FACT SHEET
PROPOSED AMENDMENT TO THE NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR
POLLUTANTS FOR PHOSPHORIC ACID MANUFACTURING
ACTION
•	On March 24, 2020, the U.S. Environmental Protection Agency (EPA) proposed to amend
the 2015 National Emission Standards for Hazardous Air Pollutants (NESHAP) for Phosphoric
Acid Manufacturing.
•	On September 6, 2016, PCS Phosphates (now under Nutrien) petitioned EPA to review the
2015 NESHAP based on newly available data.
•	Following analysis of the petitioner's data, EPA is proposing to revise the mercury maximum
achievable control technology (MACT) floor for existing calciners from 0.14 milligrams per
dry standard cubic meter (mg/dscm) at 3-percent oxygen to 0.23 mg/dscm at 3-percent
oxygen.
•	The proposed amendment fulfills EPA's statutory requirements under the Clean Air Act
(CAA), while maintaining the intent of the emission and operational standards of the 2015
NESHAP.
•	EPA will accept comment on the proposed amendment for 45 days after publication in the
Federal Register.
BACKGROUND
•	The CAA requires EPA to regulate hazardous air pollutants, also known as air toxics, from
categories of industrial facilities.
•	EPA develops technology-based standards for controlling the emissions of air toxics from
sources in an industry group or "source category." These MACT standards are based on
emissions levels that are already being achieved by the best-controlled and lower-emitting
sources in an industry.
•	In 1999, the Phosphoric Acid Manufacturing NESHAP established MACT standards for
calciners using particulate matter as a surrogate for hazardous air pollutant metals,
including mercury.
•	In 2015, EPA amended the Phosphoric Acid Manufacturing NESHAP and set numerical
mercury limits for the source category. PCS Phosphates in Aurora, North Carolina was the
only facility in the source category operating calciners, so data from the facility were used
as the basis for the MACT floor.
•	In 2016, compliance tests for calciners at PCS's Aurora facility indicated mercury emissions
near or higher than the MACT floor.
•	PCS requested that EPA review the mercury standard based on additional data which
indicate the 2015 NESHAP did not accurately represent emissions under normal operating
loads.

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HOW TO COMMENT
•	EPA will accept comments for 45 days after the proposal is published in the Federal
Register.
•	Comments, identified by Docket ID No. EPA-HQ-OAR-2020-0016 may be submitted by one
of the following methods:
o Go to https://www.regulations.gov/ and follow the on-line instructions for
submitting comments.
o Send comments by email to a-and-r-docket@epa.gov. Attention Docket ID No. EPA-
HQ-OAR-2020-0016.
o Fax your comments to: 202-566-9744, Attention Docket ID No. EPA-HQ-OAR-2020-
0016.
o Mail your comments to: EPA Docket Center, Environmental Protection Agency, Mail
Code: 28221T, 1200 Pennsylvania Ave., NW, Washington, DC 20460, Attention
Docket ID No. EPA-HQ-OAR-2020-0016.
o Deliver comments in person to: EPA Docket Center, 1301 Constitution Ave., NW,
Room 3334, Washington, DC. Note: In person deliveries (including courier deliveries)
are only accepted during the Docket's normal hours of operation. Special
arrangements should be made for deliveries of boxed information.
FOR MORE INFORMATION
•	Interested parties can download a copy of the proposed rule notice from EPA's website
at the following address: https://www.epa.gov/stationary-sources-air-pollution/phosphate-
fertilizer-production-plants-and-phosphoric-acid#rule-history.
•	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 hardcopy at EPA Docket Center's Public Reading Room.
o The Public Reading Room is located at the EPA Headquarters Library, Room 3334 in
the WJC West Building, 1301 Constitution Ave., NW, Washington,
DC. Hours of operation are 8:30 a.m. to 4:30 p.m. Eastern Standard Time,
Monday through Friday, excluding federal holidays.
o Visitors are required to show photographic identification, pass through a metal
detector and sign 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-2020-0016.
•	For further technical information about the rule, contact John Feather, EPA's Office of Air
Quality Planning and Standards, at (919) 541-3052 or feather.john@epa.gov.
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