Amendments to In-UseTesting for Heavy-Duty Diesels, Measurement and Instrumentation, and Off-Highway Engine Regulations The U.S. Environmental Protection Agency (EPA) is publishing a Direct Final Rulemaking to make several amendments to EPA's mobile source emission standards and test procedures. These revisions affect the in-use particulate matter (PM) testing program for heavy- duty diesel engines, locomotives, spark-ignition (SI) marine engines, small SI engines, Tier 4 nonroad diesel engines, and PM measurement and assessment for both laboratory and field testing. Overview This Direct Final Rule makes several revisions to EPA's mobile source emission standards and test procedures including the heavy-duty diesel engine in-use testing program. The amendments are as follows: • EPA adopted a final accuracy margin for PM for portable emission measure' ment systems that resulted from a comprehensive research program. This final PM accuracy margin will replace the interim emission measurement "accuracy" margin for the requisite portable emission measurement devices, • Delay enforcement of the PM in-use testing program for heavy-duty diesel engines until 2011, • Grant flexibilities for heavy-duty diesel engine manufacturers to complete testing obligations under PM pilot program, • Clarify the analytical requirements for in-use PM measurement as a result of lessons learned in the research program, • Clarify acceptable accounting protocols for emission control system regenera- tion events when calculating not-to-exceed (NTE) results, • Allow fuel rate information derived from the engine control module (ECM) to determine NTE mass emission rate during in-use testing, SEPA United States Environmental Protection Agency Office of Transportation and Air Quality EPA-420-F-10-042 October 2010 ------- A set of minor changes will affect categories of highway and nonroad engines, • Allow partial flow dilution sampling for transient test cycle PM measurement, • Extend interim flexibilities for locomotives, • Allow later notification deadline for small'volume manufacturers of marine SI engines to qualify for a delay in the new exhaust emission standards, • Revise the phase-in provisions for the Tier 4 nonroad emission standards to allow manu- facturers to use oxides of nitrogen and non-methane hydrocarbon (NOx+NMHC) credits to show compliance, • Amend the transitional flexibilities program for manufacturers of specialized higlvaltitude equipment, • Correct former errors in the E2 Ramped Modal Cycle, • Clarify applicable exclusions for small SI engines installed in nonhandheld equipment. Public Participation Opportunities This rule is being released as a Direct Final Rule. However, comments can be submitted under a parallel Notice of Proposed Rulemaking (NPRM). Comments will be accepted for 30 days beginning when the NPRM is published in the Federal Register. All comments should be identified by Docket ID No. EPA-HQ-OAR-2010-0142 and submitted by one of the following methods: Internet: www.regulations.gov E-mail: a'and'r'Docket@epa.gov Mail: Environmental Protection Agency Mail Code 2822T 1200 Pennsylvania Avenue NW Washington, DC 20460 Hand Delivery: U.S. Environmental Protection Agency EPA Headquarters Library EPA West Building Room 3334 1301 Constitution Avenue NW Washington, DC ------- For More Information You can access the rule and related documents on EPA's Office of Transportation and Air Quality (OTAQ) Web site at: www.epa.gov/otaq/hd'hwy.htm For more information on this Direct Final Rule, please contact the Assessment and Standards Division at: U.S. Environmental Protection Agency Assessment and Standards Division Office of Transportation and Air Quality 2000 Traverwood Drive Ann Arbor, MI48105 Voice-mail: (734) 214-4636 E-mail: asdinfo@epa.gov ------- |