HomeMy WebLinkAbout03.b. Presentation (Handout)Item 3.a.
(Handout)
Project Background
and Drivers
In 2019 Central San initiated a comprehensive asset
evaluation of the secondary process facilities at the
treatment plant, and identified the Diffuser System
in the Aeration Basins as an aging asset that is
beyond its useful life.
The existing aeration system is not able to reliably
maintain consistent dissolved oxygen levels across
the basins due to the aging original diffuser system.
The concrete basin plenums have been a problem for
many years and waste energy.
Aeration Basins Diffuser Replacement, Phase 1 will
address the west half of the Basins. The scope
renovation of Aeration Basins (A/N Tank) 1A, 16, 1C
& 1D, and includes demolition, structural,
mechanical, electrical, instrumentation, and controls.
associated with diffuser replacement in the Basins.
Project Improvements
Bid Results
Engineer's Estimate: $16,000,000
Seven (7) bids received
Lowest Bidder: C. Overaa & Co.
Aeration Basin Structure
• Replace plenum with new concrete
slab
• Rehabilitate concrete walls in the
Aeration Basins
Aeration Diffuser Svs+r
• Replace aeration header piping, valves
and drop legs
• Replace diffusers with pre -purchased
fine bubble type diffuser system
• Replace motor control centers (MCCs) at
Substation 32F and install new wiring
and instrumentation
• Install new gates including drainage
gates, isolation gates, and stop logs
• Install new mixed liquor recirculation
pumps —.A
No.
Bidder
Total Bid
1
C. Overaa & Co.
$11,449,000
2
GSE Construction Company, Inc.
$12,996,600
3
W.M. Lyles Co.
$14,444,800
4
Mountain Cascade, Inc.
$15,290,964
5
Gamey Pacific, Inc.
$16,070,000
6
Anvil Builders, Inc.
$16,963,000
7
Myers & Sons Construction LLC
$17,885,100
Total Estimated Project Cost
No.
Item Description
Amounts
%o Construction
Cost
1
CONSTRUCTION
a. Construction Contract
$11.449,000
b. Additive Bid Item - Seismic FRP
$1,213,000
c- Contingency at 15%
$1,717,000
d. Equipment Pre -purchase (DiltuserlBreakers)
$950.000
SUBTOTAL - CONSTRUCTION
i5329600
t00`�
2
CONSTRUCTION MANAGEMENT
a. District Forces
- Operations
$250,000
• Construction Management
$1.050,000
b. Outside Services
- Inspection
$650,000
- Specialtyinspection and material testing
$250,000
- Engineering Support (HDR)
$1,000,000
SUBTOTAL -CONSTRUCTION MANAGEMENT
$3,200.000
21%
3
PREBID EXPENDITURES
a. Engineering (Staff and Consultant)
S2.350.000
SUBTOTAL- PREBID EXPENDITURES
$2,350,D00
1596
4
TOTAL PROJECT COST
20 879 0D4
Project Schedule
Award: July 20, 2023
Anticipated NTP: August 2023 Iltl�
r�
Project Completion: December 2025
3
Committee Recommendation:
Staff recommends approval of the following:
Award a construction contract in the amount of $11,449,000 for the construction
of the Aeration Basins Diffuser Replacement, Phase 1, District Project 100019, to
C. Overaa & Co., the lowest responsive and responsible bidder;
Award the additive bid item for fiber -reinforced polymer seismic
strengthening in the amount of $1,213,000, increasing the construction contract
to $12,662,000;
Authorize the General Manager to execute the Contract Documents subject to
submittal requirements; _
yr _ �—
Authorize the General Manager to execute a professional engineering services
agreement in an amount not to exceed $1,000,000 with HDR Engineering, Inc. to
provide engineering support during construction services; and
Find the project is exempt from the California Environmental Quality Act (CEQA).
M