ARCHIVED REPORTS_XR0012066 - Laserfiche WebLink

Home Browse Search

FIELD PROCEDURES I COMA% Drilling Methods Before drilling begins, we notify Underground Service Alert our intent to drill so that approximate locations of underground utility lines and structures can be marked The soil borings are started by hand-augering to a depth of 5 feet to minimize the possibility of damaging underground utilities The borings are drilled with Mobile B-57 and B-61 drill ngs equipped with 8-and 10-inch- diameter, continuous-flight, hollow-stem augers The augers are steam-cleaned before each use in each boring to minimize cross-contamination of the borings. The drill cuttings were stored on and covered with plastic before disposal in an appropriate disposal facility i Soil Sampling in Borings Soil samples for analysis and identification are collected at approximately 5-foot intervals from the borings during drilling Soil samples are collected by advancing the boring to a point gust above the sampling depth, and then driving a California-modified, split-spoon sampler containing clean brass sleeves through the hollow center of the auger into the soil The sampler is driven 18 inches with a standard 140-pound hammer repeatedly dropped 30 inches The number of blows needed to drive the sampler each successive 6 inches is counted and recorded to evaluate the relative consistency of the soil Sampling equipment is cleaned between each use with an industrial soap and clean tap water The samples selected for laboratory analysis are removed from the sampler and promptly sealed in their brass sleeves with aluminum foil, plastic caps, and duct tape. The samples are labeled and promptly placed in iced storage for delivery to a laboratory certified by the State of California. Logging of Bores Soil and samples are typically collected at 5-foot intervals, the samples are identified using visual and manual methods, and classified according to the Unified Soil Classification System. Samples not selected for chemical analysis and the soil in the sampler shoe are extruded in the field for examination The texture, color, moisture, plasticity, and consistency of soil, the blow counts, and subjective evidence of hydrocarbons, such as soil staining,obvious product odor,and photoionization detector(or similar instrument)readings are noted in the field on the Logs of Borings 08o�-�0 332-7