Type: Law Bulletins
Date: 06/17/2011

EPA Signs Final Rule Amending New Source Performance Standards for Certain Stationary Diesel Engines

On June 8, 2011, Administrator Jackson signed EPA’s final rule amending New Source Performance Standards (“NSPS”) for certain stationary compression ignition (diesel) and spark ignition internal combustion (gas-fired) engines.   The rule will be submitted to the Federal Register for publication, and will go into effect 60 days from the date of publication.  According to EPA, the rule will be fully implemented by 2018. 

The amendments for stationary diesel engines with a displacement of greater than or equal to 10 and less than 30 liters per cylinder (“l/cyl”), as well as stationary diesel engines with a displacement greater than or equal to 30 l/cyl, are consistent with EPA’s regulations for similar marine engines. 

Non-emergency stationary diesel engines with a displacement between 10 and 30 l/cyl must meet First Tier emissions standards for NOx, PM, and hydrocarbons beginning in model year 2013, and Second Tier emissions standards beginning in model year 2014 (compliance dates depend on engine displacement (liters per cylinder) and maximum engine power).  EPA noted that it expected Second Tier emissions standards to be met by using catalytic exhaust aftertreatment, such as catalyzed diesel particulate filters and selective catalytic reduction. 

The amendments made some changes to the NOx and PM standards for stationary diesel engines with a displacement greater than or equal to 30 l/cyl set forth in the original final NSPS rule (2006).  In regards to NOx, the applicable standard varies depending on the date of installation (before or after January 1, 2012) and maximum engine speed.  Engines installed after January 1, 2016 must meet a NOx standard (varies based on maximum engine speed) that is more stringent and that presumes aftertreatment will be used.   However, emergency engines and engines in Pacific island areas not required to use lower sulfur fuel will not be subject to the 2016 standard requiring aftertreatment. 

In regards to PM, EPA revised the emission standard for emergency engines with displacement of greater than or equal to 30 l/cyl and for such engines in areas not required to use low sulfur fuel.  However, EPA retained the PM standard from the original final NSPS rule for non-emergency engines in areas where low sulfur fuel is available.  The final rule also requires engines with displacement at or greater than 30 l/cyl to use 1,000 ppm sulfur diesel fuel beginning on June 1, 2012. 

The amendments allow owners and operators to develop operation and maintenance plans as opposed to following the operation and maintenance plans of the manufacturer.  However, in general, owners and operators who choose to follow their own operation and maintenance plans instead of the manufacturer’s are required to undertake additional measures to demonstrate compliance, namely implementing additional testing of their engines and maintaining certain records.  According to EPA, the amended NSPS operation and maintenance requirements only apply to operation and maintenance related to emissions.  While owners and operators can operate their engines outside the manufacturer’s settings under certain conditions, doing so will have adverse consequences.  For example, in such cases, the engine will no longer be considered a “certified engine,” the emissions warranty will be void, and the manufacturer will not be responsible for the engine’s compliance with applicable emissions standards. 

Notably, subject to certain exceptions, engines that are in one location for less than a year will generally be considered mobile nonroad engines.  One such exception consists of portable engines used to replace an “existing stationary engine at the same location on a temporary basis and that are intended to perform the same or similar functions” as a stationary engine;1  these engines shall be considered stationary engines.  However, such engines will only be subject to mobile nonroad source requirements. 

The amendments subject reconstructed engines to the emissions standards in effect for the model year in which the engine is reconstructed if one of two criteria is met: 1) “the fixed capital cost of the new and refurbished components exceeds 75% of the fixed capital cost of a comparable new engine”; or 2) “the reconstructed engine consists of a previously used engine block and all new components.”2   The emissions standards apply regardless of who modifies or reconstructs the engine, including manufacturers. 

The amended rule also provides special requirements for engines operated in remote areas of Alaska, based on the unique circumstances of those regions. 


2Id. at 35.

In This Article

You May Also Like