To: Board of Supervisors
Department or Agency Name(s): Sonoma County Public Infrastructure
Staff Name and Phone Number: Johannes J. Hoevertsz, 707-565-2550
Vote Requirement: Majority
Supervisorial District(s): First, Second, Fourth, Fifth
Title:
Title
Second Amendment - Engineering Services for Design of Leachate and Potable Water Storage Tank Replacements Project
End
Recommended Action:
Recommended action
Authorize the Chair to execute a Second Amendment to the Professional Services Agreement with GHD, Inc. for engineering services related to the Leachate and Potable Water Storage Tanks Replacement Project, expanding the scope of work and increasing the total contract budget by $78,164, for a new not-to-exceed amount of $808,134.
end
Executive Summary:
Sonoma County Public Infrastructure is requesting authorization to execute a Second Amendment to an agreement with GHD, Inc. expanding the scope of work and increasing the total contract budget by $78,164, for a new not-to-exceed amount of $808,134. The expanded scope of work includes additional engineering design, document preparation, bid assistance, and construction support services.
Discussion:
Background
On July 20, 2021, the Board approved a $651,775 contract with GHD, Inc for engineering services for the design of two new steel bolted leachate tanks at three of the County’s closed landfills (six total tanks), as well as the design of potable water storage tanks for the CSA #41 Fitch Mountain water system for a total not-to-exceed $651,775.
On May 24, 2022, the Board approved a first Amendment to the Agreement for additional design and geotechnical investigative work associated with the construction phase of the project, which increased the total, not-to-exceed contract amount to $729,970. A one-year extension was executed in 2024, extending the initial term of the agreement through July 20, 2025.
As part of the standard project delivery process, the initial construction bid did not result in an award, requiring the project to be re-bid. This triggered the need for revised cost estimates, updated technical specifications, and additional bid-phase support from GHD. These updates were necessary to reflect changes in material pricing, including tariff-related fluctuations that impacted the cost of steel and other supplies since the original design work was completed.
The project is now in active construction, with six 200,000-gallon welded steel tanks being installed across three geographically separated sites. The additional work addressed by this Second Amendment includes enhanced construction support, inspection services, and as-needed engineering responses to field conditions - ensuring continuity and quality during this complex installation phase. This amendment increases the not-to-exceed amount to $808,134.
The additional scope of work includes:
Task 5 Engineering Design and Bid Documents Preparation
Revisions to design documents and specifications required for rebidding. This includes updating the leachate and water tank specifications as well as revising the engineer’s cost estimates for both systems.
Task 6 - Bid Assistance
Required an increased budget due to a second round of responses to bidder questions and the preparation of additional addenda.
Task 7 - Construction Support Services
Expands construction support services to include rebar special inspections and geotechnical observation and testing. GHD has performed tank foundation inspection, compaction testing, and concrete inspection and reporting for the Guerneville site; drilled piers inspection, concrete inspection, key and bench inspection, and reporting for the Roblar site; and tank foundation inspection and reporting for the Sonoma site. Rebar inspections and documentation were provided for all three locations: Guerneville, Roblar, and Sonoma.
Task 9 - Additional Construction Support Services
A new Task 9 was created for as-needed construction support to address submittal reviews and responses of Request For Information (RFIs), and other construction-phase support activities as needed.
Tasks 5, 6, and 7 are adjusted to reflect additional work as revised lump sum amounts, while Task 9 will be billed on a time-and-material basis, providing a flexible mechanism to address emerging field conditions throughout the construction phase.
The additional scope and unforeseen conditions encountered since the First Amendment including re-bidding efforts, updated specifications, enhanced construction support services, and expanded inspection requirements necessitate a Second Amendment to the agreement with GHD, Inc. The Amendment will support these critical services and ensure successful delivery of the Leachate and Potable Water Storage Tanks Replacement Project.
Staff recommends that the Board authorize the Chair to execute the Second Amendment to the Professional Services Agreement with GHD, Inc., expanding the scope of work and increasing the contract amount by $78,164, for a new not-to-exceed amount of $808,134.
Strategic Plan:
N/A
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No
Prior Board Actions:
05/24/2022 Board approved the First Amendment to the Agreement for Engineering Services for Design of Leachate and Potable Water Storage Tanks Replacement Project with GHD, Inc.
07/20/2021 Board approved the Agreement for Engineering Services for Design of Leachate and Potable Water Storage Tanks Replacement Project with GHD, Inc.
Fiscal Summary
|
Expenditures |
FY24-25 Adopted |
FY25-26 Projected |
FY26-27 Projected |
|
Budgeted Expenses |
|
$78,164 |
|
|
Additional Appropriation Requested |
|
|
|
|
Total Expenditures |
|
$78,164 |
|
|
Funding Sources |
|
|
|
|
General Fund/WA GF |
|
|
|
|
State/Federal |
|
|
|
|
Fees/Other |
|
$78,164 |
|
|
Use of Fund Balance |
|
|
|
|
General Fund Contingencies |
|
|
|
|
Total Sources |
|
$78,164 |
|
Narrative Explanation of Fiscal Impacts:
Costs associated with the additional work to be completed with the Second Amendment are estimated at $78,164; increasing the total not-to-exceed amount from $729,970 to $808,134. The $78,164 in additional expenses will be funded from Former Rural Landfill Fund 41122 and the Former Urban Landfill Fund 41123. Appropriations are available in the Fiscal Year 2025-26 Integrated Waste Adopted Budget for this work. Although costs associated to this proposed Second Amendment were unknown at the time of submittal of the FY 2025 -26 Recommended Integrated Waste Budget, some portions of closed landfill maintenance projects, such as road improvements at the closed landfills, can be deferred to the following Fiscal Year if needed.
Funding sources for maintaining the county closed landfills include collection of Franchise Fees under two Franchise Agreements and the collection of Concession Fees collected under a Master Operations Agreement with Republic Services of Sonoma County, Inc.
Narrative Explanation of Staffing Impacts (If Required):
None.
Attachments:
2nd Amendment
Exhibit A-2 Scope of Work
Exhibit B-2 Cost of Services
Exhibit C-1 Schedule of Rates
Related Items “On File” with the Clerk of the Board:
GHD Agreement
1st Amendment to the GHD Agreement
GHD 1st Term Extension