Laserfiche WebLink
AEGIS ENVIRONMENTAL, INC. <br /> STANDARD OPERATING PROCEDURE <br /> RE. HOLLOW-STEM AUGER MONITORING WELL INSTALLATION AND <br /> DEVELOPMENT <br /> SOP-6 <br /> Boreholes for monitoring wells are drilled using a truck-mounted, hollow-stem auger <br /> drill rig The borehole diameter will be a minimum of 4 inches larger than the outside- <br /> diameter of the casing when installing well screen The hollow-stem auger provides <br /> minimal interruption of drilling while permitting soil sampling at desired intervals Soil <br /> samples are collected by either hammering or hydraulically pushing a conventional <br /> split-barrel sampler containing pre-cleaned 2-inch-diameter brass tubes A geologist <br /> or engineer from Aegis Environmental, Inc , continuously logs each borehole during <br /> drilling and constantly checks drill cuttings for indications of both the first occurrence <br /> of groundwater and volatile hydrocarbons using ether a portable photoionization <br /> detector, flame ionization detector, or an explosimeter The sampler is rinsed between <br /> samples and either steam-cleaned or washed with all other drilling equipment between <br /> borings to minimize the potential for cross-contamination <br /> Monitoring wells are cased with threaded, factory-perforated, and blank Schedule 40 <br /> PVC The perforated interval consists of slotted casing, generally with 0 020 inch wide <br /> by 1 5-inch long slots, with 42 slots per foot A PVC cap may be secured to the <br /> bottom of the casing with stainless steel screws, no solvents or cements are used <br /> Centering devices may be fastened to the casing to assure even distribution of filter <br /> material and grout within the borehole annulus The well casing is thoroughly washed <br /> and/or steam-cleaned, or may be purchased as pre-cleaned, prior to installation <br />