FACT SHEET
TECHNICAL AMENDMENTS TO PROCEDURE 6
ACTION
•	On September 13, 2017, the U.S. Environmental Protection Agency (EPA) finalized minor technical
amendments to a tool used to evaluate hydrogen chloride (HC1) continuous emissions monitoring
systems (CEMs) - known as Procedure 6. Procedure 6 specifies the minimum quality assurance
requirements necessary for the control and assessment of the quality of CEMs HC1 data used for
compliance with regulatory requirements.
•	Together with Performance Specification 18, Procedure 6 is used to evaluate HC1 emissions for
Portland Cement facilities, electric generating units, and industrial, commercial, and
institutional boilers and process heaters.
BACKGROUND
•	On July 7, 2015, the EPA published Procedure 6, which is a companion to Performance
Specification 18.
•	After publication, certain minor data treatment inconsistencies were identified.
•	The EPA proposed to correct the minor inconsistencies in Performance Specification 18 and
Procedure 6 through a direct final action titled, "Technical Amendments to Performance
Specification 18 and Procedure 6." 81 Fed. Reg. 31,515 (May 19, 2016). One substantive
comment was received regarding changes to Procedure 6.
•	The EPA is responding to that comment and finalizing corrections to Procedure 6 with this
action.
FOR MORE INFORMATON
•	Interested parties can download the rule from EPA's web site on the Internet under Recent
Actions at the following address: https://www.epa.gov/emc/emc-updates-and-general-
resources.
•	Other places to read the proposed rule and background information (use Docket ID No. EPA-
HQ-OAR- EPA-HQ-OAR-2013 -0696):
•	EPA's electronic public docket and comment system at http://www.regulations.gov.
•	The EPA Docket Center's Public Reading Room (for hard copies).
o The Public Reading Room is located at EPA Headquarters, Room Number 3334 in
EPA West Building, 1301 Constitution Avenue, NW, Washington,
o DC. Hours of operation are 8:30 a.m. to 4:30 p.m. eastern standard time, Monday
through Friday, excluding federal holidays.

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o You will have to show photo identification, pass through a metal detector, and sign
the EPA visitor log. Any materials you bring with you will be processed through an
X-ray machine as well. You will be provided a badge that must be visible at all times.
• For further information about the rulemaking, contact Ray Merrill at EPA's Office of Air
Quality Planning and Standards at (919) 541-5225 or merrill.raymond@epa.gov.

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