Jacobs Engineering Group Inc 9/6/2019 Amendment 1

One end of this RCP connects to the side gate valve in the SR08 structure and the other end is submerged within the Snohomish River.The condition of the existing outfall is currently unclear. In 2018,the City developed a video of the current host RCP using a remotely operated vehicle (ROV).This video showed the following salient features: • The host pipe is brick lined concrete and is in good condition, however there are a few places with bricks missing, but there appears to be concrete behind it. • The end of the pipe (at the outfall) is in rough condition for approximately 10 feet with potentially some exposed rebar at the river end within the first few feet of the pipe. • There is some concern for cracks,voids, or deformations at the river end of the pipe for approximately the first 10 feet of the pipe. • Discharge from the pipe is always submerged in the river,with exceptions during a -3.5 tide when it has been dry in the mountains for the previous couple of weeks, and then approximately half of the pipe is visible. The City is currently scheduling a Closed Circuit TV(CCTV) condition assessment of the pipe during low tide. It is expected that approximately half of the pipe will be above the water line for this assessment.The activities outlined in this subtask will commence after this CCTV assessment is complete. Specific SR08 Outfall Pipe, Rehab Design activities include: • Document Review:The Service Provider will review plans, reports, as-built drawings, inspection media, and other documents (including applicable O&M records, data regarding any repairs or maintenance requirements along the pipeline segment, GIS data, previous inspection/survey data, geotechnical information, etc.) related to the existing SR08 outfall pipeline. Review of these documents will guide the development of the rehabilitation design. • Review Design Criteria and Assumptions for Rehabilitation: An evaluation of specific requirements and impacts of the rehabilitation will be conducted,which may include: o Review of field survey results to confirm no conflicts that could affect the pipe rehabilitation process. o Hydraulic capacity o Potential for use of elastomeric check valve o Outfall discharge dilutions for range of flows (dilution modeling) o Sewer cleaning o Construction access o Rehabilitation of pipeline, manhole, outfall, as applicable o Confirmation of the adequacy for the selected rehabilitation technique o Geotechnical constraints o Evaluation of river conditions at outfall, and any follow-up recommendations for additional pipeline protection and bank stabilization to be considered during pre-design. • Permit Requirement Analysis:The Service Provider will prepare a permit matrix that identifies the permits required for the SR08 outfall rehabilitation work. (During Phase 2, Design and Bid Services, services will be provided to assist the City in obtaining the required permits identified in the matrix.) • Development of Pre-design Documents: Pre-design documents for the rehabilitation work will be developed indicating preliminary layout drawings to approximately 30% complete level.These drawings shall include site plans, plan sheets, profile sheets, locations for pipe rehabilitation, locations for proposed excavation, locations for bypass systems,etc. Up to six(6)sheets will be developed. Specifically,the following pre-design documents will be prepared: o Pre-design and layout of the sliplining rehabilitation procedures for approximately 300 LF of the existing 60" RCP and outfall. o Plan and profile sheets which indicate the limits of sewer pipe rehabilitation. Plan sheets shall include extent of rehabilitation, location of existing 36th Street Overflow structure, location and 81F A G E