This subpart establishes national emission standards for hazardous air pollutants (NESHAP) for primary magnesium refineries. This subpart also establishes requirements to demonstrate initial and continuous compliance with all applicable emission limitations, work practice standards, and operation and maintenance requirements.

You are subject to this subpart if you own or operate a primary magnesium refinery that is (or is part of) a major source of hazardous air pollutant (HAP) emissions. Your primary magnesium refinery is a major source of HAP if it emits or has the potential to emit any single HAP at a rate of 10 tons or more per year or any combination of HAP at a rate of 25 tons or more per year.

(a) The affected sources are each new and existing primary magnesium refining facility.

(b) This subpart covers emissions from each spray dryer stack, magnesium chloride storage bins scrubber stack, melt/reactor system stack, and launder off-gas system stack at your primary magnesium refining facility. This subpart also covers fugitive dust emissions.

(c) Each primary magnesium refining facility is existing if you commenced construction or reconstruction of the affected source before January 22, 2003.

(d) Each primary magnesium refining facility is new if you commence construction or reconstruction of the affected source on or after January 22, 2003. An affected source is reconstructed if it meets the definition of reconstruction in § 63.2.

(a) If you have an existing source, you must comply with each emission limitation, work practice standard, and operation and maintenance requirement in this subpart that applies to you no later than October 11, 2004.

(b) If you have a new affected source and its initial startup date is on or before October 11, 2003, you must comply with each emission limitation, work practice standard, and operation and maintenance requirement in this subpart that applies to you by October 10, 2003.

(c) If you have a new affected source and its initial startup date is after October 10, 2003, you must comply with each emission limitation, work practice standard, and operation and maintenance requirement in this subpart that applies to you upon initial startup.

(d) If your primary magnesium refinery is an area source that becomes a major source of HAP, the compliance dates in paragraphs (d)(1) and (2) of this section apply to you:

(1) Any portion of the existing primary magnesium refinery that is a new affected source or a new reconstructed source must be in compliance with this subpart upon startup.

(2) All other parts of the primary magnesium refinery must be in compliance with this subpart no later than 2 years after it becomes a major source.

(e) You must meet the notification and schedule requirements in § 63.9930. Several of these notifications must be submitted before the compliance date for your affected source.

(a) You must meet each emission limit in Table 1 to this subpart that applies to you.

(b) For each wet scrubber applied to meet any particulate matter, particulate matter less than 10 microns (PM10), chlorine, hydrochloric acid, or dioxins/furans emission limit in Table 1 to this subpart, you must maintain the hourly average pressure drop and scrubber liquid flow rate at or above the minimum level established during the initial or subsequent performance test.

(a) You must prepare and at all times operate according to a fugitive dust emissions control plan that describes in detail the measures that will be put in place to control fugitive dust emissions from all unpaved roads and other unpaved operational areas.

(b) You must submit a copy of your fugitive dust emissions control plan for approval to the Administrator on or before the applicable compliance date for the affected source as specified in § 63.9883. The requirement to operate according to the fugitive dust emissions control plan must be incorporated by reference in the source's operating permit issued by the permitting authority under 40 CFR part 70 or 40 CFR part 71.

(c) You can use an existing fugitive dust emissions control plan provided it meets the requirements in paragraphs (c)(1) through (3) of this section.

(1) The plan satisfies the requirements of paragraph (a) of this section.

(2) The plan describes the current measures to control fugitive dust emission sources.

(3) The plan has been approved as part of a State implementation plan or title V permit.

(d) You must maintain a current copy of the fugitive dust emissions control plan on-site and available for inspection upon request. You must keep the plan for the life of the affected source or until the affected source is no longer subject to the requirements of this subpart.

(a) As required by § 63.6(e)(1)(i), you must always operate and maintain your affected source, including air pollution control and monitoring equipment, in a manner consistent with good air pollution control practices for minimizing emissions at least to the levels required by this subpart.

