U. S. Environmental Protection Agency Office of Mobile Sources May 20, 1999 Third MOBILE6 Workshop to be held June 29-30, 1999 This announcement notifies all listserver subscribers of the third MOBILE6 workshop, which will be held in Ann Arbor, MI on Tuesday and Wednesday June 29 and 30, 1999. The workshop will be at the Holiday Inn North Campus, Plymouth Road at US-23, and will run from 9:00 am to approximately 4:00 pm each day. Directions to the workshop location (about 2 miles east of the EPA National Vehicle and Fuel Emission Laboratory), information about accommodations, and other additional information is available at the MOBILE6 section of the Office of Mobile Sources Web site (www.epa.gov/oms/m6.htm). A tentative agenda is provided below to assist interested parties in determining whether to attend, and which day(s) to attend. While the specific ordering of presentations may change, the separation of "first day" and "second day" presentations will be adhered to. We have attempted to group related presentations together (for example, presentations dealing with heavy-duty vehicles are all on the second day) so as to permit some parties to limit their attendance if wish. The timing of this workshop has been determined in part by the recent Notice of Proposed Rulemaking (NPRM) for Tier 2 emission standards and fuel sulfur control. It was determined, due to the interrelationship of revisions to the MOBILE model and the modeling done in support of the Tier 2/fuel sulfur rulemaking, that this workshop should be conducted during the comment period for that NPRM. This workshop will be focused almost entirely on technical presentations. EPA will provide overviews of various analyses and their results, with some comparisons to similar information from MOBILE5 where appropriate. This is specifically not a "user workshop." EPA will not be going over the proposed changes to the input file structure and data input requirements or discussing "how to run the model." The presentations from the first two MOBILE6 workshops, which are available at the above referenced web site, include discussion of the input/output (I/O) changes proposed for MOBILE6, and that material is virtually unchanged since the second workshop. EPA will plan another workshop at or near the time that MOBILE6 is released for use, which will be much more of a "user workshop," with considerable time spend detailing the input file structure changes, data requirements, and interpretation of output. A tentative agenda follows, listing the presentation topics and order as currently planned. ---------------------------------------------------------------- First day 06/29/99 Introduction MOBILE6 review process (Web site, peer and stakeholder review, providing comments on workshop presentations) Revised basic emission rates (BERs) for model year (MY) 1981-93 light-duty vehicles (LDVs) and light-duty trucks (LDTs), including separation of start and running emissions Revised BERs for Tier 1 (MY 1994+) LDVs and LDTs, and for low- emitting vehicles (LEVs); including separation of start and running emissions Modeling of onboard diagnostics (OBD) II benefits and updated inspection and maintenance (I/M) credits for exhaust emissions Separation of temperature and fuel volatility (RVP) correction factors for start and running exhaust emissions Modeling emissions impacts of fuel parameters [including fuel sulfur levels and revisions to impacts of oxygenates (alcohols, ethers) on carbon monoxide (CO) emissions] Revisions to speed corrections to exhaust emissions Modeling of emissions impacts of air conditioner (A/C) use, including estimation of usage rates Supplemental Federal Test Procedure (FTP) and how resulting emission reductions are modeled Questions and discussion ---------------------------------------------------------------- Second day 06/30/99 Introductions Updated heavy-duty engine emission conversion factors Modeling of oxides of nitrogen (NOx) "excess" emissions from heavy-duty vehicles (recent improvements in estimates of emissions from some heavy-duty engines at steady-state conditions and emissions impacts of settlement to reduce such emissions) Evaporative emissions updates (including diurnals, resting losses, running losses, gross liquid leakers, multi-day diurnals) Revisions to hot soak ("trip end") emission factors I/M credits and OBD II benefits for evaporative emissions Modeling of compressed natural gas (CNG) vehicle emissions Fleet characteristics, including updates to registration distributions and annual mileage accumulation rates by age and vehicle type and total vehicle counts Fleet activity levels, including estimates of trips per day, starts per day, miles per day by age and vehicle type Weighting of emissions estimates by facility type using vehicle miles travelled (VMT) Review of interim models: Tier 2 model and modified MOBILE5b (presentation on relationship of modeling done in support of Tier 2/fuel sulfur NPRM and MOBILE5 revisions) Interim and transition modeling issues (guidance on models available, schedule update) Questions and discussions =============================================================== As in the past, we plan to allow directly related questions to be addressed during and immediately following each presentation, and will provide time to the extent available for general questions and discussion at the end of each day. There is no requirement for advance registration for this workshop. All presentations planned should be posted at the OMS web site noted at the beginning of this notice at least one week prior to the workshop, and attendees are encouraged to review this material in advance. Emission Inventory Group Assessment and Modeling Division National Vehicle and Fuel Emission Laboratory 2000 Traverwood Drive Ann Arbor, Michigan 48105 (734) 214-4939 (fax) mobile@epa.gov (email)