City of Gonzales
PUBLIC WORKS / CITY ENGINEER DEPARTMENT
STAFF REPORT
TO: Honorable Mayor Rios and City Council
DATE: July 21, 2025
FROM: Patrick Dobbins, Public Works Director/City Engineer THROUGH: Carmen Gil, City Manager
SUBJECT: Resolution No. 2025-50 Task Order #4 Dudek Contract for WWTP Preliminary Design Report
RECOMMENDATION
It is recommended that the City Council Adopt Resolution No. 2025-50, A Resolution of the City Council of the City of Gonzales Authorizing Task Order No. 4 under a Master Service Agreement with Dudek Consulting for Preparation of a Preliminary Design Report for Rehabilitation of the Wastewater Treatment Plant in the amount of $234,959.
BACKGROUND
Wastewater discharge from residential, commercial, and industrial properties in Gonzales is conveyed to the City-owned municipal wastewater treatment plant (MWWTP). The MWWTP operates under a permit from the Central Coast Regional Water Quality Control Board (RWQCB) and has a permitted capacity of
1.30 million gallons/day (MGD). Currently, the MWWTP treats and disposes of approximately 1.20 MGD, near its permitted capacity and has struggled to meet the 2006 discharge permit requirements as the MWWTP was not designed for the amount of ag-wash water it must treat every day. In April 2023 the Central Coast Regional Water Quality Board issued a new discharge permit that contains requirements that the MWWTP is not capable of meeting.
To address the issue, the City has undertaken a multi-phased approach to upgrade the wastewater system to comply with the new RWQCB permit and expand wastewater capacity to accommodate residential and industrial developments.
AGENDA
ITEM
15 Phase 1 is to construct a 1.0 MGD Industrial Wastewater System, which will treat and dispose 1.0 MGD of ag-wash water. The City has been working diligently on Phase 1 as the IW Conveyance Pipeline was completed on June 30, 2025 and issuance of the Notice to Proceed on the Industrial Wastewater Treatment Facility (IWTF) occurring on July 1, 2025. Completion of the Industrial Wastewater System is anticipated in the Spring of 2027.
With Phase 1 well underway, the City is kicking off Phase 2 which is rehabilitation of the existing MWWTP. With the IWTF operational and treating 1.0 MGD of flow, the City will remove one treatment train from service at the MWWTP for rehabilitation followed by the second treatment train. Upon completion of Phase 2, the City’s wastewater system will be capable of meeting regulatory requirements.
As a first order of business for Phase 2, a Preliminary Design Report will be prepared to evaluate treatment technology alternatives to identify a preferred alternative to move forward into preliminary and final design. With grant support from MNS Engineers, the City was awarded a $294,000 grant from the State Water Resource Control Board on April 1, 2025 to fund this effort.
Dudek was requested to prepare a scope and fee for the Planning study to be awarded as Task Order No. 4 via the Master Services Agreement for Wastewater Design Services with Dudek, approved at the June 17, 2024 City Council meeting. Dudek was selected for this contract having been engaged to provide Wastewater Design Services through a Request for Qualifications solicitation in Spring of 2024.
REVIEW & ANALYSIS
Dudek’s design services under Task Order 4 are:
• Collect site specific data related to projected wastewater flows at the MWWTP, as well as influent wastewater characteristics and effluent discharge criteria. • Review and evaluate three biological treatment alternatives, and select a preferred alternative using specific, weighted selection criteria and alternative rankings. • Prepare a Preliminary Engineering Repot which will summarize design criteria, and include a preliminary design based on the selected treatment process.
Dudek staff has provided excellent design services on the various elements of the City’s wastewater program and staff recommends that the City Council approve Task Order No. 4 under a Master Service Agreement with Dudek to complete Design Services on the MWWTP in the amount of $234,959.
How Recommendation Supports the Vision
Gonzales will continue to be a safe, clean, family-friendly community, diverse in its heritage, and committed to working collaboratively to preserve and retain its small town charm.
Explain: This project supports our vision by making improvements to the wastewater system to increase its capacity for residential and industrial developments.
Explain how the Recommendation Directly Implements the Mission The City Council and Staff of the City of Gonzales will realize our Vision by providing the leadership, commitment and resources necessary to provide excellent services that enhance the quality of life of our diverse community. X Yes ____ No____ N/A
Explain: Maintaining and improving the wastewater treatment plant enhances the community’s quality of life by providing for treatment and safe disposal of the City’s wastewater.
City services will be delivered in a cost-effective, respectful and friendly manner to insure the safety and well being of the residents and the promotion of business, recreational, housing and employment opportunities in an environmentally sustainable manner. X Yes ____No ____ N/A Explain: See Vision explanation above.
Strong fiscal policies allow us to provide appropriate infrastructure for:
• Public Safety X Yes No N/A
• Housing X Yes No N/A
• Recreation X Yes No N/A
• Environment X Yes No N/A
• Education X Yes No N/A
Explain: See Vision above.
ALTERNATIVES
Amend or modify staff’s recommendation.
BUDGET IMPACT
This contract will be funded via $294,000 grant issued by the California State Water Resource Control Board.
CONCLUSIONS
It is recommended that the City Council Adopt Resolution No. 2025-50, A Resolution of the City Council of the City of Gonzales Authorizing Task Order No. 4 under a Master Service Agreement with Dudek Consulting for Preparation of a Preliminary Design Report for Rehabilitation of the Wastewater Treatment Plant in the amount of $234,959.
Attachments:
1. Resolution No. 2025-50
2. Task Order No. 4 with Dudek Consulting for Preparation of a Preliminary Design Report for the Municipal Wastewater Treatment Plant under their Master Service Agreement
3. Dudek’s May 15, 2025 Proposal Letter