RESOLUTION R2025-XX
RESOLUTION OF THE CITY COUNCIL OF THE CITY OF MANTECA, STATE OF CALIFORNIA, DETERMINING C. OVERAA & CO. AS THE LOWEST, RESPONSIVE, AND RESPONSIBLE BIDDER FOR THE WQCF SLUDGE THICKENER & DEWATERING UNIT NO. 3 SYSTEM DESIGN PROJECT CIP NO. 24006 & 24007; AWARDING THE CONSTRUCTION CONTRACT TO C. OVERAA & CO. IN THE AMOUNT OF $22,865,000; APPROVING AMENDMENT NO. 2 TO AGREEMENT C2023-136 FOR PROFESSIONAL SERVICES WITH CAROLLO ENGINEERS, INC. FOR AN AMOUNT NOT-TO-EXCEED $800,000; APPROVING A PROJECT CONTINGENCY OF $2,000,000; AND AUTHORIZING THE CITY MANAGER OR DESIGNEE TO EXECUTE THE CONSTRUCTION CONTRACT, AGREEMENT AMENDMENT, APPROVE CONSTRUCTION CHANGE ORDERS AND AGREEMENT AMENDMENTS UP TO THE TOTAL PROJECT BUDGET, AND TAKE ALL APPROPRIATE ACTIONS NECESSARY TO CARRY OUT THE PURPOSE AND INTENT OF THE RESOLUTION.
WHEREAS, in March 2022, the City of Manteca (City) completed a capacity assessment study (Study) for the Wastewater Quality Control Facility (WQCF). The Study identified 10 interim improvements needed to optimize the WQCF treatment process:
Glycerin Injection System (completed and in-service)
Replace Waste Activated Sludge (WAS) Pumps (in construction) Replace Return Activated Sludge (RAS) Pumps (in construction) Replace Internal Mixed Liquor Recycle Pumps (in construction) Fix Flow Split to North Plant Aeration Basin (in construction) Add New Independent Mixing System to Zone B (in construction) Add Process Aeration Control to Improve Monitoring and Control of Denitrification (in construction) Sidestream Treatment (in Design)
Centrifuge No.3 or Equivalent (included in this project, CIP 24006) Add DAF No.3 or Equivalent (included in this project, CIP 24007); and WHEREAS, on November 6, 2023, the City entered into an Agreement C2023-136 for Professional Services with Carollo Engineers, Inc. (Carollo) to evaluate, design, and prepare biddable project Plans, Specifications, and Estimates (PS&E) for the WQCF Sludge Thickener (CIP No. 24007) and Dewatering Unit No. 3 (CIP No. 24006) System Design Project (“Project”); and WHEREAS, during the initial Project evaluation, Carollo was required to prepare a Preliminary Design Report (PDR) evaluating the following alternatives:
Review addition of a third Dissolved Air Flotation Tank (DAFT) Review technology change to Rotary Drum Thickeners (RDTs) Review replacement of the existing DAFTs with Gravity Belt Thickeners (GBTs) Analysis of co-thickening of the Primary Sludge (PS) and the WAS Review addition of a third centrifuge that matches the existing units Review addition of a third centrifuge with a higher capacity than the existing units Review replacement of the centrifuges with screw press technology; and WHEREAS, the Final PDR made the following recommendations:
Sludge Thickener
Design the new sludge thickening process to allow for co-thickening of primary sludge and secondary sludge to maximize the total solids concentration of the sludge feed to the digesters and homogenize the sludge feed to reduce process upsets.
Install new RDT technology which allows for co-thickening of primary sludge and secondary sludge.
Convert existing DAFTs into sludge blending tanks and install required yard piping.
Replace MCC-E (motor control center) to support new process equipment.
Dewatering
Continue with the design of the addition of a third centrifuge that matches the existing units as this is the most economical solution.
Based on the PDR, the following recommended alternatives would be most beneficial and economical to increase treatment capacity at the WQCF:
Sludge thickening system: Replacement of the existing DAFTs with RDTs and co-thickening of PS and WAS Dewatering system: Addition of a third centrifuge that matches the existing units; and WHEREAS, on August 1, 2024, the City executed Amendment C2023-136-A1 to the Agreement for an expanded design and environmental services as recommended in the PDR for the Project; and WHEREAS, on December 17, 2024, the City Council approved the Project plans and specifications and authorized the Call for Bids; and WHEREAS, on January 29, 2025, the Project was advertised for bid, and a mandatory job walk was held on February 6, 2025 and on February 27, 2025. The deadline to submit questions and/or inquiries was on March 3, 2025 and responses to questions/inquiries received prior to the deadline was published on the City’s website on March 6, 2025; and WHEREAS, three bids were received and opened on March 11, 2025:
C. Overaa & Co. $22,865,000
Shimmick Construction $24,876,000
Clark Bros Inc. $27,300,000; and
WHEREAS, staff has requested Carollo to provide an expanded task and fee to provide engineering support during the construction phase of the project. Staff has completed agreement amendment negotiations with Carollo for an amount not to exceed $800,000; and WHEREAS, the City Council has considered all information related to this matter, as presented at the public meetings of the City Council identified herein, including any supporting reports by City Staff, and any information provided during public meetings.
NOW, THEREFORE, BE IT RESOLVED, by the City Council of the City of Manteca, as follows:
The City Council hereby finds that the facts set forth in the recitals to this Resolution are true and correct, and establish the factual basis for the City Council’s adoption of this Resolution.
The City Council hereby determines C. Overaa & Co. as the lowest, responsive, and responsible bidder for the WQCF Sludge Thickener & Dewatering Unit No. 3 System Design Project CIP No. 24006 & 24007.
The City Council hereby awards the construction contract for CIP No. 24006 & 24007 to C. Overaa & Co. in the amount of $22,865,000.
The City Council hereby approves Amendment No. 2 to Agreement C2023-136 for Professional Services with Carollo Engineers, Inc. for an amount not-to-exceed $800,000.
The City Council hereby approves a Project Contingency of $2,000,000 for the Project (CIP 24006 & CIP 24007 combined) . The Project Contingency can be used for any costs related to any phase of the Project.
The City Council hereby authorizes the City Manager or designee to execute the construction contract, Agreement Amendment, approve construction change orders and Agreement amendments up to the total Project budget, apply for permits, apply for State and Federal grants, solicit project funding support, complete and execute all associated documents, and take all appropriate actions necessary to carry out the purpose and intent of the resolution.
This Resolution shall take effect immediately upon its adoption.
I HEREBY CERTIFY that the foregoing Resolution was duly adopted by the City Council of the City of Manteca at a public meeting of said City Council held on the 15th day of April, 2025, by the following vote:
AYES:
NOES:
ABSENT:
ABSTAIN:
MAYOR: __________________________
GARY SINGH
Mayor
ATTEST: __________________________
CASSANDRA CANDINI-TILTON
City Clerk
ATTACHMENT 1
R2025-XX Page PAGE 3 of NUMPAGES 3 April 15, 2025 R20XX-XX Page PAGE 1 of NUMPAGES 2 Type approved date of resolution here