(b) You must prepare and operate at all times according to a written operation and maintenance plan for each control device subject to an operating limit in § 63.9890(b). Each plan must address preventative maintenance for each control device, including a preventative maintenance schedule that is consistent with the manufacturer's instructions for routine and long-term maintenance.

(c) You must maintain a current copy of the operation and maintenance plan required in paragraph (b) of this section on-site and available for inspection upon request. You must keep the plan for the life of the affected source or until the affected source is no longer subject to the requirements of this subpart.

(a) You must be in compliance with the emission limitations, work practice standards, and operation and maintenance requirements in this subpart at all times, except during periods of startup, shutdown, and malfunction as defined in § 63.2.

(b) You must develop a written startup, shutdown, and malfunction plan according to the provisions in § 63.6(e)(3).

(a) As required in § 63.7(a)(2), you must conduct a performance test to demonstrate initial compliance with each emission limit in Table 1 to this subpart that applies to you as indicated in paragraphs (a)(1) through (3) of this section:

(1) Within 180 calendar days after the compliance date that is specified in § 63.9883 for your existing affected source;

(2) By April 7, 2004 for a new source that has an initial startup date before October 10, 2003; or

(3) Within 180 days after initial startup for a new source that has an initial startup date after October 10, 2003.

(b) For each operation and maintenance requirement that applies to you where initial compliance is not demonstrated using a performance test, you must demonstrate initial compliance within 30 calendar days after the compliance date that is specified for your affected source in § 63.9883.

(c) If you commenced construction or reconstruction between January 22, 2003 and October 10, 2003, you must demonstrate initial compliance with either the proposed emission limitation or the promulgated emission limitation no later than April 7, 2004 or no later than 180 calendar days after startup of the source, whichever is later, according to § 63.7(a)(2)(ix).

(d) If you commenced construction or reconstruction between January 22, 2003 and October 10, 2003, and you chose to comply with the proposed emission limit when demonstrating initial compliance, you must conduct a second performance test to demonstrate compliance with the promulgated emission limit by April 11, 2005, or after startup of the source, whichever is later, according to § 63.7(a)(2)(ix).

You must conduct subsequent performance tests to demonstrate continuous compliance with all applicable emission limits in Table 1 to this subpart no less frequently than twice (at mid-term and renewal) during each term of your title V operating permit.

(a) You must conduct each performance test that applies to your affected source according to the requirements in § 63.7(e)(1).

(b) To determine compliance with the applicable emission limits for particulate matter in Table 1 to this subpart, you must follow the test methods and procedures in paragraphs (b)(1) and (2) of this section.

(1) Determine the concentration of particulate matter according to the following test methods in appendix A to 40 CFR part 60:

(i) Method 1 to select sampling port locations and the number of traverse points. Sampling ports must be located at the outlet of the control device and prior to any releases to the atmosphere.

(ii) Method 2, 2F, or 2G to determine the volumetric flow rate of the stack gas.

(iii) Method 3, 3A, or 3B to determine the dry molecular weight of the stack gas.

(iv) Method 4 to determine the moisture content of the stack gas.

(v) Method 5 or 5D, as applicable, to determine the concentration of particulate matter.

(vi) Method 201 or 201A, as applicable, to determine the concentration of PM10.

(2) Collect a minimum sample volume of 60 dry standard cubic feet (dscf) during each particulate matter or PM10 test run. Three valid test runs are needed to comprise a performance test.

(c) Compute the mass emissions rate in pounds per hour (lbs/hr) for each test run using Equation 1 of this section:

(a) You must conduct each performance test that applies to your affected source according to the requirements in § 63.7(e)(1).

(b) To determine compliance with the applicable emission limits for chlorine and hydrochloric acid in Table 1 to this subpart, you must follow the test methods and procedures specified in paragraphs (b)(1) and (2) of this section.

