Peat Characteristics & Downward migration of petroleum contamination

[stevie714]

I have an site where we have encountered petroleum contamination to depths of at least 100ft bls. The typical water table is roughly 12ft. bls. The site is underlain by silts, clays, and sandy to roughly 20ft bls. In many areas, the surficial material is underlain by peat and highly organic silts and clays. The samples recoverd from within the peat layers were dry. The peat, where present is underlain by sand which is in-turn underlain by limestone. The limestone varies greatly in induration and depth. Numerous large production wells (no longer in use) operated within +/-1500 ft. of the site. Out client feels that the peat may have "dried out" during the period of water production which may have created a cone of depression that would have influenced the site. Does anyone have any experience with sites similar to this? Additionally, what role might the peat layer play in this puzzle and where could I get some good info on peat characteristics? Sorry for the long length of this question but it is a relatively complex problem. Any info would be greatly appreciated.

Thanks in advance,

Steve