Richmond, Va, April 14, 2017 —
Restoration Advisory Board members, Defense Logistics Agency Installation Support at Richmond, Virginia leadership, and concerned citizens came together April 10, at the Bensley Community Center in Chesterfield County, Virginia, for the quarterly RAB meeting. DLA established a RAB for Defense Supply Center Richmond in January 2002 to provide a forum for the community to be involved in DSCR’s environmental cleanup.
The meeting was open to the public and is one way the installation communicates it’s ongoing environmental evaluation and cleanup efforts. The RAB is comprised of members from the community, DLA, the Environmental Protection Agency, and the Virginia Department of Environmental Quality. It provides a forum for DLA Installation Support at Richmond, Environmental Office's to discuss ongoing groundwater testing results and remediation activities for operable units on center. As an advisory board, the RAB makes suggestions, recommendations and comments on issues concerning investigations and remediation activities.
David Hufford, environmental engineer with Installation Support’s Environmental Office, opened the meeting by giving an update to several ongoing projects, including groundwater sampling at DSCR. The meeting covered Operable Unit’s 7 and 8.
Hufford reported the following: OU7: The source of OU7 was contaminated from the groundwater impacted from the former fire training area, remedial performance optimization ongoing, vapor monitoring point replacement in Bldg. 72 is complete and annual groundwater monitoring ongoing. OU8: The source of OU8 groundwater contamination came from leaks in two acid neutralization pits (concrete tanks) or its piping located on the DSCR property back in the 1960s and 1970s; conducting enhanced reductive de-chlorination pilot study, long-term pump tests, and spring biannual groundwater monitoring. He also reported the bio-enhanced directed groundwater recirculation system (pilot) has been installed, and the environmental office has received the Fall biannual sampling results.
Britt McMillan, a DLA environmental contractor with Arcadis, gave an in-depth presentation on the changes/improvements within OU7 and OU8 from 2014 to 2016. He said that the previously installed bio walls (enhanced composted mulch walls) that were positioned underground and at OU7, have slowed biological activity of those walls stopped) the down-gradient movement of the plume [groundwater movement], decreasing the size and magnitude of the plume. He said they have begun the process of doing follow-up injections to further enhance the process.
“The bio-enhanced groundwater recirculation project installed for OU8 takes the best aspects of the extraction method and the best aspects of the bio-injection method and combines them together on one system, ending up with an aggressive remediation system, “ said McMillan. “This is being implemented into the source areas, eliminating the migration of constituents of concern.”
He showed attendees the recirculation layout in the OU8 area on a diagram showing the groundwater flow from north of the contaminated area and the placement of the three extraction wells on the down-gradient. He said the natural down-gradient will pull contaminants to the collection wells. Then they take the extracted water and treat it with granular activated carbon to remove all the contaminants and inject them into the up-gradient of the source, which continues to force through in a circulating pattern through the source area. They are focusing the treatment efforts on the source area first, because it is contributing to the down-gradient flow.
“We then monitor it and once we get an idea of the groundwater flow rate and the time it takes to get through the system, we will then enhance the injection with the carbon to further treat the contaminants in the source area,” said McMillian. “Once the contaminants are removed they are gathered and held in the granular activated carbon vessel until it’s full and then send to a thermal plant for degradation.” He said they test at least every 60 days.
“The whole purpose of creating the circulation cell is to clean the area much quicker. We have introduced fluorescein dye solution, which is the same dye they use for glaucoma testing, and put the dye in the injection wells to monitor the occurrence of dye in the down-gradient wells and extraction wells documenting the time it takes to reach the wells,” said McMillan.
He added, once they have those figures it will give them a better idea how long it takes to run the system and also a better idea of the type and amount of carbon to put into each well.
“The dye study is the first step in determining the time it is going to take,” said McMillan.
The next RAB meeting will discuss OU6 updates and is scheduled for July 10.