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ADOPT A RESOLUTION APPROVING AN ADDENDUM TO THE 2005 DWSP EIR, AWARD A PROFESSIONAL SERVICES CONTRACT TO INFERRERA CONSTRUCTION MANAGEMENT GROUP, INC., AND ADOPT A RESOLUTION AUTHORIZING A CONTACT CHANGE ORDER FOR THE GROUNDWATER RECHARGE PROJECT
recommended action
RECOMMENDATION
It is recommended that the City Council adopt a resolution to:
1. Approve the Addendum to the certified 2005 Environmental Impact Report for the Delta Water Supply Project (State Clearinghouse No. 2003112060), pursuant to the California Environmental Quality Act Guidelines Section 15164, to support the proposed Groundwater Recharge Basins Project at the Delta Water Treatment Plant.
2. Approve findings pursuant to Stockton Municipal Code section 3.68.070 in support of an exception to the competitive bidding process.
3. Award a Professional Service Agreement to Inferrera Construction Management Group, Inc. of Shingle Springs, CA in the not-to-exceed amount of $728,760 for construction management services.
4. Adopt a resolution authorizing Contract Change Order No. 1 in the amount of $5,714,565 with Gateway Pacific Contractors, Inc. (Gateway Pacific) to increase the capacity and efficiency of the groundwater recharge project, for a total contract amount not-to-exceed $17,197,813.
It is also recommended that the City Manager be authorized to take appropriate and necessary actions to carry out the purpose and intent of this resolution.
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Summary
The Municipal Utilities Department (MUD) is comprised of three enterprise funds including Water, Wastewater and Stormwater Utilities. The Water Utility provides drinking water service to the northern and southern regions of the Stockton Metropolitan Area, with the California Water Service Company and San Joaquin County serving the central region. The Delta Water Treatment Plant began operation in May 2012, providing up to 30 million gallons per day of treated surface water from the San Joaquin Delta and Mokelumne River.
The DWTP was designed, in part, to protect the groundwater basin through conjunctive management of water resources and to improve the City’s water supply reliability portfolio. The construction of groundwater recharge basins adjacent to the treatment plant will increase the City’s conjunctive management capacity. When complete, the project will allow the City to directly recharge the groundwater basin using water from sources including Water Right Permit 21176, contract supplies from Woodbridge Irrigation District (WID), and possibly stormwater runoff from the City of Lodi. Water
recharged into the groundwater basin can be stored and pumped during dry years or extended droughts. The basins will also help to balance groundwater levels in the critically over-drafted Eastern San Joaquin Groundwater Subbasin to help meet the Region’s Sustainable Groundwater Management Act requirements.
If approved by the City Council, this action will adopt a resolution approving an Addendum to the 2005 Delta Water Supply Project Environmental Impact Report (Exhibit 1 to the Addendum Resolution), adopt a resolution awarding a $728,760 Professional Services Agreement to Inferrera Construction Management Group, Inc. for construction management services (Exhibit 1 to the construction management services Resolution), and adopt a resolution authorizing Contract Change Order No. 1 (CCO No.1) with Gateway Pacific (Exhibit 1 to the CCO Resolution) in the amount of $5,714,565 for a total contract not-to-exceed amount of $17,197,813.
DISCUSSION
Background
In November 2005, the City Council certified the Delta Water Supply Project (DWSP) Environmental Impact Report (EIR) State Clearinghouse number 2003112060. The 2005 DWSP EIR included a future groundwater recharge program and evaluated environmental impacts associated with implementation of groundwater recharge basins at the DWTP site.
In 2012, the MUD dedicated the Delta Water Supply Project (DWSP), a key component of the City’s conjunctive use program and to help balance groundwater levels in the Eastern San Joaquin Groundwater Subbasin. The DWSP provides surface water supplies to nearly 200,000 customers in north Stockton. The project included a river diversion and pumping station to convey water to the Delta Water Treatment Plant (DWTP) located along Lower Sacramento Road, north of Eight Mile Road between the City of Stockton and the City of Lodi.
The proposed project site encompasses approximately 130 acres and has a construction footprint of about 70 acres. The groundwater recharge infrastructure is designed to divert surplus surface water from both the Delta and the Mokelumne River to replenish the local groundwater basin.
In 2023, Geosyntec Consultants completed a feasibility study evaluating the suitability of implementing recharge basins at DWTP. The study concluded that soil conditions at the site are favorable for groundwater infiltration. Based on these findings, MUD staff solicited professional services for design, permitting, California Environmental Quality Act (CEQA) compliance, and construction of the recharge basins.
On September 10, 2024, by Resolution 2024-09-10-1207, the City Council awarded a design-build contract to Gateway Pacific to design and construct the recharge basins. The scope of work includes construction of three recharge basins, dry wells, access roads, integration into the existing SCADA system, underground piping, automatic modulating valves, flow meters, and development of operational and maintenance recharge programs.
