City of Corona
Staff Report
400 S. Vicentia Ave.
Corona, CA 92882
File #: 22-0579
REQUEST FOR CITY COUNCIL AND
CORONA UTILITY AUTHORITY ACTION
DATE: 07/06/2022
TO: Honorable Mayor and City Council Members
Honorable President and Board Members
FROM: Utilities Department
SUBJECT:
Appropriation from the Sewer Utility Fund to Water Reclamation Facility 1 Primary and Secondary Clarifiers Rehabilitation Project.
EXECUTIVE SUMMARY:
City Council consideration of a request for authorization to appropriate $79,929 from the Sewer Utility Fund (572) to Water Reclamation Facility No. 1 Primary and Secondary Clarifier Rehabilitation Capital Improvement (CIP) Project No. 69840 to complete electrical related upgrades for two rectangular primary and six secondary clarifiers. Primary and secondary clarifiers are important components of the water reclamation to meet the California Regional Water Quality Control Board Santa Ana region and National Pollutant Discharge Elimination System Permit requirements. Water Reclamation Facility No. 1 is located at 2205 Railroad Street.
RECOMMENDED ACTION:
That the:
a. City Council authorize an appropriation in the amount of $79,929 from the Sewer Utility Fund (572) to the Water Reclamation Facility 1 Primary and Secondary Clarifiers Rehabilitation Capital Improvement Project No. 69840.
b. City Council authorize the City Manager and City Attorney or their designees to negotiate and execute non-substantive extensions, change orders, and amendments up to 26% of the total contract cost or $207,594.
c. City Council authorize the Purchasing Agent to issue a change order in the amount of City of Corona Page 1 of 4 Printed on 6/29/2022
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File #: 22-0579
c. City Council authorize the Purchasing Agent to issue a change order in the amount of $207,594 to purchase order, P22172.
d. Corona Utility Authority review, ratify, and to the extent necessary, direct the City Council to take the above actions.
BACKGROUND & HISTORY:
Water Reclamation Facility No. 1 (WRF1) is located at 2205 Railroad Street. The facility treats 11.5 million gallons per day (MGD) of raw sewage. The treatment system includes the headworks, two secondary treatment plants (Plant 1A and Plant 1B), tertiary filters, and a chlorine contact basin. The headworks consist of a rotating screen unit and a grit removal system. A flow splitter separates up to
5.5 MGD of the effluent from the headworks to Plant 1A, while the remainder of the flow is sent to Plant 1B.
The design capacity of Plant 1A is 5.5 MGD. The treatment processes consists of two rectangular primary clarifiers units; an activated sludge process with nutrient removal capabilities, and secondary clarification provided by six rectangular clarifier units. The primary and secondary clarifier units are equipped for sludge recovery and conveyance to onsite biosolids handling facilities.
The design capacity for Plant 1B is 6.0 MGD. The treatment consists of two parallel oxidation ditches with separate oxic and anoxic zones and two circular secondary clarifier units with sludge recovery.
Secondary treated wastewater from Plants 1A and 1B is discharged to a flow equalization basin.
Water from the equalization basin is pumped directly to the tertiary filtration system. Effluent from the tertiary treatment system is discharged to the Santa Ana River through the Butterfield drain, pumped to three offsite percolation ponds or used in the City-wide reclaimed water distribution system.
Primary and secondary clarifiers at Plants 1A and 1B are important components of the water reclamation facility to meet the California Regional Water Quality Control Board Santa Ana region Order No. R8-2020-0021 and National Pollutant Discharge Elimination System Permit No. CA8000383 requirements. The Utilities Department (UD) has a robust operations and maintenance program that ensures compliance with all Federal and State requirements. UD’s state-certified operators monitor the facility around the clock. Maintenance staff performs weekly and monthly preventive maintenance inspections and repairs to the facility components.
ANALYSIS:
On May 19, 2021, the City Council authorized the award of a construction contract with J.R. Filanc Construction Company, Inc. (Filanc) in the amount of $822,860. The scope of work included rehabilitation of all ten (eight rectangular and two circular) clarifiers at WRF1 as part of Notice of Inviting Bids (NIB) 21-039CA bid schedules A and B.
