Magnesium Production

SEPA

Subpart T, Greenhouse Gas Reporting Program

United Stales
Envirenmontjl Protection
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Under the Greenhouse Gas Reporting Program (GHGRP), owners or operators of facilities that contain
magnesium production processes must report emissions from use of cover and carrier gases as well as for
all other source categories located at the facility for which methods are defined in the rule. Owners and
operators are required to collect emission data, calculate greenhouse gas (GHG) emissions and follow
the specified procedures for quality assurance, missing data, recordkeeping, and reporting per the
requirements of 40 CFR Part 98 Subpart T - Magnesium Production.

How Is This Source Category Defined?

The magnesium production source category is defined as consisting of any process where magnesium
metal is produced through smelting (including electrolytic smelting), refining, or remelting operations
(including primary production facilities that extract magnesium from its ore and secondary production
facilities that recover magnesium from scrap), or any process where molten magnesium is used in
alloying, casting, drawing, extruding, forming, or rolling operations.

Magnesium production facilities that emit more than 25,000 metric tons CC^e per year.

What Greenhouse Gases Must Be Reported?

Each facility must report total annual emissions for each of the following greenhouse gases used in
magnesium production facilities:

•	Sulfur hexafluoride (SFe)

•	HFC-134a

•	The fluorinated ketone FK 5-1-12

•	Carbon dioxide (CO2)

•	Any other GHG as defined in 40 CFR part 98, subpart A (General Provisions) of the rule

In addition, the facility must report greenhouse gas emissions for any other source categories for which
calculation methods are provided in the rule, as applicable. For example, magnesium production and
processing facilities with fossil fuel-fired stationary combustion units must report CO2, nitrous oxide
(N2O), and methane (CFU) emissions from stationary combustion units by following the requirements of
40 CFR part 98, subpart C (General Stationary Fuel Combustion Sources). Please refer to the relevant
information sheet for a summary of the requirements for calculating and reporting greenhouse gas
emissions from any other source categories at the facility.

How Must Greenhouse Gas Emissions Be Calculated?

For magnesium production facilities, the annual emissions of each GHG are equal to the amount of that
GHG used as a cover or carrier gas in magnesium smelting, refining and casting processes. Owners or
operators of magnesium production facilities must monitor the annual consumption of each GHG used as
a cover or carrier gas using one of three methods:

•	Maintaining inventory records, including:

Who Must Report?

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o Acquisitions: The amount of each cover and carrier gas acquired through purchases or other
transactions.

o Disbursements: The amount of each cover and carrier gas disbursed to sources and locations
outside the facility through sales or other transactions (e.g., returning used gas cylinders to
the gas distributor).

o Inventory Assessments: The change in inventory of each stored cover and carrier gas based on
inventory reviews conducted at the beginning and end of each reporting year.

•	Monitoring the changes in the masses of individual containers or cylinders as the gases are used.

•	Monitoring the flow of pure cover gas and carrier gas into the cover gas distribution system using
mass flow controllers (MFC).

A checklist for data that must be monitored is available at: https://www.epa.gov/ghgreporting/subpart-t-
checklist

What Information Must Be Reported?

In addition to the information required by the General Provisions at 40 CFR 98.3(c), each annual report
must include the following information:

•	Total facility emissions of each GHG in metric tons.

•	Type of production process (e.g., primary, secondary, die casting).

•	Amount of magnesium produced in each primary and secondary production process (in metric
tons).

•	Magnesium throughput for each magnesium melting and casting process (in metric tons).

•	Cover gas flow rate for each production process (in standard cubic feet per minute).

•	Cover gas composition for each production process (in percent by volume).

•	For any missing monitoring data, the length of time the data were missing, the method used to
estimate emissions and the quantity of emissions estimated.

•	Overall cover gas usage rate for the facility for the reporting year (in kg of GHG/metric ton of
magnesium).

•	An explanation of any change in the facility cover gas usage rate greater than 30 percent
compared with the prior reporting year (e.g., installation of new melt protection technology
reduced the cover gas usage rate by X% or leak discovered in the cover gas delivery system that
resulted in increased consumption).

•	A description of any new melt protection technologies adopted that account for changes in
emissions from the previous year.

When and How Must Reports Be Submitted?

Annual reports must be submitted by March 31 of each year, unless the 31st is a Saturday, Sunday, or
federal holiday, in which case the reports are due on the next business day. Annual reports must be
submitted electronically using the electronic Greenhouse Gas Reporting Tool (e-GGRT). the GHGRP's
online reporting system. Additional information on setting up user accounts, registering a facility and
submitting annual reports is available at https://ccdsupport.com/confluence/.

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When Can a Facility Stop Reporting?

There are several scenarios under which a facility may discontinue reporting. These scenarios are
summarized in the Subpart A Information Sheet as well as in an FAQ.

For More Information

For additional information on Subpart T, visit the Subpart T Resources webpage. For additional
information on the Greenhouse Gas Reporting Program, visit the Greenhouse Gas Reporting Program
Website, which includes information sheets on other rule subparts, data previously reported to the
Greenhouse Gas Reporting Program, training materials, and links to frequently asked questions.

This document is provided solely for informational purposes. It does not provide legal advice, have
legally binding effect, or expressly or implicitly create, expand, or limit any legal rights, obligations,
responsibilities, expectations, or benefits in regard to any person. The series of information sheets is
intended to assist reporting facilities/owners in understanding key provisions of the Greenhouse Gas
Reporting Program.

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