Public Works and Environmental Services Alert:
Fairfax County’s population continues to grow, and more people increases the volume of wastewater needing to be safely conveyed via sanitary sewer infrastructure to wastewater treatment facilities.
Areas in Tysons, Reston, Herndon and the Town of Vienna are continuing their growth into green urban centers. The full vision for Tysons is presented on the Tysons Partnership website while others are available on the Fairfax County, Town of Herndon, and Town of Vienna websites. To support this growth, utilities are expanding and upgrading their services to provide power, communications, and water and wastewater collection services.
The Fairfax County Department of Public Works and Environmental Services (DPWES) is responsible for wastewater collection and treatment, overseeing more than 3,300 miles of sanitary sewers pipes and 59 wastewater pump stations. Wastewater inside the majority of the County’s sanitary sewer pipes moves downhill by gravity. However, pump stations are necessary when the sewage inside pipes must be moved uphill to an area of higher elevation, where that sewage can then continue flowing downhill to the treatment plant.
Wastewater collected in the County sanitary sewer network is conveyed to one of several wastewater treatment plants serving the County’s needs, including the Noman M. Cole, Jr., Pollution Control Plant in Lorton operated by DPWES as well as DC Water’s Blue Plains Treatment Plant in southwest DC. DPWES manages the County’s contractual relationships with other entities like DC Water to ensure the County’s wastewater needs are met.
The Tysons East Pump Station project is one project in a program of critical projects being implemented to ensure future wastewater capacity needs are met in the northeast portion of the County. The purpose of the Tysons East Pump Station is to divert, when necessary, wastewater that would normally flow to DC Water’s Blue Plains Treatment Plant uphill and into the sewershed flowing to the County’s Noman M. Cole, Jr., Pollution Control Plant.
The County is a participant in an Intermunicipal Agreement with DC Water and other regional partners that allows County sewage to flow through DC Water’s Potomac Interceptor pipe to their Blue Plains Treatment Plant. The Intermunicipal Agreement establishes limitations on how much flow the County can convey via the Potomac Interceptor, and how much treatment capacity is available to Fairfax County in the Blue Plains Treatment Plant. While the capacity in the Potomac Interceptor for new sewage flow is limited, the County has available capacity in our Noman M. Cole, Jr. treatment plant.
The County is a participant in an Intermunicipal Agreement with DC Water and other regional partners that allows County sewage to flow through DC Water’s Potomac Interceptor pipe to their Blue Plains Treatment Plant. The Intermunicipal Agreement establishes limitations on how much flow the County can convey via the Potomac Interceptor, and how much treatment capacity is available to Fairfax County in the Blue Plains Treatment Plant. While the capacity in the Potomac Interceptor for new sewage flow is limited, the County has available capacity in our Noman M. Cole, Jr. treatment plant.
The station needs to be located along the existing Scotts Run Interceptor sewer to divert wastewater flow to the Noman M. Cole, Jr., Pollution Control Plant sewershed when necessary to comply with the restrictions on wastewater flows in the Potomac Interceptor.
The Tysons East Conveyance System Modifications Preliminary Engineering Report (PER) was completed to evaluate potential locations for the new Tysons East Pump Station. Although 10 locations were studied, the study identified that only location would be feasible. As shown in figure 1, the new pump station will be located in the vicinity of Scotts Run Road, and a new forcemain will be constructed in the vicinity of Lewinsville Road and Tyco Road to push the sewage into the Noman M. Cole, Jr. sewershed. A diversion structure will be built on the existing Scotts Run Interceptor, located in close proximity to the selected Tysons East Pump Station location, to divert flow through a gravity sewer to the new station.
This project will add a new pump station to the sewerage system maintained by Fairfax County’s Wastewater Collection Division (WCD). For information figure 2 below shows the location of current pump stations operated by WCD. More than three quarters of the County’s existing 59 pump stations are located in residential areas.
Project details will be further developed during the design phase. After the site is successfully acquired, DPWES intends to design the project with input from the community to align the appearance of the facility and grounds with the character of the neighborhood, minimize odors and noise, and protect the floodplain and protected environmental resources on the site.
During the design process, the community will also have the ability to provide their input through the County’s Public Facilities 2232 Review. This review will be initiated by the design team when the pump station design has reached the stage when more details on what will be built have been developed. This will include issues such as building façade, location on the parcel, landscaping and screening, stormwater management, and other related issues. A public notice will be posted to the people in the vicinity of the station to provide the design documents developed and receive any comments they may have on the design.
During design, all necessary permitting will be obtained for the construction of the project to address site development, resource protection area conservation, and other regulatory issues. Design and permitting for the project is anticipated to take approximately 24 months. The construction duration and schedule will be further developed during the design phase of the project.
The engineer’s preliminary opinion of the construction cost for this project is $59 million. It is being fully funded through the County’s sewer fund supported by sewer user fees. No tax dollars are funding these improvements.
The project manager for this project is Thomas Grala. You can reach Mr. Grala with any questions or comments on the project at thomas.grala@fairfaxcounty.gov or call 703-324-5815, TTY 711. The project is located in the Board of Supervisors Dranesville District.