AGENDA TITLE:
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Accept Improvements Under Contract for Solids Handling Facility Improvements at White Slough Water Pollution Control Facility Project and Adopt a Resolution Approving Change Order No. 3 and Ratifying City Manager Approval of Increased Expenses (PW)
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MEETING DATE:
November 5, 2025
PREPARED BY:
Public Works Director
recommendation
RECOMMENDED ACTION:
Accept improvements under contract for Solids Handling Facility Improvements at White Slough Water Pollution Control Facility Project and adopt a resolution approving Change Order No. 3 and ratifying the City Manager’s approval of the increased expenses.
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BACKGROUND INFORMATION:
On April 15, 2020, Council authorized the City Manager to execute a Professional Services Agreement with Carollo Engineers, Inc. to provide assistance with the procurement and installation of a new sludge dewatering press and digester mixing system improvements at the White Slough Water Pollution Control Facility (WSWPCF).
In certain conditions, the performance of the existing sludge dewatering equipment at WSWPCF was not able to remove the amount of moisture needed to properly handle the material. Based on the recommendations from Carollo Engineers, Inc., the City decided to install a new screw press to improve the sludge dewatering process; and to install a new sludge mixing system in Digester No. 3 needed to improve the sludge stabilization process.
Specifications for this project were originally approved by Council on October 19, 2022. The project was advertised on November 5, 2022.
On January 18, 2023, Council awarded the contract to Garney Pacific Inc, of Tracy ($2,424,725).
Project work was suspended by mutual agreement from June 2, 2023 until June 3, 2024, due to equipment delivery lead times.
On October 2, 2024, City Council authorized the City Manager to execute change orders not to exceed $150,000.
The original contract was $2,424,725, with the final contract amount being $2,585,783.00. This increase (through three change orders) of $161,058.00 was primarily due to a combination of unforeseen conditions and additional work requested by the City. A description of each change order is as follows:
Change Order No. 1 ($10,617.00): Included emergency repair of an 18” headworks pipe and pot holing for existing utilities near the Digestors.
Change Order No. 2 ($109,835.00): Owner requested changes at the screw press and piping in the Digester area.
Change Order No. 3 ($40,606.00): Owner requested added cleanouts to piping from Digesters, added curb, gutter, driveways and grating.
Change Order No. 3 inadvertently exceeded the City Manager’s Change Order Authority by $11,058.00, therefore staff is requesting that Council approve Change Order No. 3 and ratify the expense.
All work was completed in substantial conformance with the contract requirements approved by City Council. Photos of the completed project are attached as Exhibit A.
Following acceptance by the City Council, as required by law, the City Engineer will file a Notice of Completion with the County Recorder’s office. The notice serves to notify vendors and subcontractors that the project is complete and begins their 30-day period to file a stop notice requiring the City to withhold payments from the prime contractor in the event of a payment dispute.
Therefore, staff recommends that the City Council accept improvements under contract for Solids Handling Facility Improvements at White Slough Water Pollution Control Facility Project and adopt a resolution approving Change Order No. 3 and ratifying the City Manager’s approval of the increased expenses.
STRATEGIC VISION:
5A. Infrastructure: Invest in innovative infrastructure with a high Return of Investment.
FISCAL IMPACT:
The project will reduce staff time and ongoing maintenance costs. This project is necessary to maintain wastewater treatment compliance and to avoid potential fines and penalties from the State. This project did not impact the General Fund.
FUNDING AVAILABLE:
This project was funded through Wastewater Capitol.