HomeMy WebLinkAbout08. Award a construction contract in the amount of $11,449,000 to C. Overaa & Co., the lowest responsive and responsible bidder for Aeration Basins Diffuser Replacement, Phase 1, District Project 100019DCENTRALSAN
MEETING DATE: JULY20, 2023
BOARD OF DIRECTORS
POSITION PAPER
Page 1 of 12
Item 8.
SUBJECT: AWARD A CONSTRUCTION CONTRACT IN THE AMOUNT OF $11,449,000
TO C. OVERAA & CO., THE LOWEST RESPONSIVE AND RESPONSIBLE
BIDDER FORAERATION BASINS DIFFUSER REPLACEMENT, PHASE 1,
DISTRICT PROJECT 100019; INCLUDEAWARD OFANADDITIVE BID
ITEM IN THE AMOUNT OF $1,213,000 FOR SEISMIC UPGRADES;
EXECUTE A PROFESSIONAL ENGINEERING SERVICES AGREEMENT IN
ANAMOUNT NOTTO EXCEED $1,000,000 WITH HDR ENGINEERING, INC.
TO PROVIDE ENGINEERING SERVICES DURING CONSTRUCTION; AND
FIND THE PROJECT IS EXEMPT FROM THE CALIFORNIA
ENVIRONMENTAL QUALITYACT (CEQA)
SUBMITTED BY:
INITIATING DEPARTMENT:
WILLIAM GRANT, ASSOCIATE ENGINEER ENGINEERING AND TECHNICAL SERVICES -
CAPITAL PROJECTS
REVIEWED BY: CRAIG MIZUTANI, SENIOR ENGINEER
EDGAR J. LOPEZ, PROVISIONAL DIRECTOR OF ENGINEERING AND
TECHNICAL SERVICES
GREG NORBY, DEPUTY GENERAL MANAGER, OPERATIONS
Roger S. Bailey Kenton L. Alm
General Manager District Counsel
ISSUE
The Board of Directors (Board) must consider award of the contract or reject bids within 50 days of the bid
opening. Authorization is also required for the General Manager to execute a professional engineering
services agreement in an amount over $200,000.
July 20, 2023 Regular Board Meeting Agenda Packet - Page 45 of 112
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BACKGROUND
The existing aeration system in the treatment plant (plant) is not able to reliably maintain consistent air
levels across the basins due to the deficient and fouling diffuser system. The concrete basin plenums
have been a problem for many years and waste energy. This has led to concerns over the ability to
consistently meet National Pollutant Discharge Elimination System (NPDES) discharge limits, future
nutrient removal requirements, and the overall useful life of the aeration basins system.
A detailed condition assessment of the aeration system was completed as part of the Steam and Aeration
Blower Systems Renovations, District Project 7349. The assessment recommended diffuser
replacement, mechanical asset rehabilitation/replacement, controls upgrades, concrete repairs, and
structural improvements. This Project is intended to address these issues to prolong the remaining useful
life of the aeration basins and to continue meeting regulatory requirements and coordinate with potential
future changes in mind, such as nutrient removal.
This Project generally consists of the renovation of Aeration Basins Tank 1 A, 1 B, 1 C & 1 D, and includes
demolition, structural, mechanical, electrical, instrumentation, and controls associated with diffuser
replacement. The other four aeration tanks will be addressed in Phase 2, which is tentatively scheduled to
start in 2026. The Project is located within the plant, as identified in Attachment 1.
Central San and HDR Engineering, Inc. (HDR) prepared the plans and specifications for the Project. The
Engineer's Estimate for construction is $16,000,000. This Project was advertised on May 1 and May 8,
2023. Seven (7) sealed bids ranging from $11,449,000 to $17,885,100 were received and publicly
opened on June 6, 2023. The Engineering Department conducted a technical and commercial review of
the bids and determined that C. Overaa and Co. (Overaa) is the lowest responsive and responsible bidder.
A summary of bids received is shown in Attachment 2. The bids received were very competitive, and
Overaa has performed an internal review of their escrow bid documents and has no issues with their
pricing. Overaa is on site at the plant and currently working on two other capital projects.
