Browse: Departments Dates Agencies
ENVIRONMENTAL PROTECTION AGENCY
Veterans Affairs Department
CFR Citation: 40 CFR Part 63
RIN ID: RIN 2060-AE43
OAR ID: [OAR-2002-0034; FRL-7554-5]
NOTICE: Part II
DOCUMENT ACTION: Final rule.
SUBJECT CATEGORY: National Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries
EFFECTIVE DATES: April 22, 2004.
DOCUMENT SUMMARY: This action promulgates national emission standards for hazardous air pollutants (NESHAP) for iron and steel foundries. The EPA has identified iron and steel foundries as a major source of hazardous air pollutant (HAP) emissions. These standards implement section 112(d) of the Clean Air Act (CAA) by requiring all major sources to meet HAP emissions standards reflecting application of the maximum achievable control technology (MACT).
The HAP emitted by facilities in the iron and steel foundries source category include metal and organic compounds. For iron and steel foundries that produce low alloy metal castings, metal HAP emitted are primarily lead and manganese with smaller amounts of cadmium, chromium, and nickel. For iron and steel foundries that produce high alloy metal or stainless steel castings, metal HAP emissions of chromium and nickel can be significant. Organic HAP emissions include acetophenone, benzene, cumene, dibenzofurans, dioxins, formaldehyde, methanol, naphthalene, phenol, pyrene, toluene, triethylamine, and xylene. Exposure to these substances has been demonstrated to cause adverse health effects, including cancer and chronic or acute disorders of the respiratory, reproductive, and central nervous systems. When fully implemented, the final rule will reduce HAP emissions from iron and steel foundries by over 820 tons per year (tpy).
SUMMARY: Environmental Protection Agency,
SUPPLEMENTAL INFORMATION
Regulated Entities. Categories and entities potentially regulated by this action include:NAICS Category code \1\ Examples of regulated entities Industry.......................................... 331511 Iron foundries. Iron and steel plants. Automotive and large equipment manufacturers. 331512 Steel investment foundries. 331513 Steel foundries (except investment). Federal government................................ ......... Not affected. State/local/tribal government..................... ......... Not affected. \1\ North American Industry Classification System.
This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. To determine whether your facility is regulated by this action, you should examine the applicability criteria in Sec. 63.7682 of the final rule. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.
Docket. The EPA has established an official public docket for this action including both Docket ID No. OAR20020034 and Docket ID No. A 200056. The official public docket consists of the documents specifically referenced in this action, any public comments received, and other information related to this action. All items may not be listed under both docket numbers, so interested parties should inspect both docket numbers to ensure that they have received all materials relevant to the final rule. Although a part of the official public docket, the public docket does not include Confidential Business Information or other information whose disclosure is restricted by statute. The official public docket is available for public viewing at the EPA Docket Center (Air Docket), EPA West, Room B102, 1301 Constitution Avenue, NW., Washington, DC. The EPA Docket Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Reading Room is (202) 5661744, and the telephone number for the Air Docket is (202) 5661742.
Electronic Docket Access. You may access the final rule electronically through the EPA Internet under the Federal Register listings at http://www.epa.gov/fedrgstr/.
An electronic version of the public docket is available through EPA's electronic public docket and comment system, EPA Dockets. You may use EPA Dockets at http://www.epa.gov/edocket/ to view public comments, access the index listing the contents of the official public docket, and to access those documents in the public docket that are available electronically. Once in the system, select ``search,'' then key in the appropriate docket identification number. Although not all docket materials may be available electronically, you may still access any of the publicly available docket materials through EPA Dockets. (See Docket No. A200056 in the Air Docket).
Worldwide Web (WWW). In addition to being available in the docket, an electronic copy of today's final rule is also available on the WWW through the Technology Transfer Network (TTN). Following the Administrator's signature, a copy of the rule will be placed on the TTN's policy and guidance page for newly proposed or promulgated rules at http://www.epa.gov/ttn/oarpg. The TTN provides information and technology exchange in various areas of air pollution control. If more information regarding the TTN is needed, call the TTN HELP line at (919) 5415384.
Judicial Review. This action constitutes final administrative
action on the proposed NESHAP for iron and steel foundries (67 FR
78274, December 23, 2002). Under section 307(b)(1) of the CAA, judicial
review of the rule is available only by filing a petition for review in
the U.S. Court of Appeals for the District of Columbia Circuit by June
21, 2004. Only those objections to the NESHAP which were raised with
reasonable specificity during the public comment period may be raised
during judicial review. Under section 307(b)(2) of the CAA, the requirements that are
[[Page 21907]]
the subject of today's final rule may not be challenged separately in
civil or criminal proceedings brought by the EPA to enforce these requirements.
