How do I perform the initial performance test if I have chosen to install a NO X -diluent CEMS?

If you elect to install and certify a NO X -diluent CEMS under § 60.4345, then the initial performance test required under § 60.8 may be performed in the following alternative manner: (a) Perform a minimum of nine RATA reference method runs, with a minimum time per run of 21 minutes, at a single load level, within plus or minus 25 percent of 100 percent of peak load, while the source is combusting the fuel that is a normal primary fuel for that source. The ambient temperature must be greater than 0 °F during the RATA runs. (b) For each RATA run, concurrently measure the heat input to the unit using a fuel flow meter (or flow meters) and measure the electrical and thermal output from the unit. (c) Use the test data both to demonstrate compliance with the applicable NO X emission limit under § 60.4320 and to provide the required reference method data for the RATA of the CEMS described under § 60.4335. (d) Compliance with the applicable emission limit in § 60.4320 is achieved if the arithmetic average of all of the NO X emission rates for the RATA runs, expressed in units of ppm or lb/MWh, does not exceed the emission limit. [71 FR 38497, July 6, 2006, as amended at 91 FR 1983, Jan. 15, 2026]