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The additional analysis of the in-situ soil for soluble metals (STLC — Soluble Threshold Limit Concentration) collected and analyzed from the former glass handling/burial area "did not reflect hazardous waste concentrations."Comment: once again, which samples were of soils, soils and wastes or wastes? Which samples were analyzed for STLC concentrations? Based on the tables, it appears that only the stockpile samples were analyzed for STLC, if this is the case, then it should be stated in the summary document. The term "in-situ soil' (e.g., soil in place) as used in the sentence is not clear. A total of eight soil samples were collected within noted soil depressions or low areas. Six samples were collected at six to eight inches bgs of the depression (ABSP1A-ABSP2C). Additionally, two deeper soil samples were later collected at the location of ABSP2B, at depths of 1.5 feet and 3 feet bsg of the base of the depression. Comment: please indicate/describe in the document text the location, origin, and nature of the "depressions." AGE indicated samples are "soil samples" are they of soil or wastes or both? How was the "base of the depression" determined, by the presence of native soils? A total of four shallow soil samples collected from these areas indicated minor detections of PCBs (Aroclor 1254 only). The depth of each of the samples is approximately 8 to 10 feet below the natural land grade and therefore are not shallow soils. Additionally, the DTSC HHRH Note 3 (May 2015) listed screening levels for general PCBs at 0.78 mg/kg which is greater than all the soil sample detections. Comment: are these samples of wastes or soils?Are these samples from soil borings only? Please indicate the locations of the samples (e.g., borings or trench nomenclatujre in the summary document text) and whether the samples are of soils or wastes or both. Soil stockpile samples from the glass management area "(S series)" with detections of metals, were below the California Human Health Screening Level (CHHSL) concentrations and consistently detected low total metals concentrations. Soluble metals concentrations were generally low or typical for background concentrations on commercial land. Comment: please define "S Series."Are the samples analyzed soil or waste or both? During the initial investigation of the former PNA site, the majority of the trenches (T1 toT23) "demonstrated" minor amounts of residual glass present within native soils. Trenches "established"within the "stabilized cover area" T1 to T23 (July 2015) produced minor glass waste and mostly clean native soil. In August 2015 waste was transported to the Forward Landfill in Manteca, CA for disposal. Approximately 297 tons of waste glass, minor garbage and cover soils were disposed. Comments: what do you mean by "trenches established?" Do you mean exploratory trenches excavated? Please define the "stabilized" cover area, is this a different area than the area that was previously covered/capped?"What do you mean by"stabilized"?Why were excavated materials from exploratory trenches disposed of offsite? Typical practice during site investigations at WDS properties is to place the excavated materials back into the trenches from which they were excavated since it is a site investigation and not a remedial action project. The statement references "minor amounts of residual glass within native soils" and then indicates later disposal of"waste glass and minor garbage" please clarify/make consistent. At the direction of State of California — CalRecycle, a limited ground penetrating radar survey (GPR August 2015) initially indicated limited amounts of buried glass across the area of T1 to T23. A secondary GPR and magnetometer survey conducted at the southwest boundary of the property and off-site, indicated the presence of buried glass and ancillary metals across two cells, generally limited near the southwestern portion of the investigation. Comments: The geophysical survey reports were not included with this submittal and should be provided/accompany this summary document. The lateral extent of the waste cells based on the geophysical survey should be shown on an appropriate figure(s) that also shows the borings and trenches and should have been used to select locations of exploratory trenches to define the waste extent. In addition, a geophysical survey would likely not indicate the presence of buried glass; rather it would likely Ninyo&Moore 1 500 E.Louise Avenue,Lathrop,San Joaquin County,California 1 104690095 1 August 11,2017 51