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CAMBR A STANDARD FIELD PROCEDURES FOR ENVIROCORE® SAMPLING This document describes Cambria Environmental Technology's standard field methods for Envirocore'soil and groundwater sampling These procedures are designed to comply with Federal, State and local regulatory guidelines Specific field procedures are summarized below Objectives Soil samples are collected to characterize subsurface lithology, assess whether the soils exhibit obvious hydrocarbon or other compound vapor odor or staining, estimate groundwater depth and quality and to submit samples for chemical analysis Soil Classification/Logging All soil samples are classified according to the Unified Soil Classification System by a trained geologist or engineer working under the supervision of a California Registered Geologist (RG) The following soil properties are noted for each soil sample • Principal and secondary grain size category(i e , sand, silt,clay or gravel) • Approximate percentage of each grain size category, • Color, • Approximate moisture content, • Observed odor and/or discoloration, • Other significant observations(i e ,cementation,presence of marker horizons,mineralogy),and • Estimated permeability Soil Sampling The Envirocore'(dual-tube)system consists of a segmented casing with an internal sampler which is driven hydraulically into the subsurface The casing and the sampler are driven simultaneously in three-foot increments Continuous sample cores are collected by the sampler in 1 5-mch diameter sample tubes which are either 6-inch long stainless steel or 3-foot long butyrate The ground surface immediately adjacent to the boring is used as a datum to measure sample depth The horizontal location of each boring is measured in the field relative to a permanent on-site reference using a measuring wheel or tape measure Drilling and sampling equipment is steam-cleaned or washed prior to drilling and between borings to prevent cross-contamination Sampling equipment is washed between samples with trisodium phosphate,Alconox® or an equivalent EPA-approved detergent, and double rinsed with de-ionized water Hydrocarbon Field Screening When hydrocarbons are a chemical of concern, soil samples are field screened for the presence of hydrocarbon vapors After a soil sample has been collected, soil from the remaining tubing is placed inside a sealed plastic bag and set aside to allow hydrocarbons to volatilize from the soil After ten to fifteen minutes, a portable GasTecha or photoionization detector measures volatile hydrocarbon vapor concentrations in the bag's headspace, extracting the vapor through a slit in the plastic bag The measurements are used along with the field observations,odors,stratigraphy and groundwater depth to select soil samples for analysis