Project Details

Project Type:	Trenchless Project
Location:	Concord, California
Owner:	Central Contra Costa Sanitary District
Engineer:	Carollo Engineers
Contract Value:	$20,650,750
Contract Type:	Public Works
Completion Date:	In Progress

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Project Highlights:

• Four Tunnel Shafts using interlocking sheet pile methods
• Unique Octagon Shaped Configuration of the shafts
• Substantial Ground Dewatering
• 540 LF of twin 48” diameter RCP Sewer installed open cut
• Concrete encasement of the open cut pipeline
• 838 LF of 72” diameter RCP installed by MTBN
• 3,009 LF of 96” diameter RCP installed by EPBM
• 36” Venturi Sewer Flow Metering Structure (40’ Deep)

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Downloads:

• Trenchless News-- Summer 2008 (445KB PDF)
• A-Line Relief CCCSD News Fall 2008 (6.4MB PDF)
• A-Line Relief CCCSD News Summer 2008 (19.2MB PDF)
• A-Line Relief Sewer Investing (8MB PDF)

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This is a joint project between the City of Concord and the Central Contra Costa Sanitary District to increase the wet weather flow capacity of the districts A-Line interceptor. The A-Line interceptor is the “backbone” of the districts collection system. It receives the vast majority of the districts sewage and transports it to the Martinez treatment plant facility. These interceptor upgrades will also eliminate the need for one of the cities sewer pumping stations.

The project installs approximately 4,500 feet of new sewer lines ranging in diameter from 48 to 96 inch. It will also convert an existing city pump station into a Venturi metering structure. To minimize construction impact nearly 4,000 feet of the pipe was installed by tunneling methods. With trenchless construction, the district was able to minimize impact to traffic and avoid local congestion. The Project was located near Buchanan Fields Golf Course and under a number of heavily traveled streets.

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Articles & News

Trenchless News-- Summer 2008

The City of Concord, CA in unison with Central Contra Costa Sanitary District (CCCSD) is in the process of getting an essential sewer line replacement which will decommission one of the largest pumping stations in the country.
Download a copy of this article (445KB PDF)

A-Line Relief CCCSD News Fall 2008

Infrastructure Improvements by the City and CCCSD.
Download a copy of this article (6.4MB PDF)

A-Line Relief CCCSD News Summer 2008

CCCSD sewer system has been updated to one of the best in California.
Download a copy of this article (19.2MB PDF)

A-Line Relief Sewer Investing

Sewer Construction increased capacity and reduced potential for wet weather overflow.
Download a copy of this article (8MB PDF)

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