Finally, while we believe this PLT program takes into account the circumstances of this industry, we also understand that alternative plans may be developed that better account for the individual needs of an individual manufacturer. Thus, a manufacturer may submit an alternative plan for a PLT program, subject to our approval. A manufacturer's petition to use an alternative plan needs to address the need for the alternative and include justifications for the number and representativeness of engines tested. The alternative plan must also have specific provisions regarding what constitutes a PLT failure for an engine family.
L. Miscellaneous Compliance Issues
We are extending the general compliance provisions for land-based nonroad engines to Category 1 and Category 2 marine diesel engines. These include the tampering, defeat device, imported engines and vessels, and general prohibition provisions.
M. Averaging, Banking, and Trading Program
Along with the emission standards, we are including a marine averaging, banking, and trading (ABT) program. An ABT program is an important factor that EPA takes into consideration in setting emission standards that are appropriate under section 213 of the Clean Air Act. ABT reduces the cost and improves the technological feasibility of achieving the standards, helping to ensure the attainment of the standards earlier than would otherwise be possible. Manufacturers gain flexibility in product planning and the opportunity for a more cost-effective introduction of product lines meeting a new standard. ABT also creates an incentive for the early introduction of new technology, which allows certain engine families to act as trail blazers for new technology. This can help provide valuable information to manufacturers on the technology before manufacturers need apply the technology throughout their product line. This early introduction of clean technology improves the feasibility of achieving the standards and can provide valuable information for use in other regulatory programs that may benefit from similar technologies.
The voluntary ABT program allows the certification of one or more engine families within a given manufacturer's product line at emission levels above the applicable emission standards, provided that the increased emissions are offset by one or more families certified below the emission standards. The average of all emissions for a particular manufacturer's production (weighted by sales-weighted average power, production volume and useful life) must be at or below the level of the applicable emission standards. In addition to the averaging program just described, the ABT program contains banking and trading provisions, which allow a manufacturer to generate emission credits and bank them for future use in its own averaging program or sell them to another entity. Compliance is determined on a total mass emissions basis to account for differences in production volume, power and useful life among engine families.
The ABT program for marine diesel engines over 37 kW is based on the corresponding ABT programs recently adopted for land-based nonroad engines (63 FR 56967, October 23, 1998) and locomotives (63 FR 18978, April 16, 1998), which roughly correspond to the Category 1 and Category 2 engines, respectively. A manufacturer choosing to participate in the ABT program must certify each participating engine family to a family emission limit (FEL) determined by the manufacturer during certification testing. A separate FEL must be determined for each pollutant the manufacturer includes in the ABT program. The ABT program is limited to HC+NOx and PM emissions. Thus, only two different FELs may be generated for a given engine family.
Consistent with the recently finalized land-based nonroad engine program, marine engine credits are to be calculated based on the difference between the applicable standard(s) and FEL(s). However, credit calculation for marine engines is somewhat different than that for land-based nonroad engines, in that a load factor is inserted in the equation. This term is necessary because, contrary to land-based nonroad case, not all marine engines are expected to operate at the same load. The credit calculation equation is as follows:
Emission credits=(Std-FEL)×(UL)×(Production)×(AvgPR)×(10-6)×(LF)
Where:
・Std=the applicable cycle-weighted marine engine THC+NOx and/or PM emission standard in grams per kilowatt-hour.
・FEL=the family emission limit for the engine family in grams per kilowatt-hour. (The FEL may not exceed the limit established in §94.304(m) for each pollutant.)
・UL=the useful life in hours.
・Production=the number of engines participating in the averaging, banking, and trading program within the given engine family during the calendar year (or the number of engines in the subset of the engine family for which credits are being calculated). Quarterly production projections are used for initial certification. Actual applicable production/sales volumes are used for end-of-year compliance determination.
・AvgPR=average power rating of all of the configurations within an engine family, calculated on a sales-weighted basis, in kilowatts.
・LF=the load factor, dependent on whether the engine is intended for propulsion or auxiliary applications, as follows:
A. 0.69 for propulsion engines
B. 0.51 for auxiliary engines.
We are prohibiting the generation of credits for one pollutant and the simultaneous use of credits for the other pollutant within the same engine family. In other words, a manufacturer may not simultaneously generate HC+NOx credits and use PM credits on the same engine family, and vice versa. This is consistent with the recently finalized emission standards for land-based nonroad diesel engines. This also reflects the inherent trade-off between NOx and PM emissions in diesel engines.
FEL upper limits apply in the same manner as those in the comparable land-based ABT programs to ensure that the emissions from any given family certified under this ABT program not be significantly higher than the applicable emission standards. In general, these FEL upper limits correspond to the existing previous tier of standards for the various classes. In other words, the FEL upper limits are generally the Tier 1 standards for engines certifying according to the ABT provisions relative to the Tier 2 standards. Since we are not including any Tier 1 standards for marine engines in this rulemaking, the land-based Tier 1 standards serve as FEL upper limits for the Tier 2 marine engine standards. When the ABT provisions for land-based nonroad engines were recently revised, there were no Tier 1 standards in place for some land-based categories and pollutants. These cases correspond to some Category 1 marine engines. In those cases we chose FEL upper limits based on typical in-use emission levels of precontrol engines, or existing California Air Resources Board emission standards.
