Laserfiche WebLink
DUDEK <br />this, it is likely that the regulatory agency would require additional investigation to evaluate appropriate <br />mitigation methods for the proposed land use change. <br />Work Plan <br />Dudek will prepare a site -specific work plan for the investigation in general accordance with ASTM <br />Standard E1903-19 under the supervision of a Professional Engineer or Professional Geologist <br />licensed in California. The work plan will include a statement of objectives, site history, scope of work, <br />proposed sampling locations, target analytes, and a schedule. Dudek will submit the draft work plan to <br />the City for review. Following the City's approval, Dudek will submit the work plan to the appropriate <br />regulatory agency. Work will not commence until the regulatory agency approves the work plan. <br />Pre -field Activities <br />Dudek will prepare a site -specific Health and Safety Plan describing safety aspects of the work to be <br />performed at the site. The Health and Safety Plan will be prepared in compliance with the Occupational <br />Safety and Health Administration regulation 29 CFR 1910.120. <br />Dudek will contact an Underground Service Alert prior to the commencement of field work to mark <br />underground utility locations (in the public right-of-way). Dudek field staff will clearly mark each <br />proposed boring location in white paint prior to contacting the Underground Service Alert. Dudek will <br />contact a private utility locator to clear the potential boring locations of subsurface utility conflicts within <br />the site boundary. <br />Dudek will obtain a permit from the Orange County Health Care Agency for a boring/probe survey. <br />Subsurface Investigation <br />The scope of the subsurface investigation includes the advancement of soil borings, which will be <br />converted into temporary soil vapor probes. Dudek will collect soil vapor samples to evaluate remaining <br />impacts from the former gas station. <br />Up to eight borings will be advanced to a total depth of 10 feet below ground surface using direct push <br />technology. The soil will be logged and screened using a photoionization detector. Temporary soil vapor <br />probes will be installed at each boring location. Soil vapor samples will be collected at 5 feet and 10 <br />feet below ground surface at each of the probe locations; if saturated soils are encountered, probe <br />sample depths may be adjusted. <br />A tracer gas compound will be used to test for leaks around the temporary soil vapor probe penetration <br />seal at the ground surface and within the sampling system. A default of three purge volumes will be <br />extracted prior to sampling from the probe locations. The soil vapor samples will be collected in <br />accordance with the Department of Toxic Substances Control (DTSC) guidance and analyzed by a <br />State of California Certified analytical laboratory for volatile organic compounds by U.S. Environmental <br />Protection Agency (EPA) Method 8260B using a mobile analytical laboratory. <br />At the end of the sampling event, the soil boring locations will be resurfaced and matched to the existing <br />ground surface. Drilling equipment will be appropriately decontaminated before the commencement of <br />any drilling activities and in-between boreholes. Dudek assumes that no waste will be generated during <br />the sampling. Dudek also assumes that the field work will be completed in one day, refusal will not be met <br />in the borings, and that the site and proposed sample locations are accessible. <br />Various Environmental Services Sample Project Budgets 4 <br />