FACT SHEET
Amendments to the Standards of Performance for
New Stationary Compression Ignition Engines Located in Remote Areas of Alaska
ACTION
•	On June 27, 2019 the U.S. Environmental Protection Agency (EPA) issued a direct final
rule and parallel proposal to amend the New Source Performance Standards (NSPS) for
Stationary Compression Ignition (CI) Internal Combustion Engines.
•	The direct final rule and parallel proposal revises the particulate matter (PM) emission
standard for new stationary CI engines located in remote areas of Alaska. The rule
specifies that 2014 model year and later stationary CI engines in remote areas of Alaska
must meet the Tier 3 standard for PM rather than the Tier 4 standard.
•	In 2011, EPA revised the rule to remove the requirement for these engines to meet the
Tier 4 standards for other pollutants.
•	EPA is publishing these changes as a direct final rule because the changes are
noncontroversial and no adverse comments are anticipated. If adverse comments are
received, EPA will address the comments in a subsequent final rule based on the parallel
proposal that is being issued in conjunction with the direct final rule amendments.
•	The direct final rule is effective 90 days after date of publication in the Federal Register
unless EPA receives significant adverse written comment by 30 days after the date of
publication.
BACKGROUND
•	EPA promulgated the NSPS for Stationary CI Internal Combustion Engines on July 11,
2006.
•	The NSPS limits emissions of PM, carbon monoxide (CO), nitrogen oxides (NOx), and
non-methane hydrocarbons (NMHC) from stationary CI internal combustion engines to
the same stringent levels required by EPA's nonroad diesel engine regulations. The NSPS
also limits the amount of sulfur in the diesel fuel used to run these engines.
•	In 2011, EPA revised the NSPS for stationary CI engines in remote areas of Alaska to
remove the requirement to meet emission standards for CO, NOx, and NMHC that
necessitate the use of add-on emission controls. EPA is now making that same revision
for the PM emission standards.
•	Remote areas of Alaska are defined in the NSPS as those that either are:
o Not accessible by the Federal Aid Highway System (FAHS), or
o Meet all of the following criteria: (1) the only connection to the FAHS is through
the Alaska Marine Highway System, or the stationary CI engine operation is
within an isolated grid in Alaska that is not connected to the statewide electrical
grid referred to as the Alaska Railbelt Grid; (2) at least 10 percent of the power
generated by the stationary CI engine on an annual basis is used for residential
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purposes; and (3) the generating capacity of the source is less than 12
megawatts, or the stationary CI engine is used exclusively for backup power for
renewable energy.
FOR MORE INFORMATION
•	Interested parties can download a copy of the direct final rule and parallel proposed
rule notice from EPA's website at the following address:
https://www.epa.gov/stationarv-engines/new-source-performance-standards-
stationary-compression-ignition-internal-O.
•	Today's action and other background information are also available either electronically
at https://www.regulations.gov. EPA's electronic public docket and comment system, or
in hard copy at the EPA Docket Center's Public Reading Room.
o The Public Reading Room is located at the EPA Headquarters Library, room
number 3334 in the EPA WJC West Building, 1301 Constitution Ave., NW,
Washington, DC. Hours of operation are 8:30 a.m. to 4:30 p.m., Eastern Time,
Monday through Friday, excluding Federal holidays.
o Visitors are required to show photographic identification, pass through a metal
detector and sign the EPA visitor log. All visitor materials will be processed
through an X-ray machine as well. Visitors will be provided a badge that must be
visible at all times.
o Materials for this proposed action can be accessed using Docket ID No. EPA-HQ-
OAR-2018-0851.
•	For further technical information about the rule, contact Melanie King, EPA's Office of
Air Quality Planning and Standards, at (919) 541-2469 or king.melanie@epa.gov.
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