FROM: James D. Herberg, General Manager
Originator: Kathy Millea, Director of Engineering
SUBJECT:
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VFD REPLACEMENTS AT PLANT NO. 1, PROJECT NO. FR1-0011
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GENERAL MANAGER'S RECOMMENDATION
recommendation
RECOMMENDATION: Recommend to the Board of Directors to:
A. Receive and file Bid Tabulation and Recommendation for VFD Replacements at Plant No. 1, Project No. FR1-0011;
B. Award a Construction Contract to ACS Engineering, Inc. for VFD Replacements at Plant No. 1, Project No. FR1-0011, for a total amount not to exceed $1,214,888; and
C. Approve a contingency of $121,488 (10%).
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BACKGROUND
The City Water Pump Station, Trickling Filter Pump Station, and Return Activated Sludge (RAS) Pump Station are essential pump stations at Orange County Sanitation District (OC San) Plant No. 1. The City Water Pump Station provides potable water to Plant No. 1, the Trickling Filter Pump Station pumps primary effluent to the top of the Trickling Filters to be treated, and the RAS Pump Station returns process flow to the beginning of the Activated Sludge-1 Facility. The pumps at these stations each have a variable frequency drive (VFD) to allow the pump speeds to fluctuate depending on flow conditions. There are two existing VFDs at the City Water Pump Station, three existing VFDs at the Trickling Filter Pump Station, and one existing VFD at the RAS Pump Station.
RELEVANT STANDARDS
* Comply with California Public Contract Code Section 20103.8, award construction contract to lowest responsive, responsible bidder
* Maintain a proactive asset management program
* 24/7/365 treatment plant reliability
PROBLEM
The existing VFDs are at least 14 years old and are at the end of their useful service life. Replacement parts and manufacturer support services are no longer available, so they can no longer be worked on, and if they fail, OC San staff will not be able to repair them. When a VFD on a pump fails, the pump cannot be operated a...
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