WATER QUALITY CONTROL PLANT
WET WEATHER AND DIGESTER IMPROVEMENTS PROJECT
PROJECT ACCEPTANCE (PROJECT NO. SS1301)
JULY 26, 2023
WQCP Weather and Digester Improvements Project
PRESENTATION CONTENTS
• Project Overview
• Project Photos
• Cost Summary
WQCP Weather and Digester Improvements Project
PROJECT OVERVIEW
Project to comply with plant
NPDES permit requirements.
Includes:
Mandated Wet Weather Flow
Improvements (increasing
secondary treatment capacity
by 10 million gallons per day)
Mandated Digester
Replacement and
Rehabilitation (addressing
aging digester infrastructure
and plant reliability)
WQCP Weather and Digester Improvements Project
PROJECT OVERVIEW
Components of the project included:
Upgraded secondary treatment facilities
including aeration basins, new secondary
clarifier, and extending the mixed liquor
channel.
Demolition of two digesters, and
replacement with a new high-solids digester.
Rehabilitation of a third digester to
withstand stronger seismic events.
Addition of digester facilities, including
digester gas conditioning system, digested
sludge thickening equipment, and a polymer
storage facility.
Two new storm water pump stations to treat
stormwater runoff from the plant grounds.
WQCP Weather and Digester Improvements Project
AERATION BASINS
INSTALLATION OF NEW DIFFUSERS
IN AERATION BASINS
CONSTRUCTION OF NEW BAFFLE
WALLS IN AERATION BASINS
WQCP Weather and Digester Improvements Project
SECONDARY CLARIFIER 4
BEFORE DURING CONSTRUCTION
WQCP Weather and Digester Improvements Project
SECONDARY CLARIFIER 4
NEAR COMPLETION COMPLETED
WQCP Weather and Digester Improvements Project
DIGESTER 1
BEFORE AFTER DEMOLITION
WQCP Weather and Digester Improvements Project
NEW DIGESTER 1
DURING CONSTRUCTION
WQCP Weather and Digester Improvements Project
NEW DIGESTER 1
COMPLETED
WQCP Weather and Digester Improvements Project
NEW RECUPERATIVE THICKENING SYSTEM
DURING CONSTRUCTION COMPLETED
WQCP Weather and Digester Improvements Project
DIGESTER 3
BEFORE DURING CONSTRUCTION
WQCP Weather and Digester Improvements Project
DIGESTER 3
NEW ROOF INSTALLATION NEAR COMPLETION WITH NEW
ROOF
WQCP Weather and Digester Improvements Project
OTHER CONSTRUCTION PHOTOS
CONSTRUCTION OF STORM WATER
PUMP STATION 4
CONSTRUCTION OF STORM WATER
PUMP STATION 5
WQCP Weather and Digester Improvements Project
OTHER CONSTRUCTION PHOTOS
MODIFICATIONS AT MIXED LIQUOR
CHANNEL
INSTALLATION OF NEW BOILERS IN
DIGESTER CONTROL BUILDING 1
WQCP Weather and Digester Improvements Project
OTHER CONSTRUCTION PHOTOS
CONSTRUCTION OF DIGESTER GAS CONDITIONING SYSTEM
WQCP Weather and Digester Improvements Project
CONSTRUCTION COST
The total construction cost incurred to date for the project is summarized as follows:
The Project is largely funded by a loan from the State of California State Revolving Fund.
Projected Actual
Flatiron West, Inc. Contract $49,601,891.00 $49,579,559.50 Construction Contingency (20%) $4,180,045.00 $4,150,667.50 Total Project Budget $53,781,936.00 $53,730,227.00