How far can MTBE travel in streams and rivers before it volatilizes?
Although MTBE can volatilize from water, half-lives in rivers and streams can be greater than 1 day, and travel distances range from about 0.8 km for shallow streams to more than 900 km for deep rivers before half of the MTBE is volatilized (Pankow and others, 1996). Ice on rivers and streams will stop all volatilization of MTBE from the water. Factors that affect the volatilization rate of MTBE in surface water include water velocity, water depth, water temperature, wind speed, and air temperature; in many cases, MTBE volatilizes at rates that are most dependent on the depth and velocity of the flow. No single volatilization rate characterizes the loss process from streams and rivers. In deep and slow moving flows, MTBE volatilizes at rates similar to those for the BTEX compounds. In shallow and fast moving flows, MTBE volatilizes at rates that are significantly slower than those for BTEX compounds (Pankow and others, 1996).
