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): Countywide
Title:
Title
Gas Collection and Control System and Leachate Collection and Recovery System Maintenance - First Amendment
End
Recommended Action:
Recommended action
Authorize the Chair to execute the First Amendment to the Professional Service Agreement for Gas Collection and Control System and Leachate Collection and Recovery System Maintenance By and Between the County of Sonoma and Tetra Tech BAS, Inc. to increase the total annual limit by $140,000 from $273,630 to $413,630.
end
Executive Summary:
The Department of Public Infrastructure (SPI) is requesting an increase to the total annual limit established for the Gas Collection and Control System and Leachate Collection and Recovery System Maintenance with Tetra Tech BAS, Inc. (Tetra Tech), from $273,630 to $413,630, representing an increase of $140,000 per year for Non-Routine Services for each of the two optional extension years of the Agreement.
Non-routine services are currently limited to $175,000 per year and would increase to $315,000 per year with approval of this First Amendment. The Amendment will provide for additional non-routine services to enhance monitoring and reporting of landfill gas at the Healdsburg Closed Landfill, improve maintenance of the flare and gas field at this site, and update the schedule of charges for hourly rates listed within Exhibit B-1 Costs of Services.
Discussion:
Background
The Healdsburg Landfill operated as a Class III sanitary landfill until closure in August of 1989. The closed landfill has an adjacent Landfill Gas Collection and Control System (LFGCCS), including a landfill gas flare which can burn 400 cubic feet per minute of landfill gas (LFG) extracted from gas extraction wells. The system was installed in 2001 to reduce the possibility of LFG migration outside of the landfill footprint and prevent LFG migration up through the landfill surface and into the atmosphere.
On January 5, 2021, the Board approved an Agreement with Tetra Tech BAS, Inc. to provide landfill gas collection and control system maintenance, surface emissions monitoring, and reporting services at the Healdsburg Closed Landfill for a not-to-exceed $273,620 per year. At that time, the Northern Sonoma County Air Pollution Control District served as the regulatory agency overseeing the closed landfill. However, in 2022, the California Air Resources Board (CARB) assumed this regulatory role and modified the operational and monitoring requirements of the LFGCCS.
Additional Non-Routine Services
CARB requires that the gas flare operate uninterrupted and continuously, a threshold that the existing LFGCCS struggles to meet. Although the LFGCCS system was appropriately sized at the time of installation to handle the expected gas flow rate, the quantity of landfill gas recovered has declined over time and is now below the minimum flow rate required for the existing gas control device to operate, leading to periodic unplanned shutdowns, and subsequentially preventing a continuous operation per CARB regulations.
At the request of SPI, CARB issued an Alternative Compliance Option (ACO) on June 25, 2024 (On-File), to allow for an intermittent operations plan of the LFGCCS with additional monitoring, not included in the Agreement’s original scope of work. The ACO can only be implemented under certain conditions, for example, when the flare has enough qualifying shutdowns in a one week period, the flare can then be operated 22 hours per day rather than 24 hours per day. Even with an approved ACO, the goal is to maintain the well fields quality and run the flare 24 hours per day 7 days a week.
Lastly, a methane gas exceedance was registered at the landfill resulting in additional Surface Emissions Monitoring (SEM), increasing the monitoring requirement from an annual basis to a quarterly basis.
As the amount of non-routine work required to meet regulatory requirements has increased, SPI is recommending approval of this First Amendment Agreement with Tetra Tech. If approved, the annual contract amount for Non-Routine Services would increase by $140,000 for each of the two optional extension years allowed under the Agreement. In addition, the First Amendment will update the schedule of charges for hourly rates listed within Exhibit B-1 Costs of Services. The additional Non-routine services will include quarterly SEM monitoring, provide for additional flare callout response, implementation of flare operation per ACO, and installation of inline landfill gas monitor at the inlet to the flare station.
Strategic Plan:
N/A
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No
Prior Board Actions:
01/05/21 - Board approved the Gas Collection and Control System and Leachate Collection and Recovery System Maintenance Agreement with Tetra Tech.
Fiscal Summary
|
Expenditures |
FY24-25 Adopted |
FY25-26 Projected |
FY26-27 Projected |
|
Budgeted Expenses |
$105,000 |
$140,000 |
$70,000 |
|
Additional Appropriation Requested |
|
|
|
|
Total Expenditures |
$105,000 |
$140,000 |
$70,000 |
|
Funding Sources |
|
|
|
|
General Fund/WA GF |
|
|
|
|
State/Federal |
|
|
|
|
Fees/Other |
$105,000 |
$140,000 |
$70,000 |
|
Use of Fund Balance |
|
|
|
|
General Fund Contingencies |
|
|
|
|
Total Sources |
$105,000 |
$140,000 |
$70,000 |
Narrative Explanation of Fiscal Impacts:
Total estimated value of non-routine work to be completed annually for the duration of this Agreement shall not exceed $315,000. There are sufficient appropriations in the FY 24-25 Former Urban Landfill Fund (41123-34050300) adopted budget for this additional work.
Funding for maintenance at the Healdsburg Landfill is stipulated by the Landfill Settlement Agreement (LSA) between the County of Sonoma and the Committed Cities, which became effective on April 1, 2015. The LSA directs the collection of Concession Fees for each ton of Municipal Solid Waste and Organic Waste received at one of five County-owned Solid Waste Facilities.
Narrative Explanation of Staffing Impacts (If Required):
N/A
Attachments:
1st Amendment
Exhibit A-1
Exhibit B-1
Related Items “On File” with the Clerk of the Board:
Tetra Tech BAS, Inc. Agreement
CARB Alternative Compliance Option