Presumptive NOx emission limits Dry-bottom wall-fired (75 units subject to presumptive limits) Bituminous 0.39 Sub-bituminous 0.23 Lignite 0.29 Tangential-fired (110 units subject to presumptive limits) Bituminous 0.28 Sub-bituminous 0.15 Lignite 0.17 Cell Burners (27 units subject to presumptive limits) Bituminous 0.40 Sub-bituminous 0.45 Dry-turbo-fired (4 units subject to presumptive limits) Bituminous 0.32 Sub-bituminous 0.23 Wet-bottom tangential-fired (3 units subject to presumptive limits) Bituminous 0.62