ARCHIVED REPORTS XR0010058 - Laserfiche WebLink

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Lo in of B rin ' Soil cuttings and samples are logged using the Unified Soil Classification System Samples not selected for chemical analysis are examined in the field The texture, color, moisture, plasticity, and consistency of soil, the blow counts, and subjective evidence of hydrocarbons, such as soil staining, obvious product odor, and photoionization detector (or similar instrument) readings are noted in the field on the Logs of Borings. Sampling of Drill Cuttings Soil samples are collected from the stockpiled drill cuttings into a clean brass sleeve by driving the sleeve into the stockpiled soil using a hand-operated percussion sampler or similar tool. The sleeve is removed from the sampler and promptly sealed with Teflon tape and plastic caps. ' The sample is then labeled and placed in aced storage. Chain of Custody Records are initiated by the geologist and accompany the samples to the analytical laboratory. Disposal of the drill cuttings at an appropriate disposal facility is the responsibility of the client ' Monitoring-Well CoDgruction ' Monitoring wells are constructed in the borings with thread-pointed Schedule 40 PVC casing. No chemical cements, glues, or solvents are used in well construction The screened portion of each well consists of factory-perforated casing, typically with slots of 0 010 or 0 020 inches in width. The well screen extends from the total depth of the well to approximately five feet above the groundwater surface. This screened interval allows sampling at the air-water ' interface during seasonal and other fluctuations of the groundwater level The annular space in the well is packed with sand compatible with well slot size to approximately two feet above the slotted interval A two to three foot thick bentonite plug is added above the sand pack to ' prevent the cement from entering the well pack. The remaining annulus is backfilled to grade with a bentonite cement slurry. ' Wells are protected with a traffic-rated, cast-aluminum utility box equipped with a PVC skirt. The box has a watertight seal to protect against surface-water infiltration and must be opened ' with a special wrench The design of this box discourages vandalism and reduces the possibility of accidental disturbance of the well ' Well Development The newly installed groundwater monitoring wells are allowed to stabilize a minimum of 24 1 hours after installation prior to development to allow the grout to seal. Before developing the monitoring wells, a water sample is collected for subjective analysis from near the water surface in the well with a dedicated disposable bailer The wells are developed by pumping, ' balling, and or surge-block techniques. Well development continues until the discharge water is relatively clear of silt and sand. Clay-size sediments derived from the screened portion of SHELLSIFLDMTHDS doe 2 1