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<br /> CITY OF EVERETT SPECIAL 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 and
<br /> 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
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<br /> with water, then over excavate and replace the affected areas with suitable fill at no
<br /> additional cost to the Owner. Upon completion of dewatering operations, restore the
<br /> normal water table to its natural level in such a manner as to not disturb the pipe,
<br /> its foundation and structures. Contractor shall be solely responsible to control the
<br /> rate and effect of the dewatering in a manner to avoid all objectionable settlement
<br /> 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 Boring ,
<br /> Logs in Appendix A or the Contractor may perform its own soils investigation.
<br /> Contractor shall be responsible for cost of additional investigative work Contractor
<br /> requires for designing the dewatering system. Plan and implement trench
<br /> dewatering systems using accepted and professional methods of design and
<br /> engineering consistent with the best modern practice. Trench dewatering systems
<br /> shall be comprised of gravel-lined sumps, dewatering pumps, piping and
<br /> 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 without
<br /> interruptions. If necessary, provide 24-hour supervision and follow-up by personnel
<br /> skilled in the operation, maintenance, and replacement of dewatering system
<br /> components. Damage to Work in place and the excavation, including damage to
<br /> the trench bottom, due to"boiling", material removal, or discharge pumping from the
<br /> excavated area, that may result from negligence, inadequate or improper
<br /> installation, maintenance and operation of the dewatering system, or mechanical or
<br /> electrical failure of the dewatering system shall be Contractor's responsibility to
<br /> 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 Restoration
<br /> or other excavation activity performed as part of this Contract with no direct
<br /> compensation made.
<br /> 7-08.3(2) Laying Pipe
<br /> 7-08.3(2)A Survey Line and Grade I
<br /> Delete both paragraphs of 7-08.3(2)A and substitute the following:
<br /> Provide surveys required to construct the sewer line including, but not limited
<br /> to, alignment stakes, offset stakes, grade hubs, and intermediate staking. Use
<br /> main survey control points shown on the Plans, unless Engineer directs
<br /> otherwise. If a Bid item for "Surveying" is not listed in the Proposal, then this
<br /> item shall be included with the Work with no direct compensation made. ,
<br /> Water Main Replacement"V" Division 7—STORM,SEWER,WATER April,2021
<br /> WO No.—UP3730 SP—170 ,
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