Abstract:
This research work aims at evaluating the accuracy of a clean-up endpoint set by Lebanese authorities for sandy beaches following an oil spill that hit Lebanon in 2006. This was done by evaluating two factors affecting clean-up endpoint determination: background levels of Total Petroleum Hydrocarbons (TPH) in beaches, and TPH mobility. To determine background TPH levels, TPHs were analyzed in beaches that were not affected by the oil spill, and in beaches that were affected by the spill but were subject to subsequent treatment. The TPH concentrations of the two types of beaches were not statistically different, and averaged 249 mg kg−1 of sand. To measure TPH mobility, leaching tests were performed on a stockpile of untreated contaminated sand (110 g of TPH/kg sand). The average TPH concentration in the sand leachate (19.9 mg L−1 ± 7.04) slightly exceeded the national TPH standard of 20 mg L−1. Since the mobility of pollution is associated with toxicity, the evaluation of the clean-up endpoint will depend essentially on the results of the TPH mobility tests. The maximum TPH concentration in treated sand should correspond to TPH levels below 20 mg L−1 in leachate, as per the national standard. More research work, particularly sand clean-up tests and bioassays, is necessary to determine the maximum TPH concentration to be observed in sandy leachates, which would enable us to determine the maximum total TPH concentration allowed in the sand, and thus decide on the accuracy of the clean-up endpoint of 5,000 mg TPH/kg sand. © 2017 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license.