Outline. The information presented in this preamble is organized as follows:
I. Background
II. Summary of the Final Rule
A. What Is the Affected Source?
B. What Are the Emissions Limitations?
C. What Are the Operation and Maintenance (O&M) Requirements?
D. What Are the Requirements for Demonstrating Initial and Continuous Compliance?
E. What Are the Notification, Recordkeeping, and Reporting Requirements?
F. What Are the Compliance Deadlines?
III. Summary of Environmental, Energy, and Economic Impacts
A. What Are the Air Quality Impacts?
B. What Are the Cost Impacts?
C. What Are the Economic Impacts?
D. What Are the Nonair Health, Environmental, and Energy Impacts?
IV. Summary of Major Comments and Responses
A. Why Did We Revise the Proposed Affected Source Designation?
B. Why Did We Revise the Proposed Emissions Limits?
C. Why Did We Revise the Proposed Work Practice Standards? V. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments
G. Executive Order 13045: Protection of Children From Environmental Health and Safety Risks
H. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use
I. National Technology Transfer Advancement Act
J. Congressional Review Act
VI. Statutory Authority
I. Background
Section 112(d) of the CAA requires us (the EPA) to establish national emission standards for all categories and subcategories of major sources of HAP and for area sources listed for regulation under section 112(c). Major sources are those that emit or have the potential to emit at least 10 tpy of any single HAP or 25 tpy of any combination of HAP. Area sources are stationary sources of HAP that are not major sources. Additional information on the NESHAP development process can be found in the preamble to the proposed rule (67 FR 78274).
We received a total of 83 comment letters on the proposed NESHAP from trade associations, individual plants, consultants, vendors, State agencies, environmental groups, and private citizens. We provided a 60 day comment period and held a public hearing on January 22, 2003 to provide the opportunity for oral presentations of data, views, or arguments concerning the proposed rule.
Today's final rule reflects our full consideration of all the
comments we received. A detailed response to all the comments is
included in the Background Information Document (BID) for the Promulgated Standards (Docket ID No. OAR20020034).
II. Summary of the Final Rule
A. What Is the Affected Source?
The affected source is each new or existing iron and steel foundry that is a major source of HAP emissions. A new affected source is an iron and steel foundry for which construction or reconstruction began after December 23, 2002. An existing affected source is an iron and steel foundry for which construction or reconstruction began on or before December 23, 2002. The final rule defines an ``iron and steel foundry'' as:
A facility or portion of a facility that melts scrap, ingot, and/or other forms of iron and/or steel and pours the resulting molten metal into molds to produce final or near final shape products for introduction into commerce. Research and development facilities and operations that only produce noncommercial castings are not included in this definition.
The final rule covers emissions from metal melting furnaces, scrap preheaters, pouring areas, pouring stations, automated conveyor and pallet cooling lines that use a sand mold system, automated shakeout lines that use a sand mold system, and mold and core making lines. The final rule also covers fugitive emissions from foundry operations. B. What Are the Emissions Limitations?
The final rule includes emissions limits for metal and organic HAP
as well as operating limits for capture systems and control devices.
Particulate matter (PM) and opacity serve as surrogate measures of
metal HAP emissions; emissions limits for total metal HAP are included
as alternatives to the PM limits. The final rule also includes
emissions limits for volatile organic HAP (VOHAP) and triethylamine
(TEA). Except for the fugitive emissions opacity limit, each of the
emissions limits apply to emissions discharged to the atmosphere
through a conveyance. The term ``conveyance'' means the system of
equipment that is designed to capture pollutants, convey them through
ductwork, and exhaust them using forced ventilation. The opacity limit
for fugitive emissions applies to each building or structure housing
any emissions source at the iron and steel foundry. The emissions limitations and work practice requirements are:
Emissions limit or work practice
Emissions source standard
Electric arc metal melting furnace,
existing iron and steel foundry.
Cupola metal melting furnace at an
Cupola metal melting furnace or
at a new iron and steel foundry.
Electric induction metal melting
new iron and steel foundry.
All metal melting furnaces.........
Pouring area or pouring station at
Fugitive emissions from a building
Scrap preheater at an existing iron
Scrap preheater at a new iron and
Automated conveyor and pallet
mold system at a new iron and
steel foundry.
TEA cold box mold and core making
Furan warm box mold and core making
The final rule requires a capture system for those emissions sources subject to VOHAP or TEA limits. You (the owner or operator) must establish operating limits for identified capture system parameter (or parameters) that are appropriate for assessing capture system performance. At a minimum, the limits must indicate the level of ventilation draft and damper position settings. You must operate the capture systems at or above the lowest value or setting established in the operation and maintenance (O&M) plan.
