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C. 2

To:	Board of Supervisors
From:	Brian M. Balbas, Public Works Director/Chief Engineer
Date:	October 20, 2020

Contra

Costa

County

Subject:

APPROVE the Storm Damage Repair, Alhambra Valley Road at Ferndale Road Project and take related actions under CEQA.

APPROVE	OTHER
RECOMMENDATION OF CNTY ADMINISTRATOR	RECOMMENDATION OF BOARD COMMITTEE

Action of Board On: 10/20/2020

APPROVED AS RECOMMENDED

OTHER

Clerks Notes:

VOTE OF SUPERVISORS

AYE:

John Gioia, District I Supervisor
Candace Andersen, District II Supervisor
Diane Burgis, District III Supervisor
Karen Mitchoff, District IV Supervisor
Federal D. Glover, District V Supervisor

Contact:	Sandeep Singh 925-313-2022
cc:	Ave' Brown Sandeep Singh

I hereby certify that this is a true and correct copy of an action taken and entered on the minutes of the Board of Supervisors on the date shown.
ATTESTED: October 20, 2020
David Twa,

BY:	, Deputy

RECOMMENDATION(S):

APPROVE the Storm Damage Repair, Alhambra Valley Road at Ferndale Road Project (Project) and AUTHORIZE the Public Works Director, or designee, to advertise the Project, Alhambra Valley area. [County Project No. 0672-6U6211, DCD-CP#19-38] (District V).


DETERMINE the Project is a California Environmental Quality Act (CEQA), Class 1(c) Categorical Exemption, pursuant to Article 19, Section 15301 of the CEQA Guidelines, and

RECOMMENDATION(S): (CONT'D)

DIRECT the Director of Department of Conservation and Development to file a Notice of Exemption with the County Clerk, and

AUTHORIZE the Public Works Director or designee to arrange for payment of a $25 fee to the Department of Conservation and Development for processing, and a $50 fee to the County Clerk for filing the Notice of Exemption.

FISCAL IMPACT:

Estimated Project cost: $1,030,000. 100% Local Road Funds.

BACKGROUND:

The purpose of this project is to reconstruct the road embankment and stabilize the roadside shoulder along the eastbound lane of Alhambra Valley Road near Ferndale Road. The embankment area has been closed off with concrete k-rails and traffic has been reduced from a two-way road to a single lane road with stop signs installed on both sides of the k-rail. Repair of the embankment is necessary to prevent further deterioration of the roadway section and to restore the eastbound lane to its original state.

The project will require installing an approximately 78-foot long soldier pile retaining wall along the south side of the roadway to support the reconstructed roadway. The piles for the retaining wall will be set via drilling; no pile driving will occur. The anticipated maximum excavation depth is approximately 37 feet for the piles and approximately 12 feet at the base of the retaining wall where timber lagging will be installed. Three drainage inlets will be established in place of existing catch points. A portion of an existing corrugated metal pipe will be replaced with high-density polyethylene pipe and a new segment of high-density polyethylene pipe will be installed roadside of the retaining wall. A flared end section will be set at the outfall. A hot mix asphalt dike, concrete v-ditch, section of guardrail, and minor concrete vegetation control will be constructed along the top of the reconstructed slope. Equipment staging will likely occur just east of the project site on the south side of the road and just west of the project site, along the north side of Alhambra Valley Road westbound lane and across from the work zone. Some debris and sediment removal may be required in the slide area and upstream drainage ditch. Roadway surface drainage will be restored to previous conditions. Concrete k-rails and channelizers will limit the roadway to one-way traffic for the duration of construction at this site. Three oak trees will be removed. Construction is currently anticipated to occur in the summer of 2021 and take approximately 20 days to complete.

CONSEQUENCE OF NEGATIVE ACTION:

Delay in approving the project may result in a delay of design, construction, and may jeopardize funding.