Agenda Item Wording:
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Water Reclamation Facility (WRF) - Master Plan Final Update - Receive a final report and presentation on the Master Plan for the Water Reclamation Facility.
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Deadline for Action: 6/17/2024
Submitting Department: Public Works
Contact Name and Phone Number: Ben Litwack, Public Works Manager, ben.litwack@visalia.city, 713-4671
Department Recommendation:
Staff recommends that Council receive a report and presentation on the Master Plan for the Water Reclamation Facility (WRF).
Background Discussion:
In 2008, a Facility Master Plan was completed for the Visalia Water Reclamation Facility (WRF), designed with a 20-year outlook. Typically, Master Plans are updated every 8-10 years to ensure that they remain aligned with the evolving needs and growth of the community. Over time, significant developments and changing conditions necessitated an update to address current and future challenges effectively.
Carollo is well-respected and prominent engineering firm that specializes in water and wastewater management. With offices nationwide, Carollo has provided direct services locally out of their Fresno office, but has the ability to call on specific areas of expertise from their resources throughout the country. Carollo is familiar with the WRF facility, and prepared the previous 2008 Master Plan. On April 3, 2023, Council approved a contract with Carollo to perform a Condition Assessment, Facility Plan and Master Plan update. The Facility Plan was presented to the City Council on February 20, 2024, and provided a comprehensive review of the facility’s conditions, along with a 6-year strategy for required near-term improvements. Subsequently, Carollo has now completed their review and update to the Facility’s longer-term Master Plan, which includes a 20-year roadmap to plan for build-out growth conditions and long-term improvements. This process has identified needed Capital Improvement Projects and addresses the need for future expansion of specific processes and components of the WRF.
In 2018, the WRF underwent a substantial upgrade, enhancing its treatment and disinfection capacity to 22 million gallons per day (MGD) with the installation a membrane bioreactor system (MBR) and a UV treatment system along with additional equipment designed to increase sludge digestion and dewatering capability. To manage costs, some equipment was sized for an average annual daily flow (AADF) of 18 MGD. Despite these upgrades, the facility must also adapt to changing conditions. Water conservation efforts within the City and increased loadings have significantly impacted the factors used to calculate the WRF's capacity. Through Carollo’s recent Condition Assessment, it was determined that the WRF's effective total capacity currently stands at 13.9 MGD.
Through Carollo’s Condition Assessment and Facility Plan, they identified critical near-term improvements needed to address these capacity issues. The plan outlines measures to increase the WRF's firm capacity, ensuring necessary redundancy, to 16.3 MGD by the end of 2027, also ensuring the facility can accommodate the City's projected AADF of 15.1 MGD in 2030. These improvements are essential for maintaining efficient and reliable operations while supporting the City's growth and sustainability goals.
Carollo Engineers has now completed the Master Plan Update for the WRF and an accompanying report, which outlines a comprehensive strategy for long-term projects to be designed and implemented from 2028 through 2037 as well as changes in operational strategies to accommodate capacity increases. These projects aim to increase the WRF's firm capacity to 21.4 MGD, sufficient to handle the projected AADF in 2044, while also providing necessary redundancy in the Plant’s systems and processes. The flow projections considered in this Master Plan include both residential and industrial development, as well as the latest estimated projections for the Goshen Community Services District (GCSD). It is important to note that the increase in capacity for GCSD is contingent upon amendments to the existing agreement between the two entities, and the District’s ability to pay their share of the up front costs for capacity.
The improvements outline in the Master Plan consist of the following:
• The sludge retention time (SRT) in the MBR will be reduced from 12 to 8 days. This will increase flow capacity while still providing adequate treatment capacity.
• An extra RAS pump, aeration blower, and additional membrane cassettes will be added to the MBR system.
• A third UV channel will be constructed to increase disinfection capacity.
• A 10th anaerobic digester, the same size as digester 8 and the proposed digester 9, will be constructed along with a 3-day sludge storage tank to increase sludge handling capacity. These new tanks will be complemented by a new sludge feed system consisting of 4 new dewatering feed pumps.
• To increase biogas capacity, a new flare will be installed which will be able to handle the projected flow of 25,000 square cubic feet per hour (scfh).
• To increase dewatering capacity, a fourth screw press will be installed with the same capacity as the existing two screw presses and the third one proposed in the near-term projects.
The Total Project Capital Cost for the recommended projects in the Master Plan is estimated at $92,740,000. Additionally, the Rehabilitation and Replacement Costs for the 20-year planning horizon are projected to be $53,000,000. These investments are crucial for ensuring the long-term functionality and reliability of the WRF, enabling it to meet the growing needs of the community while maintaining high standards of environmental stewardship and operational efficiency. The Master Plan provides a strategic roadmap for achieving these goals, ensuring that the WRF remains a vital asset for the City of Visalia.
Fiscal Impact:
The report identifies a list of the necessary long-term projects to be designed and implemented from 2028 through 2037. The cost estimate total is approximately $146,040,000, of which, $92,740,000 is for design and implementation of the long-term projects from 2028-2037 and $53,300,000 is for repair and rehabilitation costs over the next 20 years. Staff will be exploring funding opportunities to complete the projects identified in the report.
With the completion of the Master Plan, a rate study has been proposed in the 2024/2025 Budget to evaluate current rates and fees to determine if additional adjustments will be necessary to cover the ongoing costs of operations and the necessary capital improvement projects.
Prior Council Action:
April 3, 2023: Council approved a contract with Carollo to perform a Condition Assessment, Facility Plan, and Master Plan Update for the WRF.
December 18, 2023: Council approved Contract with Carollo for engineering services related to the identified near-term projects.
December 18, 2023: Council approved a request from the Goshen Community Services District to increase sewer discharge capacity.
February 20, 2024: Council received a report and presentation on the Facility Plan, Condition Assessment, and Master Plan update for the WRF.
Other: None
Alternatives: N/A
Recommended Motion (and Alternative Motions if expected):
recommendation
Receive a report and presentation on the Master Plan for the WRF.
end
Environmental Assessment Status: N/A
CEQA Review: N/A
Attachments:
Master Plan - Final
WRF - Council Meeting 6_17_2024_EDIT