City of Alexandria Takes Additional Cleanup Steps Regarding Former Gas Plant

ALEXANDRIA, VA -- The City of Alexandria announced Friday that it has taken additional steps to address environmental issues related to a former manufactured gas plant in Old Town. The next step will involve storm sewer pipe cleanup and inspection work the week of Feb. 13, from 7 a.m. to 6 p.m., near the unit block of Oronoco Street, the City said. Some parking and sidewalk access will be limited in the area during this work, and there may be minor traffic disruptions, the City noted. Here's more about the cleanup efforts, from the City news release:

The Alexandria Town Gas plant at the corner of Lee and Oronoco Streets operated from 1851 to 1946, and was owned by the City for most of that time. In the 1970s, the site was developed into an office and townhome complex and an outfall pipe was installed to direct stormwater into the nearby Potomac River. Over time, residue from the plant site has been identified in the area intermittently, resulting in part from ground contamination from the plant’s operation and in part from contaminants that have entered the stormwater pipe and traveled to the river.

The site has been entered into the Virginia Voluntary Remediation Program, which allows the City to work closely with the Virginia Department of Environmental Quality. The City has taken many measures, in a multi-year, phased plan, to prevent further discharges related to the plant.

Potomac Riverkeeper (PRK), a nonprofit organization focused on preventing pollution along the Potomac River, has shared data samples and concerns about the spread of contaminants. The City appreciates PRK's input and technical contributions, and City and PRK staff are working together to develop solutions. On the basis of PRK's initial data, the City conducted a video inspection of the stormwater pipe between N. Union and N. Fairfax Streets and has done additional sediment sampling to identify areas requiring further work.

Next, City contractors will conduct a thorough inspection and cleanout of the outfall pipe. The work will begin on Feb. 13 and should take approximately one week, weather permitting. The report on this work will include recommendations on further remedial actions to prevent contaminants from entering the pipe.

As the next phase of this project, the City has planned and budgeted for 2017 to dredge and remove contaminated sediment from around the outfall. A special mat will be installed to “cap” the remaining sediment and prevent contaminants from moving into groundwater and seeping into the river. The City and its environmental consultants will also continue to perform soil sampling in the area of the former plant to identify any areas where residue may remain beneath the ground.

Work involving the former gas plant site is unrelated to the City’s accelerated efforts to address its aging combined sewer outfall (CSO) system. The outfall impacted by the former gas plant is part of the City’s dedicated storm sewer system and only conveys stormwater to the Potomac River; it is not a combined sewer outfall.

Read more about Alexandria's environmental endeavors on the City Web site here.

PHOTO of water at Oronoco Street courtesy of City of Alexandria