Bid schedule C was also awarded, which was bid as an alternative bid item. The scope of work consisted of removing the existing stationary scum piping at the eight rectangular clarifiers and replacing the scum piping system, including a motor-driven assembly that can be operated remotely or by set time intervals.
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File #: 22-0579
Below is the list of approved change orders to date on the project and the remaining balance of the change order authority.
No Description Credit Change
Order
Balance
Approved change order authority $164,572.00
1 Credit for material change from fiberreinforced pipe to stainless steel$67,854.67 $232,426.67 2 Replace circular clarifier # 2 damaged Hframe$52,815.00 $179,611.67 3 Installation of additional flights at two
primary rectangular clarifiers
$6,513.68 $173,097.99
4 Time and material - Install strongback truss
support for scum system arm for both
circular clarifiers
$8,431.90 $164,666.09
5 Install stainless steel plates to cover
opening left after the removal of the
existing scum system
$20,359.25 $144,306.84
The UD is requesting change order no. 6 to replace existing electrical conduits and wiring to the scum system drives. According to the bid documents, existing conduits and wiring were to be used to power the newly-installed scum piping system. However, after the old scum piping system was removed and further inspection of the conduits and wiring by the Maintenance and Operations staff, it was determined that it would be beneficial to reroute them. The existing wiring conduit is routed below the concrete deck through the aeration effluent channel in a wet environment and is subject to moisture and other gases that cause corrosion. Staff proposes to run the electrical conduits and wiring to all eight rectangular clarifiers above the concrete deck to eliminate a corrosive environment and resulting failures.
Filanc provided a proposal in the amount $213,618. City staff also obtained a proposal from our oncall electrical contractor and confirmed that the cost was comparable. Staff further revised the scope of work and asked the contractor to revise their proposal. In response, Filanc submitted a revised proposal in the amount of $187,235 to complete the work.
Proposed electrical upgrades cost includes labor and materials of the following:
· 600 feet of 1” polyvinyl chloride (PVC) coated galvanized rigid steel conduit · 600 feet of 2” PVC coated galvanized rigid steel conduit · 8 equipment connections for 480-volt with seal tight flexible conduit with PVC coated fittings · 8 circuit disconnects NEMA4X Poly
· All new copper #10 XHHW conductor for each 3-phase equipment (8) · All new copper #14 XHHW conductor for controls for each equipment · Overhead conduit rail stands/supports with anchors
· Support for start-up and testing of all 8 pieces of equipment and controls There is currently $144,307 available in the previously approved change order authority; staff is City of Corona Page 3 of 4 Printed on 6/29/2022
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File #: 22-0579
There is currently $144,307 available in the previously approved change order authority; staff is requesting additional funding in the amount of $79,929 to authorize change order no. 6 to complete the project. The remaining balance of approximately $37,000 will be used as needed for project management and miscellaneous materials purchased by City staff for the project.
FINANCIAL IMPACT:
The UD requests an appropriation in the amount of $79,929 from the Sewer Utility Fund (572) to the Water Reclamation Facility 1 Primary and Secondary Clarifiers Rehabilitation CIP No. 69840.
Fund 07/01/22 Est.
Working Capital
Budgeted
Revenues/
Sources
Budgeted
Expenditures/
Uses
Working
Capital
Impacts
06/30/23 Est.
Working Capital
Sewer Utility Fund 572 $38,460,751 $33,146,726 ($42,353,028) Appropriation ($79,929)
$29,174,520
ENVIRONMENTAL ANALYSIS:
This action is categorically exempt pursuant to Section 15301(d) of the Guidelines for the California Environmental Quality Action (CEQA), which states that “Restoration or rehabilitation of deteriorated or damaged structures, facilities, or mechanical equipment to meet current standards of public health and safety, unless it is determined that the damage was substantial and resulted from an environmental hazard such as earthquake, landslide, or flood” is therefore exempt from CEQA. This action involves repairs/rehabilitation to existing structures to meet current standards of public health and safety and therefore is exempt from the requirements of CEQA. Therefore, no environmental analysis is required.
PREPARED BY: AFTAB HUSSAIN, MAINTENANCE MANAGER
REVIEWED BY: TOM MOODY, DIRECTOR OF UTILITIES
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