HomeMy WebLinkAboutAgenda Report - April 7, 2021 C-11AGENDA ITEM
CITY OF LODI
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COUNCIL COMMUNICATION
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AGENDA TITLE: Accept Improvements Under Contract for Well 27 Granular Activated Carbon Filter
System
MEETING DATE: April 7, 2021
PREPARED BY: Public Works Director
RECOMMENDED ACTION: Accept improvements under contract for Well 27 Granular Activated
Carbon Filter System.
BACKGROUND INFORMATION: In 2018, Well 27 was taken out of service after routine water
samples indicated the presence of the regulated chemical known as
1,2,3,- trichloropropane (1,2,3 -TCP). This project was needed for
the well to meet State drinking water standards and return to service.
For decades, Granular Activated Carbon (GAC) has been utilized at several well sites within the City to
adsorb dibromochloropropane. The State Water Resources Control Board has identified GAC as a best
available technology for removing 1,2,3 -TCP contamination from drinking water.
This project consisted of furnishing and installing a GAC treatment system for Well 27, located at 2160
West Century Boulevard (intersection of Heavenly Way and West Century Boulevard), complete with four
low profile tanks, approximately 200 linear feet of 10 -inch water pipe, 100 linear feet of eight -inch water
pipe, and 60 linear feet of eight -inch wastewater pipe, and other incidental and related work.
The plans and specifications for this project were approved on February 19, 2020. On April 15, 2020, the
contract was awarded to Diede Construction, Inc., of Woodbridge, in the amount of $1,063,900, and the
City Manager was authorized to execute change orders in an amount not to exceed $54,000.
The final contract completion date (extended by change order) was March 17, 2021. Work was
completed on March 9, 2021. Photos of the completed work are shown in Exhibit A. The final contract
amount was $1,089,298, due to two change orders, amounting to $25,398.
Change Order No. 1 included rerouting the existing chlorine feed line to accommodate the new GAC
treatment system and installing a new eight -inch tee on the eight -inch wastewater pipe, which was shown
as existing on as -built plan, but did not exist in the field ($18,639).
Change Order No. 2 included replacing a 10 -inch check valve with a flanged spool to allow for
backwashing of carbon in the GAC System ($6,759).
Following acceptance by the City Council, as required by law, the City Engineer will file a Notice of
Completion with the County Recorder's office. The notice serves to notify vendors and subcontractors
that the project is complete and begins their 30 -day period to file a stop notice requiring the City to
withhold payments from the prime contractor in the event of a payment dispute.
APPROVED:
SleWen Schw-ahauef, City Manager
K =RPROJECTS\WATER\Well 27\Well 27 Granular Activated Carbon (GAC) Filter System\CAccept.doc 3/23/2021
Accept Improvements Under Contractfor Well 27 Granular Activated Carbon Filter System
April 7, 2021
Page 2
FISCAL IMPACT: Annual operation and maintenance costs for the water utility will increase
as a result of Well 27 being placed back into service and the addition of the
GAC treatment system.
FUNDING AVAILABLE: This project was funded by Water Capital Fund (56199000.77020).
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Charles E. Swimley, Jr.
Public Works Director
Prepared by Jimi Billigmeier, Associate Civil Engineer
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Attachment
cc: Andrew Richle, Utilities Superintendent
Travis Kahrs, Water Plant Superintendent
Mike Weltzin, Diede Construction
K:\WP\PROJECTS\WATER\Well 27\Well 27 Granular Activated Carbon (GAC) Filter System\CAccept.doc 3/23/2021
EXHIBIT
Well 27 Granular Activated Carbon Filter System