Upon an inspection of the facility, it was discovered that two of our three siphons are currently not operational, and mobilization of a contractor to clean these siphons and possibly perform repair work to restore their full operational capacity is needed. The repair is necessary because there is no reasonable bypass alternative if the last pipe of the wastewater siphon fails, which would mean millions of gallons of untreated sewage per day discharging into the Potomac River.

Work includes removing sediment from a valve vault, replacing the vales, and cleaning the siphon barrels. Valve vault cleaning and valve work will take place in Scott’s Run Nature Preserve. Siphon barrel cleaning will take place in Carderock National Park.

The total duration of the project is anticipated to be 6 to 9 months. The portion of the project occurring in Scotts Run Nature preserve is anticipated to be 3 months with two separate park closures. The first closure will begin on March 28, 2024 for approximately 6 weeks. At a later time, Scotts Run Nature will close for a second phase of the project to complete maintenance repairs. More details on this additional closure will be released once additional investigations are made during the initial phase. Once work is completed in Scotts Run Nature Preserve cleaning of the siphon pipes will occur in Carderock Park.

Farifax County will identify methods to optimize and enhance its inspection and cleaning procedures to reduce the likelihood of this type of response in the future.

A specialty contractor was hired to complete the cleaning of the project. They have chosen equipment that is no larger/heavier than the current pick-up trucks being used for park and sewer maintenance. These were specifically chosen to not damage critical root zones of trees. The limits of disturbance will be to the already trafficked trails and the construction staging area for equipment will be in the upper parking lot to limit potential of materials going into the river/floodplain.

The park is being closed to facilitate an emergency project to clean and perform necessary repairs on wastewater pipes that extend across the Potomac River into Maryland. This work will require construction access to the site by construction crews and equipment using the trail – making it unsafe for pedestrian traffic. The closure is also necessary to protect the beautiful and unique natural resources of the park which could be damaged and/or destroyed with large volumes of visitors venturing off-trail to attempt to circumvent perimeter fencing.

The Fairfax County Park Authority has 420 parks throughout Fairfax County with a variety of amenities and experiences available. Please use the Park Amenity Locator to search for other alternatives based on a number of different criteria – from athletics fields, courts and playgrounds to fishing, historic features and trail access. Hikers are also welcome to utilize Trail Buddy – an online trail-finder application – for information on both Park Authority and Non-Park Authority trails in Fairfax County.

Safety of residents and commuters is a top priority. The contractor will be beginning their work onsite at 7 a.m. and will be ending their day at 7 p.m. There will be limited traffic in and out of the parking lot once the contractors arrive in the morning as the movement of the construction equipment will be occurring inside the park. Materials and construction equipment for the project will be safely stored onsite. Additionally, Fairfax County McLean District Police have been notified of the project and will be monitoring traffic patterns in the area to ensure safety of residents and commuters.

Work on this project will be limited to the Scott’s Run Nature Preserve and Carderock National Park in Potomac Maryland. No work will be occurring outside of these two parks.

We are striving to get this work completed as swiftly as possible but are limited to the site conditions. Due to the location of the vault being next to the Potomac River the project is completely dependent to the weather and the water levels of the river. Our contractor is going onsite every morning to check the levels of the river to determine if the vault is accessible and it is safe to complete work.