Special Notice / Hearing: None__
Vote Required: Majority
To: Honorable Board of Supervisors, Acting as the Governing Board of the Crystal Springs County Sanitation District
From: James C. Porter, Director of Public Works
Subject: Seneca Lane Mudslide Sewer Stabilization Project - Crystal Springs County Sanitation District [Project No. SMF51, File No. E4989]
RECOMMENDATION:
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Acting as the Governing Board of the Crystal Springs County Sanitation District, adopt a resolution authorizing the Director of Public Works to proceed with:
A) Preparing plans and specifications for the Seneca Lane Mudslide Sewer Stabilization Project; and
B) Advertising for bids on the Seneca Lane Mudslide Sewer Stabilization Project, and reporting back to this Board with recommendations on awarding a contract.
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BACKGROUND:
The County of San Mateo experienced significant storm-related damage as a result of heavy rainfall and elevated streamflow throughout the 2017 storm season. On January 23, 2017, the Governor declared a State of Emergency for many California counties, including San Mateo County due to the heavy storm systems in January and the resulting flooding, erosion, and damage to local infrastructure. The Federal Emergency Management Agency (FEMA) later announced a federal disaster declaration and disaster assistance availability for San Mateo County due to severe winter storms, flooding, and mudslides from January 18 to January 23, 2017.
On February 7, 2017, your Board, in accordance with Government Code section 8630 and Chapter 2.46 of the San Mateo County Ordinance Code, ratified action by the Director of Emergency Services proclaiming a local state of emergency. The action was taken after several weeks of severe storms caused a mudslide, damaging a sewage pipe located behind the property at 1560 Seneca Lane, in unincorporated San Mateo County and within the boundaries of the Crystal Springs County Sanitation District.
Your Board subsequently renewed the emergency proclamation on February 14, February 28, March 14, March 28, April 11, April 25, May 2, May 16, June 6 and June 27, 2017. Renewal of the emergency proclamation is necessary to maintain eligibility for state and federal financial assistance.
On March 14, 2017, your Board adopted Resolution No. 075084 authorizing the Department employees to serve as agents authorized to execute in the name of the County of San Mateo all necessary applications, contracts, agreements, amendments and payment requests hereto for the purposes of securing grant funds and to implement and carry out the purposes specific in the grant applications with FEMA and the California Office of Emergency Services (Cal OES).
A temporary bypass pumping system is currently in place to continue providing sewer service to the 47 District customers upstream of the damaged sewer main. District staff have been monitoring the pumping system regularly to ensure it is functioning properly while geotechnical investigations were conducted and repair options evaluated.
Winterization measures were developed and implemented prior to the 2017-18 rainy season to ensure the project area was protected and to minimize additional movement of the mudslide. The District has been working with FEMA and Cal OES to apply for FEMA disaster relief funds for the costs incurred in responding to the emergency and for the permanent repair of the sewer main. FEMA and Cal OES have determined that the site would be eligible for funding and are working with the District to establish an appropriate scope of work and funding amount. The FEMA disaster number assigned to this mudslide is FEMA-4305-DR-CA.
DISCUSSION:
To mitigate the mudslide damage and construct a permanent repair of the sewer main, the Department authorized task orders in accordance with an existing on-call services agreement with BKF Engineers, Inc. (BKF). Their work included conducting a geotechnical investigation, preparing a feasibility study for the Seneca Lane Mudslide Sewer Stabilization Project (Project), and preparing design alternatives and plans and specifications for the selected alternative.
Several alternative repair designs were considered for the Project. Based on the results of the geotechnical investigation and feasibility study, the Department is recommending replacing the sewer main in its original alignment and constructing a soldier pile wall with steel ground anchors or tie-backs (Project) to restore the structural conditions that existed prior to the mudslide and protect the sewer main from future movement. The total estimated cost for the Project is $2.7M, which includes an estimated construction cost of approximately $2.05M. Other alternatives were eliminated due to access limitations and higher costs.
Project construction will occur within and adjacent to the existing sewer easements that are on private property. New public utility easements will be negotiated from impacted property owners as necessary for the proposed soldier pile wall and tie-backs.
In order to expedite the project schedule and because the timing on obtaining FEMA funding is uncertain, we are requesting that your Board authorize the Director of Public Works to proceed with preparation of the plans and specifications and call for bids for the Project to help ensure construction of the Project during the summer/fall 2018 or as soon as FEMA/Cal OES funding approval has been obtained. In a subsequent Board action, we will present plans and specifications for your Board’s adoption and recommend awarding the Project to the lowest responsible bidder. Your Board has previously approved the use of this “streamlined” process to shorten the time required to award a contract in order to ensure compliance with specific funding or construction deadlines.
County Counsel has reviewed and approved the resolution as to form.
Approval of this action will contribute to the Shared Vision 2025 outcome of a Healthy Community by maintaining the integrity of the sanitary sewer infrastructure and protecting the environment for the benefit of the public.
FISCAL IMPACT:
The estimated construction cost is approximately $2,050,000. The cost associated with Department staff time, consultant fees, and additional sewer easement acquisitions is approximately $650,000. All costs are proposed to be financed initially by District funds as FEMA funds are available only on a reimbursable basis.
There is no impact on the General Fund.