WORK PLANS - Laserfiche WebLink

Home Browse Search

r r • Mr. Gerald Djuth, P.E. November 3, 2003 Page 2 Characterization of Downgradient Impacts Geoprobe characterization of impacts downgradient of the facility fence line will be conducted according to the following procedures. Prior to the initiation of work, LFC will coordinate with the City of Tracy to secure access to anticipated drilling locations within public easements and rights-of-way. Locations are anticipated to be along White Oak Drive, Acorn Court, Golden Rain Drive or Greenoaks Drive. No significant disruption to the neighborhood is anticipated. Borings will not be placed on private property during this investigation. Prior to initiation of field work, necessary permits will be obtained through the City of Tracy Department of Development and Engineering Services and San Joaquin Environmental Health Department, and approval of this Work Plan will be sought through the CV-RWQCB. The utility locating service will be contacted to identify subsurface utilities, and overhead utility safety concerns will be identified. Boring Locations The location of the proposed Geoprobe borings are based on the observed flow direction as groundwater leaves the plant(to the north northwest). All borings will be located in the rights-of way along White Oak Drive, Acorn Court, Golden Rain Drive or Greenoaks Drive. The initial borings will be located downgradient of impacted fenceline wells RW-1 and RW-2, as shown schematically in Figure 1. To confirm that these boring locations are downgradient of impacts, the groundwater elevation in existing site wells will be surveyed relative to equilibrated water levels in the Geoprobe borings. As work progresses, boring locations may be adjusted from those shown in Figure 1 to maintain downgradient locations. The initial two borings are anticipated to be located about 80 feet downgradient of the fenceline. If diesel is encountered in soils or groundwater(as determined by odor or staining), the next boring will be moved approximately 100 feet downgradient, or to the next accessible, downgradient location. If this new location shows diesel impacts,the following boring will be located about an additional 100 feet downgradient of the previous boring(as schematically depicted in Figure 1). If diesel impacts are not observed in the initial two borings (as determined by odor or staining), or other downgradient boring pairs, and relative water levels indicate that they are downgradient of the impacted wells, a downgradient monitoring well will be located based on the observed groundwater gradient. Data generated from all borings advanced during the investigation will be used to determine the well location. It will be hydraulically along the downgradient centerline between wells RW-1 and RW-2. Well construction is described below. Boring locations may be modified in the field, based on accessibility, the presence of overhead or subsurface obstructions,