File #: 2023-3299    Version: 1 Name:
Type: Consent Status: Passed
File created: 11/1/2023 In control: OPERATIONS COMMITTEE
On agenda: 12/6/2023 Final action: 12/6/2023
Title: TRICKLING FILTER C ROTATING ASSEMBLY REPLACEMENT FOR PLANT NO. 2, PROJECT NO. MP2-019
Sponsors: Riaz Moinuddin
Attachments: 1. Agenda Report
Related files: 2022-2309, 2022-2360, 2022-2419, 2022-2447, 2023-2978, 2023-3354
FROM: Robert Thompson, General Manager
Originator: Riaz Moinuddin, Director of Operations & Maintenance

SUBJECT:

title
TRICKLING FILTER C ROTATING ASSEMBLY REPLACEMENT FOR PLANT NO. 2, PROJECT NO. MP2-019
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GENERAL MANAGER'S RECOMMENDATION

recommendation
RECOMMENDATION: Recommend to the Board of Directors to:

A. Approve a Sole Source Purchase Order Contract to Ovivo USA, LLC for a direct replacement Center Mast Assembly for the Plant No. 2 Trickling Filter "C" Center Rotating Assembly Replacement at Plant No. 2, Project No. MP2-019, for a total amount not to exceed $586,272; and

B. Approve a contingency of $58,627 (10%).
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BACKGROUND

The Orange County Sanitation District (OC San) trickling filters at Plant No. 2 consist of three 150-foot diameter rotating assemblies installed in 2008. The Plant No. 2 trickling filter process provides secondary treatment rated at 60 MGD average during dry weather and approximately 182 MGD during peak wet weather capacities. The trickling filters are engineered to remove the organic content in wastewater utilizing micro-organisms living on the filter media. Each trickling filter is equipped with a motor-operated rotary distributor assembly to uniformly distribute the primary treated flow over the media.

Following structural failures of the rotating assembly in Trickling Filter A (TF A), fabrication of a new Center Mast Assembly was approved in June 2022. Subsequently, similar structural deficiencies were identified in the Trickling Filter B (TF B) Center Mast Assembly and fabrication of replacement pieces were approved in July 2022. These new assemblies incorporated structural design enhancements to better withstand stress and metal fatigue and the new assemblies for TF A and TF B were installed in July and August of 2023.

RELEVANT STANDARDS

* Maintain a proactive asset management program
* Maintain a culture of improving efficiency to reduce the cost to provide the current service level or...

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