If you use a wet scrubber to control PM or total metal HAP emissions from a metal melting furnace, scrap preheater, pouring area, or pouring station, the 3hour average pressure drop and scrubber water flow rate must not fall below the minimum levels established during the initial (or subsequent) performance test. If you use a combustion device to control VOHAP emissions from a cupola metal melting furnace, the 15minute average combustion zone temperature must not fall below 1,300 degrees Fahrenheit ([deg]F). Periods when the cupola is off blast and for 15 minutes after going on blast from an off blast condition are not included in the 15minute average. If you use a combustion device to control VOHAP emissions from a scrap preheater or TEA cold box mold or core making line, the 3hour average combustion zone temperature must not fall below the minimum level established during the initial (or subsequent) performance test. If you use a wet acid scrubber to control TEA emissions, the 3hour average scrubbing liquid flow rate must not fall below the minimum level established during the initial (or subsequent) performance test and the 3hour average pH level of the scrubber blowdown (or the pH level during a production shift) must not exceed 4.5.
Operating limits do not apply to control devices for automated conveyor and pallet cooling lines or automated shakeout lines that use a sand mold system at a new iron and steel foundry. The final rule requires a continuous emissions monitoring system (CEMS) for these emissions sources. However, the final rule includes procedures for requesting alternative monitoring requirements. To obtain approval of alternative monitoring requirements, you must submit a monitoring plan containing information needed to demonstrate continuous compliance along with performance test results showing compliance with the emissions limit.
The final rule also includes work practice standards. Facilities must meet certification requirements for their charge materials or develop and implement a scrap selection and inspection program to minimize the amount or organics and HAP metals in furnace charge materials. The certification option requires the foundry to purchase and use only certifiedmetal ingots, pig iron, skittle, or other materials that do not include postconsumer automotive body scrap, postconsumer engine blocks, oil filters, oily turnings, lead components, mercury switches, plastics, or organic liquids. The scrap selection plan option requires scrap specifications, a certification that the scrap supplier has implemented procedures to remove mercury switches and lead components from automotive scrap, and visual inspection procedures to ensure materials meet the specifications.
The owner or operator of an existing iron and steel foundry must install, operate, and maintain a gasfired preheater where the flame directly contacts the scrap charged. As alternative compliance options, the owner or operator may meet a 20 ppmv limit for VOHAP emissions or may charge to a preheater only materials subject to the scrap certification requirement. The owner or operator of a new iron and steel foundry must meet the 20 ppmv limit for VOHAP emissions and the operating limit for combustion devices. As an alternative compliance option for new scrap preheaters, the owner or operator must meet the scrap certification requirements.
Plants with a furan warm box mold or core making line at a new or existing iron and steel foundry must use a binder chemical formulation that contains no methanol, as listed in the Material Data Safety Sheet. This requirement applies to the catalyst portion (and not the resin portion) of the binder system.
C. What Are the Operation and Maintenance Requirements?
All foundries must prepare and follow a written operation and maintenance (O&M) plan for capture systems and control devices. The plan must include operating limits for capture systems; requirements for inspections and repairs; preventative maintenance procedures and schedules; and procedures for operation of bag leak detection systems (including corrective action steps to be taken in the event of a bag leak detection system alarm). The plan also must contain procedures for igniting gases from mold vents in pouring areas and pouring stations that use sand mold systems. These procedures may consider the ignitability of the mold gases, accessibility to the molds, and safety issues associated with igniting the gases.
The final rule also requires a startup, shutdown, and malfunction
plan that meets the requirements in Sec. 63.6(e) of the NESHAP General
Provisions. The plan must include procedures for operating and
maintaining the emissions source during periods of startup, shutdown,
and malfunction and a program of corrective action for malfunctioning
process equipment, air pollution control systems, and monitoring
systems. The final rule requires that the plan also include a
description of the conditions that constitute a shutdown of a cupola
and normal operating conditions following startup of a cupola. The
owner or operator may use the standard operation procedures manual for
the emissions source or other type of plan if it meets EPA's
requirements. For more information on startup, shutdown, and malfunction plans, see the amendments
[[Page 21909]]
to the NESHAP General Provisions published on May 30, 2003 (68 FR 32586).
