The Army Corps of Engineers will conduct tests to determine if perchlorate in Spring Valley groundwater near Sibley Memorial Hospital comes from the same source as the perchlorate in the groundwater at AU’s campus.
The source of perchlorate in Sibley’s groundwater remains unconfirmed, but Army Corps experts believe a former munitions pit on the South side of campus called Lot 18 is causing the high perchlorate levels in both locations, project manager Dan Noble told the Resident Advisory Board on Nov. 7.
Perchlorate, a dangerous chemical that can cause thyroid disorders, was used at AU during World War I to make chemical weapons.
Lot 18 was the site of a major Army Corps’ excavation after several dangerous chemicals, including arsenic, mustard gas and perchlorate, were discovered there in 2004, The Eagle previously reported.
The Army Corps will be taking water samples from a testing well at Kreeger Hall near Lot 18 and from a testing well near Sibley Hospital, according to Army Corps project manager Todd Beckwith. The Kreeger Hall testing site has the highest concentration of perchlorate in Spring Valley, according to Noble.
If perchlorate isotopes taken from the Kreeger Hall testing site and from the Sibley well are the same, then the source of the perchlorate is likely Lot 18, according to Joyce Conant, the Spring Valley Project’s public relations specialist.
The perchlorate levels at six other wells in Spring Valley also exceeded the advisory health limit, according to Beckwith.
The Army Corps will also conduct groundwater tests at 4900 Glenbrook Rd. and on Loughboro Road because these wells could also be contaminated with perchlorate from Lot 18, he said.
Groundwater around AU contains levels of perchlorate exceeding the advisory health limit, and levels of the chemical in Spring Valley groundwater increased by five parts per billion from 2007 to 2009.
The groundwater investigation started in 2005 when 38 monitoring wells were installed to help determine contaminated areas.
The Army Corps reported in February that perchlorate levels at the Kreeger site were decreasing, The Eagle previously reported. But Spring Valley residents were skeptical because the findings were based on readings made more than two years apart and during different seasons.
The decision to conduct more groundwater tests at AU came last month after the Army Corps released the results of a test conducted in November 2009.
The Army Corps will now sample groundwater from the area every three months because perchlorate levels in the groundwater change according to the seasons and the amount of precipitation, Noble said.
The Army Corps has not drawn up plans to remove perchlorate from the groundwater.
“It is premature to say what will be done to cleanup the groundwater, but there are a wide range of alternatives that could be considered,” Conant said.
The Army Corps will share the results of groundwater tests at AU and in Spring Valley with the Department of Health, the Environmental Protection Agency and AU officials throughout 2011, according to Conant.
mellmauer@theeagleonline.com
