The Well Completion Report for Well #3 is attached as Appendix A. According to the Well Completion Report and the City’s GWP, the well is 265 feet deep with screen from 215 to 265 feet below the land surface. The well casing and screen is steel material, nominally 4-inches in diameter. If Contractor’s opinion of optimal materials and/or methods to accomplish the scope of work differs from these specifications, Contractor shall propose alternatives prior to the listed deadline for submittal of questions and comments. Proposed alternatives shall be submitted in writing to the City and Stantec with a justification for each alternative proposed. The following specifications do not relieve the Contractor from any items included elsewhere in the bidding requirements and contract forms. A. Mobilization and Demobilization 1. Mobilization shall include all site preparation work and materials including site access, sedimentation and erosion control measures, and other preparatory work as required by these specifications. Following acceptance of work by the City, Contractor shall remove its equipment and restore the site as near as possible to prework conditions through backfilling ruts or depressions created by the Contractor’s equipment and applying seed/straw around the former wellhead. Site restoration and removal of Contractor’s equipment shall occur within seven (7) days of completion abandonment. Contractor shall provide Stantec and the City photographs of the restored site for approval prior to complete demobilization. B. Well #3 Abandonment 1. Depth Check - Contractor shall check the well depth from the land surface to the entire depth of the well before it is sealed to ascertain freedom from obstructions that may interfere with sealing operations. There are no known obstructions or remaining downhole equipment. 2. Chlorination - The Contractor shall thoroughly chlorinate the well before sealing. Disinfection shall occur by placing a chlorine solution so that a concentration of at least 100 milligrams per liter (mg/L) of available chlorine exists in all parts of the well at static conditions. The amount of liquid or solid chlorine tablets to be added shall be calculated by the Contractor to meet this minimum concentration based on the current static water level, well diameter, and well depth. The chlorinated water shall sit for a period of at least 12 hours prior to sealing. 3. Casing Removal - The top five (5) feet of casing shall be cut off and removed, to be salvaged or disposed of by Contractor. 4. Sealing - The Contractor shall completely seal the well with bentonite-cement to within a minimum of five feet from the ground surface, by introduction through a pipe initially extending to the bottom of the well. The pipe shall be raised but remain submerged in cement as the well is filled. The remaining space shall be filled with clean fill that is mounded a minimum of one foot above the surrounding ground surface. Grouting materials shall be NSF/ANSI Standard 60-certified and prepared according to manufacturer specifications. Displaced water may be discharged to land surface on the well lot, provided water remains on the well lot, infiltrates, and does not reach neighboring properties. Displaced water shall be dechlorinated using NSF/ANSI Standard 60-certified chemicals, dosed according to manufacturer specifications
