The Navy has decided to remove the lead contaminated soil at the Carderock Naval Surface Warfare Center (sometimes known as David Taylor) on the Clara Barton Parkway.
As part of a general base cleanup, the Navy discovered that what had been a basement firing range was contaminated with lead from the bullets that had been shot there. The range has a dirt floor, and the dirt was found to have a lead level on average of 1,000 parts per million, with some samples reaching 10,000.
That translates to an average of a million parts per billion. The regulatory level is 15 parts per billion.
Initially the Navy had proposed pouring concrete over the range, but it has now decided to remove the soil. The deciding factor was that if the Navy put down the concrete, it would amount to a land-use restriction. “If we leave this in place, we are going to have to leave a restriction,” said Andrew Gutberlet, who is managing the cleanup for the Navy.
If a land-use restriction is put in place, the concrete would have to be studied every five years for as long as the Navy operates the base. If the Navy cleans it up, it can do a final test to confirm that it got all of the contaminated soil and be done. “The ability to walk away is going to make a difference,” Gutberlet said.
The Navy will use a vacuum truck to create a slurry and suck the soil up to a water-tight truck. “There won’t be any lead contamination there,” said Bill Spicer of the Center.
Gutberlet estimates that they will need to remove 200 cubic yards of soil to get all of the contaminants.
The soil will be carted to Hagerstown, where it will be tested again. If it is found to be contaminated, it will then be taken to a hazardous waste landfill. If it is clean, it will likely be used as “daily cover” in a normal landfill, Gutberlet said.
THE OTHER PARTS of the cleanup are progressing as well, Gutberlet said. A storage yard filled with scrap metal was scheduled to be emptied this week. The soil, which has some metal contamination, will then be removed beginning in mid-June. (See sidebar “Traffic Patterns.”)
He expects the cleanup to last through the summer. “The actual removal is going to last probably until the end of August,” Gutberlet said.
After the yard has been emptied, the land will be planted with grasses and left wild. “The native-type grasses that used to be in this area 100 years ago” will repopulate the area, Spicer said. This type of grass requires minimal maintenance and grows tall, which will be attractive for several animal species, Spicer said. “You’re talking about a great habitat.”
In total, the base will need to remove 22,000-25,000 cubic yards of soil to complete the cleanup, Gutberlet estimated. A trailer will hold 20-30 cubic yards of soil.
Gutberlet expects the base to be completely cleaned up by early next year. “The entire program should be complete by the end of January,” he said.