To: Board of Directors, Sonoma Valley County Sanitation District
Department or Agency Name(s): Sonoma Valley County Sanitation District
Staff Name and Phone Number: Greg Guensch 707-547-1972
Vote Requirement: 2/3rd
Supervisorial District(s): First
Title:
Title
Environmental Resource Consulting and Engineering Design Services for Sonoma and Kohler Creeks Bank Repair Project
End
Recommended Action:
Recommended action
A) Authorize Sonoma County Water Agency’s General Manager acting on behalf of Sonoma Valley County Sanitation District to execute the Third Amended and Restated Agreement for Engineering and Design Services for Sonoma and Kohler Creeks Bank Repair Project with Prunuske Chatham, Inc. to provide creek bank repair environmental resource consulting and engineering design services. The amended agreement increases the amount by $298,900; expands the scope of work to include engineering Project design to 100 percent, completion of the required environmental documentation to complete the Project, and assistance during bidding and construction; and extends the agreement term by 18 months for a new not-to-exceed agreement total of $348,900 and end date of December 31, 2023.
B) Adopt a Resolution Authorizing Adjustment to the Board Adopted Budget for Fiscal Year 2020-2021 for the Sonoma Valley County Sanitation District Operations Fund in the amount of $298,900 for Environmental Resource Consulting and Engineering Design Services for the Sonoma and Kohler Creeks Bank Repair Project.
(2/3rd Vote Required)(First District)
end
Executive Summary:
In an ongoing effort to maintain the sanitary sewer collection system in Sonoma Valley, avoid unnecessary damage or failures and repair costs, and protect the environment, the Sonoma Valley County Sanitation District (District) is proposing to perform creek bank stabilization work at 13975 Arnold Drive, Glen Ellen, California (Project). The purpose of the Project is to stabilize two areas of eroding bank on Sonoma Creek and one area of erosion on Kohler Creek that pose risks to the sanitary sewer trunk main, two manholes, and a siphon under Sonoma Creek that are owned by the District. The purpose of this amended agreement is to finalize plans, specifications, the design report, and other Project materials for the selected design alternatives, and to obtain regulatory compliance documents necessary to advertise the Project for construction.
Discussion:
HISTORY OF ITEM/BACKGROUND
The District operates the sanitary sewer collection system in Sonoma Valley. A portion of the sewer pipeline system, in the Glen Ellen area, runs parallel to Sonoma Creek and crosses Kohler and Sonoma creeks near the confluence of these two channels. The District is proposing to repair two sites on the bank on Sonoma Creek and one site one Kohler Creek in order to protect sanitary sewer infrastructure that is exposed and at risk of damage and possible failure during high-intensity stream flows. The sites are located on private property along the back yard of 13975 Arnold Drive in Glen Ellen. After monitoring these sites, attempting minimal impact measures since 2012, and implementing emergency repairs in April 2019, staff now recommend implementing necessary repairs for a longer term solution to protect the District’s sanitary sewer infrastructure (including the trunk main, two manholes, and a siphon under Sonoma Creek that could result in a wastewater spill into Sonoma Creek). The Project will also reduce the potential for future public health and environmental impacts, fines, and costly emergency repairs.
Severe erosion occurred during the unusually wet 2016-2017 winter, and subsequent high flows that resulted from a storm event on February 26, 2019, exposed some of the at-risk infrastructure. Temporary emergency measures were installed in April 2019 to stop the erosion and protect infrastructure from damage. These measures were constructed under a temporary emergency permit using Federal Emergency Management Agency (FEMA) public assistance grant funding, however, and it was not possible to design and implement measures that met all the permitting and California Environmental Quality Act (CEQA) requirements. As such, the District must remove or modify the temporary measures and replace them with permanent measures that have been properly permitted and satisfied CEQA requirements.
These sites are identified as vulnerabilities in the District's FEMA-approved 2016 Local Hazard Mitigation Plan. Specific hazards listed include static and seismic embankment failure potential and potential exposure and damage of pipeline due to erosion and debris impact during periods of rapid creek flow.
Sonoma Creek at this location also provides habitat for threatened and endangered species and it is important to avoid impacts to this sensitive area. The sensitive nature of the site and the severity of the bank erosion warrants the services of a specialist in bio- and geo-technical stream bank repair in sensitive settings.
District and Prunuske Chatham, Inc. (Consultant) entered into an agreement for creek bank repair environmental resource consulting and initial engineering design assessment, dated December 19, 2018 in the amount of $50,000.
The agreement was first amended on April 10, 2019, at no additional cost to the District or extension of term to add a task to develop the scope for the future complete engineering design of the Project, including associated required environmental documentation. The initial engineering and environmental concept design has been completed.
The agreement was next amended on November 17, 2020 to extend the term of the agreement by six months to provide additional time to develop the full scope for additional design and construction support by Consultant for a new term end date of June 30, 2021.
SERVICES TO BE PERFORMED
Under the proposed amended agreement, Consultant will provide engineering Project design to 100 percent, assistance during bidding and construction, and completion of the required environmental documentation and permitting to execute the Project.
The original agreement and first amended agreement included tasks to identify and analyze, at the concept level, treatments for channel bed and banks, including related incidental modifications of the pipe system in the immediate vicinity.
The additional cost is $298,900, for a new not-to-exceed agreement total of $348,900. The new end date is December 31, 2023.
The third amended agreement includes two options for District to extend this agreement for a period of one year each by providing written notice to Consultant thirty days in advance of the expiration date of the agreement and of the first extension option.
Prior Board Actions:
12/11/2018: Approved agreement between District and Prunuske Chatham, Inc. for environmental resource consulting and engineering design services. Cost $50,000; term end December 31, 2020.
Fiscal Summary
Expenditures |
FY 20-21 Adopted |
FY21-22 Projected |
FY 22-23 Projected |
Budgeted Expenses |
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|
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Additional Appropriation Requested |
$298,900 |
|
|
Total Expenditures |
$298,900 |
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|
Funding Sources |
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General Fund/WA GF |
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State/Federal |
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Fees/Other |
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|
|
Use of Fund Balance |
$298,900 |
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Contingencies |
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Total Sources |
$298,900 |
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|
Narrative Explanation of Fiscal Impacts:
Additional appropriations are required to process this expense in the Sonoma Valley County Sanitation District Operations Fund. A budgetary resolution has been submitted with this item.
Staffing Impacts: |
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Position Title (Payroll Classification) |
Monthly Salary Range (A-I Step) |
Additions (Number) |
Deletions (Number) |
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Narrative Explanation of Staffing Impacts (If Required):
N/A
Attachments:
Attachment 1: Resolution
Attachment 2: Amended Agreement with Prunuske Chatham, Inc.
Related Items “On File” with the Clerk of the Board:
None