ARCHIVED REPORTS_2019 SOIL MGMT PLAN (JULY-REVISED)

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Brusca File No. 137-002 Page 8 May 23, 2018 Murphy Parkway Property Waste Materials Reuse Workplan resistance to leaching and by creating an elevated pH environment. The cement treatment process results in an impermeable monolith that substantially reduces surface area available for leaching. Moreover, the increased pH of the treated material (caused by alkali nature of Portland cement) limits the solubility of metals. As such, incorporating the materials from WU1 into floor slab and pavement subgrades that will be treated with cement affords an even greater reduction of the potential for leaching of soluble metals in these materials. Following the placement of the WU1 materials beneath the building floor slab (and to a lesser degree beneath concrete pavements) and the treatment of these materials with cement, the potential for leaching of metals from these materials to groundwater is considered to be negligible. Planned waste reuse areas (building pad and adjoining concrete paved dock areas) are shown on Plate 5. Pavement subgrades within areas surrounding the waste reuse areas (including the vast majority of the WU1 area) also will be cement treated as a part of the construction process. Specific measures for the placement and cement treatment of the materials are presented below. 6.0 PROCEDURES OF REUSE OF WU1 MATERIALS 6.1 Notification At least one week prior to the onset of construction activities at the site that involves the relocation of the stockpiled materials from WU1 and the placement of these materials within building pad and pavement subgrades, the SJCEHD, the CVRWQCB, and CalRecycle will be notified of the work schedule. 6.2 Placement and Cement Treatment of WU1 Materials All of the materials contained in the stockpiles of material removed from WU1 will be placed within the upper one foot of the building pad subgrade for the proposed approximate 870,000 square-foot concrete tilt up building planned to be constructed on the site. Materials placement and compaction should conform to the requirements of project plans and specifications, including the project Foundation Investigation prepared by Raney Geotechnical, Inc.; a copy of the Foundation Investigation is included in Appendix B of this Workplan.10 As indicated earlier in this Workplan, Raney Geotechnical, Inc. has reviewed the stockpiled materials from WU1 and has determined that the materials are acceptable for onsite reuse in engineered fills from a geotechnical standpoint. As described in the appended Foundation Investigation, the upper one foot of the building pad subgrade will be treated with at least five percent Portland cement, as determined by dry unit weight. The treated mixture will be moisture conditioned and compacted to at least 92 percent of the maximum dry density as determined by the ASTM D1557-02 test procedure. Any materials generated during trimming of the treated building pad to final grade, and all materials generated during foundation and utility trench excavation within the upper one foot of the building pad should be placed beneath areas adjoining the building that are designated to be 10 Raney Geotechnical, Inc.; “Foundation Investigation, Murphy Parkway Warehouse, Murphy Parkway near D’Arcy Parkway, Lathrop, California”; December 19, 2016.