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: 4/5th
Supervisorial District(s): Countywide
Title:
Title
Award of Construction Contract for the Wildlife Exclusion Perimeter Fence Phase 2 - Fence Drainage Crossing Repair Project - Charles M. Schulz - Sonoma County Airport
End
Recommended Action:
Recommended action
A) Adopt and approve plans and specifications for the Charles M. Schulz - Sonoma County Airport Wildlife Exclusion Perimeter Fence Phase 2 - Fence Drainage Crossing Repair Project.
B) Find Diamond D Construction LLC’s bid non-responsive and award the construction contract to the lowest responsive and responsible bidder, Roebbelen Contracting, Inc., in the amount of $374,028.40 including the base bid and bid alternate 1.
C) Delegate authority to the Sonoma County Public Infrastructure (SPI) Director to execute the construction contract.
D) Delegate authority to the SPI Director to approve change orders for the project up to 10% in the amount of $37,402.84, for a total contract not to exceed amount of $ 411,434.24.
end
Executive Summary:
Sonoma County Public Infrastructure (SPI), Airport Division (Airport) requests that the Board adopt and approve the plans and specifications and award a construction contract for the Wildlife Exclusion Perimeter Fence Phase 2 - Fence Drainage Crossing Repair Project at the Charles M. Schulz - Sonoma County Airport. The recommended award will be made to Roebbelen Contracting, Inc., the lowest responsive and responsible bidder, in the amount of $ $374,028.40. With the requested 10% contingency of $37,402.84, the total authorized contract amount will not exceed $411,431.24.
Discussion:
In November 2024, a rapidly intensifying bomb cyclone and prolonged atmospheric river produced more than 12 inches of rain over three days at the Airport. Flooding and debris loading damaged two perimeter-fence drainage crossings over Airport Creek that had been constructed as part of the Phase 1 Wildlife Exclusion Perimeter Fence project. This Phase 2 project will repair the two crossings and improve their resilience to future flood events.
Project Overview
• The project includes removal and disposal of damaged fence and footings at the East and West Airport Creek crossings; excavation and subgrade preparation; construction of reinforced Portland cement concrete spread footings with continuous keyways; installation of replacement wildlife-exclusion fencing and metal debris racks; placement of Class II riprap; hydroseeding of disturbed areas; and installation of approximately 70 linear feet of permanent 5-strand barbed-wire fencing in the Sonoma Airport Conservation Management Area (SACMA) Preserve.
• The contract allows 40 working days: 20 working days for mobilization and 20 working days for field construction. Field work must occur within the environmental permit window of June 15 through October 15. The construction sequencing provides up to 15 working days for the initial field-active interval and up to five working days for debris-rack installation and restoration after fabrication.
• Bid alternate 1 is the installation of field fencing that will support seasonal cattle grazing and vegetation-management operations while avoiding permanent in-channel structures on an Airport Environmental Mitigation site as required in the mitigation bank approvals.
The project is designed and permitted in accordance with FAA Advisory Circular 150/5370-2G and applicable environmental requirements, including Section 404 of the Clean Water Act and California Fish and Wildlife Code Section 1602. Construction is restricted to a dry-season window between June 15 and October 15 of any given year, consistent with environmental permit conditions. The engineer’s opinion of probable construction cost is $285,175 with the base bid estimated at $267,300 (the base bid will be covered with a 95% federal share Airport Improvement Grant) and bid alternate 1 estimated at $17,875 (not grant eligible, and covered through Airport operations funds.
The Airport has received FAA Airport Infrastructure Grant (AIG) No. 3-06-0241-084-2026, awarded on August 28, 2026, in the amount of $350,000 for design and construction of the Airport Creek fence drainage crossing repairs. The grant provides a 95% federal share of allowable project costs, subject to a maximum federal obligation of $350,000. Local Airport operations funds will cover the required match and costs not reimbursed by the grant.
Procurement and Bid Results
The project was advertised for bidding on 6/29/2026. Bids were opened on July 29, 2026.
