The project was initiated by the consulting Engineer in August 2022 and the 95% complete design documents were completed in June 2023. Easement acquisition is ongoing.
The Fairfax County Department of Public Works and Environmental Services (DPWES) has received multiple odor complaints related to the wastewater collection system in the vicinity of Columbia Pike and Lake Barcroft. In February 2020, our consultant completed an evaluation report and recommended implementation of a vapor phase odor control system within the Holmes Run Stream Valley Park. This was followed by a more detailed evaluation and a pilot study which concluded in the Fall of 2021.
The goal of the project is to mitigate sewer related odors along an approximate one-mile-long area within the Holmes Run Stream Valley Park south of Columbia Pike. The project consists of installing a vapor-phase odor control unit (7,000 cfm carbon adsorption unit) near Holmes Run, inlet duct work and plenum, discharge duct work and dispersion stack, 13 manhole air inlet assemblies including isolation valves, and up to 1,500 feet of underground 12 to 16-inch diameter jumper ventilation lines between manholes to maximize odor removal farther upstream and downstream from the odor control facility.
The project is in the Lilian Carey and Holmes Run Stream Valley Parks south of Columbia Pike. The carbon adsorber and dispersion stack will be located just before the first stream crossing near Manholes 22 & 27 as shown on the figures below. An example carbon adsorber and air inlet (gooseneck) assembly is shown in the photos below.
Minimizing sewer odors within Lilian Carey Park and the Holmes Run Stream Valley Park.
Reduction of H2S and other odorous compounds inside the wastewater collection system for improved safety and to help prolong the life of the sewer system.
The project is expected to be bid during the 4th Quarter of 2023. Construction is expected to begin in the 1st Quarter of 2024 and be substantially complete in the 1st Quarter of 2025. The schedule is subject to change.
What To Expect
This new ventilation system will significantly reduce odors within and around the Lilian Carey and Holmes Run Stream Valley Parks.
Project Cost and Funding Source
The Current total project estimate for this project is $5,619,274, which will be funded through the County’s Capital Improvement Program (CIP).
For information, please email email@example.com, Mujahid Ali, P.E., AVS; Project Manager, Wastewater Design and Construction Division, Department of Public Works, and Environmental Services.