CITY OF SAN MATEO
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CITY OF SAN MATEO
Agenda Report
City Hall
330 W. 20th Avenue
San Mateo CA 94403
www.cityofsanmateo.org
Agenda Number: 6 Section Name: CONSENT CALENDAR Account Number: 72-4671 File ID: 26-11100 TO: City Council
FROM: Alex Khojikian, City Manager
PREPARED BY: Public Works Department
MEETING DATE: May 18, 2026
SUBJECT:
Wastewater Treatment Plant Immediate Actions Projects Package-III —Appropriation and Contingency Increase RECOMMENDATION:
Adopt a Resolution to appropriate $1,200,000 from the Sewer Fund unassigned fund balance to the Wastewater Treatment Plant Immediate Actions Projects (IAP) Package-III project; increase the contingency reserve by $1,200,000 for the associated construction contract with Mountain Cascade, Inc.; and authorize the Public Works Director to issue change orders within the increased contingency.
BACKGROUND:
The City is currently under a Regional Water Quality Control Board Cease and Desist Order requiring improvements to its sewer collection system and Wastewater Treatment Plant (WWTP) to eliminate sanitary sewer overflows and unauthorized discharges of untreated or partially treated wastewater to San Francisco Bay. The Clean Water Program (CWP) includes several capital improvement projects that are currently under construction to support the City’s compliance with the Cease and Desist Order.
The WWTP Immediate Actions Projects Package-III (IAP-III) project is a component of the CWP and includes improvements to the WWTP’s effluent pump station, site waste pump station, and plant-wide mechanical and electrical equipment, as well as replacement of effluent flowmeters and sludge heating and recirculation piping. The project is part of CWP’s efforts to modernize the existing WWTP and maintain safe and reliable operations. The effluent pump station improvements include replacing pipes and installing new effluent pumps and flow meters.
On May 15, 2023, the City awarded a construction contract to Mountain Cascade, Inc. (MCI) for $11,344,696, which was approximately 25% below the engineer’s estimate of $15,248,000. Council approved the contract amount along with a $2,270,000 contingency (20% of the contract value) to allow staff to mitigate the risk and impacts from other active construction efforts, as well as impacts due to unanticipated field conditions.
As of April 2026, construction of IAP-III has progressed substantially; however, several unforeseen and differing site conditions and field discrepancies from contract drawings have materially impacted cost, schedule, and constructability.
The majority of these unanticipated changes have primarily occurred at the Site Waste Pump Station (SWPS) and the Effluent Pump Station (EPS). The summary of these changes is described below:
1. Differing Site Conditions at the SWPS
Field investigations revealed that an existing 48-inch sanitary sewer settled and has a lower elevation than what is shown in the contract documents. Corrective work requires approximately 40 working days of effort and includes:
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• Demolition and replacement with a pile-supported manhole • Additional pile support for downstream structures
• Elevation modifications to maintain hydraulic performance • A Dissolved Air Flotation Thickener (DAFT) bypass to allow construction access
2. Electrical Infrastructure Failures at the EPS
The project design assumed reuse of existing conduits; however, field conditions indicate corrosion, water intrusion, and/or other obstructions have rendered the conduits and raceway too degraded for its intended reuse.
Corrective work requires approximately 60 working days of effort and includes:
• New reinforced concrete duct banks
• Additional pull boxes and rebar reinforcement
• Settlement mitigation using deflection/expansion couplings • Crawlspace slab repairs
• Rerouting conductors to avoid plant shutdowns
• Wiring modifications
The resulting delays, expanded scope, and corrective work necessitates a contingency increase to complete IAP-III and maintain the June 2026 substantial completion target. If these issues are not promptly addressed, the Project will be delayed resulting in further cost and schedule impacts.
Approximately $1,360,000 of the $2,270,000 owners’ contingency has been negotiated for additional work required to evaluate and restore failed infrastructure necessary for this Project. An additional $250,000 was negotiated for a new electrical duct bank because the existing conduits could not be reused. These changes result in having only $660,000 remaining in contingency. An additional $1,200,000 (increasing the remaining contingency to $1,860,000) is needed to complete the changes described in the above paragraphs.
To ensure there is sufficient funding to complete the IAP-III, staff recommends a $1,200,000 contingency increase to fund the completion of the project.
BUDGET IMPACT:
There is currently not sufficient budget in the WWTP IAP-III (46T010) project available to fund the expanded scope and needs from these unforeseen issues in addition to the remaining planned work for the project. Sufficient funds are available in the unassigned balance of the Sewer Fund for the requested appropriation of $1,200,000. Approval of this action will increase the IAP-III contingency by $1,200,000, raising the total authorized contingency from $2,270,000 to $3,470,000. This additional appropriation will boost the remaining contingency from $660,000 to $1,860,000, providing the funds needed to complete the project.
ENVIRONMENTAL DETERMINATION:
The Council action approving a budget appropriation is not a project subject to CEQA, because it consists of a fiscal activity which does not involve any commitment to any specific project which may result in a potentially significant physical impact on the environment. (CEQA Guidelines Section 15378(b)(4).) In addition, the City prepared a Final Programmatic Environmental Impact Report (Final PEIR) in accordance with the California Environmental Quality Act (CEQA) (SCH No. 2015032006). Council on June 6, 2016, certified the PEIR. In accordance with CEQA, the Final PEIR serves as the primary environmental compliance document for the implementation of the Clean Water Program. The City prepared Addenda to the Final PEIR that was approved on July 16, 2018 (Addendum 1) and April 15, 2019 (Addendum 2). This work is within the scope of the Project evaluated in the PEIR and Addendum.
NOTICE PROVIDED
All meeting noticing requirements were met.
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ATTACHMENTS
Att 1 – Proposed Resolution
STAFF CONTACT
Thomas Ruark, Senior Project Manager
[email protected]
(650) 522-7280
Thomas W. Williams, Engineering Manager
[email protected]
(650) 522-7307