Use of Cometabolic Air Sparging to Remediate Chloroethene-Contaminated Groundwater Aquifers
Abstract
The United States Department of Defense (DoD) is faced with the task of remediating many sites contaminated with a variety of compounds, including chlorinated aromatic hydrocarbon (CAH) compounds. When a contaminant release occurs, these compounds may be present in the geologic media in any or all of three phases: adsorbed to soils, in free-phase form, or dissolved in groundwater. Of the three phases, dissolved contaminants in the groundwater are considered to be of greatest concern because of the risk of human exposure through drinking water; primary concerns for sorbed and free-phase contaminants often reside with their potential impact to groundwater. CAHs, used for years as industrial cleaners and degreasers, comprise some of the most common groundwater contaminants found at federal installations; chloroethenes and chloroethanes are among the most common solvents. The United States Air Force (USAF) uses more than 900 sites contaminated with chlorinated solvents in excess of drinking-water standards, and that may require cleanup. Industry, other government agencies, and up to 85% of Superfund sites (United States Environmental Protection Agency [U.S. EPA] and USAF, 1993) face similar cleanup situations. The Environmental Security Technology Certification Program (ESTCP) supported an 18-month field study to investigate the cometabolic air sparging (CAS) process at McClellan Air Force Base, California. McClellan AFB (McAFB) was selected as the demonstration site for a variety of reasons: (1) McAFB has significant CAH groundwater contamination; (2) previous studies supported by the Air Expeditionary Forces Technologies Division (AFRL/MLQ), Tyndall AFB, Florida demonstrated that indigenous bacteria at McAFB could utilize propane as a growth substrate and support cometabolic CAH degradation; and (3) McAFB is a member of the Strategic Environmental Research and Development Plan (SERDP) National Environmental Technologies Test Site Program (NETTS).
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2001
- Accession Number
- ADA604321
Entities
Organizations
- Air Force Research Laboratory