To: Board of Directors, Russian River County Sanitation District
Department or Agency Name(s): Russian River County Sanitation District
Staff Name and Phone Number: Kevin Booker (707) 521-1865
Vote Requirement: 4/5th
Supervisorial District(s): Fifth
Title:
Title
Sewer System Evaluation Capacity Analysis Plan Update
End
Recommended Action:
Recommended action
A) Authorize Sonoma County Water Agency’s General Manager acting on behalf of Russian River County Sanitation District to execute an agreement with Woodard & Curran Inc., in a form approved by County Counsel, for engineering services through October 31, 2025, in the not-to-exceed amount of $450,000.
B) Adopt a Resolution authorizing adjustments to the Board Adopted Budget for Fiscal Year 2023/2024 for the Russian River County Sanitation District Operations Fund in the amount of $105,000.
(4/5th Vote Required) (Fifth District)
end
Executive Summary:
This item requests authority for Sonoma County Water Agency’s (Sonoma Water) General Manager acting on behalf of Russian River County Sanitation District (District) to enter into an agreement with Woodard & Curran Inc. (Consultant), to prepare a revised System Evaluation and Capacity Assurance Plan (SECAP). The National Pollution Discharge Elimination System (NPDES) permit (No. CA0024058, Section 6.3.6.2) requires an updated SECAP addressing collection system flood control and flow reduction mitigation. Under this agreement, Consultant will assess historical rainfall, flooding, and sewer data; develop flood analysis models; update the sewer hydraulic model; evaluate sewer capacity and flooding impact; identify capacity solutions and mitigation measures; and update the SECAP with an updated SECAP design storm event.
Discussion:
HISTORY OF ITEM/BACKGROUND
District encompasses a 2,700-acre area in Sonoma County along the Russian River and State Highway 116 corridor, and serves the unincorporated communities of Rio Nido, El Bonita, Guerneville, Guernewood Park, Vacation Beach, and adjacent areas. District, which is operated and managed by Sonoma Water, provides wastewater collection, conveyance, and treatment to approximately 3,300 parcels. The collection system includes approximately 39 miles of sewer pipelines and 11 sewage pump stations and conveys wastewater to District’s wastewater treatment plant, located on Neeley Road at the southern end of the District.
District requires a revised SECAP to comply with subsection 6.3.6.2.2.3 of Order R1-2021-0002 issued by the North Coast Regional Water Quality Control Board to District and Sonoma Water. This subsection of the Order requires that District prepare a revised SECAP describing the results of a work plan created under a separate agreement. The revised SECAP will include an engineering evaluation and a plan to correct identified deficiencies in the collection system and treatment plant, including engineering and contingency measures as well as cost-effective, long-term approaches that will be implemented to prevent, reduce, and mitigate for spills. Additionally, the revised SECAP will identify Capital Improvements Projects that eliminate, reduce, and mitigate overflow events.
District completed a SECAP in 2016 based on the model analyses and results of its 2015 Sanitary Sewer Capacity Assessment. District is currently in the process of updating the model and capacity assessment for existing and future conditions. The update to the sanitary sewer model includes updating model pipe networks to include recent system changes, updating existing and projected future wastewater flows, reviewing and comparing actual wastewater treatment flow data to simulated flow events, and updating the capacity assessment. These updates will be incorporated into a revised SECAP.
In addition, District will complete an engineering study to evaluate impacts of various flooding conditions on the District sanitary sewer system. The purpose of the engineering study is to:
1. Determine flooding conditions of the Russian River and its tributaries during various flood events.
2. Evaluate the 10-year 24-hour return frequency storm event used in the 2015 SECAP and update the design storm as appropriate.
3. Determine impacts of various flood events on the collection system and treatment plant, identifying where the highest risk of sanitary sewer overflows and treatment system bypasses could occur.
4. Identify a mitigation and response plan for preventative measures, public notification, spill response, and site management.
The results of this engineering study will be incorporated into the updated SECAP.
SELECTION PROCESS
Consultant was selected from a list of qualified consultants developed from a competitive selection process. Attached is a memo that explains the competitive selection process.
Consultant was selected for the subject work because Consultant has experience with the updated Sanitary Sewer Capacity Assessment that will be incorporated into the SECAP. Further, Consultant has experience with Sonoma Water’s 2015 SECAP that requires updating.
District may seek to amend or enter into subsequent agreement(s) with Board approval if required, relying upon this competitive selection process, after the preliminary or initial work is completed.
SERVICES TO BE PERFORMED
Under the agreement, Consultant will assess historical rainfall, flooding, and sewer data; develop flood analysis models; update the sewer hydraulic model; evaluate sewer capacity and potential flooding impacts; identify capacity solutions and mitigation measures; and update the SECAP with the updated design storm event.
The cost of services will not exceed $450,000; the term end date is October 31, 2025.
The agreement includes two options for District to extend the term 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. The extension will be formalized in an amended agreement or amendment signed by District and Consultant.
County of Sonoma Strategic Plan Alignment:
N/A
Sonoma Water Strategic Plan Alignment
Wastewater Treatment and Water Reuse, Goal 1: Improve operational reliability of wastewater treatment and water reuse systems.
The revised SECAP and engineering report will allow Sonoma Water to identify and develop capital improvement projects that address potential capacity deficiencies and mitigate spills.
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
No
Prior Board Actions:
05/09/2023: Approved amended agreement between Sonoma County Water Agency, Occidental County Sanitation District, Russian River County Sanitation District, Sonoma Valley County Sanitation District, and South Park County Sanitation District and Woodard & Curran, Inc. to develop a work plan for preparing a revised SECAP. Cost $675,000; term end December 31, 2025.
07/30/2013: Approved agreement between Sonoma Water, Sonoma Valley County Sanitation District, Russian River County Sanitation District, and RMC Water and Environment for sanitary sewer hydraulic modeling, capacity assessment, and sewer master planning services. Cost $798,324; term end December 31, 2016.
Fiscal Summary
|
Expenditures |
FY 23-24 Adopted |
FY24-25 Projected |
FY 25-26 Projected |
|
Budgeted Expenses |
$210,000 |
$110,000 |
$25,000 |
|
Additional Appropriation Requested |
$105,000 |
|
|
|
Total Expenditures |
$315,000 |
$110,000 |
$25,000 |
|
Funding Sources |
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General Fund/WA GF |
|
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State/Federal |
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Fees/Other |
$315,000 |
$110,000 |
$25,000 |
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Use of Fund Balance |
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Contingencies |
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|
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Total Sources |
$315,000 |
$110,000 |
$25,000 |
Narrative Explanation of Fiscal Impacts:
Budgeted amount of $210,000 is available from FY 2023/2024 appropriations for the Russian River County Sanitation District Operations fund. Additional appropriations of $105,000 are required from the Russian River County Sanitation District Operations Fund to process this expense. With Board approval, unused appropriations budgeted in FY 2022/2023 and rolled over to FY 2023/2024 will be made in the Russian River County Sanitation District Operations Fund pursuant to the attached budgetary resolution. FY 2024/2025 and 2025/2026 appropriations will be budgeted in those fiscal years.
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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:
Resolution
Competitive Selection Process Memo
Related Items “On File” with the Clerk of the Board:
None.