City of Corona
Staff Report
400 S. Vicentia Ave.
Corona, CA 92882
File #: 22-0526
REQUEST FOR CITY COUNCIL AND
CORONA UTILITY AUTHORITY ACTION
DATE: 06/15/2022
TO: Honorable Mayor and City Council Members
Honorable President and Board Members
FROM: Utilities Department
SUBJECT:
Second Amendment to the Professional Services Agreement with Albert A. Webb Associates for the engineering design of Water Reclamation Facility No. 1 Digester Dome Replacement Project.
EXECUTIVE SUMMARY:
The Second Amendment to the Professional Services Agreement with Albert A. Webb Associates is for the design of a fixed concrete dome for Anaerobic Digester No. 2 at Water Reclamation Facility No. 1. The existing digester has a floating steel dome that has corroded beyond repair and must be replaced immediately to maintain the sludge processing operations and the other treatment processes to maintain regulatory compliance.
RECOMMENDED ACTION:
That the:
a. City Council approve the Second Amendment to the Professional Services Agreement to increase the total compensation to an amount not to exceed $451,440 and extend the term through June 30, 2023, for Water Reclamation Systems Design services. b. City Council authorize the City Manager, or his designee, to execute the Second Amendment to the Professional Services Agreement with Albert A. Webb Associates, including making minor and non-substantive changes.
c. City Council authorize the Purchasing Manager to issue a change order to Albert A Webb Associates’ purchase order in the amount of $201,440 through June 30, 2023. d. City Council authorize the creation of a new Capital Improvement Project titled, “Water City of Corona Page 1 of 4 Printed on 6/9/2022
powered by Legistar™
File #: 22-0526
d. City Council authorize the creation of a new Capital Improvement Project titled, “Water Reclamation Facility No. 1 Digester Dome Replacement Project.” e. City Council authorize an appropriation in the amount of $250,000 from the Sewer Utility Fund (572) to the newly created Water Reclamation Facility No. 1 Digester Dome Replacement Project.
f. Corona Utility Authority review, ratify, and to the extent necessary, direct the City Council to take the above actions.
BACKGROUND & HISTORY:
The Utilities Department (UD) operates three water reclamation facilities. Water Reclamation Facility No. 1 (WRF1) receives and treats approximately 11.5 million gallons per day of raw sewage. Sludge processing and solids handling occurs at WRF1 for all three treatment facilities. WRF1 has three circular concrete digesters that hold approximately 500,000 gallons (each) of sludge that are processed and dewatered every day. Digester No. 2 is unique, as it was originally equipped with a floating cover. It is an industry best practice to drain and remove all fluids and sludge approximately every five years to not only conduct a visual inspection of the concrete structure and the internal components of the Digester, but to remove accumulated grit and debris to restore design sludge treatment and holding capacity. The UD’s anerobic digesters are an essential part of the wastewater treatment process to keep the facility in regulatory compliance.
ANALYSIS:
The existing dome at WRF1 is made of carbon steel and was installed in 1968. During the last scheduled inspection, it was discovered that the structural members of the floating steel dome of Digester No. 2 had started to corrode. Based on this inspection report, a project to replace the dome was scheduled to begin design during Fiscal Year (FY) 2023 with construction in FY 2024. However, during the most recent inspection, staff found that the steel floating dome had further corroded creating a potential for a catastrophic structural failure. Due to safety and regulatory concerns, the digester has been taken out of service until the necessary upgrades are completed. Currently, Digesters Nos. 1 and 3 have concrete covers and have been performing well. Based on the performance of Digesters Nos. 1 and 3, the Department is recommending Digester No. 2 also be equipped with a concrete cover.
The UD was planning to begin a new Capital Improvement Project (CIP) for this project in FY 2023 and install a new concrete cover in FY 2024. However, it is necessary to fast track the design and replacement of the dome due to its impacts on the treatment process.