D. What Are the Requirements for Demonstrating Initial and Continuous Compliance?
Emissions Limits
Foundries must demonstrate initial compliance by conducting performance tests for all emissions sources subject to an emissions limit. To determine compliance with the metal HAP emissions limits, EPA Methods 1 through 4, and either Method 5, 5B, 5D, 5F, or 5I, as applicable (to measure PM) or Method 29 (to measure total metal HAP) are required. To determine compliance with the organic HAP limits, foundries can use EPA Method 18 to measure VOHAP, Method 25 to measure total gaseous nonmethane organics (TGNMO) as hexane, or Method 25A to measure total organic compounds (TOC) as hexane. All of these methods are in appendix A to 40 CFR part 60.
The performance test requirements for automated conveyor and pallet cooling lines and automated shakeout lines at new foundries allow you to either meet the 20 ppmv emissions limit directly using the volatile organic compound (VOC) CEMS to measure total hydrocarbons (as a surrogate for VOHAP) or to establish a sitespecific VOC limit for the CEMS that is correlated to the VOHAP emissions limit. The final rule also includes procedures for computing the flowweighted average of multiple exhaust streams from automated conveyor and pallet cooling lines or automated shakeout lines, and for determining compliance for combined emissions streams. Procedures for establishing operating limits for capture systems and control devices, and revising the limits, if necessary or desired, after the initial performance test are given in Sec. 63.7733 of the final rule. Previous performance tests (conducted since December 22, 2002) may be used to establish operating limits.
Monitoring of capture system and control device operating parameters is required to demonstrate continuous compliance with the operating limits. These requirements include bag leak detection systems for baghouses and continuous parameter monitoring systems (CPMS) for capture systems (unless damper positions are fixed) and control devices. For wet acid scrubbers, the final rule allows plants to measure the pH every 8 hours during process operations using a pH probe and meter as an alternative to a pH CPMS. The owner or operator of automated conveyor and pallet cooling lines or automated shakeout lines that use a sand mold system at a new iron and steel foundry must monitor organic HAP emissions using a CEMS unless they apply for alternative monitoring requirements. Technical specifications, along with requirements for installation, operation, and maintenance of CPMS and CEMS, are included in the final rule. Records are required to document compliance with the monitoring, inspection, and maintenance requirements for monitoring equipment. The final rule requires performance tests every 5 years to demonstrate continuous compliance with the PM (or total metal HAP), VOHAP, and TEA emissions limits and every 6 months to demonstrate continuous compliance with the opacity limit for fugitive emissions. Subsequent performance tests are not required for foundries that demonstrate continuous compliance using a CEMS.
Work Practice Standards
No performance test is required to demonstrate initial compliance with the work practice standards. Foundries must certify that they have prepared the required plans, have installed a direct flame contact gas fired scrap preheater if applicable (or that they will comply by meeting the 20 ppmv emissions limit or by only preheating scrap that meets the scrap certification requirements), that they will meet each applicable work practice requirement, and that they have records documenting their certification.
Records are required to demonstrate continuous compliance with compliance certifications or to document conformance with their scrap inspection and selection plan. Foundries also must keep records of the chemical composition of all catalyst binder formulations applied in a furan warm box mold or core making line.
Operation and Maintenance Requirements
Foundries must certify in their notification of compliance status
that they have prepared the O&M plan and that the plant will operate
equipment according to the plan requirements. Records are required to
demonstrate continuous compliance with other requirements in the O&M
plan for capture systems, control devices, and bag leak detection
system corrective actions. To demonstrate continuous compliance with
the plan for mold vent ignition, foundries must make a compliance
certification in each semiannual report that they have followed the procedures in their O&M plan.
E. What Are the Notification, Recordkeeping, and Reporting Requirements?
These requirements rely on the NESHAP General Provisions in 40 CFR part 63, subpart A. Table 1 to subpart EEEEE (the final rule) shows each of the requirements in the General Provisions (Sec. Sec. 63.1 through 63.15) and whether they apply.
The major notifications include onetime notifications of applicability (due no later than 120 days of promulgation), performance tests (due at least 60 days before each test), performance evaluations, and compliance status. The notification of compliance status is required no later than 60 days after the compliance demonstration if a performance test is required or no later than 30 days after the compliance demonstration if no performance test is required.
Foundries are required to maintain records that are needed to document compliance, such as performance test results; copies of the startup, shutdown, and malfunction plan; O&M plan; scrap selection and inspection plan, and associated corrective action records; monitoring data; and inspection records. Records of annual usage, chemical composition, and HAP content are also required for chemical binders and coating materials. In most cases, records must be kept for 5 years, with records for the most recent 2 years kept onsite. However, the O&M plan; scrap selection and inspection plan; and startup, shutdown, and malfunction plan are to be kept onsite and available for inspection for the life of the affected source (or until the affected source is no longer subject to the rule requirements.)
