title: Performance of deep-rooted phreatophytic trees at a site containing total petroleum hydrocarbons.
abstract: Poplar and willow tree stands were installed in 2003 at a site in Raleigh, North Carolina containing total petroleum hydrocarbon - contaminated groundwater. The objective was groundwater uptake and plume control. The water table was 5 to 6 m below ground surface (bgs) and therefore methods were used to encourage deep root development. Growth rates, rooting depth and sap flow were measured for trees in Plot A located in the center of the plume and in Plot B peripheral to the plume. The trees were initially sub-irrigated with vertically installed drip-lines and by 2005 had roots 4 to 5 m bgs. Water balance calculations suggested groundwater uptake. In 2007, the average sap flow was higher for Plot B (approximately 59 L per day per tree) than for Plot A (approximately 23 L per day per tree), probably as a result of TPH-induced stress in Plot A. Nevertheless, the estimated rate of groundwater uptake for Plot A was sufficient, relative to the calculated rate of groundwater flux beneath the stand, that a high level of plume control was achieved based on MODFLOW modeling results. Down-gradient groundwater monitoring wells installed in late 2011 should provide quantitative data for plume control.
authors.affiliation: URS Corporation, Morrisville, North Carolina, USA. ari.ferro@urs.com
authors.forename: Ari M
authors.initials: AM
authors.lastname: Ferro
authors.forename: Tareq
authors.initials: T
authors.lastname: Adham
authors.forename: Brett
authors.initials: B
authors.lastname: Berra
authors.forename: David
authors.initials: D
authors.lastname: Tsao
mesh_terms: D057914:Agricultural Irrigation; D001673:Biodegradation, Environmental; D002678:Chimera; D060587:Groundwater / Q000737:chemistry*; D006838:Hydrocarbons / Q000378:metabolism; D008954:Models, Biological; D009657:North Carolina; D010578:Petroleum / Q000378:metabolism; D059392:Petroleum Pollution / Q000517:prevention & control; D018517:Plant Roots / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D018526:Plant Transpiration / Q000502:physiology; D032107:Populus / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D032108:Salix / Q000033:anatomy & histology / Q000254:growth & development / Q000502:physiology*; D012621:Seasons; D012987:Soil; D014197:Trees; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D006838:Hydrocarbons; D010578:Petroleum; D012987:Soil; D014874:Water Pollutants, Chemical