ARCHIVED REPORTS XR0011179 - Laserfiche WebLink

Home Browse Search

Mr Kenneth R Earnest �F February 11, 1943 Page 2 Ground water monitoring wells MW-4 and MW-5 were constructed of 4-inch-diameter, Schedule 40 PVC casing Vapor extraction wells VW-1, VW-2, VW-3, and VW-4 were constructed of 2-Inch-diameter, Schedule 40 PVC casing Monitoring and vapor extraction well construction details are contained in Enclosure C The monitoring wells were developed, purged, and sampled in accordance with methods outlined in Enclosure A A ground water sample from each well (MW-4 and MW-5) was submitted for laboratory analysis of BTEX and TPHg by Cal-EPA and EPA-approved methods In accordance with the requirements of San Joaquin County, a ground water sample was also collected from monitoring well MW-4 for analysis of fecal coliform content Soil Barings Soil samples collected from the borings consisted of silty clay, sandy silt, silt, silty sand, sand, clayey slit, clayey sand, and sandy clay For example, the lithology of soil samples collected from the soil boring for monitoring well MW-5 is described in detail by depth as follows from below the asphalt road base to 12 feet below grade, the soil encountered consisted of a silty clay, from 12 feet to 23 feet below grade, a silty sand was encountered, under the silty sand, a clayey silt was present to 33 5 feet, below this level, a silty clay was present to 48 feet, from 48 to 55 feet, a sand was encountered, under the sand, silty clay was present to 70 feet, below the silty clay, a silt was encountered to 75 feet, from 75 to 87 5 feet, the total depth of the boring, a silty clay was encountered The vertical sequence of strata encountered in each boring indicates that the soil strata beneath the site does not appear to be laterally continuous Contacts between the soil types vaned between gradational and sharp Soil boring logs containing detailed descriptions of soil conditions for each boring are included in Enclosure B Soil Sample Analytical Results A portion of each soil sample collected from the soil bonngs was sealed in a plastic bag and allowed to reach ambient air temperature The headspace of the bag was then screened in the field with a photoionization detector (PID) The highest PID reading for each sample was recorded on the right-hand side of the boring logs (Enclosure B) Soil samples were selected for chemical analysis on the basis of PID screening results and the location of the soil samples in relation to the most likely source of petroleum constituents Forty-three soil samples were submitted for analysis of concentrations of BTEX and TPHg Analytical results of soil samples submitted by AMV are summarized in Table 1 Copies of certified analytical reports for each soil sample submitted to the laboratory during this phase of work are contained in Enclosure D ACTON • NIICKELSON • ran DAN, INC Consulting scientists, Engineers, and Geologists