were excavated from both Sites 1 and 2 and stockpiled onsite for aeration Soil excavation and stockpiling was completed on 25 October 1993, the soil aeration began the same day The aeration pile was covered with 6 mil polyethylene sheeting at all times, except when adding or removing soil and was secured inside a padlocked fence. A conventional tractor with a disc-tilling attachment was used to aerate the soil for a total of 16 days The rate of soil tilling for Sites 1 and 2 was 60 cubic yards per day and 600 cubic yards per day, respectively The soil aeration task was conducted by ERM and Sunriver between 25 October 1993 and 15 November 1993 The aerated soil was sampled for post treatment confirmation on 13 December 1993 by ERM under San Joaquin County's supervision Twelve confirmation samples were submitted to Anametrix Laboratory of San Jose, California (a state-certified laboratory) for TPHg analysis by EPA Method 8015- Modified and for BTEX by EPA Method 8020 The analytical results confirmed that the cleanup goals (100 ppm TPHg and 1 ppm BTEX total) for the soil were attained and no further aeration was needed A letter describing the soil aeration process and the post treatment confirmation data was sent to the Unified Air Pollution Control District on 29 December 1993 (see Appendix B) DISPOSAL OF AERATED SOIL The treatment of the TPH-impacted soils from both sites by aeration was successfully completed and cleanup goals were attained The confirmation sample analytical results indicated that all chemical concentrations were below the detection limit of the analytical method We therefore request that the County grant clearance to spread the treated soil along the northeast corner of the property as proposed in the Final Remediation Plan SITE CLOSURE The soil excavation and aeration activities conducted at both sites successfully remediated TPHg-impacted soils to achieve the cleanup goals The soil remediation via excavation was completed to the extent possible since additional excavation beneath the buildings would have been impractical and would necessitate the demolition of the site buildings We propose to leave the residual TPH-impacted soils underneath the buildings in place since they pose no significant threat to human health and the environment or the local ground water quality In addition, we believe the potential impacts to ground water posed by the residual soils are not significant since the residual TPH