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field reports. Without documentation and confirmation sampling and testing, it can not be verified <br /> that the wastes were adequately removed. Furthermore, there was no data provided to indicate <br /> the lateral and vertical extent of the wastes based on the site investigations prior to conducting <br /> waste excavation remedial action. The figures indicates this area as "deep soil Excavation Area", <br /> this terminology is inconsistent and confusing. Was the waste excavation remedial action <br /> overseen by a competent person that oversaw and directed waste excavation and stockpiling, <br /> managed excavated materials in accordance with BMPs, documented field methodologies, <br /> conducted air monitoring, collected confirmation samples, etc.? <br /> Excavations removed the waste and adequately defined the horizontal and vertical extent of the <br /> potentially buried waste, on the property to the west. Excavation was required to depth of 13 feet <br /> at some locations, through the use of an excavator through the encountered the waste glass and <br /> near native soil. Comments: The wording of this statement is confusing and unclear. The <br /> statement suggests waste excavation was used to delineate the lateral and vertical extent of <br /> wastes. What is meant by "potentially buried waste?" Waste was obviously buried at some <br /> locations. Documentation to support the statement that waste removal was defined was not <br /> provided and there were no available reports for review indicating the lateral and vertical extent of <br /> wastes prior to implementing the waste excavation remedial action. Daily field reports, <br /> confirmation sampling and analytical data and a figure indicating the lateral and vertical extent of <br /> wastes prior to excavation and the extent of wastes excavated, confirmation sample locations and <br /> analytical data needs to be provided. <br /> Approximately two waste cells of 2,000 square feet of area each "(30 to 35 feet north to soil and <br /> 65-70 feet east to west)" had demonstrated some waste glass and debris, with a variable <br /> thickness. Removal of the waste from the site (PENDING) to a Class 11 landfill is proposed. <br /> Comments: the wording is unclear and vague, (e.g., what is meant by "Approximately two waste <br /> cells of 2,000 square feet of area each (30 to 35 feet north to soil and 65-70 feet east to west)" <br /> mean? What does "demonstrated" mean and how much is "some waste glass and debris with <br /> variable thicknesses?" This is supposed to be a technical report, so it needs to indicate waste <br /> locations, waste depths and thicknesses; terms such as "some" and "variable thickness" does not <br /> provide the technical information to understand the lateral and vertical extent of wastes with <br /> respect to what was excavated. What was the range of depths of waste excavation? What were <br /> the lateral and vertical extents of excavation based on what, visual observations?Also, it is stated <br /> removal of the waste from the site is "PENDING," however, the previous statements said <br /> excavations removed the waste. <br /> Analytical tables were included in this brief document. Comments: Based on the AGE table, from <br /> trenches T1 to T23, samples analyzed were only from a depth of approximately 5 feet bgs. <br /> Typically this is not how a waste investigation is conducted and it is not clear without looking at <br /> each individual trench log, whether the samples analyzed consisted of soil, soil mixed with wastes <br /> or underlying/adjacent soils. Typically when conducting a waste investigation project <br /> (e.g., characterize/delineate wastes), samples are collected from the surface/near surface to <br /> evaluate the potential presence and adequacy of the cover soils, within the wastes, and <br /> underlying the wastes in native soils to confirm underlying soils are not impacted. Taking samples <br /> at the same depths in exploratory trenches regardless of subsurface conditions encountered does <br /> not adequately characterize the wastes. Trench logs were not included in the submittal so an <br /> evaluation of whether samples analyzed were wastes or soils, or both is not known. This <br /> information needs to be provided. Based only on reviewing the tables, it appears that analytical <br /> data is minimal for trenches T24 through T91 (not adequately described in summary document <br /> text), with no analytical data from most of these exploratory trenches. <br /> Ninyo&Moore 1 500 E.Louise Avenue,Lathrop,San Joaquin County,California 1 104690095 1 August 11,2017 47 <br />