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I FIELD METHODS AND PROCEDURES HEALTH AND SAFETY PLAN Field work performed by ENSR and ENSR's subcontractors at the site is conducted according ' to guidelines established in a Health And Safety Plan (HASP) The HASP is a document that describes the hazards that may be encountered in the field and specifies protective equipment, work procedures and emergency information ENSR and its subcontractors are briefed on the contents of the HASP prior to initiating field work Locating Underground Utilities Prior to commencement of any work conducted below surface grade, the location of the borings is marked with white paint as required by law An underground locating service such as ' Underground Service Alert (USA) is contacted The locating company contacts the owners of the various utilities in the vicinity of the site to mark the locations of their underground utilities DRILLING AND SOIL SAMPLING Hollow Stem Auger Soil Borings Soil borings and soil sampling are performed under the direction of an ENSR geologist The soil borings are advanced using a truck mounted hollow-stem auger drill rig ' To reduce the chances of cross-contamination between boreholes, all down hole drilling equipment is steam-cleaned between each boring To reduce cross-contamination between samples, the split-spoon sampler is washed in soap solution and double rinsed between each sampling event Soil sampling beyond 5 feet bgs is conducted in accordance with ASTM 1586-84 Using this fprocedure, a 2-inch outside diameter split spoon sampler or a 2 inch inside diameter California - type sampler is driven into the soil by a 140-pound weight falling 30 inches After an initial set of 6 inches, the number of blows required to drive the sampler an additional 12 inches is known as penetration resistance, or the "N" value The N value is used as an empirical measure of the relative density of cohesionless soils and the consistency of cohesive soils ' Continuous Core Sampling Soil sampling beyond 5 feet bgs is conducted in accordance with ASTM 1586-84 Using this procedure, a 4-inch outside diameter split spoon sampler or a 4 inch inside diameter California - type sampler is driven into the soil simultaneously and at the same depth as the drill bit advances As these tools are advanced, the sampling barrel collects the sample This sampler is then retrieved while the hollow stem augers remain in place, protecting the integrity of the hole A new sampler is lowered into place, and advanced further to collect the next sample interval This process continues until a desired depth has been reached