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Is methane generated on site and used for fuel subject to Part 68?

A wastewater treatment plant generates methane through a natural digestion process, then stores and uses the methane as fuel. Under 40 CFR Part 68, must the owner or operator of this stationary source evaluate the amount of methane to determine whether more than a threshold amount is present in any process?

No. The Chemical Safety Information, Site Security, and Fuels Regulatory Relief Act, enacted on August 5, 1999, excluded flammable substances from coverage under the Risk Management Program when used as fuel or held for sale as fuel at a retail facility (the Act defines a retail facility as a stationary source at which more than one-half of the income is obtained from direct sales to end users or at which more than one-half of the fuel sold, by volume, is sold through a cylinder exchange program). Therefore methane used as fuel at a wastewater treatment plant is no longer covered by the Risk Management Program. Stationary sources, including wastewater treatment plants, holding regulated flammable substances that are not used as fuel and not held for sale as fuel at a retail facility are still covered by the RMP if more than a threshold quantity is present in a process.