All foundries must make semiannual compliance reports of any deviation from an emissions limitation (including an operating limit), work practice standard, or O&M requirement. If no deviation occurred and no monitoring systems were out of control, only a summary report is required. More detailed information is required in the report if a deviation did occur. An immediate report is required if actions taken during a startup, shutdown, or malfunction were not consistent with the startup, shutdown, and malfunction plan.
F. What Are the Compliance Deadlines?
Existing iron and steel foundries must comply with most
requirements by April 23, 2007. The final rule requires existing
foundries to comply with the work practice standards in Sec. 63.7700(b)
[[Page 21910]]
or (c), as applicable, by April 22, 2005. New or reconstructed iron and
steel foundries that start up on or before April 22, 2004 must comply
by April 22, 2004. New or reconstructed iron and steel foundries that
start up after April 22, 2004 must comply upon initial startup.
III. Summary of Environmental, Energy, and Economic Impacts A. What Are the Air Quality Impacts?
Most iron and steel foundries have had emissions controls in place
for many years similar to those in the final rule. Overall, we expect
the final rule to reduce HAP emissions by more than 820 tpy. The NESHAP will also reduce PM and VOC emissions by about 2,550 tpy.
Implementation of scrap selection and inspection procedures is expected
to reduce mercury emissions by 1.4 tpyan 80 percent reduction from current levels.
B. What Are the Cost Impacts?
The total annualized cost of the final rule is estimated at $21 million, including costs for control equipment, compliance tests monitoring, recordkeeping, and reporting. This cost also includes the annualized cost of capital and the annual operating and maintenance costs for supplies, control equipment, monitoring devices, and recordkeeping media.
The nationwide total capital cost of the final rule is about $188
million. The capital costs associated with the final rule are primarily
due to the costs of installing modular pulsejet baghouse systems to
control emissions of metal HAP and PM from cupolas currently controlled
using venturi scrubbers. This capital cost is estimated at $175 million
and includes the cost of removing the venturi scrubbers and installing
modular pulsejet baghouse systems. Based on information provided by
the iron and steel foundry industry, we used a retrofit cost factor of
2.2 (i.e., the cost of installing a baghouse at an existing facility
was estimated to be 2.2 times the cost of installing an identical
baghouse at a new facility). This retrofit cost factor is considerably
higher than the typical retrofit costs suggested by the literature
(typical retrofit cost factors range from 1.2 to 1.5). As the cost of
operating a baghouse is less than the cost of operating a PM wet
scrubber due to lower energy consumption (lower pressure drop) of the
baghouse system and the avoidance of wastewater treatment/disposal
costs, the annual operating and maintenance cost of the final rule is
actually estimated to be less than the cost of operating the current
control equipment for cupolas. Therefore, there will be a net savings
in the annual operating and maintenance costs for baghouses over venturi scrubbers of $6 million.
The cost impacts also include:
C. What Are the Economic Impacts?
We conducted a detailed assessment of the economic impacts associated with the final rule. The compliance costs are estimated to increase the price of iron and steel castings by 0.1 percent with domestic production declining by 8,400 tons in aggregate. The analysis also indicates no impact on the market price for foundry coke, which is used by cupolas in the production of iron castings. Foundry coke production is projected to decrease by less than 0.1 percent.
Through the market impacts described above, the final rule is
predicted to have distributional impacts across producers and consumers
of iron and steel castings. Consumers would incur $13.2 million of the
overall regulatory burden of the final rule ($21.2 million) because of
higher prices and forgone consumption. Domestic producers of iron and
steel castings are expected to experience profit losses of $9.0 million
due to compliance costs and lower output levels, while foreign
producers may experience profit gains of $1 million associated with the
higher prices. For more information, consult the economic impact analysis that is available in the docket.
D. What Are the NonAir Health, Environmental, and Energy Impacts?
The final rule will generally provide positive secondary
environmental and energy impacts. Replacing cupola wet scrubber control
systems with baghouses will increase emissions of sulfur oxides by 370
tpy. However, due to the lower energy requirements for operating a
baghouse versus a wet scrubber, which more than offset the energy
requirements of the other new control equipment, the final rule is
projected to result in a net reduction in annual energy consumption of
121,000 megawatt hours per year. This will lead to a reduction in
emissions of nitrogen oxides and sulfur oxides from power plants of
roughly 180 tpy and 370 tpy, respectively. Therefore, the final rule
will have no net impact on emissions of sulfur oxides. There is
uncertainty about the estimates of secondary emission reductions due to
energy savings because we have not conducted a detailed analysis that
identifies the fuel sources used at power plants from which the energy
savings will be realized. Furthermore, the SO
IV. Summary of Major Comments and Responses
A. Why Did We Revise the Proposed Affected Source Designation?
Comment: Industry commenters felt the metal casting department should be separated into two separate affected sources: a melting department and a casting department. The commenters also suggested that we clarify that a foundry may contain multiple affected sources of a single type, such as more than one melting department, which may be operationally different and physically removed from each other. Some commenters felt that HAP emissions from melting are insignificant and suggested that this process either be excluded as an affected source or listed as a separate source category and then delisted.
