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PGSF WMVD Storm and Combined Sewer Design Scope of Work 08-25-2023 <br /> <br />33 of 41 <br /> <br />Category 2: Sensitive information <br />Category 2: For official use only / disclosure permissible by law. <br />TCEs, provide engineers estimate of cost for the trenchless activities and installation, provide <br />estimated construction schedules for the trenchless installation, and provide all calculations in <br />support of design. <br />For the rehabilitation of the existing casing, STC will perform calculations to determine lining <br />thickness for the installation. STC will also develop layout areas for the construction and provide cost <br />and schedule updates throughout the project delivery. <br />Activities/Approach: <br />STC will work in conjunction with B&C to develop drawings at the Preliminary, 60%, and Final Design <br />stages of the project. STC will provide technical information for the development of drawings that will <br />be drafted by B&C. STC will provide mark-ups of the plan and profile sheets provided by B&C. STC <br />will be the EOR for the casing installation beneath BNSF and the rehabilitation of the existing casing <br />beneath BNSF and will stamp the drawings. The design will be optimized for ease in permitting and <br />will incorporate specific risk mitigation measures as agreed upon with B&C and the City of Everett. <br />The design will consider project constraints and criteria developed by others. <br />STC will develop specifications for the trenchless installation of the casing beneath BNSF. STC will <br />provide the following specifications/special provisions for inclusion in the contract documents: <br />• Trenchless Casing Pipe Installation <br />• Casing Pipe <br />• Trenchless Rehabilitation of Existing Casing <br />• Minimum wall thickness of rehabilitation material for inclusion in the specifications for the <br />product pipe (by others). <br />The trenchless specifications shall include requirements for launch and retrieval pits, contact <br />grouting, annular space grouting, and provisions for settlement monitoring of the BNSF railroad. <br />Project specific requirements can be included in the trenchless specification, or the requirements <br />referenced to standard specifications or specifications prepared by others. STC will review <br />specifications that are referenced in the trenchless specifications to ensure that all pertinent <br />information is included to allow trenchless construction. <br />STC will provide cost estimates for the trenchless project components at the Preliminary, 60%, and <br />Final Design stages. These cost estimates will specifically address all labor, equipment, and <br />materials necessary to install the casing. Costs of product pipe, casing spacers, and product pipe <br />installation will be developed by others. Cost estimates for launch and receiving pits for trenchless <br />installation will be by others. STC will provide parameters, such as likely construction method, shaft <br />sizes, necessary depths, and any special shoring requirements to B&C for use in development of the <br />cost estimate. STC will review the cost estimate for the launch and retrieval pits to ensure that all <br />elements of construction are captured. <br />STC will provide an estimated construction schedule for the trenchless installation elements of the <br />project. The schedule will include mobilization and demobilization of the trenchless contractor, <br />construction of the launch and reception pits, installation of the casing pipe, contact grouting, <br />installation of the product pipe and annular grouting. <br />Task Assumptions <br />• Trenchless specifications will be developed by STC and prepared in the format requested by <br />B&C. B&C will provide a formatted template for use by STC. If WSDOT or City of Everett <br />Standards are intended for use, STC will provide the special provisions that are necessary to