July 26, 2022
Public Works
DATE: July 26, 2022
TO: Mayor Butt and Members of the City Council
FROM:
Joe Leach, Public Works Director
Mary Phelps, Project Manager I
Subject:
Resolution proposing Contract Amendment to Phase I of
the Sludge Thickener Project
FINANCIAL IMPACT: The total cost for the Sludge Thickener Project and all additional change orders will not exceed $683,829 and
will be paid from the Wastewater Enterprise Fund (4003- 40322931-400708-01M10).
PREVIOUS COUNCIL
ACTION:
June 15, 2022, Resolution 72-21
STATEMENT OF THE
ISSUE:
Public Works staff is recommending City Council adopt a resolution authorizing a contract amendment to the
Sludge Thickener project at the Wastewater Treatment
Plant. The Sludge Thickener project will continue to be managed by Veolia, with the construction subcontract
awarded to Myer & Sons, a Contractor from Richmond,
California
RECOMMENDED ACTION:
ADOPT a resolution to issue a contract amendment to
Veolia Water for the contract change orders for the
Sludge Thickener Project at the Wastewater Treatment
Plant (WWTP) to Myers and Sons (construction), in an
amount not to exceed $683,829 (contractor cost of
$596,455 plus a 16.5 percent Veolia mark-up of
$74,125), plus a contingency of $147,213 ($67,386.30
plus a 9 percent Veolia mark-up of $13,249) Public
Works – (Joe Leach 620-5478/ Mary Phelps 621-1269).
AGENDA
REPORT
July 26, 2022
DISCUSSION:
The purpose of the Richmond WWTP Sludge Thickener Project is to remove the aging and unreliable dissolved air floatation thickener “DAFT” with efficient, reliable sludge thickener facilities compatible with the WWTP’s current and future treatment processes.
On June 21, 2021, City Council adopted Resolution 72-21 authorizing $586,818.07 for the design costs Phase I Sludge Thickener Project at the WWTP.
During the current design Phase I, it was discovered that a Waste Activated Sludge (WAS) buffer tank is needed for the Sludge Thickener Project. The reason is that, with the Critical Improvements Project, the Plant is changing the aeration technology in the aeration basins. In order to accommodate the operation of the new technology and to ensure operational flexibility and consistent performance of the new thickener systems, the buffer tank was needed. Additionally, due to construction constraints, including presence of shallow bedrock and conflicts with existing utilities, the project site has been moved (after the 50% design submittal was submitted) from the initial DAFT 2 area to the Center Island. Therefore, the Basis of Design Report must be updated and the 50% design submittal modified to reflect the design suitable for the new site.
Specific tasks include:
Review of as-built drawings for the new site
Develop potholing map (done by Contractor, Myers & Sons) Determination of appropriate footprint for the Rotary Drum Thickeners (RDT) and WAS buffer tank
Work with stakeholders to determine the appropriate size of the WAS buffer tank Update the Draft Basis of Design Report
Coordinate with subconsultants (i.e., air permit, geotechnical and surveying) Provide modified 50% Design Submittal
Conduct 50% Design Submittal Review
The estimated cost for this changed design condition is $160,462 (Project cost $147,213, plus Veolia’s 9 percent mark-up of $13,429). Additionally, a schedule extension is requested for 42 days to accomplish this work. This change order request has been reviewed by both City Staff and Veolia for cost and schedule impacts, and has been determined to be reasonable and necessary.
City staff is requesting City Council adopt the resolution authorizing the change order.
DOCUMENTS ATTACHED:
Attachment 1 – Resolution
Attachment 2 – TA - Sludge Thickener Project PHASE Change Order Attachment 3 – Resolution 72-21
Attachment 4 – TA – Sludge Thickener Phase I – fully executed