Response: We considered splitting the metal casting department into
a melting department and a casting processing department. This further
classification of the affected sources might have been appropriate
because the melting furnaces (melting department) are often separate
from the pouring, cooling, and shakeout lines (casting processing
department). However, most commenters requesting a change in the [[Page 21911]]
affected source or separate source categories thought that we could
then either delist melting departments or that the emissions from the
melting department could be excluded from emissions limitations. Even
if the melting department were a separate source category or affected
source, these sources would still be colocated at major source
facilities, and we would still be required to develop MACT standards
for them. Furthermore, we do not consider emissions exceeding 100 tpy
of metal HAP from melting furnaces to be de minimis as suggested by
industry. Consequently, it is necessary and appropriate to establish MACT standards for these emissions sources.
A secondary rationale for requesting a change in the affected source was the fear of triggering new source MACT requirements. However, upon clarification that defining the melting department as a separate source would not eliminate the requirements to control melting furnace emissions, these commenters supported a broad definition of the affected source.
Therefore, in response to these comments, we have written the final
rule to include a broader definition of the affected source (i.e., the
iron and steel foundry). This broad definition eliminates a somewhat
artificial separation of the mold and core making processes, which can
often occur in close proximity, if not in conjunction with the casting
(pouring) operations. This approach also avoids instances where an
existing foundry might make minor equipment changes that might subject
one process or a single piece of equipment subject to the new source
emissions limits. This could occur if the affected source was defined
as each ``metal melting department'' which could be delineated as each melting furnace at the foundry.
B. Why Did We Revise the Proposed Emissions Limits?
Metal Melting Furnaces
Comment: Most industry commenters opposed the proposed PM limit for melting furnaces and scrap preheaters, especially at a new affected source (i.e., the 0.001 gr/dscf). According to the commenters, the limit cannot be maintained on a continuous basis, will not be guaranteed by vendors, will result in high costs, will be subject to measurements errors, and stretches the capability of Method 5 (40 CFR part 60, appendix A). Several commenters stated that the emissions reductions that would be achieved did not warrant the costs associated with the PM limits. Five commenters stated that the MACT floor determination did not adequately account for inherent variability and operation under the worst foreseeable conditions. Another commenter stated that it was inappropriate to apply any variablity factor in establishing the MACT floor emissions limits. One commenter noted that a limit based on the 95th percentile of performance would suggest that the unit is out of compliance 5 percent of the time.
Several commenters stated that the EPA should not specify the control equipment in establishing the new source PM emissions limits, that the facility EPA used for new source MACT for cupolas was not representative, or that the more stringent limit was a disincentive to modernize plants. Two commenters noted that the vendor guarantee for the facility is 0.0016 gr/dscf (instead of 0.001 gr/dscf as reported by EPA) because the guarantee was 0.001 in grains per actual cubic feet. While two equipment vendors stated that they could not guarantee a long term performance of 0.001 gr/dscf, a representative for control device vendors stated that the 0.001 gr/dscf PM emissions limit for new sources is reasonable and appropriate and that a variety of fabric collector designs can achieve similar results. Most commenters recommended a limit of 0.005 gr/dscf or 0.0052 gr/dscf (which was proposed as the limit for certain new operations at integrated iron and steel plants). One commenter suggested a limit of 0.002 gr/dscf because baghouses achieving an average outlet PM concentration of 0.001 gr/dscf would be out of compliance with a limit of 0.001 gr/dscf about half the time.
Response: The CAA directs EPA to set limits that are at least as stringent as the MACT floor. For existing units, the MACT floor is the average emissions limitation achieved in practice by the best performing 12 percent of the existing units (for which we have emissions information). The MACT floor for new sources must not be less stringent than the emission control that is achieved in practice by the bestcontrolled similar source. Consequently, the comments related to vendor guarantees and high costs are not relevant in establishing the MACT floor for new and existing sources.
