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testing program that was conducted (e.g., it is not clear how many samples from where were analyzed for what Constituents of Potential Concern [COPC]).At a minimum, it is recommended that a summary analytical table for metal and petroleum hydrocarbon concentrations be provided to facilitate the evaluation of the work conducted related to this PSA investigation. If other COPCs were detected, then summary tables for these should also be prepared. It is understandable that summarizing analytical data for COPCs that were all "not detected" may not be necessary. It is not clear what samples and how many, were analyzed for what COPCs. The report states the property consists of seven parcels, (but only lists three in the text) totaling approximately 113 acres. Later it is stated that two parcels have been included in the investigation "198-120 main" and "198-120-09 southern." This is confusing. In addition, the terms "main"and "southern"do not appear to be defined. One boring log, AB18, indicates a minor lens" of broken glass (boring log suggests it may be approximately 2 feet thick). The report text does not mention this lens, nor describes encountering glass or any wastes at any locations where borings were advanced. There is no description of wastes in the report text. The boring is located within the area of reported waste disposal. Figure 2 indicates "AST-1992"and "AST-1995", referring to former ASTs and the corresponding years of the reported leaks. There were no borings at the southern 2/3 of the AST-1992 area as shown, and it does not appear that this area was restricted from access.Also, Figure 2 indicates in italics "AST' on an unpaved road south of the office and shop area with no borings in this area. It is not clear, but possibly the AST designation on the road does not belong at this location? The aerial photograph used as the base map for Figure 2 (as well as other aerial photographs around this time period) shows highly discolored, exposed, stockpiled materials south of the office; and east, south and west of the shop area. What is the nature of these materials? Are they part of the glass manufacturing process or are they wastes? Although not known, they could be stockpiled glass and the blue color related to the coloration of the glass? Two statements regarding soil sample analytical results were provided as follows: • Constituents of concern were not detected at or above laboratory reporting limits in any of the analyzed soil samples collected from the borings. • Additional analytes of concern were non-detect. What are the `Additional analytes of concern" and why is this a separate comment?A summary of what samples were analyzed for what COPCs would provide clarification (e.g., PCB and PAH analytical results were not discussed in the report). It would be clearer to state, for example, "PAH concentrations were analyzed for in x samples and type(s) (e.g., soil, soil and waste, native soil) and were not detected at concentrations exceeding their respective laboratory reporting limits). Were the "soil" samples analyzed only soil? Borings and samples are referred to as "soil' only. Or did some samples consist of waste or waste mixed with soil? The report refers to the samples as "soil' samples only; however, it appears some sample locations (borings) were in areas of waste disposal. Comparison to TTLC concentrations is appropriate if wastes are planned to be removed; however, comparison of analytical results to other levels such as Regional Screening Levels or health based screening levels may be more appropriate if wastes are planned to remain on site. Ninyo&Moore 1 500 E.Louise Avenue,Lathrop,San Joaquin County,California 1 104690095 1 August 11,2017 21