DATE: 06/17/2026
TO: Honorable Mayor and City Council Members
Honorable President and Board Members
FROM: Utilities Department
2026-228
REQUEST FOR CITY COUNCIL AND
CORONA UTILITY AUTHORITY ACTION
SUBJECT:
NEW OPERATING AND MAINTENANCE PROJECT FOR REPLACEMENT OF
VARIABLE FREQUENCY DRIVES AT THE MANGULAR BLEND STATION EXECUTIVE SUMMARY:
This staff report asks City Council to approve the creation of a new operating and maintenance project to complete the evaluation and replacement of five variable frequency drives at the Mangular Blend Station and authorize an appropriation of $225,500 from the Water Utility Fund 570 to this project.
RECOMMENDED ACTION:
That the City Council:
a. Authorize the creation a new operating and maintenance project titled “Mangular Blend Station Variable Frequency Drive Replacement.”
b. Authorize an appropriation in the amount of $225,500 from the Water Utility Fund 570 to the new project titled Mangular Blend Station Variable Frequency Drive Replacement.
That the Corona Utility Authority review, ratify, and to the extent necessary, direct the City Council to take the above actions.
BACKGROUND & HISTORY:
The Utilities Department’s Mangular Blend Station located at 1422 West Ontario Avenue serves as a primary blending facility within the City’s potable water system. The station blends groundwater with imported surface water to ensure consistent water quality and to maintain compliance with state and federal drinking water regulations. The facility also provides on‑ site chemical addition, including the controlled application of sodium hypochlorite and ammonia for chloramination, to ensure effective disinfection and stable residual levels within the distribution system. In addition, the station is equipped with five high‑ capacity booster pumps that convey the blended water into two higher‑ elevation pressure zones, supporting system cycling, water storage tank levels, and overall distribution system resiliency.
On May 25, 2026, the Mangular Blend Station lost power due to a Southern California Edison outage. This outage resulted in multiple breakers in the facility tripping, including the booster pump breakers, a motor control center (MCC) panel breaker, and the generator panel breaker. Ultimately all five of the variable frequency drives (VFDs) running this facility were destroyed. The Mangular Blend Station cannot operate without at least three functioning VFDs, with two additional VFDs acting as backup.
ANALYSIS:
In order to ensure the Mangular Blend Station continues to operate, the Utilities Department requires the installation of five replacement Allen-Bradley VFDs. These VFDs will be supplied by Royal Industrial Solutions under their existing agreement. AllenBradley VFDs have been designated as Exclusive Standard Equipment by Utilities Department under Public Contract Code (PCC) 3400 approved through Resolution 2022- 046.
Before completing replacement of the VFDs, Utilities Department will investigate the protective equipment at Mangular Blend Station to determine why the VFDs were destroyed during the outage. The surge protectors, fuses, and breakers should have protected the VFDs from any damage. To ensure the new VFDs will be protected in the event of a subsequent outage, this investigation will determine a cause and provide a course of correction prior to installation.
Utilities Department estimates the following will be needed to complete the investigation and replacement of equipment at Mangular Blend.
Task Vendor Est. Cost
VFD Purchase and Installation Royal Industrial
Solutions
$175,000
Protective Device Investigation Rockwell Automation* $15,000 Active Filter Inspection TCI Active Filter $2,500
Task Vendor Est. Cost
Electrical Engineer Evaluation Albert Webb &
Associates
$10,000
Breaker Evaluation Baker Electric $2,500
10% Contingency $20,500
Total $225,500
*Subcontracted through Royal Industrial Solutions
In order to maintain water distribution system supply and resiliency, Utilities Department requests approval of a new operating and maintenance project titled “Mangular Blend Station Variable Frequency Drive Replacement” and an appropriation of $225,500 from the Water Utility Fund 570.
FINANCIAL IMPACT:
Approval of the recommended actions will result in an appropriation in the amount of $225,500 from the Water Utility Fund 570 to the newly created Operating and Maintenance Project titled “Mangular Blend Station Variable Frequency Drive Replacement.” There is sufficient working capital in the Water Utility Fund 570 for the recommended action.
ENVIRONMENTAL ANALYSIS:
This action is categorically exempt pursuant to Section 15302 (c) of the Guidelines for the California Environmental Quality Action (CEQA), which states that “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 consists of the replacement of existing VFDs at the Mangular Blend Station and therefore, is exempt from the requirements of CEQA. No environmental analysis is required.
PREPARED BY: ERIN KUNKLE, MAINTENANCE MANAGER
REVIEWED BY: TOM MOODY, UTILITIES DIRECTOR
ATTACHMENT:
1. Exhibit 1 – Resolution No. 2022-046