HomeMy WebLinkAboutF-3.1. Purchase of Replacement Membrane Filters_ApprovedCONSENT ITEM F-3
TO: HONORABLE CHAIRPERSON AND MEMBERS OF THE AZUSA UTILITY BOARD
FROM: TIKAN SINGH, GENERAL MANAGER
DATE: NOVEMBER 25, 2024
SUBJECT: APPROVE THE PURCHASE OF REPLACEMENT MEMBRANE FILTERS FROM
DUPONT WATER SOLUTIONS FOR THREE FILTRATION UNITS AT THE WATER
TREATMENT PLANT
BACKGROUND:
In September 2009 the Joseph F. Hsu Water Filtration Treatment Plant began operations treating
surface water from the San Gabriel River watershed. The Treatment plant is rated at 12 million gallons
per day and operates as a conventional treatment process, including coagulation, flocculation,
sedimentation, and filtration. The filtration process at the Water Treatment Plant uses Dupont Water
Systems polyvinylidene fluoride (PVDF) ultrafiltration membrane filter modules as the filter media. The
existing membranes have reached their useful life and need to be replaced. With Utility Board approval,
ALW staff completed the first phase of the membrane replacements in August 2024. To complete the final
phase of this Capital Improvement Project, staff recommends the purchase of the remaining filter medias
from Dupont for three filtration units.
RECOMMENDATION:
Staff recommends that the Utility Board take the following action:
1) Approve the purchase of 396 replacement L20N membrane modules and 792 filtrate cup
assemblies pursuant to purchasing requirements of the Azusa Municipal Code Chapter 2,
Article VII, Section 2-517(a)(35) treatment equipment (Solicitation and bidding exemptions);
and
2)Authorize the City Manager or his/her designee to issue a purchase order to Dupont Water
Solutions for a not-to-exceed amount of $475,553.60.
Approved
Utility Board
1/2/2024
Purchase Membrane Filters at WTP
November 25, 2024
Page 2
ANALYSIS:
The Water Treatment Plant treats surface water using membrane filters which are manufactured
by Memcor, a division of Dupont. There are six membrane units, and each unit contains one hundred
thirty-two L20N membrane modules. Low-pressure feed pumps take raw water through the membrane
fibers with a porosity of 0.04 microns. The extremely small pore size prevents particulate matter and
pathogenic organisms from passing into the finished water. The membranes require frequent backwashing
and cleaning using acid and chlorine as the treatment process operates 24 hours a day. In October 2013,
under warranty, ALW did a full replacement of the filter media, including installing 792 new modules.
The existing membranes are now over 10 years old and have reached their useful life. Currently, they
require continuous maintenance and pinning. The lifespan of the filter media, according to the
manufacturer, is typically seven years. Key indicators to assess the condition of the modules include
frequency of maintenance and repair work on the modules; eventually, continuous maintenance results in
some modules requiring to be isolated and removed from the treatment process due to damage beyond
repair.
In early August 2024, ALW staff began the first phase of the membrane changeout CIP project.
Filter Units 1, 2, and 3 were completely replaced during a three-week period, and the modules are
performing very well. At this time, ALW Staff will replace and install the remaining 396 new modules
for units 4, 5, and 6. This will be the final phase of modules to be replaced and will complete the Membrane
Changeout CIP project.
Staff is recommending purchasing 396 new L20N filter media modules from Dupont (sole source
supplier for Memcor products) to replace the existing three membrane units. This is a proprietary water
treatment product. Pursuant to Sections 2-517(a)(35) Water Treatment and 2-520(b) Sole Source of the
City’s Purchasing Policy, this is exempt from competitive purchasing. This current water treatment
product is required to integrate with the existing Water Treatment Plant processes.
FISCAL IMPACT:
The total cost to purchase 396 membrane modules for three membrane units and the necessary
assembly equipment for ALW Staff to install the modules is $475,553.60. Funding is available in the
Water Division’s Capital Improvement Program, account 32-80-000-721-7130/72125A-7130.
Purchase Membrane Filters at WTP
November 25, 2024
Page 3
Prepared by: Prepared by:
Carlos Solis Gabriela Enriquez
Water Treatment Superintendent Management Analyst
Reviewed and Approved: Reviewed and Approved:
Melissa Barbosa Danny Smith
Assistant General Manager - Water Operations Utilities Admin & Finance Manager
Reviewed and Approved: Reviewed and Approved:
Tikan Singh Sergio Gonzalez
General Manager City Manager
Attachment:
1) Dupont Membrane Quote
2) Sole Source Letter