8 Implementing Phytoremediation of Petroleum Hydrocarbons Chris D. Collins Summary An evaluation of the current “state of the art” for the phytoremediation of total petroleum hydrocarbons (TPH) is given, which will allow for well-informed decisions to be made when the technology is being applied to this contamination problem. Information is provided on phytotoxicity, plant selection, and management as well as useful supple- mentary practical data sources. A management decision tree is presented to aid in the successful application of phytoremediation to TPH-contaminated sites. Finally, defici- encies in the current knowledge are identified, which need to be addressed to improve the effectiveness of phytoremediation to this problem. Key Words: Total petroleum hydrocarbons; plant selection; field application; decision tree. 1. Introduction 1.1. Total Petroleum Hydrocarbons in the Environment The petroleum hydrocarbons are some of the most universally detected organic pollutants in the environment because of the high industrial use of petroleum products world wide. The world petroleum consumption in 2001 was 77 million barrels per day (1), this scale of use results in a high potential for contamination from both accidental and fugitive releases. For example, in the United Kingdom alone there are estimated to be 120,000 contaminated petrol station sites with an associated remediation cost of £2.5 billion. The remedia- tion of contaminated oil terminals and refinery sites will increase this figure. The US petroleum industry alone spent $0.8 billion dollars in 2001 on re- mediation (2). The large scale and economic importance of this contamination 99 From: Methods in Biotechnology, vol. 23: Phytoremediation: Methods and Reviews Edited by: N. Willey © Humana Press Inc., Totowa, NJ