WORK PLANS - Laserfiche WebLink

Home Browse Search

Pombo Property Soil& Groundwater Sampling - (if applicable), consistency of the earth materials, pertinent soil or bedrock characteristics, and any evidence of contamination will be noted. All water-bearing zones and the depths at which they are encountered will be noted on these logs. All borings will be drilled in such a manner as to prevent cross contamination between strata. Water samples will be taken at the soil/groundwater interface (if encountered), and the borings will then be terminated with a cement and three percent (3%) Bentonite mixture. 2.2 Soil Sampling All soil sampling equipment will be thoroughly steam cleaned before and between sampling to prevent cross contamination. Relatively undisturbed soil samples will be taken at intervals of not more than five feet (5') in order to evaluate the subsurface materials. The soil samples will be taken using a Geop obe® core sampler with plastic liners. The sampler will be pushed (Direct Push Technology) continuously by the hydraulically powered, percussion system. The laboratory samples will not have headsp ce and will immediately be sealed in their liners using plastic caps. The remaining sample will be removed from its liner to be used as an aide to the on-site geologist in logging the material at that depth. Soil samples will be collected at five foot intervals for geological interpretation and laboratory analysis (1 to 2 laboratory soil samles per boring). All soil samples will be delivered, under chain of custody, to an analytical laboratory licensed by the State of California for hazardous materials work. The samples shall be analyzed for Total Petroleum Hydrocarbons (gasoline & diesel), BTX&E (Benzene, Toluene, Xylene, and Ethyl Benzene) and MTBE by method 8020. The minimum detection limits used for each analyte will be .005 mgIkg for BTX&E, 0.01 mg/Kg for the Oxygenated compounds (0.1 mg/Kg for tertiary-Butanol), 1.0 mg/Kg for gasoline, and 2.5 mg/Kg for diesel. Laboratory analyses of the Organophosphate group and Chlorinated Pesticides will be conducted on selected samples. Method 8010 will be used for the various freons. All rinse water will be removed by the driller, V&W .Drilling, Inc. Drill cuttings are not produced by this method. 2.3 Groundwater Sampling A travel blank, provided by the laboratory, will accompany the sample vials from the time they are picked up from the lab tote time they are delivered to the lab. This travel blank will be listed on the Chain o Custody, but will be analyzed only if all samples contained the same contaminants. 3