United States Air and Radiation EPA420-F-03-023 Environmental Protection June 2003 Agency Office of Transportation and Air Quality Draft is the The draft nonroad model calculates past, present, and future emission inventories (i.e., tons of pollutant) for all nonroad equipment categories except commercial marine, locomotives, and aircraft. Fuel types included in the model are: gasoline, diesel, compressed natural gas, and liquefied petroleum. The model estimates exhaust and evaporative hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), particulate matter (PM), sulfur oxides (SOx), carbon dioxide (CO2). The user may select a specific geographic area (i.e., national, state, or county) and time period (i.e., annual, monthly, seasonal, or daily) for analysis. What are the the of to and the draft The emission inventories produced by the two versions are the same if the scenario inputs are the same, but NONROAD2002a has a few en- hancements: " National Inventory Format (NIF) 2.0 output option for the National Emissions Inventory (NEI) from the Reporting Utility " Update of Florida Bade County (Federal Information Processing Standards (FIPS) Code 26025) to Miami-Bade County (FIPS 26086) 9 More "what-if" analysis ability for fuel sulfur-to-sulfate conversion rate (this is not expected to be used by state and local air agencies) i Printed on Recycled Paper ------- How is the for NONROAD2002a? The review period for draft NONROAD2002a will last until August 20, 2003, which is the same as the review period for the proposed Nonroad Diesel Rule. will the final NONROAD be A final NONROAD model will be released in 2004, after the final Non- road Diesel Engine Rule has been published. What are the major in the and the June version? Some of the most important changes affect compression-ignition (CI) engines where the associated NOx and PM inventories are reduced by about 35 to 50 percent, depending on year and pollutant. The new SOx inventories are also less than the prior version — about 75 percent less for compression-ignition (CI) engines and 65 percent less for spark-ignition (SI) engines. More details of the inventory changes can be found in the workshop presentations from November 5, 2002, which are available on the nonroad modeling web page at: www.epa.gov/otaq/nonrdmdl.htm. the all of final to date? No. The model does not fully reflect the new recreational equipment and large SI engine standards that were published in the Federal Register in September 2002 (67 FR 68243). These will be added at a later date. How do I for from the and ignition standards? Until these benefits are incorporated into the NONROAD model, users will need to estimate the exhaust, diurnal, hot soak, running loss, and permeation emissions and benefits based on the information in the Sep- tember 2002 Regulatory Support Document for this rule (EPA-420-R- 022). This document can be downloaded from the EPA Office of Trans- portation and Air Quality web site at: www.epa.gov/otaq/recveh.htm. ------- the Tier 4 and fuel standards? No. These standards will be incorporated into the final version of NON- ROAD when the rule becomes final. What is on the of the for official EPA is allowing the use of the draft NONROAD2002a Model and associ- ated default inputs in development of inventories supporting State Imple- mentation Plans (SIPs). Although NONROAD2002a or its default inputs may change between the public release of the draft and the final version, now anticipated for 2004, the draft NONROAD2002a Model currently represents EPA's best tool for estimating nonroad emissions, as evidenced by the Agency's use in the Nonroad Diesel Engine Notice of Proposed Rulemaking (NPRM). Therefore we are allowing state agencies to use the draft model in SIPs during the period between public release of the draft and final versions of the model. EPA will not require that inventories developed using the draft version be updated following release of the final version. However, since this release does not include the benefits of the September 2002 final rule for recreational vehicle, large SI, and diesel recreational marine engines, and it also doesn't include the benefits that will be associated with the final nonroad diesel rule, states may choose to update SIPs after EPA releases the final version of NONROAD. After the release of the final version of NONROAD, states that are just beginning new SIP development, or are in the early stages of SIP devel- opment, should use the final version of NONROAD for those new SIPs. the for of the be for No. Option files created with previous versions of the model are not compatible with NONROAD2002a. ------- How can I if I Please send an email with your question to nonroad@epa.gov or write to: U.S. Environmental Protection Agency Assessment and Standards Division Air Quality and Modeling Center 2000 Traverwood Drive Ann Arbor, MI 48105 ------- |