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I <br />EXHIBIT A <br />SCOPE OF SERVICES <br />F <br />1. The City of Everett, Washington (City) has selected HDR to provide engineering analysis, <br />design, and permitting assistance for modifying Diversion Structure No. 0 (DS -0) at the Water <br />Pollution Control Facility (WPCF). <br />2. The DS -0 Project will begin with an investigation and analysis of the recommendations in <br />the City of Everett 2014 Comprehensive Sewer Plan (CSP) Capital Improvement Project <br />WPCF-4. The capacity of the siphon pipes between the Siphon Headworks and DS -0 is limited <br />by hydraulic restrictions in DS -0. The CSP identified three alternatives to minimize the head in <br />DS -0, downstream piping and maximize the hydraulic capacity of the siphon system. The <br />sewer plan identified three alternatives for the improvements at DS -0: <br />1. A 96 -inch gravity sewer pipe. <br />2. A 100 mgd pump station. <br />3. A 250 mgd pump station. <br />3. These alternatives increase the peak flow conveyance into the Oxidation Pond. Variations <br />of these alternatives will be considered along with alternatives to increase the conveyance <br />capacity to the WPCF. This could be accomplished by increasing the size of the existing 54 - <br />inch pipe or constructing a parallel pipe. <br />4. Although SR03 (overflow weir at the siphon headworks) is currently in CSO compliance, <br />modeling analysis suggests that with the implementation of the Hayes St. regulator relocation <br />and other various upstream interceptor improvements, SR03 would likely no longer be in <br />compliance. This project would improve the capacity of the siphons to convey the additional flow <br />coming from the collection system without causing SR03 to go out of compliance. <br />5. The CIP currently identifies alternative 1, the 96 -inch pipe as the preferred alternative. This <br />option would install approximately 1,000 LF of 96 -inch pipe from the DS -0 to discharge to the <br />Oxidation Pond. Figure 18 of the Sewer Plan identified the routing of the 96 -inch pipe to the <br />Aeration Pond; however, to reduce the impact on the treatment facilities, the pipe would be <br />routed to the Oxidation Pond. The figure below illustrates the general vicinity of the proposed <br />project. The DS -0 structure would be expanded to accommodate the additional pipe connection <br />and include the installation of a long weir to reduce surcharging during high flows to the <br />Oxidation Pond. Additional modifications are needed to improve plant operator accessibility, <br />safety and flow control function. <br />CT,%Of -ver e?l—V./ Ci Diversion Siiucture 0 � �+ _CCne Ci cervices <br />