North Four Corners News ♦ June 2024

WSSC Project to Repair, Replace Sections of Sewer Main in Our Neighborhood’s Northwest Branch Park

By Ken Hawkins

In January 2023, an alert member of the NFCCA listserv posted that a large crack had developed on the walking trail in Northwest Branch Park, just north of where the Lockridge tributary trail meets the main trail on the west bank of the branch.  Montgomery Parks was alerted, given the size of the cracks, and that it was apparent that the trail bed supports large pipes under its surface.  In May, the Washington Suburban Sanitary Commission (WSSC) notified neighbors of its intent to rehabilitate what it calls the Northwest Terrace Aerial Sewer in a fifteen-month project that will begin construction this fall.

What we enjoy as a nice area for a wooded hike was established and has served as a watershed for drinking water and the drainage of sanitary sewage from our homes and thousands of others.

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Cracks appear along the sewer mains off the Lockridge Drive entrance to the Northwest Branch Trail in our neighborhood.

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The layout of the trails follows the sewer mains directly for both the tributaries and the main channel of the branch — including those along Lockridge Drive, Hannes Street, and Loxford Terrace.  The environmentally sensitive area through which these lines run was set aside by the WSSC in the 1920s as a watershed for the collection and treatment of drinking water for lower Montgomery County.  The Burnt Mills dam and two brick buildings on Colesville Road at the Northwest Branch are remnants of this system, which was used until 1960.  Sanitary sewage systems were not installed by WSSC in this area until the mid- to late 1950s.  That’s when the 30-inch sewer main now endangered by the trail erosion was installed.

The use of this area for park uses came later.  Northwest Branch Park was assembled piecemeal by the Maryland-National Capital Park and Planning Commission (M-NCPPC) beginning in the 1950s.  The Burnt Mills section was not secured for park uses until 1962.

Lawrence Cumberbatch, WSSC’s manager of the Northwest Terrace Aerial Sewers project, provided more information about the coming project:  it is to rehabilitate and, in some critical places, replace the 30-inch sewer main on the NWB’s west side that acts as collector for the affected neighborhoods.

“The underground sewers and the manholes are going to be lined using trenchless methods and the above-ground aerial sewers, their supports and trusses are going to be replaced.  The aerial sewers are in dire need of repair.  We are very concerned regarding the catastrophic impact that a failure of these assets would have on the park and the surrounding communities if the rehabilitation work is not carried out in the near future.  We are also concerned regarding the greater impact on the park if we are forced to carry out emergency repairs rather than the planned rehabilitation.”

Cumberbatch reported that the carrying capacity of this sewer main is between 100,000 and 1,000,000 gallons of sewage water per day.*

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Supports no longer fully hold up the Lockridge sewer main.

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WSSC is not exaggerating the need for repair of this main:  there is visible breaking down of the concrete pipe where it crosses both the Lockridge and Hannes/Loxford tributaries; the supports for the sewer main at Lockridge are tilting and one can easily see them toppling at any time.  I walked the project site on 18 May and the trees marked for removal are concentrated around the aerial part of the sewer line and in the narrower spots on the access roads that we use as walking trails.  All of the trees marked for removal are less than eight inches in diameter.

While this project may temporarily inconvenience our direct access to the Northwest Branch Park, other nearby trails will be available and open, including those on the east side of the branch, accessible from the Burnt Mills West Special Park, as well as Sligo Creek Park, Rock Creek, etc.  The project will benefit the environmentally sensitive areas of the Northwest Branch Park, including the vernal pond adjacent to the project area, by preventing the gradual leakage or catastrophic spillage of raw sewage.   ■

[To see the work being done in our neighborhood, click on the buttons below.  On the “WSSC Construction” website, increase the magnification for projects to show up.]

*This statistic was updated since publication.