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removed from the site sometime between 1993 and 2005. Cullet is an essential component in the manufacture of float glass, and as such, this stored material was utilized by the plant to produce finished product. Photographs from 2005 and 2006 showed that the cullet storage area had been graded flat. The area of excavation east of the staging area remains a rectangular shaped depression. Comment: Although not known, the historical aerial photograph review appears to have been conducted to evaluate the lateral extent of waste disposal planned to be covered. It is not clear where the area was that is referred to in the statement the cullet was first placed "on the storage area" sometime between 1963 and 1974. Information not previously obtained from other documents was included in this document. It is not clear what is meant by "The cullet was removed from the site sometime between 1993 and 2005," where was it removed from and where was it placed and what is the source of the information? Based on a review of the historical photos and observations, the area previously used for cullet staging was east of the west access road and south of the earthen berm/levee. For this work plan, the total area has been divided up into three separate areas. Comment: while the three areas are defined and shown on a figure, it is not clear on what basis they were divided and why this was done? In December 2012, the LEA performed a quarterly inspection and informed Pilkington NA that to meet minimum state requirements, a one (1) foot thick layer of soil would need to be placed over the cullet staging area and graded to allow runoff and prevent ponding and erosion of the soil cover. The engineered cover was proposed to consist of three layers; granular bentonite, blended agricultural soil, and hydro-seed. A 0.25-0.5 inch layer of granular bentonite clay, typically used in engineered landfills, is proposed to be placed on the former cullet staging area, overlain with six-inches of a blended agricultural soil, and then topped by a hydro-seed application of native grasses and clover. The report provided scheduling and indicated a Cullet Staging Area Cover Report would be prepared and submitted to the LEA. 01,111, According to information provided by AGE, the photographs from September and December 2013 show construction of the cover referenced in the previous Cullet Staging Area Cover Work Plan. This document consists of Figure 2 which primarily focuses on the glass manufacturing plant (office and shop), and the area to the south.A 2011 aerial photograph was the base map for this figure. Comments: This figure identifies the locations of two previous above ground storage tanks (ASTs) (An AST is also indicated to the east?) and based on the "Legend," indicates the location of"soil' borings and groundwater sampling. Boring locations appear to be in the general area of former ASTs and to the south at a location of waste disposal based on historical aerial photographs. However, based on background information, particularly historical aerial photographs (Appendix B), other areas of surface disturbance could potentially be the locations of waste disposal and borings were not proposed in these area. It is not clear why the area was planned to be investigated by borings as opposed to exploratory trenching. The latter is the preferred method of evaluating waste disposal sites when there is available access and because this method provides more reliable subsurface information that can be directly observed. Also, based on the 1968 historical aerial photograph, the locations and number of borings south of the office and shop area appears to be inadequate to delineate the waste Ninyo&Moore 1 500 E.Louise Avenue,Lathrop,San Joaquin County,California 1 104690095 1 August 11,2017 1