Bids for seismic strengthening with fiber -reinforced polymer (FRP), an additive bid item, ranged from
$445,129 to $1,408,000. The Engineer's Estimate is $2,200,000, and Overaa provided a bid price in the
amount of $1,213,000. This item was included in the Project as an additive item because there was
uncertainty whether the Contractors would be able to complete the work within the seasonal constraints
provided in the contract. Overaa, the specialty FRP contractor, and staff have discussed this topic, and the
schedule can accommodate the proposed work. Therefore, staff recommends including the additive bid
item to the project. Seismic retrofitting the tanks with the new diffuser system replacement is the opportune
time to perform the upgrade since the project already includes building a new concrete floor and baffle
walls within the tanks for better maintenance and process improvements. The higher seismic performance
criteria is recommended since the aeration basins are critical and needed facilities to the treatment plant
and the structures will meet modern or to date design criteria under the California Building Code (CBC) for
earthquakes.
Central San will administer the construction contract and provide contract administration, survey, office
engineering, and submittal review. Construction inspection will be provided by a third party who will
supplement staff on an as -needed basis. Staff recommends that HDR, the designer of the Project, be
retained to provide engineering services during construction (ESDC) for Phase 1, as well as RAS Piping
Renovations, DP 100051, which was awarded at the March 16, 2023 Board Meeting. Staff has negotiated
the scope of work and fees for the ESDC work to be performed on an as -needed basis.
CEQA:
Staff has concluded that this project is exempt from the California Environmental Quality Act (CEQA)
under Central San's CEQA Guidelines Section 15302 since it involves replacement of an existing facility
on the same site (the treatment plant) and with the same purpose and level of activity as the facility being
July 20, 2023 Regular Board Meeting Agenda Packet - Page 46 of 112
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replaced. Approval of this project will establish the Board of Directors' independent finding that this project
is exempt from CEQA.
ALTERNATIVES/CONSIDERATIONS
1. Reject all bids, which is not recommended because of the favorable bid pricing and the need to
restore reliable aeration air to the biological process within the basins.
2. Reject the additive bid item for seismic strengthening of the basin structures with FRP in the amount
of $1,213,000. This work is a preventative measure to protect the aeration basins in the event of a
seismic event by upgrading the structures to a higher level of seismic criteria for underground tanks.
Preparing the basins for this type of work or any tank shutdown requires a significant amount of work
by staff. Postponing the seismic improvements and conducting the work as a standalone Project
would significantly increase the overall costs to perform the seismic work, as additional cleaning and
protecting the new diffuser system would be required along with other activities. Allowing the FRP
work to be installed before the new diffuser system is installed is a significant cost -benefit.
FINANCIAL IMPACTS
The total estimated project cost is $20,879,000, which includes the planning, design, bidding, construction
contract, District -furnished equipment (diffuser system), construction management, consultants, and
contingency, as detailed in Attachment 3.
This Project is a phase of the Aeration Basins Diffuser Replacement, DP 100019, included in the Fiscal
Year (FY) 2023-24 Capital Improvement Budget (CI B) on page 266 with a total estimated project budget
of $59,480,000. This Project, Phase 1, was estimated at $25,000,000; therefore, a savings of upwards of
$4,121,000 is expected. The adjustments to future budgets will be made after the award of the Project.
COMMITTEE RECOMMENDATION
The Engineering and Operations Committee reviewed this matter at its meeting on July 10, 2023, and
recommended approval.
RECOMMENDED BOARD ACTION
Staff recommends 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;
2. 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;
3. Authorize the General Manager to execute the Contract Documents subject to submittal
requirements;
4. 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
5. Find the project is exempt from the California Environmental Quality Act (CEQA).
July 20, 2023 Regular Board Meeting Agenda Packet - Page 47 of 112
Page 4 of 12
Strategic Plan Tie -In
GOAL ONE: Customer and Community
Strategy 1— Deliver high-quality customer service
GOAL TWO: Environmental Stewardship
Strategy 1 - Achieve compliance in all regulations, Strategy 4 - Identify and advance sustainability initiatives, including
reducing energy usage and emissions
GOAL FIVE: Safety and Security
Strategy 1 - Reduce and eliminate risks of injury or illness, Strategy 2 - Protect personnel and assets from threats and
emergencies
GOAL SIX. Infrastructure Reliability
Strategy 1 - Manage assets optimally, Strategy 2 - Execute long-term capital renewal and replacement program
GOAL SEVEN: Innovation and Agility
Strategy 1 - Leverage data analytics to become a more efficient utility
ATTACHMENTS:
1. Project Location Map
2. Summary of Bids
3. Post Bid/P reconstruction Estimate
4. Presentation
July 20, 2023 Regular Board Meeting Agenda Packet - Page 48 of 112
Page 5 of 12
Aeration Basins Diffuser Replacement, Phase 1
District Project 100019
Map Date: 6/21/2023
rro
Q Project Location
Q District -Owned Property
Martinez ,�, Detail
Concord
Pleasant Hil
Project
Location
o
Note: I 0 200 400 I Map Displayed in North American Datum of 1983I Attachment
Central San data as of June 2023. Feet California State Plane, Zone III FIPS 0403, US Feet 1
July 20, 2023 Regular Board Meeting Agenda Packet - Page 49 of 112
Page 6 of 12
ATTACHMENT 2
AERATION BASINS DIFFUSER REPLACEMENT, PHASE 1
DISTRICT PROJECT 100019
SUMMARY OF BIDS
PROJECT NO.: 100019 NO. OF ADDENDA: 3 DATE/TIME: JUNE 6,2023/2 PM
PROJECT NAME: AERATION BASINS DIFFUSER REPLACEMENT, PHASE 1
PROJECT MANAGER: WILLIAM GRANT
PROJECT LOCATION: 5019 IMHOFF PLACE, MARTINEZ, CA
ENGINEER'S EST.: $16,000,000
NO.
