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• • wells are constructed at a WDS, they are monitored monthly (field monitoring) and sampled quarterly for a minimum of one year at which time the results are summarized in a report. -� _ On to AGB, the This email correspondence states that the LEA has spoken with the other agencies and that the final report submitted by AGE in July will need additional information. The LEA stated that the final report lacks trench logs and delineation information. The LEA indicated that the report will also need to include estimates of remaining waste for the site. The LEA requested "disposal information"for the waste that was removed from the site. Figures, Bonn an rte Oe6Brtvironmenjal,lngAu W, Although not known, it is likely this information was requested by the regulatory agency/ies and provided by AGE as it was missing from some earlier reports/documents. Comments: The AGE documents/reports that included tables summarizing analytical data indicated that for trenches T1 to T23, samples were all collected at 5 feet bgs; however, the summary table included with this submittal titled: "Investigation Tre[n]cn[h]ing Field Log" (referred to herein as Trench Summary Table) and review of the trench logs indicates that glass wastes typically occurred at shallower depths and at one location only extended to 5 feet bgs; therefore, it appears that the 5 foot samples, based on information provided were collected in soils and none appear to have been collected in wastes. The summary table indicates that trenches T7113, T1 OB, T11 B were up 11.5 feet deep; however, waste does not appear to extend below 5 feet, what was the reason for excavating to these depths? Trench logs were not provided for these trenches, nor were the locations shown on Figure 2 - Summary Trenching and Sampling Map. The summary table should also include thickness of the cover soil as encountered in the borings and trenches. Where are the trench logs for T24 to T110? Some of these trenches were at the locations of waste excavation and without these logs and summaries of what was encountered, the lateral and vertical extent of wastes does not appear to have been delineated. As stated, the analytical summary tables included in AGE reports indicated all samples from T1 to T23 were collected at 5 feet bgs; however, trench logs indicate trenches were shallower (e.g., trench log T1 appears to have a total depth of only 3.75 feet bgs, T2 only 4 feet bgs. How can samples be collected at depths greater than what was excavated? The Trench Summary Table indicates that 23 trenches were excavated on April 20, 2015; however, samples are indicated as collected a day later? This does not make sense. Samples should be collected at the time of excavation. Collecting a sample from a trench that was open overnight and analyzing it for VOCs may not be representative of actual site conditions. Although not entirely clear, it appears that the Trench Summary Table indicates that most trenches were not excavated to native soils(native soils are indicated in some logs so it is assumed when it is not stated, that the excavation did not extend to depths of native soil). Based on this, is it possible additional wastes exist at greater depths? The Trench Summary Table indicates trench T29 was excavated on July 30, 2015 and sampled April 21, 2015. Ninyo&Moore 1 500 E.Louise Avenue,Lathrop,San Joaquin County,California 1 104690095 1 August 11,2017 59