2006/05/17 Council Agenda Packet

EXHIBIT A-3 SCOPE OF WORK 7 5. Potential impact of construction activities on existing structures including pipelines, bridges, dikes, etc. This will include potential impacts of HDD operation on existing structures, as well as potential impacts of a buried pipe trench on existing piles located at east transition section. (ZZA) C. Geotechnical Report. The results of the engineering analyses will be used to develop geotechnical recommendations for design. The data and recommendations will be summarized in two separate geotechnical design memorandums prepared by ZZA and Bennett Staheli Engineers covering pile supported/buried pipeline issues and HDD issues respectively. The HDD report will be based on field and laboratory data located along the HDD segment and presented in the ZZA report. Eight (8) copies of each draft report and eight (8)copies of each final report will be provided to the City. D. Document review. The geotechnical subconsultants will review the "90 percent" submittal of the plans and specifications to confirm consistency with the geotechnical design recommendations. Task 13. Final Design Prepare final design contract documents for the proposed Phase 6 HDD Project as follows: A. Final Design of Pipeline. Prepare a detailed final design of Pipeline No. 2 and 3 based on the design concepts described in the Predesign Memorandum. The final design includes a HDD installed pipeline, pile-supported elevated pipeline, and buried (if selected) pipeline. The design analysis shall include the following: • Evaluation of internal working and surge pressures, external loading conditions, temperature stresses, required pipe bending stresses, and definition of the final pipe wall thickness design. • Pile bent support system, including seismic and thrust restraint design. • HDD pipe design, including drill rig thrust block design, deep conductor casing installation, pilot bore and ream drilling sequence for twin installations, steel pipe breakover and setback distances, hydraulic and pneumatic thrust assist, drill fluid pressure monitoring, steel pipe staging and welding requirements, and steel pipe filling and testing. B. Prepare Contract Drawings. The work associated with facilities to be designed includes: • Plan and profile drawings for Pipelines No. 2 and 3 (HDD, pile-supported and buried configuration) • Surface restoration requirements • Temporary erosion/sedimentation control plans • Wetland restoration requirements • Connection details (new pipe to existing) • Cathodic protection system details • Air valve details 5 4 MWH Page 14 EVERETT PHASE 6 HDD PROJECT 5/1/06 EXHIBIT A-3-SCOPE OF WORK