WORK PLANS - Laserfiche WebLink

Home Browse Search

Drilling and Sampling of Borings The four investigative borings, B-1 through B-4, will be drilled to about 30 feet in depth using direct-push hydraulically-driven soil coring equipment. For each boring, continuous soil cores will be collected to total depth in each boring in a clear plastic acetate tube, nested inside a stainless steel core barrel. After each four-foot core barrel is brought to the surface and exposed, the core will be sliced lengthwise to expose the soil core, examined, logged, and field screened for hydrocarbons by a qualified geologist using sight, smell, and an organic vapor monitor (OVM). Soil samples will then be collected from specific zones of interest using glass jars with Teflon-lined septums as follows: (1) The selected soil interval will be packed tightly into the jar, making sure that air pockets are minimized; (2) The jar will be tightly sealed with a Teflon-lined cap; and (3) The sealed soil sample will be labeled and immediately placed in cold storage for transport to the analytical laboratory under formal chain-of-custody. All coring and sampling equipment will be thoroughly cleaned and decontaminated between each sample collection by triple rinsing first with water, then with dilute tri-sodium phosphate solution, and finally with distilled water. Cleaning rinseate will be contained onsite in a sealed drum pending laboratory results. Following completion, the investigative borings will be grouted to match existing grade using cement\sand slurry. Soil cuttings generated during this investigation will be stored onsite in sealed DOT-approved containers. All coring and sampling equipment will be thoroughly cleaned and decontaminated between each sample collection by triple rinsing first with water, then with dilute tri-sodium phosphate solution, and finally with distilled water. Cleaning rinseate will be contained onsite in a sealed drum pending laboratory results. Laboratory Analysis of Soil and Water Samples Approximately 12 soil samples (three samples per boring) will be analyzed for the following parameters: USEPA Method 8015M Total Petroleum Hydrocarbons (Diesel & Motor Oil); and USEPA Method 8260B TPHg/BTEX All analyses will be conducted by a State-certified analytical laboratory with two-week turnaround on results. Preparation of Summary Report A report of findings will be prepared for submittal to Client. This report will describe all investigative methods and results, and will include graphical depictions of site geology and HVOC groundwater impacts, tabulated laboratory analytical results, and laboratory data reports and chain-of-custody records. 1090 ADAMS STREET, SUITE K, BENICIA, CA 94510 PH (707) 748-7743 FAX (707) 748-7763