Current through Register Vol. 50, No. 9, September 20, 2024
A. Purpose. The
purpose of these regulations is to limit the quantity of particulate matter
(suspended particulate matter) and fluorides emitted from all horizontal stud
Soderberg primary aluminum plants and all prebake primary aluminum plants in
Louisiana.
B. Scope. This
Subchapter applies to the primary aluminum industry utilizing the horizontal
stud Soderberg process and the prebake process.
C. General Definitions
1. Pot Line Primary Emission Control Systems.
The system which collects and removes contaminants prior to the emission point.
If there is more than one such system, the primary system is that system which
is more directly related to the aluminum reduction cell.
2. Prebake Process Primary Aluminum Plants.
Plants whose electrolytic cells require multiple consummable carbon electrodes
in which the binder has been solidified by baking prior to insertion into the
cell.
3. Horizontal Stud Soderberg
Process Primary Aluminum Plant. Plants whose electrolytic cells have horizontal
Soderberg (self baking) Anode(s).
D. Emission Limitations. No person shall
cause, suffer, allow, or permit emissions to the atmosphere in excess of the
limitations stated in this Subchapter. Notwithstanding the specific limits set
forth in this Subchapter, in order to maintain the lowest possible emission of
air contaminants, the highest and best practicable treatment and control
currently available shall be provided in every case of new construction and/or
major modifications at existing facilities.
1.
Particulate Emissions-Horizontal Stud Soderberg Process
a. The total emission of particulate matter
to the atmosphere from the reduction process (potlines) from the primary
aluminum industry for the horizontal stud Soderberg process shall not exceed
20.0 pounds per ton (10 kilogram/metric ton) of aluminum produced based on the
average of three 24-hour sampling periods.
b. The method of obtaining representative
samples of particulate matter emitted to the atmosphere from the reduction
process (potlines) shall be either:
i. that
method which, at the time of determining emissions, is required for new primary
aluminum plants under the New Source Performance Standards under the Federal
Clean Air Act ( 42 U.S.C. 1857 c-6), or, if such method has not been
promulgated; then
ii. that method
which may be agreed upon by and between the department and the United States
Environmental Protection Agency.
2. Particulate Emissions-Prebake Process
a. The total emission of particulate matter
to the atmosphere from the reduction process (potlines) shall be reduced to the
lowest level consistent with the highest and best practicable technology
available to the primary aluminum industry for the prebake process, but in no
case shall the emission of particulate matter exceed 17.0 pounds average per
ton (8.5 kilograms average per metric ton) of aluminum produced.
b. The method of obtaining representative
samples of particulate matter emitted to the atmosphere from the reduction
process (potlines) shall be either:
i. that
method which, at the time of determining emissions, is required for new primary
aluminum plants under the New Source Performance Standards under the Federal
Clean Air Act ( 42 U.S.C. 1857 c-6), or, if such method has not been
promulgated; then
ii. that method
which may be agreed upon by and between the department and the United States
Environmental Protection Agency.
3. Fluoride Emissions-Horizontal Stud
Soderberg Process. The fluoride emissions from horizontal Stud Soderberg
process aluminum plants shall be abated by using a potline primary emission
control system designed to have an average collection efficiency of 90 percent
and an average removal efficiency of 98.5 percent of the fluorides
collected.
4. Fluoride
Emissions-Prebake Process. The fluoride emissions from prebake process aluminum
plants shall be abated by using a potline primary emissions control system
designed to have an average collection efficiency of 95 percent and an average
removal efficiency of 98.5 percent of the fluorides collected.
E. Monitoring. Each horizontal
stud Soderberg process primary aluminum plant and prebake process primary
aluminum plant shall submit a detailed monitoring program subject to revision
and approval by the Office of Environmental Services. The program shall include
regularly scheduled monitoring for emissions of total particulates as well as
ambient air sampling for suspended particulates.
1. Note. Measurement of Concentrations. The
methods listed in LAC 33:III.711.C, Table 2 and LAC 33:III.1503.D.2, Table 4,
or such equivalent methods as may be approved by the department, shall be
utilized to determine these particulate concentrations.]
F. Reporting
1. Data shall be periodically reported for
each source and station included in the approved monitoring program as follows.
a. Ambient Air. Suspended particulate
concentrations expressed as [MICRO]g/m3.
b. Particulate Emissions. Results of all
emission sampling conducted for particulates, expressed in pounds per ton of
aluminum produced. The method of calculating pounds per ton shall be as
specified in the approved monitoring programs. Particulate data shall be
reported as total particulates.
c.
Compliance with LAC 33:III.2303.D.1 and 2 shall be determined by measurements
of emissions from the potline primary control system plus measurements of
emissions from the roof monitor and other points of emission to the atmosphere.
Calculated emissions to the potrooms from the reduction cells based on hooding
efficiency determined for gaseous fluoride may be substituted for roof monitor
emission measurements in determining compliance with the regulation.
d. Changes in collection efficiency of any
portion of the collection or control system that resulted from equipment or
process changes.
2.
Every horizontal stud Soderberg process primary aluminum plant and prebake
process primary aluminum plant shall furnish, upon request, to the department
such other data as the administrative authority may require to evaluate the
plant's emission control program. Such plants shall immediately report any
unauthorized emissions of any air contaminants to SPOC in accordance with LAC
33:I.3923.
G. Operating
Practices
1. All hood covers must be in good
repair and properly positioned over the pots. The amount of time hood covers
are removed during pot working operations must be minimized.
2. Any pot found emitting excess particulate
and fluorides (fuming cell) will be scheduled for rework before the end of the
shift.
3. If tapping crucibles are
equipped with hoses which return aspirator air under the hood, the hoses will
be maintained in good working order and the air return system must function
properly.
AUTHORITY NOTE:
Promulgated in accordance with
R.S.
30:2054.
