The 36-inch transmission main — the same size as the large pipe that burst and shut down N. Glebe Road near Chain Bridge in November — was placed out of service in 2013 due to concerns about a catastrophic failure. A transmission line was built parallel to it after a major water main break on N. Old Glebe Road in 2009 and is currently providing service to the area.
County officials say rehabbing the old main, which was built in 1972, will help provide redundancy in the county’s water system. Arlington’s water comes from the Washington Aqueduct in D.C., by way of pipes that cross the Potomac River at Chain Bridge then branch out to various parts of the county.
The project will run along N. Glebe Road from Old Glebe Road to Little Falls Road — a distance of about 0.8 miles. Residents should expect lane closures and daytime water service interruptions during the course of the project, the county staffers said in a report to the County Board.
The Board is expected to vote on the contract at its meeting this Saturday.
More from the staff report:
This contract is for the rehabilitation of a transmission main built in 1972 in the right-of-way of North Glebe Road between Old North Glebe Road and Little Falls Road. The transmission main was placed out of service due to a catastrophic failure in 2009. The proposed rehabilitation work will prevent the likely future failure of this transmission main and bring it back to service which will provide redundancy for the water main network.
The proposed transmission main rehabilitation is part of the Water Main Rehabilitation / Replacement program outlined in the Capital Improvement Plan. Inspection and evaluation of the existing transmission main subsequent to the November 2009 break revealed that the transmission main was subject to failure. Therefore, a 36″ transmission main was installed in parallel and the existing failing transmission main was placed out of service in 2013. The proposed rehabilitation work consists of lining the existing transmission main that was placed out of service and replacing some portions of it. The overall goal for the proposed rehabilitation is to reinstate the transmission main which is currently out of service and provide the required redundancy to meet water demand in the area. […]
The scope of this project involves the rehabilitation of existing infrastructure along the same corridor and the construction will cause some water services disruptions throughout the duration of the project. These disruptions will not be for an extended period. Traffic flow will be maintained throughout the project duration by keeping at least one lane open each direction during working hours throughout the project duration. The traffic impacts of the project have been communicated via the project website and through Civic Association presidents. Progress updates regarding the construction of the project will continue to be regularly provided to the communities via the two channels noted above.
Upon contract award and before the start of construction, a detailed letter about the project and construction schedule will be sent to the presidents of both Civic Associations and then be distributed to residents who will be directly impacted by the project. Additionally, water service disruptions will be coordinated with the affected residents in advance of any shutdowns. All shutdowns will be limited to construction hours during the work day.