Reso 1996-156 to 160 - Laserfiche WebLink

Home

SCOPE OF SERVICES INTRODUCTION Engineering services includes the engineering design and construction support services for Disinfection System Improvements at the City of San Leandro Water Pollution Control Plant as generally recommended in the feasibility report on Chlorination Handling Facility Upgrade of October, 1992. The modification will include installation of up to two (2) flash mixing devices in the secondary effluent line; removal of the existing gas chlorine feed system and replacement with a sodium hypochlorite storage and feed system; and baffling improvements to the existing chlorine contact tank to maximize contact time. The new sodium hypochlorite storage and feed system will include three (3) bulk storage tanks of about 7,000 gallons to be located within the existing covered storage area, two (2) chemical metering pumps for disinfection, a transfer pump for moving concentrated hypochlorite between storage tanks and associated electrical and process control instrumentation. The existing residual chlorine analyzer and flow metering pacing system can be used to pace the new feed equipment, but consideration will be given to incorporating an ORP system for better pacing control. Secondary containment will be provided by a concrete parapet wall around the storage tanks and a sump pump in the storage area. As part of the Preliminary Design, an evaluation will be made for coordinating hypochlorite usage for prechlorination and activated sludge bulking. It is anticipated that the City's staff will develop the equipment for a portable system using hypochlorite in connection with the development of the disinfection system so that both systems are complimentary of one another. ENGINEERING DESIGN SERVICES The engineering design services for the disinfection system improvements include: Task 1 - Preliminary Design The purpose of this task is to establish, in detail, the facilities and system components needed for each of the process units. Work in this task involves selection of unit components and materials, development of preliminary plans and elevations showing Exhibit A Page 1 of 4 9/26/88 Rev. 1/10/90 Rev.