Phytoremediation Using Poplar Trees as a Corrective Action at a UST Release Located in Maybell, CO – A Project Overview

摘要

A release from an Underground Storage Tank system located in the alluvial plain created by the Yampa River in the high desert mesa of Northwest Colorado is being remediated using phytoremediation. The project is the first application of phytoremediation to address BTEX impacted groundwater under the Colorado Division of Oil & Public Safety Petroleum Storage Tank Remediation Program. Site characteristics including a shallow water table, remote location, distribution of hydrocarbons, and the estimated higher cost of alternatives suggested the potential for the selection of this remedial option. As part of the regulatory approval process, a pilot study was conducted and incorporated field data with laboratory analyses using a hydroponic growth chamber at the University of Colorado, Denver (UCD, Ramaswami et al, 2001). The pilot test confirmed that poplar trees can be effective for phtyoremediation of BTEX, that growth of poplar trees are not inhibited by BTEX concentrations found at this site, and that phytoremediation using Poplar trees has a high potential for success. The UCD pilot study findings, supported by a favorable economic and technical analysis, resulted in State of Colorado approval of the corrective actions proposed for this project. In June 2002, to implement the approved corrective action plan, 300 Lombardy Poplar (Populus x Nigra 'Italica') saplings were planted. Groundwater characteristics and tree monitoring data, collected prior to and during the first growing season, is presented. The regulatory perspective, site characterization, hydrocarbon distribution, location of existing trees, strategy behind new plantings, planting methodology, and tree maintenance issues are also discussed.