We disagree that the limit will result in significant measurement errors or that it stretches the capability of Method 5 (40 CFR part 60, appendix A). We require a minimum gas volume of 60 dry standard cubic feet (dscf) to ensure that sufficient PM is collected to evaluate the compliance of the emissions source with the PM emissions limits. In addition, the practical quantification limit for Method 5 is a filterable PM catch of 3 milligrams (mg), which is 0.0463 grains (gr). At the practical quantification limit of 3 mg of PM collected from 60 dscf of gas, the practical quantification limit of Method 5 as required in the rule is less than 0.0008 gr/dscf. If less than 3 mg of dust is collected during a test in which at least 60 dscf of gas are collected, we have reasonable assurance that the emissions source is in compliance with a 0.001 gr/dscf PM emissions limit. Without a minimum gas volume of 60 dscf, we could not confidently establish that an emissions source meets the 0.001 gr/dscf emissions limit.
As noted by the commenters, the emissions limits must be achieved at all times, and it is important that the MACT floor limit adequately account for the normal and unavoidable variability in the process and in the operation of the control device. The choice of selecting the 90th, 95th, or 99th percentile performance value depends largely on the adequacy of the data. As there were only 10 to 15 emissions tests for a given type of unit or source with which to assess the performance and variability of baghouse control systems, selecting a higher percentile range is appropriate to reflect additional uncertainty. In response to comments concerning the potential variability in process and control system performance and in recognition of the fact that the available emissions data are from a fairly limited number of shortterm tests, we have reevaluated the MACT floor determination using the 99th percentile of performance. This approach is designed to account for the different sources of variability, including variations in how the process is operated, changes in control device parameters, and variability associated with sampling and analysis.
By selecting the 99th percentile, we have sufficiently accounted for process operation, control device performance, and measurement variability. The 99th percentile is appropriate in this case because it accounts for the extreme end of the range of performance that could occur. Based on this reevaluation of the MACT floor limits, we have adjusted the floor for cupolas at existing sources from 0.005 gr/dscf to 0.006 gr/dscf. We have adjusted the floor for cupola and electric arc furnaces at new sources from 0.001 gr/dscf to 0.002 gr/dscf. This new source limit of 0.002 gr/dscf is consistent with the vendor guarantee when corrected from actual to standard conditions (0.0016 gr/ dscf).
We do not believe that setting a limit at the 95th or 99th percentile means that the emissions source will be out of
[[Page 21912]]
compliance 5 percent or 1 percent of the time. Through proper operation
and maintenance of the control device and process equipment, the owner
or operator can avoid periods of poor performance. As such, a properly
operated and maintained control device applied to normal process
operations should not experience performance levels that exceed the
limit. In the rare event of an unavoidable failure such as a
malfunction, the owner or operator can continue to demonstrate
compliance by following the procedures in the startup, shutdown, and
malfunction plan. If the limit is exceed as a result of variability
that can and should be controlled (i.e., a preventable event), then the event is a deviation.
We understand industry concerns over the representativeness of the test data for one of the foundries that was mentioned. Fortunately, emissions test data are available for an equivalent control system that does not control an additional process which might dilute the emissions. The performance level for this system is also a PM emissions limit of 0.002 gr/dscf. Consequently, the limit for new sources is not dependent only on the source test data from the one facility cited by the commenters.
Unlike cupolas and electric arc furnaces, the furnace control system that represents MACT for electric induction furnaces at new sources is a traditional baghouse, followed by a cartridge filter, followed by a high energy particulate air filter. The limit for this system is still 0.001 gr/dscf when evaluated at the 99th percentile. Therefore, the data clearly support that MACT for electric induction furnaces at new sources is 0.001 gr/dscf.
In the final rule, we have established emissions limits for the emissions sources and do not require a specific type of control device. Foundry owners or operators may use any control measure that will meet the applicable standard. In trying to understand the differences in the performance achieved by certain systems, we evaluated and compared baghouse design, cleaning mechanism, flow rate, temperature, fabric material, and airtocloth ratio for each system as operated during the emissions source test. Certainly a number of these factors influence the performance of a fabric filter control system. In evaluating the performance of the cupola control systems, the horizontallydesigned baghouses exhibited the best performance of the systems tested. The description regarding these systems was provided primarily to document why the low outlet PM concentrations observed were real and not the result of an unknown source testing error. We do not endorse any specific baghouse design.
Because the affected sources will be required to comply with the emissions limits at all times, the limits established must account for the normal and unavoidable variability inherent in the process and in the control device operation. The emissions rate for a given emissions source does vary over time, as is demonstrated by the variability seen between individual test runs and repeat tests. As such, the MACT floor should not be developed based on the stack test data without accounting for variability. For each facility for which we have stack test emissions data, we have estimated the emissions limitation that the facility can achieve on a continuous basis by applying statistics to the available emissions data to estimate the emissions rate that facility can achieve at least 99 percent of the time.