This project helps implement public outreach goals and proposed projects within the Eastern San Joaquin Subbasin Groundwater Sustainability Plan (GSP), which was developed in accordance with the Sustainable Groundwater Management Act (SGMA). The project addresses critical overdraft conditions and promotes long-term groundwater sustainability for the region.
The Water Advisory Group and Council Water Committee reviewed staff recommendations to adopt the Addendum to the 2005 DWSP EIR, award a contract to Inferrera Construction Management Group, Inc. for construction management services, and approve CCO No. 1 to the Gateway Pacific contract at meetings held on July 3, 2025, and July 10, 2025, respectively.
Present Situation
To comply with CEQA, an Addendum to the certified 2005 DWSP EIR was prepared by Helix Environmental Planning, a subcontractor to Gateway Pacific. The Addendum incorporates updated technical analyses in areas such as air quality, biological resources, and cultural resources, confirming that the proposed enhancements do not result in environmental impacts beyond those previously disclosed in the 2005 DWSP EIR.
On May 1, 2025, MUD staff issued a Request for Proposals (RFP) for construction management services. On May 29, 2025, the following six firms submitted proposals:
|
Company |
Location |
Cost |
|
Esposo Property Maintenance And Construction |
Stockton, CA |
$595,212 |
|
Alpha CM, Inc |
Folsom, CA |
$617,891 |
|
Inferrera Construction Management Group, Inc |
Shingle Springs, CA |
$728,760 |
|
Dillon & Murphy Engineering |
Lodi, CA |
$866,506 |
|
Kjeldsen, Sinnock & Neudeck, Inc |
Stockton, CA |
$905,827 |
|
Hazen and Sawyer |
Sacramento, CA |
$1,883,730 |
A selection committee evaluated the proposals based on criteria including the firms’ understanding of the scope of work, proposed project approach, experience with similar services, team qualifications, and overall cost. Inferrera Construction Management Group, Inc. met or exceeded expectations in all categories and was determined to be the most qualified firm.
In addition, construction of the recharge basins requires a full-time inspector and a part-time construction manager to ensure all work is completed in accordance with the approved engineering design drawings. MUD does not have the internal staffing or technical expertise to perform these functions; therefore, it is necessary to hire Inferrera Construction Management Group, Inc. to provide construction management services.
On initial review of the draft project design plans, it was found that modifications to the original design-build contract with Gateway Pacific were necessary to increase the estimated recharge capacity from approximately 11,000 acre-feet per year to nearly 20,000 acre-feet per year. Upgrades to the habitat plan and visitor center design will also support educational outreach initiatives for local schools and the community about water conservation and sustainability, groundwater recharge, and the protection of natural ecosystems.
Environmental Clearance
CEQA Guidelines Section 15164 allows for an addendum to a certified EIR if changes to the project do not result in new significant environmental effects or substantially more severe impacts. The proposed Groundwater Recharge Basins Project:
• Does not involve new or expanded project elements outside the scope analyzed in the 2005 DWSP EIR.
• Does not trigger any new significant impacts not previously disclosed.
• Remains consistent with the original project objectives and environmental mitigation framework.
Therefore, an Addendum to the certified 2005 DWSP EIR satisfies environmental requirements for this project.
Findings
Pursuant to Stockton Municipal Code section 3.68.070, the City Council may approve findings which support and justify an exception to the competitive bidding process. The following findings support and justify an exception:
1. A strict cost-competitive basis for the selection of professional services may lower the quality and thoroughness of the services provided because it does not consider experience, reputation, quality of work and track record handling similar projects.
2. Considering the size, complexity, and schedule requirements of the project, the City does not have sufficient staff resources nor the expertise to act as the inspector or the construction manager for a groundwater recharge construction project.
3. Use of the RFP process is appropriate for this Professional Services Contract because it relies on the evaluation of professional qualifications and performance as the basis for selection of a vendor. Use of these criteria ensures that the selected firm will provide the highest quality professional service, which is in the public interest.
4. The City negotiated a contract following the solicitation of competitive proposals in accordance with SMC section 3.68.070.A.3.
The proposed resolution will award a Professional Services Agreement to Inferrera Construction Management Group, Inc, in the not-to-exceed amount of $728,760 for construction management services.
FINANCIAL SUMMARY
There are sufficient funds available in the Water Capital Improvement Projects Fund under Project Number UH21005 to cover the costs associated with executing a $728,760 contract with Inferrera Construction Management Group, Inc. for construction management services, and approving a contract change order to Gateway Pacific in the amount of $5,714,565 for a total contract not-to-exceed amount of $17,197,813. No additional funding is required or being requested in connection with the approval of the Addendum to the 2005 DWSP EIR (State Clearinghouse No. 2003112060).
The City has secured three separate grant awards to support this project:
• SGMA Round 1 Grant - $300,000 (fully received in FY 2023-24)
• IRWM Grant - $2,000,000 (two reimbursement requests submitted to date totaling $250,000)
• WaterSMART Grant - $400,000 ($165,000 received to date in FY 2024-25)
This action has no impact on the General Fund or any other unrestricted funds.