During the Cold War, Hanford Site was used to manufacture and process weapons-grade plutonium. Today, the site is one of the largest environmental clean-up projects in the United States. The Hanford 200 West Groundwater Treatment facility has the ability to treat seven major contaminants.

By: Ken Martins, CH2M HILL Senior Principal Technologist

Ken Martins will present his paper, “Treating Three Varied Contaminants in a Single Process, Initial Operations Results for Hanford’s Anoxic Biological Reactors”, at the Water Quality Technology Conference in Long Beach, California on Wednesday, November 6. To see the full schedule of CH2M HILL speakers and presentations, click here.

Hanford Site—a complex along the Columbia River in Washington State formerly used to manufacture and process weapons-grade plutonium, was established in 1943.The Site was operated by the Department of Energy and created as part of the Manhattan Project during the Cold War era. In the process of producing plutonium and nuclear materials, some 450 billion gallons of liquids (sodium dichromate contaminated water) were discharged into the groundwater and soil. Today, the site is one of the largest environmental clean-up projects in the United States, encompassing 65 square miles of ground water.

Designed by CH2M HILL, the Hanford 200 West Groundwater Treatment facility is a unique groundwater treatment facility, started-up in January 2012, which has the ability to treat seven major contaminants (radionuclides, carbon tetrachloride, nitrate, hexavalent chromium, etc.) in the tainted groundwater.

Biological treatment is commonly used to remove organic materials and nitrate in water. However, in this design, the anoxic fluidize bed reactor also destroys carbon tetrachloride and reduces hexavalent chromium.  The pretreatment process is ion exchange to remove radiological contaminants prior to the biotreatment.

Here’s how it works:

  1. Water is pre-treated for radionuclides using ion exchange
  2. Water is blended with other groundwater and treated with biological processes to remove carbon tetrachloride, hexavalent chromium and nitrate contaminants in a single process
  3. Effluent flows to an aeration basin and membrane bioreactor, where excess COD is consumed and liquids and solids are separated
  4. Clarified water is air stripped to remove remaining contaminants and injected into the aquifer
  5. Waste activated sludge is thickened, dewatered, and stabilized

Over the next 25 years, the facility will treat approximately 24 billion gallons of groundwater and remove an estimated 110,000 pounds of contaminants from the Columbia River region.

In my presentation, I will discuss the initial operating results with regards to the co-treatment of carbon tetrachloride and other volatile organic compounds (VOCs) with hexavalant chromium and nitrate. Results have varied based on whether biological processes are conducted in an anoxic or near anaerobic state.

The facility was the recipient of the 2013 Global Water Awards during the Global Water Summit in Seville, Spain, recognized with the Water and Wastewater Project of the Year Distinction Award.

Ken Martins is a Senior Principal Technologist at CH2M HILL and a registered chemical engineer with 31 years career experience, 22 of which he has spent at CH2M HILL.  Ken specializes in industrial water/wastewater and groundwater treatment.  Ken’s recent work has been related to industrial wastewater reclaim, specialized contaminant removal, and zero discharge-focused technologies.