Permitting a New, Cleaner Fuel to Replace a More Polluting Fuel

Within the last few years, the U.S. EPA has made an interesting determination relative to “accommodating” a new fuel; even when that fuel does not alter the maximum firing (heat release) capability of the emission unit on a short-term (hourly) or annual (12-month rolling) basis and emissions for any pollutant do not exceed the existing short-term or annual permitted emission limits.  It is the U.S. EPA’s interpretive decision that the new fuel cannot be “accommodated” and therefore, cannot be fired above baseline actual emissions without showing an emission increase that could quickly lead to expensive and time consuming New Source Review (NSR) permitting.

This interpretive implementation leads to an absurd result in the case of a fuel, such as natural gas, that is typically cleaner emitting than coal and oil fuels.  The new, cleaner fuel could only be fired up to the baseline actual emissions level plus the NSR significance thresholds without triggering NSR permitting.  If use of the emission unit is desired beyond that operational level, it would then be acceptable to switch back to the originally permitted, “dirtier” fuel and operate up to the original permitted emission level.  Use of the proposed cleaner fuel at that same heat release level would result in cleaner emissions, but would trigger NSR permitting.

This “negative-environmental” outcome is not just a hypothetical situation, but has real world significance.  Many utility and industrial sources are presently looking to utilize cheaper, and cleaner, natural gas as their fuel of choice.  This interpretation by the U.S. EPA, if taken at face value, certainly does not promote switching to cleaner burning fuels.