(1) Determine the concentration of chlorine and hydrochloric acid according to the following test methods in appendix A to 40 CFR part 60:

(i) Method 1 to select sampling port locations and the number of traverse points. Sampling ports must be located at the outlet of the control device and prior to any releases to the atmosphere.

(ii) Method 2, 2F, or 2G to determine the volumetric flow of the stack gas.

(iii) Method 3, 3A, or 3B to determine the dry molecular weight of the stack gas.

(iv) Method 4 to determine the moisture content of the stack gas.

(v) Method 26 or 26A, as applicable, to determine the concentration of hydrochloric acid and chlorine.

(2) Collect a minimum sample of 60 dscf during each test run for chlorine and hydrochloric acid. Three valid test runs are needed to comprise a performance test.

(c) Compute the mass emissions rate (lbs/hr) for each test run using Equation 1 of this section:

(a) You must conduct each performance test that applies to your affected source according to the requirements in § 63.7(e)(1).

(b) To determine compliance with the applicable emission limit for dioxins/furans in Table 1 to this subpart, you must follow the test methods and procedures specified in paragraphs (b)(1) and (2) of this section.

(1) Determine the concentration of dioxin and furan according to the following test methods in appendix A to 40 CFR part 60:

(i) Method 1 to select sampling port locations and the number of traverse points. Sampling ports must be located at the outlet of the control device and prior to any releases to the atmosphere.

(ii) Method 2, 2F, or 2G to determine the volumetric flow of the stack gas.

(iii) Method 3, 3A, or 3B to determine the dry molecular weight of the stack gas.

(iv) Method 4 to determine the moisture content of the stack gas.

(v) Method 23 to determine the concentration of dioxins/furans. For each dioxin/furan congener measured in accordance with this paragraph (b)(v), multiply the congener concentration by its corresponding toxic equivalency factor specified in Table 2 of this subpart.

(2) Collect a minimum sample of 100 dscf during each test run. Three valid test runs are needed to comprise a performance test.

For a wet scrubber subject to operating limits for pressure drop and scrubber water flow rate in § 63.9890(b), you must establish site-specific operating limits according to the procedures in paragraphs (a) and (b) of this section.

(a) Using the continuous parameter monitoring system (CPMS) required in § 63.9920, measure and record the pressure drop and scrubber water flow rate at least every 15 minutes during each run of the particulate matter performance test.

(b) Compute and record the average pressure drop and scrubber water flow rate for each individual test run. Your operating limits are the lowest average individual pressure drop and scrubber water flow rate values in any of the three runs that meet the applicable emission limit.

(a) For each affected source subject to an emission limit in Table 1 to this subpart, you have demonstrated initial compliance if:

(1) You have met the conditions in Table 3 to this subpart; and

(2) For each wet scrubber subject to the operating limits for pressure drop and scrubber water flow rate in § 63.9890(b), you have established appropriate site-specific operating limits and have a record of the pressure drop and scrubber water flow rate measured during the performance test in accordance with § 63.9916.

(b) You have demonstrated initial compliance with the work practice standards in § 63.9891 if you have certified in your notification of compliance status that:

(1) You have prepared a fugitive dust emissions control plan according to the requirements in § 63.9891 and submitted the plan for approval; and

(2) You will operate according to the requirements in the plan.

You must demonstrate initial compliance by certifying in your notification of compliance status that you have met the requirements in paragraphs (a) and (b) of this section.

(a) You have prepared the operation and maintenance plan according to the requirements in § 63.9910; and

(b) You will operate each control device according to the procedures in the plan.

For each wet scrubber subject to the operating limits for pressure drop and scrubber water flow rates in § 63.9890(b), you must at all times monitor the hourly average pressure drop and liquid flow rate using a CPMS according to the requirements in § 63.9921(a).

(a) For each wet scrubber subject to the operating limits in § 63.9890(b) for pressure drop and scrubber water flow rate, you must install, operate, and maintain each CPMS according to the requirements in paragraphs (a)(1) and (2) of this section.

