City Council Agenda Report
TO: Mayor Clauzel and Members of the City Council
FROM: Fernando Ulloa, City Manager
BY: Mike Willett, Public Works Director
MEETING DATE: July 15, 2025
ITEM NO: 6.10
SUBJECT: Approve an Amendment to Contract with Woodard & Curran for Update to Chrome 6 Feasibility Study and Authorize the Finance Department to make the Necessary Budget Amendment.
RECOMMENDATION
Motion to Approve an Amendment to Contract with Woodard & Curran for Update to Chrome 6 Feasibility Study and Authorize the Finance Department to make the Necessary Budget Amendment.
BACKGROUND
In 2017, Woodard & Curran completed a feasibility study for the City of Patterson evaluating potential treatment strategies for Hexavalent Chromium (Chrome 6) in the municipal water system. Due to regulatory changes and evolving groundwater management needs, the study was reinitiated in 2025.
Following the submittal of a preliminary proposal in October 2023, City staff requested additional evaluation criteria related to aquifer management, regulatory compliance and regional growth, necessitating an amendment to the existing contract.
ANALYSIS
The amended scope of work includes a broader set of technical and planning elements designed to better inform future infrastructure decisions. Key components of the update include:
· Evaluation of treatment options to comply with the revised Chrome 6 Maximum Contaminant Level (MCL).
· Analysis of wellhead versus centralized treatment strategies. · Assessment of alternative water supply sources, including Upper Aquifer groundwater and surface water from nearby irrigation districts.
· Planning-level evaluation of conveyance system hydraulics. · Incorporation of updated demand projections and Lower Aquifer pumping limits from the Delta-Mendota Subbasin Groundwater Sustainability Plan (GSP). · Consideration of co-treatment for other constituents including 1,2,3-TCP, TDS, and nitrate.
· Integration with SGMA compliance and growth-related infrastructure planning.
This updated study ensures the City has a comprehensive and up-to-date foundation for addressing long-term water quality and supply challenges.
FISCAL IMPACT
The total cost of the contract amendment is $84,980. Funding for this amendment was included in the FY 2024-25 budget under the Groundwater Management Activities line item (611-790- 7586). However, because the work was anticipated to begin late in the fiscal year, any unused funds originally allocated for this activity that were not spent during FY 2024-25 created budget savings. Those savings are adequate to fund this request and are now available for use in FY 2025-26 as an element of Fund Balance.
Approval of this action authorizes the use of Fund Balance in FY 2025-26 to support the amended scope of work with Woodard & Curran.