Central Contra Costa Sanitary District (CCCSD) and the City of Concord (City) teamed with Carollo Engineers, DCM-GeoEngineers and Bennett Trenchless Engineers to design and manage the construction of a new interceptor sewer that will eliminate the need for a 50-mgd pumping station.

The A-Line Relief is a six-mile long gravity relief interceptor sewer located in the northern portion of CCCSD’s service area and will be constructed in phases over the next 15 years. The current phase of design and construction includes approximately 3,050 ft of 96-in., 870 ft of 72-in., and 540 ft of twin 48-in. RCP under Walnut Creek. This gravity tie-in will eliminate the largest wastewater pump station in the county. The new pipelines were constructed through a variety of surface conditions including a municipal golf course and driving range, under the approach landing path of a municipal airport, across a major regional recreation trail, busy city streets in a fully developed commercial neighborhood and under the earthen Walnut Creek flood control channel…

This article was published in Trenchless Technology. Click to view full article below.