ARCHIVED REPORTS_2012_6 - Laserfiche WebLink

Home Browse Search

standards outlined in the EMP Workplan. Groundwater samples were retained for submittal to a chemical analytical laboratory following well development. Data loggers were deployed in the sounding ports of the wells and were used to record water levels during well development and post development recovery. Stored data were downloaded onto a portable computer and well recovery analyses were performed to calculate the hydraulic conductivity of the aquifer materials. f surging the well screen to loosen fine sand silt and clay Well development consisted o su g g Y ' and bailing groundwater from the well to remove sediment, induce formational water flow into the well, and reduce the turbidity of the water. Select monitoring parameters were measured and recorded in the field as water was bailed from the well. Development was considered complete when the monitoring parameters stabilized and turbidity was reduced to an acceptable level (approximately 5 NTU). Development Method —The Phase II monitoring wells were developed using a bailer equipped with a rubber gasket to surge groundwater through the screened section of the well. The gasket was approximately the same size as the inside diameter of the well casing, effectively forcing water through the screen to loosen fines and induce formational water into the well. Each well screen was surged in 18-inch increments over the course of 25 to 35 minutes until the entire saturated portion of the well screen was surged. After surging was completed, groundwater was bailed from the well and retained in a 55-gallon drum. Volumes of water removed from the wells were ' calculated by measuring the height of water in the drums. Monitoring Parameters - A Horiba U52 water quality meter was used in the field to ' measure indicator parameters at graduated volumes. The following indicator parameters were recorded: • Temperature (degrees Celsius) • pH (units) • Oxidation Reduction Potential (milliVolts) • Electrical Conductivity (millimhos/centimeter) • Turbidity (Nephelometric Turbidity Units) ' Groundwater was bailed from the wells until the indicator parameters stabilized. Due to problems caused by rainy conditions in the field, turbidity was only recorded in well MW-9A. Wells MW-10A and MW-11A were developed until relatively clear water was removed from these wells and all other indicator parameters stabilized. ' Development Log-A log of well development was recorded in the field. The following information was included on each log sheet: EMP Report—Phase IIGeo-Logic Page ■ 13 Corral Hollow Sanitary Landfill ASSOCIATES August 21,2012