WRHSRC Research Program

Research at the WRHSRC focuses on improving clean up methods for groundwater contaminated with volatile organic compounds (VOC's), especially chlorinated solvents.

VOC's are hydrocarbons that are used in the production of paints, plastics, adhesives, gasoline, and as degreasing agents. If these substances leach underground, the dense, non-aqueous phase liquids can dissolve slowly and create large plumes of contamination that affect both vadose and saturated zones of the subsurface.

The goal of WRHSRC research is to develop technologies for the in-situ treatment of contamination in both high-concentration source zones and in lower-concentration, diffuse plumes.

Research projects are organized into four focus areas, each addressing a different aspect of cleanup. The paragraphs below provide general information about each focus area and link to technical descriptions of research projects.

Research projects often involve field studies such as this example from MClellan Air Force Base, CA. Researchers are experimenting with push-pull-well tests for the bioremediation of chlorinated solvent contamination.

Two focus areas involve bioremediation -- a cleanup method that uses microbes to injest contaminants and convert them to harmless substances.

• Focus Group 1, Anaerobic Biological Processes, works with microbes that live in environments without oxygen. Researchers are developing new microbe cultures that can treat high concentrations of chlorinated solvents and investigating ways to increase the speed and efficiency of anaerobic bioremediation. This treatment method is applied in contaminant source zones where chemical concentrations are extremely high.

• Focus Group 2, Aerobic Cometabolic Processes, works with oxygen-utilizing microbes that grow on substances such as butane and transform chlorinated solvents. Research will focus on cleanup of dilute plumes of contaminants such as trichloroethylene and trichloroethane.

• Focus Group 3, Physical and Chemical Abiotic Processes, investigates ways to chemically treat or physically remove contaminants. Research projects study ways to speed up chemical reactions and separate contaminants from soil and water molecules.

• Focus Group 4, Site Assessment and Characterization, studies the environmental conditions that control the rate and effectiveness of in-situ cleanup. Researchers are also developing new ways to monitor remediation rates and efficiency.