Addendum Natural Pressure-Driven Passive Bioventing
Abstract
This report is for ESTCP Project CU-9715. Bioventing involves injecting air into unsaturated (vadose zone) soils to provide indigenous aerobic soil microorganisms with oxygen needed to accelerate the biodegradation of contaminants that are susceptible to aerobic metabolism. While conventional bioventing uses an electric blower to transfer the air, passive bioventing relies on daily changes in atmospheric pressure to move air through vent wells screened within the contaminated vadose zone. Usually a one-way valve on each vent well permits air to pass only into the soils so as to prevent the reverse flow of air that still contains appreciable oxygen gas. This report specifically addresses the applicability of using passive bioventing at fuel contaminated sites in the Eastern United States, where vadose zones are usually shallow and remain moist throughout the year because of more uniform precipitation, compared to most sites in the Western United States. The short-term assessment of more than 10 sites and detailed evaluation of two sites with greatest potential indicate that passive bioventing has limited applicability at Eastern locations that have vadose zones less than 30 feet deep. High soil moisture in shallow, unconsolidated vadose zone profiles and the general East Coast stratigraph do not provide conditions favorable for cost-effective passive bioventing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2003
- Accession Number
- ADA421457
Entities
People
- Chris Zimmerman
- Ron Hoeppel
- Sherrie Larson
Organizations
- Naval Facilities Engineering Service Center