(1) For the pressure drop CPMS, you must:

(i) Locate the pressure sensor(s) in or as close to a position that provides a representative measurement of the pressure and that minimizes or eliminates pulsating pressure, vibration, and internal and external corrosion.

(ii) Use a gauge with a minimum measurement sensitivity of 0.5 inch of water or a transducer with a minimum measurement sensitivity of 1 percent of the pressure range.

(iii) Check the pressure tap for pluggage daily.

(iv) Using a manometer, check gauge calibration quarterly and transducer calibration monthly.

(v) Conduct calibration checks any time the sensor exceeds the manufacturer's specified maximum operating pressure range, or install a new pressure sensor.

(vi) At least monthly, inspect all components for integrity, all electrical connections for continuity, and all mechanical connections for leakage.

(2) For the scrubber water flow rate CPMS, you must:

(i) Locate the flow sensor and other necessary equipment in a position that provides a representative flow and that reduces swirling flow or abnormal velocity distributions due to upstream and downstream disturbances.

(ii) Use a flow sensor with a minimum measurement sensitivity of 2 percent of the flow rate.

(iii) Conduct a flow sensor calibration check at least semiannually according to the manufacturer's instructions.

(iv) At least monthly, inspect all components for integrity, all electrical connections for continuity, and all mechanical connections for leakage.

(b) You must install, operate, and maintain each CPMS for a wet scrubber according to the requirements in paragraphs (b)(1) through (3) of this section.

(1) Each CPMS must complete a minimum of one cycle of operation for each successive 15-minute period.

(2) Each CPMS must have valid data for at least 95 percent of every averaging period.

(3) Each CPMS must determine and record the hourly average of all recorded readings.

(a) Except for monitoring malfunctions, associated repairs, and required quality assurance or control activities (including, as applicable, calibration checks and required zero and span adjustments), you must monitor continuously (or collect data at all required intervals) at all times an affected source is operating.

(b) You may not use data recorded during monitoring malfunctions, associated repairs, and required quality assurance or control activities in data averages and calculations used to report emission or operating levels or to fulfill a minimum data availability requirement, if applicable. You must use all the data collected during all other periods in assessing compliance.

(c) A monitoring malfunction is any sudden, infrequent, not reasonably preventable failure of the monitoring to provide valid data. Monitoring failures that are caused in part by poor maintenance or careless operation are not malfunctions.

(a) For each affected source subject to an emission limit in Table 1 to this subpart, you must demonstrate continuous compliance according to the requirements in Table 4 to this subpart.

(b) For each wet scrubber subject to the operating limits for pressure drop and scrubber water flow rate in § 63.9890(b), you must demonstrate continuous compliance according to the requirements in paragraphs (b)(1) and (2) of this section.

(1) Collecting and reducing the monitoring data according to § 63.9921(b); and

(2) Maintaining the hourly average pressure drop and scrubber water flow rate at or above the minimum level established during the initial or subsequent performance.

(c) You must demonstrate continuous compliance with the work practice standards in § 63.9891 by operating according to the requirements in your fugitive dust emissions control plan and recording information needed to document conformance with the requirements.

For each emission point subject to an emission limit in Table 1 to this subpart, you must demonstrate continuous compliance with the operation and maintenance requirements in § 63.9900 by performing preventive maintenance for each control device according to § 63.9900(b) and recording all information needed to document conformance with these requirements.

(a) Deviations. You must report each instance in which you did not meet each emission limitation in § 63.9890 or work practice standard in § 63.9891 that applies to you. This includes periods of startup, shutdown, and malfunction. You must also report each instance in which you did not meet each operation and maintenance requirement required in § 63.9900 that applies to you. These instances are deviations from the emission limitations, work practice standards, and operation and maintenance requirements in this subpart. These deviations must be reported according to the requirements in § 63.9931.

