The U.S. Army unveiled environmental cleanup plans last week for two chemically contaminated sites in the Edgewood area of Aberdeen Proving Ground.
The two sites, known as the Kings Creek and G-Field disposal sites, are targeted because of suspected contaminated soil from the burning of chemical weapons and the disposal of suspected hazardous material in corroding drums.
The entire Edgewood area is included in the Environmental Protection Agency's National Priorities List, commonly known as the Superfund. The list was established by the federal EPA to identify sites that present a potential risk to the environment or public health and set priorities in channeling federal money to cleanup efforts.
The primary source of contamination in the Edgewood area is the manufacture, testing and disposal of chemical weapons that occurred decades ago, said Donald Green, environmental scientist for the 75,000-acre military installation.
At a public meeting Monday, Army officials outlined their proposal for cleaning up the Kings Creek and G-Field disposal sites to meet state and EPA standards.
The Army Corps of Engineers estimates the cost for the initial cleanup of Kings Creek at $500,000, says APG spokeswoman Barbara Filbert. Cleanup costs for the G-Field site are estimated at $325,000.
The Kings Creek site is on the northern bank of Kings Creek, on ZTC the northeastern edge of the Gunpowder Neck peninsula. The 2.2-acre area was used by the Army in the 1920s and 1930s to dispose of chemical weapons by open burning.
Today, the affected soil is discolored and devoid of vegetation, according to an environmental assessment of the site by the Army.
There are piles of scrap metal, including corroded drums, the remains of burned gas cylinders and other debris lying about, the report says.
Green said decaying drums at the site are believed to contain hazardous residues from chemical warfare agents, such as mustard gas.
Other drums may contain chloropicrin, a tear gas, and corrosive liquid smokes, including titanium tetrachloride and a sulfur trioxide-chlorosulfonic acid mixture.
The report also noted that chloroacetophenone, a non-toxic white crystalline solid, has spilled onto the ground from corroding drums.
The contaminated soil poses a threat to the nearby creek, as well as to surrounding marsh and wetlands, said the Army report.
Ground water in the Kings Creek area is not used for drinking, the report noted. All sources of public water supplies are upstream of the main Edgewood Area and will not be affected by the cleanup, officials said.
Less is known by environmental managers at APG about the G-Field drum disposal site, on Gunpowder Neck between Wright and Swaderick creeks. More than 80 drums were dumped or abandoned there, but officials do not know when or why, said APG environmental engineer John Wrobel.
"We do know the G-Field was an impact area, which means weapons were fired into it in a test situation," he said. There are no other available records of the site's history.
All the drums are old and badly corroded, Wrobel said, with some less than 50 percent intact. Most are empty, but a few are filled with a gravel mixture. There is no indication that they contain chemical material or chemical residue, the environmental report says.
Some of the drums are in low-lying areas where standing water pools during wet periods. Some drums have bulged ends, indicating that they contained material under pressure at one time, the report says.
The danger here is that officials don't know why the drums are there, and that requires proceeding cautiously, said Wrobel. The Army no longer uses the G-Field site.
While the two sites are different, the proposal for cleaning them up is virtually the same, said Wrobel.
"Most of the jobs we do are similar," he said. "What makes them different is the location and the type of equipment we use.
APG environmental managers said the following steps are proposed for cleaning up Kings Creek and G-Field:
* Test air for contamination.
* Remove and dispose of debris according to environmental regulations.
* Take soil samples for testing to EPA-certified labs.
* Remove drums and sample residual chemical material and soil underneath.
* Determine extent and depth of contamination.
L * Have hazardous waste contractors remove contaminated soil.
* Take appropriate debris to the APG Decontamination/Detoxification Facility for incineration.
* Restore site to a setting consistent with natural surroundings.
* Install erosion and storm water controls to prevent potential contamination from spreading.
Wrobel said the cleanups probably would begin in August.
The Army is taking public comments on its proposals for cleaning up the sites until June 25.
Anyone interested in commenting should write to:
Commander, Aberdeen Proving Ground Support Activity, Attention: STEAP-SH-ER (K. Stachiw), Aberdeen Proving Ground, Md. 21010-5423.
A copy of the environmental assessment is available at the U.S. Army Test and Evaluation Public Affairs Office. Call 278-2013 for more information.
The Aberdeen and Edgewood branches of the Harford County Library also have copies.
APG has set up an information line -- 272-8842 -- to answer questions on possible contamination in 13 areas being studied under its Installation Restoration Program.