BIDDER
BID PRICE
1
C. Overaa & Co.
$11,449,000
Richmond, CA 94801
2
GSE Construction Company, Inc.
$12,996600
Livermore, CA 94551'
3
W.M. Lyles Co.
$14,444,800
Fresno, CA 93711
4
Mountain Cascade, Inc.
$15,290,964
Livermore, CA 94550
5
Garney Pacific, Inc.
$16,070,000
Tracy, CA 95391
6
Anvil Builders, Inc.
$16,963,000
Emeryville, CA 94608
7
Myers & Sons Construction LLC
$17,885100
Sacramento, CA 95838'
BIDS OPENED BY: /s/Eileen Hansen
July 20, 2023 Regular Board Meeting Agenda Packet - Page 50 of 112
DATE: 6/6/23
Page 7 of 12
ATTACHMENT
AERATION BASINS DIFFUSER REPLACEMENT, PHASE 1
DISTRICT PROJECT 100019
POST-BID/PRECONSTRUCTION ESTIMATE
No.
Item Description
Amounts
% 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 (Diffuser/Breakers)
$950,000
SUBTOTAL - CONSTRUCTION
$15,329,000
100%
2
CONSTRUCTION MANAGEMENT
a. District Forces
Operations
$250,000
Construction Management
$1,050,000
b. Outside Services
Inspection
$650,000
Specialty inspection 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)
$2.350.000
SUBTOTAL - PREBID EXPENDITURES
$2,350,000
15%
4
TOTAL PROJECT COST
$20,879,000
July 20, 2023 Regular Board Meeting Agenda Packet - Page 51 of 112
Page 8 of 12
Attachment 4
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.
July 20, 2023 Regular Board Meeting Agenda Packet - Page 52 of 112
Project Improvements
3
4
sem'
Old and New Diffuser System
Page 9 of 12
Aeration Basin Structure
• Replace plenum with new concrete
slab
• Rehabilitate concrete walls in the
Aeration Basins
Aeration Diffuser SvstF
• 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 —Am
July 20, 2023 Regular Board Meeting Agenda Packet - Page 53 of 112
Page 10 of 12
Bid Results
Engineer's Estimate: $16,000,000
Seven (7) bids received
Lowest Bidder: C. Overaa & Co.
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
Garney Pacific, Inc.
$16,070,000
6
Anvil Builders, Inc.
$16,963,000
7
Myers & Sons Construction LLC
$17,885,100
5
Total Estimated Project Cost
No.
Item Description
Amounts
%Construction
Cast
1
CONSTRUCTION
a. Construction Contract
$11,449,000
b. Additive Bid Item - Seismic FRP
$1,213.000
a Contingency at 15%
$1,717,000
d. Equipment Pre -purchase (DiBuserlBreakers)
$950,D00
SUBTOTAL - CONSTRUCTION
$15,329.000
1001,
2
CONSTRUCTION MANAGEMENT
a. District Forces
- Operations
$250,000
• Construction Management
$1,050,400
b. Outside Services
- Inspection
$550,000
- Speciaftyinspection and material testing
$250,00D
- Engineering Support (HDR)
$1.000.000
SUBTOTAL -CONSTRUCTION MANAGEMENT
$3200000
21%
3
PREBID EXPENDITURES
a. Engineering (Stat and Consultant)
52.350.000
SUBTOTAL- PREBID EXPENDITURES
$2,350,D0D
15%
4
TOTAL PROJECT COST
$20,879,000
I
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7
Project Schedule _A
Award: July 20, 2023 441
Anticipated NTP: August 2023��
Project Completion: December 2025
Committee Recommendation: 40
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 y,
submittal requirements; u i►
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).
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