The U.S. Environmental Protection Agency (EPA) recently that it would not be revising its regulations on backup generators in response to three petitions for reconsideration it had received after it promulgated its in January 2013. The NESHAP (National Emission Standards for Hazardous Air Pollutants) rule had sparked controversy, because EPA allowed backup generators to operate for up to 100 hours a year, though EPA did require use of ultra-low sulfur diesel fuel beginning in January 2015.
by Â鶹ÊÓƵ, EPA sought public comment on three specific aspects of its current NESHAP rules for stationary reciprocating internal combustion engines (RICE)at  , that set numeric emission limits  and operating limits for RICE and include provisions on stationary emergency engines used for emergency demand response. EPA has determined that it will not propose any changes to the regulations at this time. addressed the three issues as follows:
- The timing of the requirement to utilize ULSD. Â EPA rejected arguments that ULSD is already sufficiently available to require its use immediately.
- The timing and required information for reporting with respect to emergency engines. EPA rejected the request to move up the reporting, finding that it would be unduly burdensome.
- Criteria for operation in non-emergency situations. EPA rejected arguments that its criteria for allowing such operation were “too indistinct and expansive.â€