H. Voluntary Low-Emitting Engine Program
In the final rule for land-based nonroad diesel engines, we included a program of voluntary standards for low-emitting engines, referring to these as "Blue Sky Series" engines (63 FR 56967, October 23, 1998). We are setting similar voluntary standards as part of this rulemaking. The program, if successful, will lead to the introduction and more widespread use of these low-emission technologies. The qualifying emission levels are listed in Table 4. The voluntary standards for the expanded subcategories above 15 L/cyl all follow the pattern of a 40 percent reduction relative to the mandatory standards. While the Blue Sky Series emission limits are voluntary, a manufacturer choosing to certify an engine under this program must meet all the provisions established to demonstrate compliance with these limits, including allowable maintenance, warranty, useful life, rebuild, and deterioration factor provisions.
The Blue Sky Series program begins immediately upon publication of this final rule and continues through the 2010 model year. We intend to evaluate the program to determine if it should be continued for 2011 and later engines, and if so, whether any changes are needed.
Creating a program of voluntary standards for low-emitting engines, including testing and durability provisions to help ensure adequate in-use performance, will be a major step forward in advancing innovative emission control technologies, because EPA certification will provide protection against false claims of environmentally beneficial products. For the program to be most effective, however, incentives for the production of these engines must be created as well.
We are concerned that such incentive programs not lead to a net detriment to the environment through the double-counting of benefits. We have therefore concluded that manufacturers choosing to sell an engine with the Blue Sky Series designation should not generate averaging, banking, and trading credits for demonstrating compliance with EPA programs. Other groups are free to design credit programs without concern for any double-counting or other unintended effect of overlapping programs.
In addition to credit-based programs, we see substantial potential for users and state and local governments to establish incentive programs. For example, state or local governments or individual ports may be able to add incentives for introducing low-emitting engine technologies in harbor and other coastal vessels.
I. Durability
As directed by the Clean Air Act, we are requiring that manufacturers design and build engines with durable emission controls. This means that manufacturers are responsible for the emission results for the engines they produce throughout their useful life. 7
We are also establishing provisions to ensure proper maintenance and repair of engines throughout their lifetime. The durability provisions, described below, are intended to ensure that engines continue to meet the applicable standards in use. The specific areas of the durability program focused on here are useful life, warranty periods, deterioration factors, and rebuilding requirements. Most of these provisions are carried over from the land-based or locomotive programs.
7 This is different from the approach used in MARPOL Annex VI, according to which manufacturers must ensure their engines meet the emission limits at the time of certification but ship owners become responsible for their continued compliance with the limits. Under that program, compliance is verified during flag-state and port-state inspections.
1. Useful Life
Useful life is the period during which the marine engine is required to meet the emission standards. For Category 1 engines, we are setting a minimum useful life of 10 years or 10,000 hours of operation. Specifically, the 10,000-hour requirement is based on an expected five-year period until the first time the engine is rebuilt, and an expected usage rate of 2,000 hours per year. For Category 2 engines, we are setting a minimum useful life of 10 years or 20,000 hours of operation. In this case, the 20,000-hour requirement for marine engines is calculated based on an operating rate of 4,000 hours of use per year, with five years between rebuilds. The useful life figures are minimum values to take into account the possibility that manufacturers may in the future design their engines for a longer period of operation before rebuilding. If an engine is designed to be in service until rebuild longer than our minimum useful life period, then the manufacturer must specify a corresponding longer useful life for that engine family.
The above approach of basing useful life on time to first rebuild was chosen because it is difficult to justify holding the engine manufacturer responsible for an engine's emissions after the engine is rebuilt. The original engine manufacturer has little, if any, control over the rebuild process. When done improperly, the rebuilding process can include changes to the engine that adversely affect emissions. At the same time, however, these engines are often kept in service much longer than the minimum useful life. Median values for service lives are 15 years for Category 1 propulsion engines and 23 years for Category 2 engines. These longer service lives mean that the engine may be exempt from in-use testing for more than half its service life. We therefore believe it is important to be able to conduct recall testing on these engines throughout the established useful life period. We are also establishing requirements for engine rebuilders.
To address the possibility of light commercial applications with much shorter design lifetimes, the final rule allows manufacturers to request a shorter useful life for certain engines.
