Regulatory Text: 
Louisiana Administrative Code, Title 33 ENVIRONMENTAL QUALITY, Part III Air (LAC 33:III)

Chapter 23. Control of Emissions for Specific Industries

Subchapter B. Aluminum Plants

Section 2303. Standards for Horizontal Stud Soderberg Primary Aluminum Plants and Prebake Primary Aluminum Plants. LAc49 to LAd34 - Revised
Approved by EPA 03/08/89 (54 FR 09795) at 52.970(c)(49) effective 05/08/89.

   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 consumable 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 administrative authority. The program shall include regularly scheduled monitoring for emissions of total particulates as well as ambient air sampling for suspended particulates.

       1.  Measurement of Concentrations. The methods listed in Table 2 and 4 or such equivalent methods as may be approved by the department, shall be utilized to determine these particulate concentrations.

   F.  Reportings

       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 ug/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 abnormal plant operations which result in increased emissions of air contaminants. Such notification does not imply the administrative authority will automatically grant an exemption to the source(s) of excessive emissions.

   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. 30:1084.
   HISTORICAL NOTE:  Promulgated by the Department of Environmental Quality, Office of Air Quality and Nuclear Energy, Air Quality Division in LR 13:741 (December 1987).

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