(b) Startups, shutdowns, and malfunctions. (1) Consistent with §§ 63.6(e) and 63.7(e)(1), deviations that occur during a period of startup, shutdown, or malfunction are not violations if you demonstrate to the Administrator's satisfaction that you were operating in accordance with § 63.6(e)(1).

(2) The Administrator will determine whether deviations that occur during a period of startup, shutdown, or malfunction are violations, according to the provisions in § 63.6(e).

(a) You must submit all of the notifications in §§ 63.7(b) and (c), 63.8(f)(4), 63.9(b), and 63.9(h) that apply to you by the specified dates.

(b) As specified in § 63.9(b)(2), if you start up your affected source before October 10, 2003, you must submit your initial notification no later than 120 calendar days after October 10, 2003, or no later than 120 days after the source becomes subject to this subpart, whichever is later.

(c) As specified in § 63.9(b)(3), if you start your new affected source on or after October 10, 2003, you must submit your initial notification no later that 120 calendar days after you become subject to this subpart.

(d) If you are required to conduct a performance test, you must submit a notification of intent to conduct a performance test at least 60 calendar days before the performance test is scheduled to begin as required in § 63.7(b)(1).

(e) If you are required to conduct a performance test or other initial compliance demonstration, you must submit a notification of compliance status according to § 63.9(h)(2)(ii), and the requirements in paragraphs (e)(1) and (2) of this section:

(1) For each initial compliance demonstration that does not include a performance test, you must submit the notification of compliance status before the close of business on the 30th calendar day following completion of the initial compliance demonstration.

(2) For each initial compliance demonstration that does include a performance test, you must submit the notification of compliance status, including the performance test results, before the close of business on the 60th calendar day following the completion of the performance test according to § 63.10(d)(2).

(a) Compliance report due dates. Unless the Administrator has approved a different schedule, you must submit a semiannual compliance report to your permitting authority according to the requirements in paragraphs (a) (1) through (5) of this section.

(1) The first compliance report must cover the period beginning on the compliance date that is specified for your affected source in § 63.9883 and ending on June 30 or December 31, whichever date comes after the compliance date that is specified for your source in § 63.9883.

(2) The first compliance report must be postmarked or delivered no later than July 31 or January 31, whichever date comes first after your compliance report is due.

(3) Each subsequent compliance report must cover the semiannual reporting period from January 1 through June 30 or the semiannual reporting period from July 1 through December 31.

(4) Each subsequent compliance report must be postmarked or delivered no later than July 31 or January 31, whichever date comes first after the end of the semiannual reporting period.

(5) For each affected source that is subject to permitting regulations pursuant to 40 CFR part 70 or 40 CFR part 71, and if the permitting authority has established dates for submitting semiannual reports pursuant to 40 CFR 70.6(a)(3)(iii)(A) or 40 CFR 71.6(a)(3)(iii)(A), you may submit the first and subsequent compliance reports according to the dates the permitting authority has established instead of according to the dates in paragraphs (a)(1) through (4) of this section.

(b) Compliance report contents. Each compliance report must include the information in paragraphs (b)(1) through (3) of this section and, as applicable, paragraphs (b)(4) through (8) of this section.

(1) Company name and address.

(2) Statement by a responsible official, with that official's name, title, and signature, certifying the truth, accuracy, and completeness of the content of the report.

(3) Date of report and beginning and ending dates of the reporting period.

(4) If you had a startup, shutdown, or malfunction during the reporting period and you took actions consistent with your startup, shutdown, and malfunction plan, the compliance report must include the information in § 63.10(d)(5)(i).

(5) If there were no deviations from the continuous compliance requirements in §§ 63.9923 and 63.9924 that apply to you, a statement that there were no deviations from the emission limitations, work practice standards, or operation and maintenance requirements during the reporting period.

(6) If there were no periods during which a CPMS was out-of-control as specified in § 63.8(c)(7), a statement that there were no periods during which the CPMS was out-of-control during the reporting period.

