FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

i 10 PARSONS A H F AI I 1 2121 North California Boulevard, Suite 500•Walnut Creek, California 94596• (925) 941-3700 • Fax: (92�) 979,,�74l'-r�vw.parsons.com 03 0("T 27 PM 1: 3 October 23, 2003 Ref: 440269 California Regional Water Quality Control Board Central Valley Region 3443 Routier Road, Suite A Sacramento, California 95827-3003 Attention: Mr. Gerald J. Djuth Subject: Work Plan for Monitoring Well Installation Offsite Southeast of MW-5R Applied Aerospace Structures Corporation Stockton, California Dear Mr. Djuth: On behalf of Group Environmental Management Company (a BP affiliated company), Parsons is pleased to submit this work plan for installation of a monitoring well offsite and downgradient of monitoring well MW-5R. In a letter dated 25 September 2003, the Regional Water Quality Control Board (RWQCB) accepted the findings and recommendation of the Soil Vapor Investigation, Vicinity of Well MW-5R (Parsons 2003) and required submission of a work plan for installation of the additional monitoring well. The rationale for the well is that during the summer and fall months, the local groundwater gradient is toward the southeast in a direction for which there are no sentry wells. It is proposed to drill and install one monitoring well approximately 300 feet southeast of monitoring well MW-5R as indicated on Figure 1. This location is on a vacant lot adjacent to the Applied Aerospace Structures Corporation site the south. Access to the lot is from the south via parking lots associated with businesses in Zephyr Court. Planning logistics include utility clearance and securing an access agreement from the property owner. A permit for well drilling and installation will be obtained from the San Joaquin County Public Health Service,Environmental Health Division (SJC/EHD). The well will be drilled using a truck-mounted hollow stem auger rig with 8-inch diameter augers. The subsurface soil will be sampled at approximately 5-foot intervals using a standard 18-inch split-spoon drive sampler. Soil samples and auger cuttings will be logged and identified using the USCS soil classification system for visual/manual methods of soil identification. Exact placement of the screened length and dedicated pump will be selected based on the results of drill hole logging. A standard 2-inch diameter well with 10-foot long screened interval will be constructed as indicated on the monitoring well construction diagram (Figure 2). —