In the two years prior to the operation of the permeable treatment wall, pictured here, WVDP conducted extensive engineering and planning to ensure it would effectively remove strontium-90.
This 2009 photo shows a trenching machine, which is capable of cutting a continuous trench up to 30 feet deep and 3 feet wide. The machine was used in a pilot study to evaluate the effectiveness of zeolite placement as the trench was dug. This ensured a consistent depth and width for the zeolite placement along the entire length of the permeable treatment wall.
WEST VALLEY, N.Y. – A unique groundwater treatment system has significantly reduced the presence of a contaminant at EM's West Valley Demonstration Project (WVDP), according to a report issued this month.
The permeable treatment wall — one of the first full-scale systems of its kind in the DOE complex to remove radioisotopes from groundwater — has decreased the concentration of the contaminant strontium-90 in the groundwater by 77 percent since the wall began operating in late 2010.
“We are very excited about the performance of the permeable treatment wall. Our sampling results indicate effective removal of contaminants from the groundwater and our wells are showing a significant decrease in strontium-90,” WVDP Director Bryan Bower said. “The wall is effectively remediating more of the groundwater plume than we could have ever achieved with our pump-and-treat system.”
The goal is for the wall to treat the contamination, which originated from a leak during commercial nuclear fuel reprocessing in the 1960s. The aquifer with the strontium-90 contamination is not used as a source for drinking water.
Funded by $6.5 million in American Recovery and Reinvestment Act dollars, the wall is an approximately 850-foot-long trench that contains nearly 2,000 metric tons of zeolite, a naturally occurring mineral formed from volcanic ash. The zeolite strips the strontium-90 from the groundwater passing through the wall.
“The zeolite is doing its job,” said Charles Biedermann, a senior consulting engineer for CH2M Hill B&W West Valley, a contractor to WVDP. “I feel it has met all of our expectations.”
WVDP is working to shut down a pump-and-treat system that had attempted to remove the strontium-90, Biedermann said.
“I’m very pleased with its performance and we’re going to continue to monitor and evaluate its effectiveness,” Biedermann said of the wall. “Hopefully we can share our experience with this technology with other DOE sites for remediation of radioisotopes in groundwater.”
In a 2012 visit to western New York, EM Senior Advisor Dave Huizenga joined Bower for a meeting with leaders from the Seneca Nation of Indians to address their concerns regarding cleanup at WVDP, specifically the groundwater plume contaminated by the strontium-90. The Seneca are concerned that the contamination may impact the Cattaraugus Creek if it is not remediated. The creek has great significance to the Seneca and travels through their territory. Tribal engagement in activities at WVDP are facilitated by a longstanding cooperative agreement between the Seneca and EM.