(7) For each deviation from an emission limitation in § 63.9890 that occurs at an affected source where you are not using a CPMS to comply with an emission limitation in this subpart, the compliance report must contain the information in paragraphs (b)(1) through (4) of this section and the information in paragraphs (b)(7)(i) and (ii) of this section. This includes periods of startup, shutdown, and malfunction.

(i) The total operating time of each affected source during the reporting period.

(ii) Information on the number, duration, and cause of deviations (including unknown cause, if applicable) as applicable and the corrective action taken.

(8) For each deviation from an emission limitation occurring at an affected source where you are using a CPMS to comply with the emission limitation in this subpart, you must include the information in paragraphs (b)(1) through (4) of this section and the information in paragraphs (b)(8)(i) through (xi) of this section. This includes periods of startup, shutdown, and malfunction.

(i) The date and time that each malfunction started and stopped.

(ii) The date and time that each continuous monitoring was inoperative, except for zero (low-level) and high-level checks.

(iii) The date, time, and duration that each continuous monitoring system was out-of-control, including the information in § 63.8(c)(8).

(iv) The date and time that each deviation started and stopped, and whether each deviation occurred during a period of startup, shutdown, or malfunction or during another period.

(v) A summary of the total duration of the deviation during the reporting period and the total duration as a percent of the total source operating time during that reporting period.

(vi) A breakdown of the total duration of the deviations during the reporting period including those that are due to startup, shutdown, control equipment problems, process problems, other known causes, and other unknown causes.

(vii) A summary of the total duration of continuous monitoring system downtime during the reporting period and the total duration of continuous monitoring system downtime as a percent of the total source operating time during the reporting period.

(viii) A brief description of the process units.

(ix) A brief description of the continuous monitoring system.

(x) The date of the latest continuous monitoring system certification or audit.

(xi) A description of any changes in continuous monitoring systems, processes, or controls since the last reporting period.

(c) Immediate startup, shutdown, and malfunction report. If you had a startup, shutdown, or malfunction during the semiannual reporting period that was not consistent with your startup, shutdown, and malfunction plan, you must submit an immediate startup, shutdown, and malfunction report according to the requirements in § 63.10(d)(5)(ii).

(d) Part 70 monitoring report. If you have obtained a title V operating permit for an affected source pursuant to 40 CFR part 70 or 40 CFR part 71, you must report all deviations as defined in this subpart in the semiannual monitoring report required by 40 CFR 70.6(a)(3)(iii)(A) or 40 CFR 71.6(a)(3)(iii)(A). If you submit a compliance report for an affected source along with, or as part of, the semiannual monitoring report required by 40 CFR 70.6(a)(3)(iii)(A) or 40 CFR 71.6(a)(3)(iii)(A), and the compliance report includes all the required information concerning deviations from any emissions limitation, work practice standards, or operation and maintenance requirement in this subpart, submission of the compliance report satisfies any obligation to report the same deviations in the semiannual monitoring report. However, submission of the compliance report does not otherwise affect any obligation you may have to report deviations from permit requirements for an affected source to your permitting authority.

(a) You must keep the records as indicated in paragraphs (a)(1) through (3) of this section:

(1) A copy of each notification and report that you submitted to comply with this subpart, including all documentation supporting any initial notification or notification of compliance status that you submitted, according to the requirements in § 63.10(b)(2)(xiv).

(2) The records in § 63.6(e)(3)(iii) through (v) related to startup, shutdown, and malfunction.

(3) Records of performance tests and performance evaluations as required in § 63.10(b)(2)(viii).

(b) You must keep the records required in §§ 63.9932 and 63.9933 to show continuous compliance with each emission limitation, work practice standard, and operating and maintenance requirement that applies to you.

(a) Your records must be in a form suitable and readily available for expeditious review, according to § 63.10(b)(1).

(b) As specified in § 63.10(b)(1), you must keep each record for 5 years following the date of each occurrence, measurement, maintenance, corrective action, report, or record.

