City Council
259 N. Wilma Avenue
Ripon, CA 95366
MEMO
To: Honorable City Council
From: James Pease, Public Works Director
Date: 11/10/2025
Subject: Stantec Consulting Services, Inc.
RECOMMENDED ACTION:
Approve and authorize the Mayor to sign the Professional Services Agreement with Stantec Consulting Services to evaluate the water quality of Well 19 in the not to exceed amount of $52,069 (funding source: Water Enterprise Capital Fund).
BACKGROUND:
Well 19 was constructed in 2022 at Mistlin Sports Park and was permitted by the State of California to supply drinking water in 2023. Two water quality issues have come up that staff is recommending be investigated.
Hexavalent Chromium (Chromium 6)
State Water Board regulations have recently been established for chromium 6 in public drinking water systems. Chromium 6 is an odorless and tasteless metal that occurs naturally throughout the environment although contaminated waste from certain industrial activities have also contributed to ground water contamination.
The City was required to conduct initial monitoring for all of its drinking water wells and the only City well impacted by these regulations is Well 19. California water suppliers with systems the size of Ripon’s are not required to meet these new regulatory limits until October 2027, although, suppliers are required to perform prescribed water quality testing prior to this date.
Based on the testing completed to date, the concentration of chromium 6 is anticipated to be very close to or exceed the State of California regulatory Maximum Contaminant Limit (MCL).
Nitrates
Nitrate concentrations have been increasing since this well has gone into service and based on the trending data, would exceed the regulatory MCL in the near future if the well was continued to be used as a primary water source. The Public Works Department has taken the proactive step to use this well only as a stand-by well until an investigation has been completed to evaluate options.
DISCUSSION/ANALYSIS:
Staff has requested a scope and fee from Stantec Consulting Services, Inc (Stantec) to perform the following water quality investigation at Well 19:
Sample and analyze two monitoring wells and production Well 19, provide direction and oversight of sampling activities, provide a technical memorandum and recommendations. Develop a vertical well profiling program based on the initial sample results and recommendations in order to identify the specific quality of water within each screened interval.
Present options for well modifications that allows the City to use Well 19 as a primary water source while meeting all State and Federal regulatory concentrations for chromium 6 and nitrates.
Stantec has submitted a proposal to complete the above items of work for a total fee of $52,069.
FISCAL IMPACT:
The attached Professional Services Agreement with Stantec Consulting Services includes a proposal outlining the tasks as Exhibit A. The cost to complete the work within the proposal is a not to exceed amount of $52,069 which will be funded by the Water Enterprise Capital Fund.
The current balance of this Fund is $8.5 million.
Attachments:
1. 2025-11-10 Well 19 Water Quality Investigation PSA