Laserfiche WebLink
EXHIBIT A <br /> Task 202-Assess Hydraulics <br /> Assess hydraulics of the CS bypass from the plant headworks and primary clarifier <br /> overflow points to the Oxidation Pond recirculation channel: <br /> 1. Confirm findings of the CS Conveyance Study which recommended two 78-inch <br /> bypass pipes. <br /> 2. Identify the size and/or shape of conveyance conduits required for the Aerated <br /> Cell 2 option to work hydraulically. <br /> 3. Prepare a hydraulic profile showing hydraulic grade line from the plant <br /> headworks and primary clarifier overflow points to the recirculation channel for <br /> maximum, 50% of maximum, and 10% of maximum CS bypass flows. <br /> 4. Review hydraulic feasibility of the Aerated Cell 2 option with City staff. <br /> Task 203—Conveyance Concepts <br /> Refine the CS Conveyance Study option concepts and prepare conceptual layouts for <br /> the Aerated Cell 2 option: <br /> 1. Use computational fluid dynamic modeling to prepare concepts for the new <br /> diversion structure and recirculation channel discharge structure for the CS <br /> Conveyance Study option. <br /> a. Prepare figures showing concepts for the diversion structure and <br /> recirculation channel discharge structure. <br /> 2. Using information from Tasks 201 and 202 and computational fluid dynamic <br /> modeling results prepare conveyance system concepts for the Aerated Cell 2 <br /> option. <br /> a. Prepare figures showing both a conceptual layout of the conveyance <br /> system and profiles for the Aerated Cell 2 option structures and <br /> conveyance conduits. <br /> b. Summarize operation of the conveyance system for flow conditions: <br /> i. When there is no CS bypass flow. <br /> ii. When there is CS bypass flow. <br /> 3. Review proposed conveyance system concepts, including operation with and <br /> without CS bypass flows, with City staff and refine based on City staff <br /> comments. <br /> Task 204 - Environmental Assessment <br /> Provide an opinion regarding environmental permitting and documentation requirements <br /> for the two conveyance options highlighting similarities and differences. For the CS <br /> Conveyance Study option consider the work will be open cut construction through the <br /> wetland and that a future project will be needed to replace the conveyance conduits from <br /> Aerated Cell 2. For the Aerated Cell 2 option consider the multiple benefits of replacing <br /> aged conveyance pipes and the ability to isolate the construction area from the <br /> wetlands: <br /> 1. Review alternative concepts prepared under Task 203. <br /> 2. Conduct a site tour to become familiar with the project sites and understand the <br /> wetland areas impacted. <br /> pw•WA\Everett\_ProposalslCombined Sewage Conveyance Improvements\Admin\WPCF CS Bypass Projectdoc Page 3 of 5 <br />