There was a total of six bids received as follows. The amounts below reflect the corrected bid tabulation, including reconciliation of Roebbelen’s bid schedule correcting math tabulation errors to the submitted unit prices:
|
Bidder’s Name |
Base Bid |
Bid Alt. 1 |
Total Bid |
|
Wildcat Engineering |
$439,705.00 |
$33,000.00 |
$472,705.00 |
|
M3 Integrated Services, Inc. |
$675,475.00 |
$36,700.00 |
$712,175.00 |
|
Granite Construction |
$349,070.00 |
$27,820.20 |
$376,890.20 |
|
Diamond D Construction (Non-Responsive) |
$243,123.00 |
$16,153.00 |
$259,276.00 |
|
Robbelen Contracting |
$366,149.20 |
$7,879.20 |
$374,028.40 |
|
Northern California Power & Equipment |
$520,520.75 |
$23,786.60 |
$544,307.35 |
During the bid evaluation Diamond D Construction LLC’s bid was determined to be non-responsive. Although Diamond D submitted financial information, the County could not verify that the documentation satisfied the evidence of financial responsibility required by Section 20-02 of the Contract Documents. They also had a suspended contractor license, which was understood to involve a bond-related administrative issue, which prevented the County from determining that Diamond D met the licensing requirements for contract award unless and until the license was restored to active status and good standing. Diamond D acknowledged these concerns and concured with the County’s determination. Staff therefore recommend finding the bid non-responsive and proceeding with the next lowest responsive and responsible bidder.
Under Addendum No. 01, bid ranking is based on the base bid plus bid alternate 1. Following correction of minor irregularities in math errors in Roebbelen’s bid schedule and exclusion of Diamond D’s non-responsive bid, Roebbelen Contracting, Inc. is the lowest responsive bidder at $374,028.40, followed by Granite Construction at $376,890.20.
On April 19, 2022, the Board approved Task Order #20 with Mead & Hunt, Inc. for general, program, and grant management consulting and design services for the Airport perimeter fence upgrade. Mead & Hunt designed and administered the Phase 1 Wildlife Exclusion Fence project and continues to provide design and bid administration services for the Phase 2 repair project.
In accordance with Public Contract Code Section 20128, the contract shall be awarded to the lowest responsible bidder. Department staff recommend that the Board of Supervisors award and authorize the Public Infrastructure Director to execute the agreement with Roebbelen Contracting, Inc. in the amount of $374,028.40. Including the 10% contingency of $37,402.84, the total authorized contract amount will not exceed $411,431.24.
CEQA Compliance:
This project is exempt from the California Environmental Quality Act pursuant to 14 Cal Code Regs Section 15301 on the basis that it is a contract for minor changes to and repair of existing public facilities.
Strategic Plan:
N/A
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No
Prior Board Actions:
9/26/2023: Board approved an Agreement with All Commercial Fence in the amount of $1,839,392.50 with an additional 10% contingency for the total contract not to exceed amount of $2,023,331.70.
6/6/2023: Board adopted the Mitigated Negative Declaration (MND) and a Mitigation Monitoring and Reporting Program and well as the Wildlife Exclusion Perimeter Fence project.
4/19/2022: Board approved Task Order #20 with Mead & Hunt, Inc. for Airport Perimeter Fence Upgrade Engineering Design to include general, program, and grant management consulting services for the Charles M. Schulz - Sonoma County Airport.
Fiscal Summary
|
Expenditures |
FY26-27 Adopted |
FY27-28 Projected |
FY28-29 Projected |
|
Budgeted Expenses |
$411,431.24 |
|
|
|
Additional Appropriation Requested |
|
|
|
|
Total Expenditures |
$411,431.24 |
|
|
|
Funding Sources |
|
|
|
|
General Fund/WA GF |
|
|
|
|
State/Federal |
$350,000 |
|
|
|
Fees/Other |
$61,431.24 |
|
|
|
Use of Fund Balance |
|
|
|
|
General Fund Contingencies |
|
|
|
|
Total Sources |
$411,431.24 |
|
|
Narrative Explanation of Fiscal Impacts:
Appropriations for this contract are included in the FY 2026/27 Airport Capital (41301-34030104) Adopted Budget. The Fence Drainage Crossing Repair Project (Phase 2) will be mostly funded through an Airport Infrastructure Grant (AIG) No. 3-06-0241-084-2026 in the amount of $350,000. The federal share of eligible work is 95% up to the $350,000, with the remaining 5% and costs not reimbursed by the grant are funded by local Airport operations funds.
Narrative Explanation of Staffing Impacts (If Required):
None.
Attachments:
Agreement with Roebbelen Contracting, Inc.
Bid Request Fence Drainage Crossing Repairs
Bid Tabulation
Related Items “On File” with the Clerk of the Board:
Plan set Fence Drainage Crossing Repairs