COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

6.2.1.1 Structures The house and barn foundations were partially sampled as previously described in Section 3.2.1 and Section 4.0. This workplan proposes to determine the extent of the contamination found during the previous initial sampling events. Surface step out samples for lead were conducted but samples were not collected below the surface level. This workplan proposes to collect ten two foot bgs samples from around the structures at the approximate locations identified in the figures from the previous sampling events. These samples will be analyzed for lead. Additional surface step out samples will be collected and analyzed for OCP's. These ten foot step out samples will be located in the cardinal directions. 6.2.1.2 Garage Interior Due to the unknown uses of the garage and the dirt floor it will be sampled for TPH-g, TPH-MO and TPH-D, lead, and OCP's. At least 2 random surface soil samples will be collected. If evidence of staining is discovered, those areas will be specifically sampled for TPH-g,TPH-MO and TPH-D. 6.2.1.3 Former Barn The exact location of the former barn that was removed in the 1990's is unknown. The approximate location of the barn will be located using historic aerial photographs. Ten equally distributed samples will be collected over a grid superimposed over the area of the former barn. The grid will be larger than the former barn (as determined from aerial photographs) to capture any potentially impacted soil spread during the demolition of the barn. The ten sample points equate to two sample points per side and two interior sample points per DTSC's latest lead/OCP guidance. These sample points will be analyzed for lead, OCP's and arsenic. Additional deeper samples will be collected and held by the lab, pending surface sample results. 6.2.1.4 Agricultural Field The agricultural field (ag field) will be sampled per the Ag Guidance and DTSC Project Manager's recommendations. Sampling will be comprised of 4:1 composite OCP samples (16 total sample points),four discreet CAM 17 surface samples,four CAM 17 background samples further described in Section 6.2.2 below, and four discreet arsenic samples. Each of these samples will be collected from locations spaced on half-acre centers. 6.2.1.5 Potential Fill Material Area The 2003 Environmental Site Assessment for this property identified potential fill material on the southern portion of the property. The school Site boundaries have changed since that report was written and the fill area no longer appears to be within the boundaries of the current school Site. However,further analysis of this area near the southern boundary of the Site will be completed. This area is being sampled for OCP's as part of the ag field sampling described in Section 6.2.1.4 above. In addition, two PCB Preliminary Environmental Assessment Workplan Proposed Podesta Ranch Elementary School December 4,2006 Page 10 of 27