Technical Description:
Vortechs Hydrodynamic Separator
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Occupying approximately 8,300 acres in southeastern
Virginia, Fort Eustis, owned and operated by the United
States Army, began operations as a training center
(known as Camp Abraham Eustis) in 1918. Over the years,
it has served both military and nonmilitary functions,
and today is a U.S. Army Transportation Training Center
with approximately 17,500 military personnel, their
dependents, and civilians living or working there.
In 1988, the U.S. Army Toxic and Hazardous Materials
Agency identified multiple potential waste sources at Fort
Eustis, and the site was formally added to the National
Priorities List (NPL) as part of the Superfund program in 1994. One of the sites identified within
Fort Eustis was Brown’s Lake, a man-made lake that receives runoff from helicopter and locomotive
maintenance areas.
Once a popular fishing spot, Brown’s Lake was closed in the late 1970s by the Fort Eustis Preventive
Medicine Group because of contamination. Throughout the 80’s and 90’s, water quality tests
continued to show high levels of pollutants, including polychlorinated biphenyls (PCBs), pesticides
and polycyclic aromatic hydrocarbons (PAHs) in the lake as well as downstream tributaries. In the
late 90’s, action was taken to both remove contamination as well as to prevent future releases from
the surrounding industrial area, but the lake remained off-limits to fishing.
Remediation was taken a step further in 2007, when a clean-up effort began on the upper drainage
ditch leading to Brown’s Lake. During storms, stormwater runoff from the 50 acre drainage area
would collect in the ditch and then discharge into Brown’s Lake. Project engineers were tasked with
removing pollutants, especially PAHs, from the stormwater prior to entering into the lake.
Working with Contech, project engineers designed a
way to dam the ditch and treat stormwater before it
reached the lake. A 20-ft concrete weir wall was installed
across the ditch to route storm flows up to 70 cfs into
a 20-ft x 30-ft Vortechs system. The system was castin-
place on-site. The Vortechs system, from Contech, is
a hydrodynamic separator designed to maximize the
settling properties of particulate pollutants. In addition
to trapping coarse solids, the multi-chamber design also
traps free oil and grease and floatables such as trash
and debris. The system is most effective at removing
particulate pollutants and contaminants bound to
particulates, so the PAHs removed would be bound to
sediment 50 microns and larger.
Maintenance of the system is easily done with
unobstructed access to sequestered pollutants in the
system’s swirl chamber. Periodic removal of pollutants
will ensure that the Vortechs system will continue to
perform as designed and help protect water quality.
In the Spring of 2017, in conjunction with the Virginia Department of Environmental Quality and Environmental Protection Agency, the installation had successfully reached a point where the lake could be reopened for catch and release fishing.
Technical Description:
Vortechs Hydrodynamic Separator
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