UD utilizes various professional services during the planning and design of Capital Improvement Projects. For large capital projects, specifications are developed, and the project bid is conducted for the whole project. However, for smaller projects, existing on-call contracts with consultants are utilized in order to quickly and efficiently complete these smaller-scale projects.
On June 6, 2019, City Council awarded Request for Proposals (RFP) 19-016CA to multiple firms for various professional services including on-call engineering and professional consulting services. RFP 19-016CA was published on November 16, 2018, in Sentinel Weekly News and other bidding platforms. Albert A. Webb Associates was awarded a professional services agreement for on-call engineering service for water reclamation design services in the amount of $250,000 per fiscal year City of Corona Page 2 of 4 Printed on 6/9/2022
powered by Legistar™
File #: 22-0526
for as needed engineering services.
Due to the urgency of this project, staff believes it is in the best interest of the City to amend the existing professional services agreement with Albert A. Webb Associates to provide design services for this project, including preparing plans and specifications and providing bid support during the project bidding phase.
Typical design cost for a capital improvement project is 10 to 20 percent of the total cost of a public project, depending on the complexity of the project. Conversion of a steel floating dome to a concrete fixed dome is a small but complex project that often includes a very aggressive design and construction completion timeline.
The scope of work for this project consists of preparing the plans and specifications as well as providing bid support for the replacement of the existing floating steel dome with a fixed concrete dome. The project will be performed with an expedited timeline while the facility remains operational.
The Engineer’s estimate of total project costs are as follows:
WRF 1 Dome Replacement Project
Design Services, including Plans, Specifications and bid support
$201,440
Demolition, mechanical piping, construction of concrete dome, electrical/instrumentation, construction sequencing and phasing and commissioning
$2,175,000
Construction and project management services $217,500
Contingencies $652,500
Total $3,246,440
Due to changing market conditions and fluctuating material costs, the UD is not asking for construction funding at this time. Funding is currently only requested for design services, and staff will return to the City Council to award the actual bids for construction once received and appropriate additional project funding as required. The cost shown above is strictly just the Engineer’s Estimate; actual costs may vary.
FINANCIAL IMPACT:
The financial impact of the Second Amendment to the Professional Services Agreement for Water Reclamation Design Services is $201,440. The UD requests an appropriation in the amount of $250,000 from the Sewer Utility Fund (572) to the newly created Water Reclamation Facility No. 1 Digester Dome Replacement Project. The requested amount will cover design costs plus an additional 10%, or $20,144, for any necessary change orders. As this is an older facility, UD is requesting the amount of $28,146 be also allocated to the project as an additional contingency for any unanticipated project needs. Any unused portion of the design money will remain in the CIP and be utilized toward construction costs.
Fund 07/01/21 Est.
Working Capital
Budgeted
Revenues/
Sources
Budgeted
Expenditures/
Uses
Working Capital
Impacts
06/30/22 Est.
Working Capital
Sewer Utility Fund 572 $38,460,751 $32,893,509 ($47,313,717) Appropriation ($250,000)
$23,790,543
City of Corona Page 3 of 4 Printed on 6/9/2022
powered by Legistar™
File #: 22-0526
ENVIRONMENTAL ANALYSIS:
This action is categorically exempt pursuant to Section 15301 of the Guidelines for the California Environmental Quality Act (CEQA), which is defined as “Existing Facilities (§ 15301) - operation, repair, maintenance, permitting, leasing, licensing, or minor alteration of existing public or private structures, facilities, mechanical equipment, or topographical features, involving negligible or no expansion of use beyond that existing at the time of the CEQA determination” and is therefore exempt from CEQA. This action merely involves the acquisition of design services for the replacement of the WRF1 digester dome. Therefore, no environmental analysis is required.
PREPARED BY: AFTAB HUSSAIN, MAINTENANCE MANAGER
REVIEWED BY: TOM MOODY, DIRECTOR OF UTILITIES
Attachment:
1. Exhibit 1 - Second Amendment to PSA with Albert A. Webb Associates City of Corona Page 4 of 4 Printed on 6/9/2022
powered by Legistar™