Code of Federal Regulations Title 40. Protection of Environment § 40.89.204 Averaging

(a) Requirements for Tier 1 engines rated at or above 37 kW. A manufacturer may use averaging to offset an emission exceedance of a nonroad engine family caused by a NO_X FEL above the applicable emission standard. NO_X credits used in averaging may be obtained from credits generated by another engine family in the same model year, credits banked in a previous model year, or credits obtained through trading.

(b) Requirements for Tier 2 and later engines rated at or above 37 kW and Tier 1 and later engines rated under 37 kW. A manufacturer may use averaging to offset an emission exceedance of a nonroad engine family caused by an NMHC+NO_X FEL or a PM FEL above the applicable emission standard. Credits used in averaging may be obtained from credits generated by another engine family in the same model year, credits banked in previous model years that have not expired, or credits obtained through trading. The use of credits shall be within the restrictions described in paragraph (c) of this section, § 89.206(b)(4) and § 89.203(b)(5)(ii).

(c) Averaging sets for emission credits. The averaging and trading of NO_X emission credits, NMHC + NO_X emission credits, and PM emissions credits will only be allowed between engine families in the same averaging set. The averaging sets for the averaging and trading of NO_X emission credits, NMHC + NO_X emission credits, and PM emission credits for nonroad engines are defined as follows: