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Home My WebLink About09-24-2025 URGENT Item No. 28 Board of Directors URGENT ITEM BOARD OF DIRECTORS AGENDA MATERIAL Government Code Section 54954.2(b) Rules of Procedure Chapter III.C.5 **THIS ITEM IS NOT YET AGENDIZED AND MAY OR MAY NOT BE ACCEPTED FOR THE AGENDA AS AN URGENT ITEM, SUBJECT TO THE BOARD OF DIRECTORS DISCRETION ACCORDING TO BROWN ACT RULES** Meeting Date: September 24, 2025 Item Description: The General Manager recommends to take urgent action to approve a contingency increase of $1,000,556 to the existing Construction Contract Agreement to Sancon Technologies, Inc., for Newhope-Placentia Sewer Manhole Replacements, Project No. FE21-08 due to a time-sensitive finding. This item is submitted pursuant to the provision of Immediate Action Required 54954.2(b)(2) – (two-thirds vote required). There is a need to take immediate action and the need for action came to the attention of the Clerk of the Board of Orange County Sanitation District subsequent to the agenda for this meeting being posted. Once the item is added to the agenda (Non-Consent) it must be passed by the standard required vote threshold. Facts supporting the addition of the item to the agenda under Section 54954.2(b) and Chapter III.C.5 of the Rules of Procedure: A preconstruction inspection of manhole NHP0020, within the City of Fountain Valley, revealed a significant change in the condition which precludes the scoped repair. Both the concrete and the steel reinforcement have deteriorated beyond the point of repair, requiring full replacement of the manhole structure. This updated information regarding the condition of Manhole NHP0020 was found after the Steering Committee and Board agendas were published. It took a few days to evaluate the information, perform a condition assessment, and develop a recommendation. A similar evaluation will be done for manhole NHP0135 on September 24, 2025. It may also be necessary to replace this manhole rather than execute the scoped repairs. This work is very time-sensitive due to the upcoming wet weather season. BOARD OF DIRECTORS URGENT ITEM Agenda Report Headquarters 18480 Bandilier Circle Fountain Valley, CA 92708 (714) 593-7433 File #:2025-4531 Agenda Date:9/24/2025 Agenda Item No:28. FROM:Robert Thompson, General Manager Originator: Mike Dorman, Director of Engineering SUBJECT: URGENT ITEM - NEWHOPE-PLACENTIA SEWER MANHOLE REPLACEMENTS, PROJECT NO. FE21-08 GENERAL MANAGER'S RECOMMENDATION RECOMMENDATION: Approve a contingency increase of $1,000,556 to the existing Construction Contract Agreement to Sancon Technologies, Inc., for Newhope-Placentia Sewer Manhole Replacements, Project No. FE21- 08, for a new total contingency of $1,081,902 (266%) due to a time sensitive finding. BACKGROUND ***Staff requests that this item be added to the agenda for the Steering Committee and the Board of Directors to consider adding contingency authority to repair two manhole structures in the Newhope- Placentia Trunk sewer. A preconstruction inspection revealed a significant change in the condition of the manhole structure that precludes the scoped repair and requires urgent replacement. This updated information regarding the condition of Manhole NHP0020 was found after the Steering Committee and Board agendas were published. It took a few days to evaluate the information, perform a condition assessment, and develop a recommendation. A similar evaluation will be done for manhole NHP0135 on September 25, 2025. It may be necessary to replace this manhole rather than execute the scoped repairs. This work is very time-sensitive due to the upcoming wet weather season.*** The Orange County Sanitation District (OC San) operates and maintains more than 388 miles of gravity and pressure sewer pipes. As part of its ongoing maintenance of the sewer system, three manholes originally constructed in 1958 in the Newhope-Placentia Trunk Sewer (NHP) system, were identified for potential replacement due to deterioration from hydrogen sulfide corrosion, a common issue in wastewater systems. During a detailed design evaluation, it was determined that rather than full replacement, the manholes could be rehabilitated to extend their functional lifespan. The design phase evaluation included four concrete core samples taken from manholes NHP0020 and NHP0135. The samples were collected from locations intended to represent the overall condition of the structures and were tested in a laboratory. Results showed compressive strengths near 5,700 to 6,000 psi, with acid-related surface deterioration to about 0.3 to 1.0 inches on the interior face with sound concrete behind that. All cores showed similar favorable results, leading to the decision to rehabilitate the manholes rather than replace them. Because the wall cores appeared Orange County Sanitation District Printed on 9/24/2025Page 1 of 3 powered by Legistar™ File #:2025-4531 Agenda Date:9/24/2025 Agenda Item No:28. the decision to rehabilitate the manholes rather than replace them.Because the wall cores appeared sound and similar visual corrosion was observed in the roof of the structures,there was no reason to believe that the roof corrosion was worse than the walls. As such, roof cores were not taken. RELEVANT STANDARDS ·Protect OC San assets ·Meet or surpass sanitary sewer overflow regulations ·Commitment to safety & reducing risk in all operations PROBLEM At the start of construction,it was discovered that hydrogen sulfide corrosion in Manhole NHP0020, located near the Plant No.1 entrance,was significantly worse than the design phase evaluation with both the concrete and the steel reinforcement deteriorated beyond the point of repair,requiring full replacement.A second manhole,Manhole NHP0135,was also found with similar deterioration;while not as severe,rehabilitation may be unlikely.Additional condition assessment will be performed on September 25, 2025. PROPOSED SOLUTION Approve a contingency increase to replace two of the three manholes in this contract before the wet weather season and associated high flows in the sewer system.Replacement now is recommended rather than effecting temporary repairs and full replacement in a separate contract. TIMING CONCERNS The manholes are in an advanced state of degradation and continue to corrode over time.Timely approval of this contingency will allow for prompt replacement and rehabilitation,to ensure the trunk sewer remains safe and fully operational for the upcoming wet weather season. RAMIFICATIONS OF NOT TAKING ACTION If no action is taken,the deterioration will worsen for two of the three manholes,increasing the risk of structural failure and ultimately requiring emergency replacement at a significantly higher cost and with greater impact to OC San and the surrounding community. PRIOR COMMITTEE/BOARD ACTIONS December 2024 -Received and filed Bid Tabulation and Recommendation for Newhope-Placentia Sewer Manhole Replacements,Project No.FE21-08;awarded a Construction Contract Agreement to Sancon Technologies,Inc.,for Newhope-Placentia Sewer Manhole Replacements,Project No.FE21- 08, for a total amount not to exceed $406,730; and approve a contingency of $81,346 (20%). ADDITIONAL INFORMATION N/A Orange County Sanitation District Printed on 9/24/2025Page 2 of 3 powered by Legistar™ File #:2025-4531 Agenda Date:9/24/2025 Agenda Item No:28. CEQA The project is exempt from CEQA,and a Notice of Exemption will be filed with the OC Clerk- Recorder and State Clearinghouse after the OC San Board of Directors approval of the Construction Contract Agreement. FINANCIAL CONSIDERATIONS This request complies with the authority levels of OC San’s Purchasing Ordinance.This item has been budgeted (Budget FY 2025-26,Page A-8,Small Construction Projects Program,Project No.M- FE) and the budget is sufficient for the recommended action. ATTACHMENT The following attachment(s)may be viewed on-line at the OC San website (www.ocsan.gov)with the complete agenda package: ·Presentation TB:lb Orange County Sanitation District Printed on 9/24/2025Page 3 of 3 powered by Legistar™