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4) Annular space requires 2 inches width thickness (SJC Well Standards 4.7.4) around each well casing. Please discuss the method you plan to use to ensure that requirement is met, especially when three 2-inch well casings are being installed inside a 12-inch boring to 800 feet. Will centralizers be used?What kind of centralizers,etc. - See Section 2.3.5 in well spec. "Individual well casings shall have a minimum two (2) separation between other casings and borehole wall." In addition, centralizers will also be utilized. 5) While EHD understands that the well design on Figure 2 is for"permitting and conceptual purposes only", please provide a corresponding lithological profile and discuss how the design can protect against potential migration of contaminants between lithological lavers, especially when the two proposed filter packs seem to be 120' and 160' in length. - No lithologic data is available within one mile of the proposed well site. Lithologic logs and a-log used to develop conceptual design have been included in the updated work plan (Attachment A). 6) Grain-size of the filter pack shall be matched to the slot size of the well screen (SJC Well Standards Section 13.10.2). Please discuss. - See update to work plan. 7) Filter pack material shall be placed in the well boring by use of a tremmie pipe or equivalent (Section 13.10.6). Please discuss. - See Section 2.3.6 in well spec: "Gravel packing and sealing material shall be pumped or gravity fed through the tremie pipe.The gravel pumping system shall consist of a hopper, which will allow for the calculation of the amount of gravel packing material entering the borehole.The Contractor shall provide the Owner with a schematic drawing of the system of gravel placement he intends to employ prior to the installation of casing" 8) Strongly recommend surge blocking the well before placing the transition seal or the annular seal (Section 13.10.7). If surge blocking is not to be done, please discuss how to avoid having the sand settle and creating bridging after the transition seal and annular seal are placed - Surge blocking or bailing will be done to consolidate gravel pack. Specifications in section 2.3.6, "The quantities of gravel placed in the annulus of each well shall not be less than the computed volume of the annulus." 9) There is no discussion of the grout materials for the annular(sanitary)seal in the work plan. Sealing material shall consist of neat Cement, Bentonite neat cement grout, or Bentonite clay(Section 13.12.3). Please discuss. See Section 2.2.2 in well spec: "1.The sealing material shall be composed of a slurry of sand-cement grout.The grout shall consist of a sand-cement mixture in accordance with California Department of Water Resources Well Standards, Bulletin 74-81/Supplement 74-90. 2. The mixture for the surface, or sanitary, seal shall conform to State standards and local ordinances for sanitary seals. 3. The bentonite sealing material shall be a graded chip bentonite with granules ranging from 1/4 inch to 3/8 inch. An approved product for the bentonite seals is "HOLEPLUG" as manufactured by the NL Baroid Division of NL Industries, Inc." 10) EHD had experienced problems in the past destroying nested wells,to that point that many had to be destroyed by detonation. Provide to EHD a proposal how these nested wells are be destroyed when they are no longer in service,which include both the well casings as well as the filter packs,that will meet SJC Well Standards for monitoring wells. (i.e. pressure grout may not be the answer as you would have to fill 120 to 150 feet of void space of the filter packs from what looks to be about a 10' section of screen, and against whatever head pressure at that depth.) Please discuss. - Example well destruction plan has been added to the work plan (Attachment C). 11) Please be aware that grout must be delivered by tremmie pipe down to the bottom of the well, and from there on up to the top (Section 13.17.8). - See section 2.3.7 in well spec: "The tremie pipe shall be installed no more than 5 feet above the placed gravel envelope before beginning seal placement.The bottom of the tremie pip shall remain submerged in the sealing material maintaining a positive displacement throughout the sealing process until the grouting material has reached the ground surface. 12) Please have Ron Bradley the C57 fill out the bottom of the LCD (see attached) authorizing Andrew to sign in place of him on the well permit application (since Andrew had already signed on the permit application.) - Document has been signed. 2