Public Works and Environmental Services

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703-324-5800 TTY 711
12000 Government Center Parkway
Suite 449 Fairfax, VA 22035
Carey Needham
Director, Capital Facilities

Difficult Run Pump Station Grit Mitigation and Odor Control Improvements Project

Project Number: WW-000001-015

Project Update: August 28, 2023

Work along the Difficult Run trail has been completed. Work inside pump station will continue.

Project Background

The Difficult Run Pump Station pumps flow from the Potomac Interceptor, which collects flow from northern Fairfax County to the Noman M. Cole, Jr., Pollution Control Plant in Lorton. The goal of this project is to reduce grit accumulation in the Difficult Run Pump Station and the associated force main, to provide odor control, and to increase the pumping capacity at the pump station.

Difficult Run Pump Station
Difficult Run Pump Station building


Project Location

The project is located at 9950 Colvin Run Road, Great Falls. The project is located adjacent to the Difficult Run Trail.

Map - Location of Difficult Run Pump Station
Location of Difficult Run Pump Station


Project Benefits

  • Increases pumping capacity to match the growth in the area.
  • Provides flexibility in managing increasing sewer demands in a growing population.
  • Provides means of odor control to ensure minimal community impacts.
  • Reduces operation and maintenance costs related to grit accumulation.


The construction contract was awarded in spring 2023. Construction is expected to be completed in fall 2024.

What To Expect

Construction activities will be limited to the pump station property and easements. The Difficult Run Trail will remain open at all times during construction. There will be no interruption to sanitary sewer service.

Project Cost and Funding Source

The construction cost for the Difficult Run Pump Station Grit Mitigation and Odor Control Improvements is approximately $5.3 million. Wastewater construction projects are funded through the county’s Capital Improvement Program.


For questions about construction of the project, please email Agata Fallon, P.E. at or call 703-324-5613.

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