Laserfiche WebLink
_ — - `. =rr. � y."€� j-yyf.�'. ' y ? �; - t. ""'raaC w " <br /> 1 <br /> NMI <br /> September 13, 1991 <br /> Unocal Station No. 6981, Stockton, California <br /> a, o Submit one sample from the bottom c " teach boring for permeability, sieve, <br /> and hydrometer analyses to evaluate the physical properties of the soil. These <br /> analyses will be used �oevaluate <br /> untcred aE1er an 51 feetcluitard is below surf rce grade.reseni below the <br /> ground water previous y- <br /> 1 <br /> o Collect four soil samples from the drill cuttings. These samples will be <br /> :omposited into one sample and analyzed for the above constituents and for <br /> to,al lead. <br /> o Store the cuttings in a hazardous waste bin onsite until cuttings are disposed <br /> of at an appropriate facility. <br /> o Evaluate disposal options of soil and water, apprise Unocal of these options, <br /> and work with Unocal's subcontractors to remove and dispose of soil and <br /> water. <br /> o Transport a portable vapor-extraction system to the site. <br /> o Conduct a vapor-extraction test (VET) to obtain vapor samples and vacuum <br /> pressure and flow rate information. We will use the data to evaluate whether <br /> vapor extraction is a feasible remediation alternative. <br /> o Submit vapor samples to a h,boratory for analyses of TPHg and benzene, <br /> toluene, ethvlbenzene, and total xylene isomers BTEX. <br /> o Survey the additional wells with respect to mean sea level. This data will be <br /> used to evaluate the ground-water flow direction and gradient beneath the <br /> site. <br /> a Interpret field and laboratory data of soil and water sample.' to evaluate if <br /> hydrocarbon constituents in soil and ground water beneat'1 the site are <br /> delineated. We will discuss our interpretation of the data with Unocal and <br /> make recommendations. <br /> a Prepare Problem Assessment Report(PAR) summarizing our field methods, <br /> laboratory procedures, laboratory results, conclusions,and recommendations <br /> if the extent of residual hydrocarbons in soil and ground water is delineated. <br /> If the extent of hydrocarbons in soil and dissolved hydrocarbons in ground <br /> water is not delineated,we will prepare a status report with recommendations <br /> for additional work. <br /> ....... -- <br /> 3&03z•aw <br />