Laserfiche WebLink
FIRM OVERVIEW AND BACKGROUND <br /> aft, Nip _ Honouliuli Wastewater Treatment <br /> r <br /> ;. Plant Effluent Disinfection Project <br /> I <br /> • r• CITY AND COUNTY OF HONOLULU,DEPARTMENT OF ENVIRONMENTAL SERVICES, <br /> r.11 •. EWA BEACH,HAWAII <br /> aPIP 1/P • (-L- 1:..; Client Reference: <br /> a• YAR " `' . r .= Mr.Wesley Yokoyama,Chief,Wastewater Engineering and Construction, <br /> • City and County of Honolulu <br /> 808.768.8790 / wyokoyama@honolulu.gov <br /> The current NPDES permit for Honolulu's Honouliuli Wastewater <br /> Treatment Plant requires a compliance schedule for enterococci Project Highlights <br /> monitoring and a determination as to if proposed discharge • New 50-mgd average/122-mgd <br /> limits can be achieved without disinfection.Effluent sampling peak disinfection facility. <br /> and related studies conducted by the City in 2019 indicated <br /> • <br /> exceedances of final enterococcus limits,concluded that Close coordination with other major <br /> disinfection is necessary to comply with the new limits,and design and construction projects. <br /> authorized proceeding with the effluent disinfection project. • Complex hydraulics and construction <br /> sequencing. <br /> Summary of Scope <br /> • Compliance schedule-driven. <br /> Carollo was selected to provide the engineering planning and <br /> design services associated with project implementation to achieve The design will be coordinated with other major capital projects at the <br /> permit compliance by June 30,2030.The new facilities will be WWTP relative to facility siting,power and other utility requirements, <br /> designed with the flexibility to handle an average,maximum month as well as plant tie-ins.Specific coordination is required for the <br /> flow of 50-mgd and peak hour flows as high as 122-mgd.System ongoing headworks,pump station,energy savings,solids process <br /> hydraulics will be a key consideration to effectively integrate the upgrades,miscellaneous improvements,and secondary treatment 0 <br /> new disinfection system into the existing hydraulic profile of the <br /> projects.Constructibility and the sequence of construction activities c <br /> plant and deep ocean outfall.Sea level rise resulting from climate will also need to be carefully evaluated. z o <br /> change will be a factor in the hydraulic analysis.Improvements <br /> to the existing outfall structure at the plant may be needed. z O <br /> Z <br /> _ � . <br /> Initial planning efforts evaluated alternative disinfection technologies — <br /> w 5 <br /> and considered how new treatment processes under design and -0 <br /> construction at the plant may affect technology selection.Additional " r nr` ;ter `" Z Z <br /> sampling,testing,and laboratory studies are also anticipated. \ c <br /> m <br /> m <br /> ._.. <br /> Carollo is designing the UV disinfection 7Z: z azi <br /> D <br /> s r <br /> system to accommodate a range of r , -o Z <br /> I <br /> I' Z- <br /> flows. This requires close coordination <br /> r 0 <br /> ith ongoing design and construction . ", . ��. �� m m <br /> projects upstream and downstream of <br /> 7=1 <br /> o <br /> the new disinfection system. Z <br /> m <br /> P G_ <br /> C) <br /> m <br /> m <br /> m <br /> D < <br /> O N <br /> D ? <br /> N <br /> D v <br /> —I I <br /> O <br /> Z <br /> CAROLLO/ QUALIFICATIONS /JUNE 2024 12 <br /> \\io-bd-1\BD-DATA\Marketing\Pursuits\CIient83(HON)\HawaiiCounty\EnvMgmtDept\On-Call FY24-25\Qua10624\PL.4-CommunityPlanning_Community\Indd\O1_FirmOverview_PL4 <br />