Control of Emissions of Air Pollution From Locomotive Engines and Marine Compression-Ignition Engines Less Than 30 Liters per Cylinder

Locomotives and marine diesel engines are important contributors to our nation's air pollution today. These sources are projected to continue to generate large amounts of particulate matter (PM) and nitrogen oxides (NO<INF>X</INF>) emissions that contribute to nonattainment of the National Ambient Air Quality Standards (NAAQS) for PM<INF>2.5</INF> and ozone across the United States. The emissions of PM and ozone precursors from these engines are associated with serious public health problems including premature mortality, aggravation of respiratory and cardiovascular disease, aggravation of existing asthma, acute respiratory symptoms, chronic bronchitis, and decreased lung function. In addition, emissions from locomotives and marine diesel engines are of particular concern, as diesel exhaust has been classified by EPA as a likely human carcinogen. EPA is proposing a comprehensive program to dramatically reduce emissions from locomotives and marine diesel engines. It would apply new exhaust emission standards and idle reduction requirements to diesel locomotives of all types--line-haul, switch, and passenger. It would also set new exhaust emission standards for all types of marine diesel engines below 30 liters per cylinder displacement. These include marine propulsion engines used on vessels from recreational and small fishing boats to super-yachts, tugs and Great Lakes freighters, and marine auxiliary engines ranging from small gensets to large generators on ocean-going vessels. The proposed program includes a set of near- term emission standards for newly-built engines. These would phase in starting in 2009. The near-term program also contains more stringent emissions standards for existing locomotives. These would apply when the locomotive is remanufactured and would take effect as soon as certified remanufacture systems are available (as early as 2008), but no later than 2010 (2013 for Tier 2 locomotives). We are requesting comment on an alternative under consideration that would apply a similar requirement to existing marine diesel engines when they are remanufactured. We are also proposing long-term emissions standards for newly-built locomotives and marine diesel engines based on the application of high-efficiency catalytic aftertreatment technology. These standards would phase in beginning in 2015 for locomotives and 2014 for marine diesel engines. We estimate PM reductions of 90 percent and NO<INF>X</INF> reductions of 80 percent from engines meeting these standards, compared to engines meeting the current standards. We project that by 2030, this program would reduce annual emissions of NO<INF>X</INF> and PM by 765,000 and 28,000 tons, respectively. These reductions are estimated to annually prevent 1,500 premature deaths, 170,000 work days lost, and 1,000,000 minor restricted-activity days. The estimated annual monetized health benefits of this rule in 2030 would be approximately $12 billion, assuming a 3 percent discount rate (or $11 billion assuming a 7 percent discount rate). These estimates would be increased substantially if we were to adopt the remanufactured marine engine program concept. The annual cost of the proposed program in 2030 would be significantly less, at approximately $600 million.