ARCHIVED REPORTS_XR0011601 - Laserfiche WebLink

Home Browse Search

" Monitoring wells were protected with a traffic-rated, cast-aluminum utilit i uIpp%O*lthlJature 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 We waited a minimum of 24 hours after well installation before developing the ground-water monitoring wells to allow the grout to seal. Before developing the monitoring wells, a water sample was collected for subjective analysis from near the water surface in the well with a Teflon bailer cleaned with a laboratory-grade detergent and deionized water. Floating product was not encountered. =; The wells were developed with a surge block and pump. Well development continued until the discharge water was clear of silt and sand. Clay-size sediments derived from the screened portion of the formation cannot be entirely eliminated by well development `' After the wells stabilized for a minimum of 24 hours, the wells were purged of stagnant water and a sample was collected for laboratory analysis. The well was purged of approximately 3 to 5 well s<_ volumes of water with a submersible pump, or until pH, conductivity, and temperature of the purged water had stabilized. Water purged from the wells was stored in labeled, 55-gallon, steel drums approved for this use by the Department of Transportation until suitable disposal options ._ were selected based on laboratory analysis. Ground-Water Sampling The static water level in each well was measured to the nearest 0.01 foot with a Solinst electric water-level sounder cleaned with a laboratory-grade detergent and deionized water before use in each well. A clean bailer was used to obtain a sample from the surface of the water in the well for subjective analysis of hydrocarbons. The sample was retrieved and examined for floating product, �-s sheen, color, and clarity. Approximately 3 well volumes (approximately 50 gallons) were purged from each well with a a stainless-steel electrical submersible pump to allow sampling of representative formation water. The pump, cables, and hoses were cleaned with a laboratory-grade detergent and water before use in each well. The wells were purged until pH, temperature, and electrical conductivity of the water stabilized, as measured by portable meters calibrated to a standard buffer and conductivity `rl standard. The water level was allowed to recover to at least 80 percent of the initial water level. A sample of the formation water then was collected from the surface of the water in each of the wells with the Teflon bailer and slowly transferred to laboratory-cleaned sample containers. The recovered fluids from sampling in each well were directed into type 17-E, steel, 55-gallon liquid waste drums approved for this use by the Department of Transportation. Water samples were stored in laboratory-cleaned, 40-milliliter glass vials or other appropriate containers that contained a preservative, such as hydrochloric acid. The water samples were sealed with Teflon-lined lids so that no air bubbles were detected. The sample containers were labeled in k_ - the field with the job number, sample location and depth, and date, and promptly placed in iced => storage for transport to the laboratory. Chain of Custody Records were initiated in the field by the geologist and accompanied the samples to a laboratory certified by the State of California for the analyses requested. Samples were transported promptly to an approved laboratory.