We recently published an article in the Journal of Contaminant Hydrology you can download on the dissipation of MTBE at contaminated service stations in Connecticut following the MTBE ban.
Application of first order kinetics to characterize MTBE natural attenuation in groundwater by M. Metcalf, G. Stevens and G. Robbins
Download it at: http://authors.elsevier.com/a/1SXpyccWifJAZ