In July, the DOE and CH2M HILL broke ground on an $80m groundwater treatment facility for startup in 2012. Contractors are currently designing the facility and installing several wells that will be part of a treatment system that will pump more than 85 million gallons of contaminated groundwater per month from a large area in the center of the Hanford Site known as the Central Plateau.
The new treatment system will pump contaminated water from the ground and remove several chemical and radioactive contaminants. The facility will cover an area about the size of a football field and is expected to treat an estimated 25 billion gallons of groundwater beginning in December 2011. The facility will bring together for the first time technologies that will be able to remove nitrates and metals, as well as radioactive and organic contaminants, and return the water to the aquifer cleaned to the Federal Drinking Water Standard.
During the Cold War, billions of gallons of liquids contaminated with chemicals and radioactive elements were discharged from plutonium production facilities to several soil disposal sites across the Hanford Site. Discharges in the western area of Hanford’s Central Plateau resulted in a five-square-mile area of groundwater contaminated above drinking water levels. Leaks from large underground storage tanks also contributed to a much smaller area of contamination. The primary contaminants of concern are carbon tetrachloride, a solvent used in processing facilities, and Technetium 99, a radioactive byproduct of processing. Smaller areas of other contaminants in the same area will also be treated by this system.
“We’re holding the line on groundwater contamination in this area and not letting it get to the Columbia River,” said Dave Brockman, Manager of DOE’s Richland Operations Office. “This treatment system will not only remove contamination but also shrink the area of contamination so it won’t move from the center of the Hanford Site to the river.”
The facility is funded by the American Recovery and Reinvestment Act. By using $80 million in Recovery Act funding, Hanford officials will build a larger facility in one phase, allowing the treatment system to operate at full capacity five years earlier, potentially reducing the time required for cleanup, and saving an estimated $25 million in long-term cleanup costs.
U. S. Department of Energy and contractor CH2M HILL Plateau Remediation Company (CH2M HILL) are accelerating groundwater cleanup efforts at Hanford’s 100 Area.
Hanford’s 100 Area stretches 16,600 acres along the Columbia River and once housed nine plutonium production reactors. The Project’s environmental cleanup goals include removing contaminated soil and treating groundwater to remove contaminants. The contaminant considered of greatest concern in 100 Area groundwater is hexavalent chromium.
Recently in the 100 Area, CH2M HILL completed upgrades and expansions of the K Area groundwater treatment system, including adding an additional treatment facility. The K Area spans 535 acres and includes the K East and K West reactors, adjacent fuel storage basins, and several facilities and waste sites that supported reactor operations from the 1950s to the 1970s. Operation of the newest groundwater treatment system began in May, and within one month, the overall treatment capacity for the K Area Project reached over 35 million gallons per month – three times its previous capability.
As of June 2009, over 206 million gallons of water have been treated, removing more than 49 kilograms of hexavalent chromium from Hanford’s K Area.
“The K Area treatment systems are important to containing chromium and eventually restoring the groundwater to meet drinking water levels,” said Dave Brockman, Manager of DOE’s Richland Operations Office. “These actions also support our goals to contain complete cleanup of the Columbia River Corridor by 2015, with final treatment systems for groundwater in place.”
CH2M HILL is expanding other treatment facilities in the 100 Area including H Area, near Hanford’s “H” Reactor. In addition, designs for upgrading the D Area groundwater treatment system, near “D” and “DR” reactors are under way with construction expected to start early 2010.
Sodium dichromate, a chemical used as a corrosion inhibitor, was added to the river water used to cool Hanford’s older nuclear reactors while they were operating. Over time, the soil and groundwater became contaminated with chromium because of leaks in the dichromate transfer systems and piping and because cooling water treated with dichromate was periodically discharged to the soil near the K Reactors.
Once all systems along the river are operational, CH2M HILL expects the 100 Area Groundwater Treatment Systems to pump and treat at a rate of more than 90 million gallons per month– over three times the capacity available along the River before the treatment system expansions began.
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