ARCHIVED REPORTS_REMOVAL ACTION COMPLETION REPORT

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Draft Removal Action Completion Report Neighborhood C, Mountain House,CA Page 4 3.2.3 Contaminant Control Appropriate measures were implemented to ensure contaminant control. The primary mechanism of unwanted contaminant movement was anticipated to be wind-blown fugitive dust. The Dust Control Plan in the RAW identified measures to be taken to control fugitive dust and associated contaminant migration. Contingency contaminant control measures are described in the RAW were not required. Air monitoring was conducted at property fenceline locations and within the exclusion zone according to the Air Monitoring Plan. Equipment used to move contaminated soil was decontaminated at the end of designated use by removing soil within the entombment trench. Due to the location of the designated meeting area and temporary equipment storage, some of the equipment used to move contaminated soil was temporarily stored at the laydown area during worker breaks without being decontaminated. As a result, the haul route and laydown area required scraping at the conclusion of contaminated soil movement to remove fugitive waste soil. Additional confirmation samples were subsequently collected as discussed in Section 4.2.1. 3.2.4 Permits and Plans All necessary permits and regulatory approvals were obtained prior to the implementation of removal action activities. Draft amendment to the Voluntary Cleanup Agreement (VCA), dated October 4, 2013 was sent to the DTSC. The DTSC issued the fully executed amendment to the VCA on October 11,2014. DeSilva Gates obtained dust control permits from the San Joaquin Valley Air Pollution Control District. 3.2.5 Field Documentation The Professional Geologist and Air Monitoring Officer maintained field logbooks during the removal action activities. Field observations, on-Site personnel, equipment used, and other project information were documented in the logbooks. Copies of the field logbooks are included in Appendix B. 3.2.6 Chain-Of-Custody Records Chain-of-custody forms were used to document sample collection and the shipment of samples to the laboratory for analysis. All sample shipments were accompanied by a completed chain-of-custody form. If multiple containers/coolers were sent to a laboratory on any single day, the chain-of-custody forms included in each cooler was for only the included samples. The chain-of-custody forms identified the samples shipped and maintained the custodial integrity of the samples.The samples were considered to be in the custody of the sampler or last custodian until received by the laboratory. Chain-of-custody procedures are discussed in the Quality Assurance Project Plan (QAPP) in the RAW. Chain-of-custody forms are included with the laboratory analytical results in Appendix C. 3.2.7 Photographs Photographs were taken at the Site for the excavation areas, sample locations, and other areas of interest. The photographs were used to verify information written in the field logbook. Photographs were often noted in the logbook when they were taken. Photographs are included in Appendix B. 3.3 TRENCH EXCAVATION The entombment area within the proposed Great Valley Parkway north of the dieldrin removal area was excavated in preparation for deposition of waste soil. The RAW indicated that the entombment area would be excavated to a depth of six to eight feet below proposed final grade level. In variance from the RAW, the actual depth within the entombment area was 16 to 18 feet below proposed final grade. This was due to the earthwork contractor's decision and operational concerns, since the removal action was conducted in concert with mass grading operations for the entire Neighborhood C. Soil removed from the