FROM: James D. Herberg, General Manager
Originator: Riaz Moinuddin, Director of Operations & Maintenance
SUBJECT:
title
PLANT NO. 1 ACTIVATED SLUDGE AERATION DIFFUSER MEMBRANE REPLACEMENT REPAIR
end
GENERAL MANAGER'S RECOMMENDATION
recommendation
RECOMMENDATION:
A. Approve a Purchase Order Contract to SS Mechanical Construction Corp. to provide Aeration Basin Disc Replacement, Specification No. S-2022-1334, for a total amount not to exceed $171,930 for the period beginning October 1, 2022, through September 30, 2023, with four (4) one-year renewal options; and
B. Approve an annual contingency of $17,193 (10%).
body
BACKGROUND
The Activated Sludge Process uses fine bubble diffusion aeration systems to treat primary effluent by dissolving oxygen in the primary effluent to support highly concentrated bacteria which metabolizes organic matter in wastewater. There are 16 reactor basins with 8,500 individual rubber membranes located at the bottom of each reactor basin at Orange County Sanitation District (OC San) Plant No. 1. Compressed air is piped to the individual membranes and forced through tiny holes in the rubber membranes making fine bubbles.
The rubber membranes have an approximate life expectancy of 7 to 10 years. The discs must be replaced as the holes in the discs become stretched or clogged and the rubber becomes brittle. As a result, the efficiency of the whole system is diminished.
RELEVANT STANDARDS
* Meet volume and water quality needs for the GWRS
* Maintain a proactive asset management program
* Maintain a culture of improving efficiency to reduce the cost to provide the current service level or standard
PROBLEM
Some of the Plant No. 1 Activated Sludge diffuser membranes have been in operation for over 10 years and need replacement. As a result, the oxygen transfer efficiency has diminished which results in higher energy costs.
PROPOSED SOLUTION
Approve a low bid Purchase Order Contract with SS Mechanical...
Click here for full text