Fate and Transport of Methanol Fuel from Spills and Leaks

This paper describes the results of a computer simulation that models the transport and fate of methanol introduced into surface water and ground water environments. Several different scenarios involving substantial (5,000 gallon) releases of methanol were modeled using GEOTOX, a multimedia environmental compartment model for examining the transport and transformation of chemical substances in various environmental release situations. These results provide an improved theoretical basis to help explain the fate of methanol spilled or leaked into fresh surface or ground waters and better determine the extent of related public health risk. For comparative purposes, one fuel spill scenario was also modeled for the common gasoline constituents, benzene, toluene, ethylbenzene and xylenes (BTEX). The results presented in this paper show that approximately all of the methanol introduced into the environment from any of the three release scenarios will be removed fairly quickly due to either volatilization, advection or degradation. Thus the possibility of contaminating groundwater supplies to the extent of endangering human health is very small. In comparing the results of the first scenario to a similar gasoline release, the hazard posed by the BTEX compounds of the gasoline release will be greater than that of the methanol release. The BTEX compounds will persist much longer in the environment than methanol.