Cleanup Objectives: Biodegrade subsurface volatile organic compounds (VOCs) through reductive dechlorination and control contaminant migration

Greener Remediation Strategy:

Planted 660 cottonwood trees across 4,000 square meters in 1996 to:

• Establish root biomass promoting activity of indigenous microbes
• Enhance transpiration of ground water through the trees, helping to control hydraulic gradient and downgradient migration of VOCs

Results:

• Produced virtually no process residuals
• Reduced VOC concentrations in ground water approximately 65% within first four years
• Increases treatment efficacy over time according to plant growth
• Incurred $193,200 in capital costs including $2,100 for plants, $10,000 for irrigation, and $90,000 for monitoring wells
• Incurred average annual maintenance costs of $252,000 for extensive monitoring of ground water (plume control), vegetation, climate and other site parameters affecting the (federal interagency) demonstration
• Supported transfer of property to community as part of base realignment and closure, without disruption to ongoing activities

Property End Use: Recreation