Formatted Title
New Advances in Phytoremediation and Successful Treatment on Chlorinated Solvents Sites
Background/Objectives
The objective is to present advanced microbial technology and design methodology that improves the success rate and expands new opportunities for utilizing enhanced phytoremediation. In 2014, Intrinsyx Environmental collaborated with NASA and the EPA to introduce endophytic bacteria from Dr. Sharon Doty (University of Washington) with hybrid poplar trees to address TCE groundwater contamination at the MEW Superfund site (Doty et al., 2017).
The success of this first pilot on the MEW site has expanded to full-scale endophyte-assisted phytoremediation deployments on Superfunds, state-mandated cleanups, and Fortune 500 redevelopment sites on 35 sites across the nation. Endophyte-enhanced tolerance and appropriate trees, plants, and grasses selection of unique varieties are keys to successful phytoremediation on polluted sites with phytotoxic concentrations of both organic and inorganic contaminants.
Approach/Activities
This presentation covers design methodologies and data from full-scale phytoremediation on the MEW Superfund site, as well as lessons learned from utilizing endophyte-assisted phytoremediation system (EAPS) technology. These synergistic bioremediation tools and innovative techniques have been deployed to address several classes of pollutants, including chlorinated VOCs, petroleum hydrocarbons, and 1,4-dioxane alone and in mixed waste situations. Updated data will be shared from the MEW Superfund site at the NASA Ames/ Moffett Airfield to the results of this pilot, which was a collaboration with the EPA Region 9, NASA, and the University of Washington. Future redevelopment plans for the site will be discussed.
Results/Lessons Learned
Success with phytoremediation comes from careful site assessment and selection of appropriate tree and microbe varieties. Data and lessons learned will be highlighted from contaminated sites across the U.S. where EAPS is currently installed to treat chlorinated solvents (PCE/TCE/DCE), petroleum hydrocarbons, and 1,4-dioxane compounds in soil and groundwater. Among the lessons learned along the way, are confirmation that endophytes contribute to phytoremediation success and improved plant establishment, in-planta degradation, and enhanced source-zone depletion rates. Data suggest that the selection and application of appropriate endophytes are the key factors in plant establishment on sites with phytotoxic concentrations of petroleum hydrocarbons or chlorinated solvents. Additionally, selecting site-appropriate tree varieties and providing them with consistent care is vital for establishment and long-term success on contaminated sites. EAPS now represents a standalone treatment for mitigating contaminant migration and in situ degradation of soil and groundwater contaminants.