DATE: 08/06/2025
TO: Honorable Mayor and City Council Members
Honorable President and Board Members
FROM: Utilities Department
2025-312
REQUEST FOR CITY COUNCIL AND
CORONA UTILITY AUTHORITY ACTION
SUBJECT:
PROFESSIONAL SERVICES AGREEMENT WITH UTILITY SYSTEM SCIENCE &
SOFTWARE FOR THE SANITARY SEWER INFLOW AND INFILTRATION STUDY EXECUTIVE SUMMARY:
This staff report asks City Council to approve a Professional Services Agreement with Utility System Science & Software for the Sanitary Sewer Inflow and Infiltration Study, which will provide the City of Corona Utilities Department monitoring, inspection, and analysis services to support the City’s efforts to identify and address sources of extraneous water entering the sanitary sewer system, so that the City may design and implement an ongoing plan to control infiltration and inflow to the sewer system per City, State, and Federal guidelines.
RECOMMENDED ACTION:
That the City Council:
a. Award Request for Proposal 25-044AG to Utility Systems Science & Software to conduct a Sanitary Sewer Inflow and Infiltration Study. b. Approve the Professional Services Agreement with Utility System Science & Software of Santa Ana, CA in the amount of $500,000 to conduct a Sanitary Sewer Inflow and Infiltration Study for an initial contract term through June 30, 2027. c. Authorize the City Manager, or his designee, to execute the Professional Services Agreement with Utility System Science & Software in the amount of $500,000 including any non-substantive extensions, purchase orders, change orders, and amendments up to the amount authorized in Corona Municipal Code Section
3.08.070(I) which is equivalent to 10% or $50,000.
That the Corona Utility Authority review, ratify, and to the extent necessary, direct that the City Council take the above actions.
BACKGROUND & HISTORY:
The City of Corona has 435 miles of gravity flow sanitary sewer lines, 22 miles of sanitary sewer force mains, 2,280 manholes, and 17 lift stations that convey wastewater through the City to the treatment facilities. The Utilities Department is responsible for maintenance and repairs of these facilities. Historically, the system has experienced higher volumes of flow during rain events. The City receives most of its annual rainfall between January and the end of March. The average depth of groundwater, as observed in both flat and hillside monitoring wells, typically ranges from 97 to 150 feet in elevation; however, this depth can decrease during the rainy season. Inflow is defined as stormwater entering the sewer system through improper connections, such as roof drains, whereas infiltration refers to groundwater permeating the system via defects like cracks, leaks, or deteriorated joints in sewer pipes. These issues can lead to capacity overloads, increased treatment costs, and environmental hazards, including sanitary sewer overflows (SSOs).
To ensure proper maintenance of these systems and prevent sewer spills, the Utilities Department aims to conduct a comprehensive Sanitary Sewer Infiltration and Inflow Study. This study represents a proactive approach to addressing challenges within the city's sewer system during rain events, intending to generate actionable data that will inform both immediate maintenance activities and long-term capital improvement planning, thereby enhancing system reliability and regulatory compliance. By leveraging historical data, advanced technologies, and strategic partnerships, the study seeks to improve system reliability and reduce environmental risks.
ANALYSIS:
On March 19, 2025, the Purchasing Division issued Request for Proposal (RFP) 25- 044AG following the City Municipal Code (CMC) Section 3.08.110 Non-Public Projects formal bidding procedure and purchasing policy on the City’s PlanetBids bidding portal.
A total of 265 firms were solicited through PlanetBids. Thirty-five (35) firms and bid service companies downloaded the RFP documents. In turn, the bid service companies notify their clients of the potential bid opportunity, thereby providing additional exposure for the project. Two (2) proposals were received through the PlanetBids bidding service by the proposal due date of May 6, 2025, from the following vendors:
The scope of work and estimated costs per task related to the Inflow and Infiltration study submitted by Utility System Science & Software are outlined as follows:
Task
Baseline
Price
Mobilization and General Conditions $0
Task 1: Equipment Installation at 20 Locations $54,200
Task 2: Reporting Data and Season Summary $77,300
Task 3: Rain Event Monitoring Data (per event) * $2,960 Task 4: Cleaning and Video/CCTV Inspection (for 100ft) * $3,600 Task 5: Site Visit Per Manhole* $150
Task 6: Monitoring Stations 1 to 5 qty. Provide Unit Price (each)* $2,710 Task 7: Monitoring Stations 6 to 10 qty. Provide Unit Price (each)* $2,710 Task 8: Monitoring Stations 11 to 15 qty. Provide Unit Price (each)* $2,710 Task 9: Smoke Testing, 1000 feet if sewer line* $5,380
Task 10: Storm Event Data Collection and Report (per event) * $2,960 Total of All Tasks $154,680
* These items are priced as “per each” and the exact number of events is unknown and will be determined based on the initial findings and the measurable rain events that occur during the study period.
Following the analysis of the proposal evaluation and interview with each bidder, Utility System Science & Software was selected as the recommended consultant for the project.
Utility System Science & Software’s proposal demonstrated superior technical expertise, extensive experience in conducting inflow and infiltration studies, and a cost-effective approach that aligns with the City’s budgetary constraints. Additionally, their proposed methodology included innovative techniques for identifying and mitigating inflow and infiltration issues, which are critical to achieving the project’s objectives. By addressing inflow and infiltration, the study contributes to the strategic goals of reducing sanitary sewer overflows, improving system efficiency, and minimizing repair costs.
Staff recommend that the City Council approve a Professional Services Agreement with Utility System Science & Software to conduct a Sanitary Sewer Inflow and Infiltration Study for $500,000. While the total base price is $154,680, many of the quoted items will Vendor City Evaluation
Ranking
Utility Systems Science & Software Santa Ana, CA 1
West Coast Safety Supply, Inc. Fullerton, CA 2
need to be used multiple times and the exact quantity is unknown and will be determined based on the initial findings and consultations with staff. Additionally, some quoted items are per rain event and the quantity of measurable rain events for the season cannot be predicted. Therefore, staff requests $500,000 so the consultant can complete the required work as rain events occur. The agreement includes installation of inflow and infiltration equipment, reporting data and rain season summary, cleaning and CCTV inspections, smoke testing, and storm event data collection and report to improve system reliability, reduce environmental risks, and support sustainable urban development.
FINANCIAL IMPACT:
Funding for the recommended action is available in the Sewer Inflow and Infiltration Study Operating and Maintenance Project No. 78460 within the Sewer Utility Fund 572.
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 involves the study of existing infrastructure to maintain public health and safety. Therefore, it is exempt from the requirements of CEQA, and no environmental analysis is required.
PREPARED BY: KATIE HOCKETT, ASSISTANT UTILITIES DIRECTOR REVIEWED BY: TOM MOODY, UTILITIES DIRECTOR
ATTACHMENTS:
1. Exhibit 1 – PSA with Utility System Science & Software
2. Exhibit 2 – Proposal