WORK PLANS - Laserfiche WebLink

Home Browse Search

ATTACHMENT A FIELD PROCEDURES Drilling Methods Before drilling begins, we will notify Underground Service Alert of 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 a mobile B-61 or similar drill rig equipped with 8-inch- outside-diameter by 4-1/4-inch-inside-diameter, continuous-flight, hollow-stem augers. The augers are steam-cleaned before use in each boring to minimize cross-contamination of the borings. The drill cuttings are stored in type 17-E, steel, 55-gallon drums or stockpiled on site and covered with plastic before disposal at an appropriate disposal facility. 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 just 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 Teflon tape and plastic caps. The samples are labeled and promptly placed in iced storage for delivery to the laboratory. SAC\N:\PJO\0805\08051520.3AL-94Virt :I A-1 Rev.0.6/8/95