CORRESPONDENCE_2002-2010 - Laserfiche WebLink

Home Browse Search

.2. Project Objective 2.1. Data Collection Either direct push equipment or a tracked excavator will be used to conduct the site investigation to determine: 1) the thickness of the cover, 2) the horizontal and vertical extents of the disposal site, 3) chemical and physical characterization of the fill material for comparison to regulatory thresholds and 4) landfill gas screening and sampling and analysis to determine if gas migration is an issue. Sampling will be conducted under the California Code of Regulations, Title 22, section 66261.10 et seq. for characterizing hazardous waste. The CIWMB will use regulatory limits established from the California Department of Toxic and Substance Control and federal levels for evaluating the soil/ash. Detailed analytical procedures are specified in section 3.9 of this plan. Since a portion of the burn -ash may need to be disposed of to a municipal solid waste landfill under clean -closure or waste reconfiguration remedial alternatives, it will be necessary to determine if the soil -ash is considered hazardous for the purpose of handling and disposition. The data from these procedures will be used to identify lead concentrations in surface soils and subsurface burn -ash. 2.2. Project Tasks During the investigation of the Santa Fe Road site a sampling location reference grid will be established and tied to an established benchmark at the site. Relocation of planned sampling locations may be performed and the location referenced to the reference grid. Sampling at a location will entail using either direct -push equipment, e.g. Geoprobe, which will drive a sampling tool down to native soil beneath the old fill, or a tracked excavator to perform trenching through the cover and waste down to native soil (expected to be the former gravel pit bottom). Under the authoritative sampling protocol, the CIWMB field engineer may change individual sampling locations based on site-specific field conditions (including unforeseen obstructions, visible signs of contaminated soils or other factors). CIWMB anticipates that approximately 25 sampling locations will be required to adequately define the horizontal and vertical extents of the fill and cover thickness (reference figure 6). Soil samples will be screened using a GMI 422 Gas Surveyor instrument and also screened for radioactivity using portable radiation detection equipment and then sent to a State of California certified hazardous waste laboratory for analysis. The trench or hole created by either the direct push sampling equipment or tracked excavator will be screened using a GMI 422 Gas Surveyor instrument capable of measuring concentrations of methane, hydrogen sulfide, carbon dioxide, oxygen and carbon monoxide. The sampling holes will be filled with native soil and bentonite. Sampling activities are scheduled to occur in 2.3. Expected Data Chemical constituent concentration data obtained during this investigation will be evaluated to determine if additional sampling is necessary. Additional sampling may be performed if it is CIWMB 13