Laserfiche WebLink
CGRS, Inc. <br />METHODS AND PROCEDURES <br />Soil Borings <br />Soil sampling will be conducted in accordance with AS"fM:D 1586-87. Using this procedure, a 2-inch O.D. <br />split-spoon sampler will be driven into [he soil by a 140 pound weight falling 30 inches. After an initial set <br />of 6 inches, the number of blows required [o drive the sample an additional 12 inches, known as the <br />penetration resistance (N value), will be recorded. The N value is an index of the relative density of <br />cohesionless soils and the consistency of cohesive soils. <br />Soil Classification/Characterization <br />As samples are obtained in the field, they will be visually inspected and classified in accordance with <br />ASTM:D 1488-84. Representative portions of the samples will then be retained for further examination and <br />for verification of the various strata, the N value, water level data, and peninent information regarding the <br />method of maintaining and advancing [he boring will be provided. Charts illustrating the soil classification <br />procedure, descriptive terminology and symbols used on the logs will be provided. <br />Decontamination <br />To avoid potential transport of contaminated materials to the project site, all drilling equipment and down- <br />hole tools will be steam cleaned prior to mobilization. <br />Monitoring Well Construction <br />Monitoring wells will be installed utilizing the following general construction criteria[: <br />• borehole diameter: minimum 6.25inches; <br />• well diameter: 2 inches; <br />• estimated depth: 15 - 30 feet below ground surface; <br />• casing material: schedule 40, Flush thread PVC: <br />• well screen: 2 inch LD., 10 feet in length, 110.01 slot PVC; <br />• estimated screened interval: 5 feet above and 10 - 25 Feet below [he groundwater table; <br />• annular pack: 10-20 silica sand; <br />• protective casing: minimum 12 inch I.D., steel flush or above grade, locking cap; and <br />• annular seal. cement grout and bentonite pellets. <br />Groundwater Sampling <br />All borings where groundwater is encountered wtll he sampled from the suspected cleanest to the most <br />contaminated according to the protocols listed below. All peninent information will be recorded on a <br />sampling information furor. <br />