Laserfiche WebLink
Ms.Amber Ginorio,RWQCB January 30,2023 <br /> Addendum to Sampling and Analysis Plan <br /> 2478 Wilcox Road,Stockton,California <br /> Page 4 <br /> SCOPE OF WORK <br /> The proposed work activities are summarized below, and are detailed in subsequent <br /> sections. It should be noted that the depth of first encountered groundwater plays an <br /> integral role in determining the boring depths, well construction, and collection of specific <br /> samples. For the purpose of this Addendum, Stratus is estimating that groundwater will be <br /> encountered at a depth ranging from 55 to 65 feet bgs. This is based on information <br /> gathered from wells located in the vicinity of the site(uploaded in Geotracker). The actual <br /> depths of the borings and well construction details will be adjusted in the field to <br /> accommodate the depth of first encountered groundwater. <br /> All work will be conducted under the direct supervision of a State of California <br /> Professional Geologist or Professional Engineer. Stratus' Standard Field Practices and <br /> Procedures and Sampling and Analysis Procedures are presented in Appendices A and B, <br /> respectively. <br /> • Drill and install three (3) 2-inch diameter groundwater monitoring wells (MW-1, <br /> MW-2, and MW-3) to a total depth of approximately 70 to 75 feet bgs. It is <br /> presumed that first encountered groundwater is at a depth of 60 feet bgs, based on <br /> information obtained on Geotracker from wells located in the vicinity of the Site. <br /> The actual depth of the proposed monitoring wells will be determined in the field <br /> and will depend on the depth of first encountered groundwater and lithology <br /> encountered. The wells will be constructed with 15 feet of 0.020-inch slotted <br /> screen. <br /> • Advance five (5) direct-push soil borings (SB-1, SB-2, SB-3, SB-4, and SB-5)to a <br /> total depth at which the groundwater capillary fringe is encountered(approximately <br /> 55 to 60 feet bgs) in the vicinity of the leach field. Borings will be continuously <br /> cored. <br /> • Advance one (1) direct-push boring (SB-6, located adjacent to the damaged outlet <br /> lateral)to a total depth of approximately 75 feet bgs(15 feet below first encountered <br /> groundwater) and collect two (2) grab groundwater samples via Hydropunch; one <br /> sample collected just below first encountered groundwater and one sample at <br /> approximately 15 feet below first encountered groundwater. Boring will be <br /> continuously cored. <br /> • Collect soil samples during the advancement of soil and well borings for <br /> lithological descriptions and for selection for chemical analysis. One sample will <br /> be collected one foot beneath the total depth the air knife advances; additional <br /> samples will be retained at 5-foot intervals and at observable fine-to-coarse-grained <br /> sediment contacts. <br /> T:\Stockton Propeller\Addendum to SAP\SM_Addendum to Sampling and Analysis Plan.docx STRATUS <br />