Upham Brook Trunk Sewer

The Upham Brook Trunk Sewer project is a three-mile alignment of new 48-inch and 54-inch gravity sewer near Richmond, Virginia, that parallels an existing 48-inch reinforced concrete pipe (RCP) sewer installed in the 1980s. This project increases the system’s capacity for Henrico County to mitigate overflows and accommodate future growth in the area. This project is one segment of a multi-phase master plan to upgrade the sanitary sewer system in the central portion of the county.

The three miles of trunk sewer traversed a wide variety of installation conditions, including in-roadway, residential, open cuts up to 40 feet deep, rock excavation, 50-foot-deep tunnel shafts, creek crossings, trenchless crossings, heavy groundwater, and wooded easements. The project included the rehabilitation of an existing 8-inch gravity sewer by cured-in-place pipe (CIPP) in the historic neighborhood of Bryan Park. The project also required the conveyance of 72 million gallons per day (MGD) of live sewer flows from existing 48-inch and 66-inch RCP trunk sewers with portions of the discharge piping extending 4,500 linear feet (LF) through residential areas.

The project team successfully navigated a challenging 2,200 LF section of 48-inch sewer installation through the Bryan Park neighborhood at depths up to 20 vertical feet (VF) along the area’s primary roadway. Despite the presence of hard rock, blasting was restricted due to the proximity to houses and existing natural gas utilities. The team leveraged various rock excavation techniques to remove a total of 29,000 cubic yards (CY) of 20,000 PSI bedrock, including limited blasting, hydraulic hammering, expansion grouting, and mechanical drum cutter excavating. The project also required maintaining service within the existing parallel 48-inch sewer during construction, which required a 4,500 LF stretch of 36-inch HDPE bypass sewer piping installed above ground through the neighborhood. The project team carefully placed the HDPE bypass piping within the neighborhood and installed ADA access ramps for pedestrian access across the 36-inch pipe installed above grade while coordinating with local homeowners to maintain access to their homes.

To safely pass beneath various surface features such as roadways, railways, and streams, the project design leveraged micro-tunnel boring machine technology to place a total of 1,365 LF of sewer pipeline and protective steel casing without disruption. These tunnels were constructed in a variety of geotechnical conditions, including soft marine deposits and 20,000 PSI bedrock with access shafts up to 50 VF in depth.

The Upham Brook Trunk Sewer project contributes to the resilience and efficiency of the community’s infrastructure, ensuring a sustainable and robust sewer system for years to come. Garney collaborated with the owner and engineer to deliver a complex project with diverse stakeholders with minimal disruption to the surrounding area through detailed planning and careful execution.