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1 <br /> CITY OF EVERETT SPECIAL PROVISIONS <br /> monitoring, reporting and removal of dewatering systems to achieve proper <br /> completion of Work performed under this Contract. <br /> Prevent the flow of surface water runoff into the trench excavation. Control <br /> surface water and other erosion control measures associated the Work in <br /> accordance with 8-01 of the Standard Specifications and modified in these Special <br /> Provisions. <br /> Maintain groundwater level at or below the bottom of the excavation in all Work <br /> areas during excavation, foundation preparation, pipe and structure installation <br /> and backfilling. Trench dewatering shall sufficiently control groundwater to prevent <br /> softening of the bottom of the excavations or formation of "quick" conditions or <br /> "boils" during excavation. Use gravel or non-moisture sensitive trench backfill in <br /> areas encountering groundwater. If foundation soils are disturbed or oversaturated <br /> with water, then over excavate and replace the affected areas with suitable fill at <br /> no additional cost to the Owner. Upon completion of dewatering operations, <br /> restore the normal water table to its natural level in such a manner as to not <br /> disturb the pipe, its foundation and structures. Contractor shall be solely <br /> responsible to control the rate and effect of the dewatering in a manner to avoid all <br /> objectionable settlement and subsidence. <br /> Direct discharge flow from trench dewatering to a nearby sewer or storm drain <br /> system unless otherwise directed by the Engineer. Obtain, at no cost, a Discharge <br /> Authorization Permit from the City prior to discharging trench dewatering flows into <br /> the City sewer or storm drain system. Control groundwater by trench dewatering <br /> systems designed and operated to minimize turbidity of the discharged flow and to <br /> prevent removal of the natural soils or imported fill. <br /> Soils data for use in planning the dewatering system is available from the Soil <br /> Boring Logs in Appendix E or the Contractor may perform its own soils <br /> investigation. Contractor shall be responsible for cost of additional investigative <br /> work Contractor requires for designing the dewatering system. Plan and <br /> implement trench dewatering systems using accepted and professional methods <br /> of design and engineering consistent with the best modern practice. Trench <br /> dewatering systems shall be comprised of gravel-lined sumps, dewatering pumps, <br /> piping and conveyance components necessary for complete and reliable function. <br /> Before dewatering operations begin, the Contractor shall have available on the <br /> Work site sufficient pumping equipment, or other machinery, or both, to assure <br /> maintaining continuous operation of the trench dewatering system. Supply power <br /> service to dewatering pumps including, but not limited to, electrical, hydraulic, gas, <br /> or diesel, Maintain the dewatering system to allow for continuous operation <br /> without interruptions. If necessary, provide 24-hour supervision and follow-up by <br /> personnel skilled in the operation, maintenance, and replacement of dewatering <br /> system components. Damage to Work in place and the excavation, including <br /> damage to the trench bottom, due to "boiling", material removal, or discharge <br /> pumping from the excavated area, that may result from negligence, inadequate or <br /> improper installation, maintenance and operation of the dewatering system, or <br /> mechanical or electrical failure of the dewatering system shall be Contractor's <br /> responsibility to repair at no cost to the City. <br /> Trench dewatering shall be included with the Work required for Sewer Pipe, <br /> Manholes, Side Sewer Connections, Storm Drain, Catch Basins, Utility <br /> Restoration or other excavation activity performed as part of this Contract with no <br /> direct compensation made. I <br /> Water Main Replacement"Q" Division 7—WATER MAIN July 8, 2016 <br /> -Broadway <br /> WO No.—UP3612 SP- 148 <br />