The U.S. Army Corps of Engineers will resume digging for World War I-era weapons near the AU campus today.
The Army Corps halted digging Dec. 5 when a 75-mm munition discovered Nov. 19 was found to contain an explosive burster charge, The Eagle previously reported.
The Department of Defense Explosive Safety Board approved a Chemical Safety Submission amendment Jan. 18, which now requires a new air-filtration unit at the interim holding facility, located on the western edge of the project land, according to an Army Corps press release.
"That filtration unit gives us a backup in the remote chance that somehow gas gets released from the stainless steel containers [where the munitions are stored]," Program Manager Ed Hughes said.
The Chemical Safety Submission amendment does not require any additional equipment or precautions at the actual Pit 3 dig site on Glenbrook Road, Hughes said.
"It does not make any changes to any of the systems we have at the site, such as the large metal structure, called the engineering containment structure," he said.
The Army Corps raised the sound level of two warning sirens located on the site because of community concerns, The Eagle previously reported.
No additional safety measures were required because AU pressed for them before the dig began in October, according to an e-mail AU President Neil Kerwin sent to the AU community yesterday.
"The safety precautions at the dig site were deemed to be sufficient, partly because the university had insisted on additional safety measures when it reviewed plans prior to the start of work," Kerwin said in the e-mail.
While the munition found Nov. 19 did contain arsine gas and an explosive charge, no fuse was present. A fuse is required for the munition to function. However, this still classified the shell as "explosively configured" and required a change to the site's maximum credible event, which is a statement describing the site's worst-case scenario, The Eagle previously reported.
With the amendment approved, future munitions found that are in a similar configuration to the one unearthed in November would not cause digging to cease, Hughes said.
"If we found similar munitions, we will be able to continue without stopping," he said.
Emergency shelter-in-place procedures will remain the same for AU and neighboring Spring Valley, according to Hughes.
"[The community doesn't] need to do anything different," he said.
The dig, originally scheduled to conclude next month, will continue into the summer months, Kerwin said in the e-mail.
Hughes said he appreciates the support he has been getting from the AU community.
"We really appreciate the university's cooperation and everyone's understanding," Hughes said. "We look forward to working closely with everyone on campus in the coming months"