(c) You must keep each record on site for at least 2 years after the date of each occurrence, measurement, maintenance, corrective action, report, or record according to § 63.10(b)(1). You can keep the records off site for the remaining 3 years.

(d) You must keep your fugitive dust emissions control plan and your operation and maintenance plan on-site according to the requirements in §§ 63.9891(d) and 63.9900(c).

Table 4 to this subpart shows which parts of the General Provisions in §§ 63.1 through 63.15 apply to you.

(a) This subpart can be implemented and enforced by us, the United States Environmental Protection Agency (U.S. EPA) or a delegated authority such as your State, local, or tribal agency. If the EPA Administrator has delegated authority to your State, local, or tribal agency, then that agency has the authority to implement and enforce this subpart. You should contact your EPA Regional Office to find out if this subpart is delegated to your State, local, or tribal agency.

(b) In delegating implementation and enforcement authority of this subpart to a State, local, or tribal agency under subpart E of this part, the authorities contained in paragraph (c) of this section are retained by the Administrator of the EPA and are not transferred to the State, local, or tribal agency.

(c) The authorities that will not be delegated to State, local, or tribal agencies are specified in paragraphs (c)(1) through (4) of this section.

(1) Approval of alternatives to the non-opacity emission limitations in § 63.9890 and work practice standards in § 63.9891 under § 63.6(g).

(2) Approval of major alternatives to test methods under § 63.7(e)(2)(ii) and (f) and as defined in § 63.90.

(3) Approval of major alternatives to monitoring under § 63.8(f) and as defined in § 63.90.

(4) Approval of major alternatives to recordkeeping and reporting under § 63.10(f) and as defined in § 63.90.

Terms used in this subpart are defined in the Clean Air Act, in § 63.2, and in this section as follows:

Chlorine plant bypass scrubber means the wet scrubber that captures chlorine gas during a chlorine plant shut down or failure.

Deviation means any instance in which an affected source subject to this subpart, or an owner or operator of such a source:

(1) Fails to meet any requirement or obligation established by this subpart, including but not limited to any emission limitation (including operating limits) or operation and maintenance requirement;

(2) Fails to meet any term or condition that is adopted to implement an applicable requirement in this subpart and that is included in the operating permit for any affected source required to obtain such a permit; or

(3) Fails to meet any emission limitation in this subpart during startup, shutdown, or malfunction, regardless of whether or not such failure is permitted by this subpart.

Emission limitation means any emission limit, opacity limit, or operating limit.

Launder off-gas system means a system that collects chlorine and hydrochloric acid fumes from collection points within the melt/reactor system building. The system then removes particulate matter and hydrochloric acid from the collected gases prior to discharge to the atmosphere.

Magnesium chloride storage bins means vessels that store dried magnesium chloride powder produced from the spray drying operation.

Melt/reactor system means a system that melts and chlorinates dehydrated brine to produce high purity molten magnesium chloride feed for electrolysis.

Primary magnesium refining means the production of magnesium metal and magnesium metal alloys from natural sources of magnesium chloride such as sea water or water from the Great Salt Lake and magnesium bearing ores.

Responsible official means responsible official as defined in § 63.2.

Spray dryer means dryers that evaporate brine to form magnesium powder by contact with high temperature gases exhausted from gas turbines.

Wet scrubber means a device that contacts an exhaust gas with a liquid to remove particulate matter and acid gases from the exhaust. Examples are packed-bed wet scrubbers and venturi scrubbers.

Work practice standard means any design, equipment, work practice, or operational standard, or combination thereof, that is promulgated pursuant to section 112(h) of the Clean Air Act.

As required in § 63.9890(a), you must comply with each applicable emission limit in the following table:

As required in 63.9916, you must demonstrate initial compliance with the emission limits according to the following table:

As required in § 63.9923, you must demonstrate continuous compliance with the emission limits according to the following table:

As required in § 63.9950, you must comply with the requirements of the NESHAP General Provisions (40 CFR part 63, subpart A) shown in the following table: