Broad Creek Augmentation Conveyance System

The Broad Creek Pumping Station (PS) pumps wastewater to the Piscataway Wastewater Treatment Plant for treatment. In recent years, heavy rainfall caused untreated wastewater to overflow into local waterways. To help mitigate this concern, the Washington Suburban Sanitary Commission (WSSC) called on Gannett Fleming, as part of a joint venture, to design the Broad Creek Augmentation Conveyance System.

What We Did

Gannett Fleming developed and evaluated pipeline routing alternatives and implemented the final design. The study process involved close coordination with the Maryland State Highway Administration, Prince George’s County Department of Public Works, the Maryland‑National Capital Parks and Planning Commission, the Maryland Department of the Environment, and other permitting agencies to determine potential constraints to the suggested alternatives.

Based on the final alignment selection, the project team prepared the design for a new force main, gravity sewer, and pressure sewer from the PS to the WWTP. Also, new headworks and emergency storage at the WWTP and improvements to the PS were designed to increase system capacity. The new conveyance system includes 5 miles of pipeline, sections of which were required to traverse environmentally sensitive areas, as well as National Park Service lands in a historic district. To minimize community and environmental impacts, the project team used microtunneling for 8,700 feet of pipeline.

Key Features

  • New parallel conveyance system included a 48-inch force main, 60-inch gravity sewer, and 42-inch pressure sewer.

  • Sections of the pipeline run through sensitive environmental areas and cross through National Park Service lands in a historic district.

  • To minimize impact, microtunneling was utilized for installation of seven sections of the conveyance system for total tunneled length of 8,700 feet.

Awards & Recognition

  • Outstanding Project Award, 2021, American Council of Engineering Companies of Maryland, Engineering Excellence Awards.

  • Honor Award, 2021, American Council of Engineering Companies Metro Washington, Engineering Excellence Awards.

  • National Recognition Award, 2021, American Council of Engineering Companies, Engineering Excellence Awards.
OUTCOMES

Met accelerated schedule for 100 percent design drawings.

Eliminated wastewater overflows.

Protected sensitive environmental and historic areas.