Technical Amendments for Marine Spark-Ignition Engines and Vessels

In the final rulemaking for new exhaust and evaporative emissions standards for nonroad spark-ignition engines, vessels, and equipment (73 FR 59034, October 8, 2008), EPA established first-ever evaporative emissions standards for marine vessels. These requirements included portable marine fuel tanks commonly used in recreational boating. During their efforts to certify portable fuel tanks to these new requirements, manufacturers working together on systems integration identified several technical issues with the performance of the tanks/ fuel systems in use that were not fully apparent to them before these standards were developed. Systems integration work conducted by the fuel tank, boat and engine manufacturers highlighted that under some circumstances there was the potential for fuel spillage to occur. Work conducted by these parties indicated that this issue applies to existing systems and tanks as well as those built to comply with EPA's evaporative emission design standard. We have engaged the industry to identify a simple, safe, and emissions neutral solution to this concern. EPA is taking direct final action to make technical amendments to the design standard for portable tanks that will allow for this solution. In addition, we are incorporating safe recommended practices, developed through industry consensus, for portable marine fuel tanks. This action is emissions neutral with respect to the diurnal emissions standard; however, to the extent that it helps reduce fuel spillage, incorporating safe recommended practices will result in a net benefit to the environment and lead to fuel savings.