The citywide decommissioning of monitoring/recovery wells as required by 6 NYCRR part 360, Environmental Conservation Law Article 23 and New York State Department of Environmental Conservation CP - 43 policy at various locations in all Five (5) Boroughs as shown in Exhibit A: Location of Wells. A. The two primary well decommissioning methods are: 1. Grouting in-place. 2. Perforating overdrill. B. In a complex situation, one or more decommissioning procedures may be used for different intervals of the same well. DECOMMISSIONING PROCEDURES: A. Wells are to be disinfected using a solution of calcium hypochlorite, such as HTH, containing approximately 65% to 75% available chlorine. Calcium hypochlorite products containing fungicides, algicides, or other disinfectants are to be avoided. B. Contractor is responsible for the verification of the depth of the well. Casing with an open annular space will be either grouted in place or removed. Casings removed from a collapsing formation, grout should be pumped through a tremie pipe so that during its removal the bottom of the casing remains submerged in grout. 1. Where casing is grouted in place, the casing should be cut off at least 24 inches below grade, where practicable. For wells located in a building, upon completion of grouting the casing should be filled to floor level with no less than 12 inches of cement. 2. Casing should be cut off not more than 3 inches from floor level. For wells terminating in a well pit, casing should be cut off not less than twelve inches below the grade established when the pit is filled. Additional grout must be added to the casing as it is withdrawn. 3. After the grout has consolidated, the top of the casing should be closed and sealed. Steel casings should be sealed with a welded steel plate; PVC casings with a permanently affixed PVC cap; C. The portion(s) of the well occupied by the well screen should be filled with clean sand or gravel (defined as being relatively free of clay and organic matter). The filling should be no less permeable than the formation surrounding the well screen and should extend no more than three feet above the top of the screen. D. Standard Grout Mixture; E. Grouting of The Wells; and F. Site Restoration. All materials, debris, tools, machinery, sealing material, grease, or other materials which have accumulated at the site should be removed and/or disposed of properly and in accordance with law. It is strongly recommended that all interested bidders attend and that bidders thoroughly review bid documents in advance of the meeting. Option 2: Or call in (audio only) +1 646-838-1534,,322816723# United States, New York City Phone Conference ID: 322 816 723# Option 3: Access the attached document "TEAMS Meeting Link RFQ 327889-3" and click on the embedded link to join. RFQ Question Submission Deadline 10/28/22 Question and Answer Release Date 11/02/22
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