COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

July 1, 2011 AEI Project No. 297937 Page 2 of 5 included the operation of a fixed waste treatment system onsite, and wastewater streams included chromium waste and heavy metals. In 1997, the Department of Toxic Substances Control (DTSC) and the EHD performed sampling at the site (Attachment A). Several of the plating tanks, plating systems and the water treatment equipment present on site at that time were sampled. Sampling results indicated hazardous materials, heavy metals, and chromium remained in the plating tanks, rinse tanks and evaporative tanks. The two soil samples collected outside the building, reportedly near a drain spout at the northeast corner of the building, identified chromium impacts above regulatory thresholds. II Geology and Hydrogeology According to the Phase I ESA, soils in the area are characterized as alluvium, lake, playa and terrace deposits; unconsolidated and semi-consolidated. Soils of this area consist mostly of non- marine deposits. No site-specific information pertaining to the depth to groundwater at the site was available; however, recorded groundwater depth data for the area identifies groundwater within 55 to 60 feet below ground surface (bgs). The anticipated groundwater flow direction based upon topography is southwest towards French Cam Slu which is located approximately 2 miles southwest of the property. III Scope of Work The scope of work proposed consists of the drilling and logging of a total of seven (7) soil borings at the property with a truck-mounted direct push drilling rig (Figure 2). The proposed boring locations, depths, and sample collection was based on the sampling by the DTSC and EHD (Attachment A). The purpose of each boring is listed below: Boring Purpose SB-1 Proposed inside near the location of sample NKL019. SB-2 Proposed inside near to the locations of samples NKLO17 and NKL018. SB-3 Proposed inside near to the locations of samples NKL008 and NKL009. SB-4 Proposed inside near to the location of sample NKL006. SB-5 Proposed inside near to the locations of samples NLK003 through NLK005. SB-6 Proposed outside in the northeast corner of the property near or in the direction of the presumed location of samples NKL021 and NLK022. SB-7 Proposed outside along the east side of the building near or in the direction of the presumed location of samples NKL021 and NLK022. Borings SB-1 through SB-5 will be advanced to a planned depth of approximately 8 feet bgs for the collection of soil samples. It is anticipated that one (1) soil sample from each boring will be analyzed. Boring SB-6 and SB-7 will be advanced to a planned depth of approximately 60 feet bgs or to first encountered groundwater, whichever is shallower, for the collection of soil and