In summary, we have established emissions limits for both new and existing emissions sources and have not specified the type of control system that must be used. For cupolas and electric arc furnaces, MACT for new sources is 0.002 gr/dscf, reflecting the 99th percentile level of performance of the median unit in the top 12 percent of best performing units. The MACT floor for cupolas at existing foundries is 0.006 gr/dscf, reflecting the 99th percentile level of control of the median unit in the top 12 percent of bestperforming units. These limits reflect our conclusion that the proposed 0.001 gr/dscf limit for cupolas and electric arc furnaces at new foundries and the 0.005 gr/ dscf limit for cupolas at existing foundries did not adequately account for the variability expected in the actual performance of the units that were used to establish the MACT floor for these emissions sources. The 0.001 gr/dscf limit for electric induction furnaces and the 0.002 gr/dscf emissions limit for cupolas and electric arc furnaces at new foundries represent emissions limits that the bestperforming sources can and do meet under the most adverse circumstances which can reasonably be expected to recur.
Comment: Three commenters recommended that the final rule include emissions limits for individual metal HAP. The commenters suggested that PM is not a good surrogate for lead (which is a semivolatile metal) or mercury (which typically has low collection efficiencies in baghouses) and does not consider the hazard of the emitted pollutants. In addition, the metal HAP in the PM from some emissions sources comprise only a small portion of emissions from the emissions source or the overall foundry and has not been characterized for other emissions sources.
Response: As described in our MACT floor documentation, metal HAP emissions reductions tracked well with PM emissions reductions for the cupola control systems we tested. Reductions in lead emissions also tracked well with PM emissions reductions. Mercury emissions were a small component of the total metal HAP emissions, but both control systems tested by EPA were ineffective in reducing mercury emissions. Therefore, we do not consider these addon control devices to be control technologies for the purpose of reducing mercury emissions. The only effective method for reducing mercury emissions at iron and steel foundries is scrap metal selection and inspection to prevent mercury contamination of the furnace charge. For all other metal HAP emissions from metal melting furnaces, the test data show that effective PM emissions control also provides effective metal HAP emissions control. In addition, PM is a reasonable surrogate for metal HAP emissions control effectiveness because MACT is a technologybased standard, and the technologies currently used by foundries that reduce metal HAP emissions are those specifically designed to control PM. Additionally, it is clear from our data the greater the PM reductions are for a specific unit, the greater are the HAP reductions. Thus, we have concluded that it is appropriate to use PM as a surrogate for HAP metals because the unit that achieves the greatest level of control of PM will also achieve the greatest level of control of metal HAP. As discussed in the following response, we have also developed an alternative limit for total metal HAP. Finally, to the extent that it is feasible to reduce metal HAP emissions by means other than operation of emission control devices, we are requiring such measures. Specifically, we are requiring a scrap selection and inspection program to reduce lead and mercury emissions. These requirements combined with the PM limits accurately reflect the MACT level of control.
Comment: Two commenters oppose the use of PM as a surrogate because
some foundries melt only high quality steel with very low tramp metal
content in the induction furnaces rather than scrap iron. Consequently,
their uncontrolled melting furnaces may have lower HAP emissions than
those from a baghouse on a furnace melting scrap with higher levels of
tramp metals. We also received comments that some foundry operations, such as dry scrubbing for sulfur dioxide control,
[[Page 21913]]
may result in disproportionately high PM emissions without correspondingly high metal HAP emissions.
Response: As discussed in our previous response, PM is a good surrogate for HAP metals other than mercury. However, we recognize that the metal HAP content of the PM can vary significantly depending on the type of metal cast. Some foundries may have very low metal HAP emissions due to very low HAP content in their casting. We also recognize that it is infeasible for all foundries to use scrap with very low HAP metal content because of the limited supply of such scrap and because various levels of certain elements are needed in certain grades and types of iron and steel casting. Also, when foundries use scrubbing techniques for reducing sulfur dioxide emissions, they may have unusually high PM emissions without correspondingly high HAP emissions. Therefore, while PM is a good surrogate with which to judge the performance of a control system to reduce metal HAP emissions, we realize that it is only a surrogate and not a direct measure of HAP emissions, and that in some cases the PM limit may have unwarranted consequences. For the above reasons, we are establishing alternative total metal HAP emissions limits that are equivalent to the PM limits. The alternative metal HAP limits are based on, and are dependent on the MACT limits for PM.
Having identified the appropriate level of control based on PM performance, we reexamined our data on metal HAP emissions and evaluated the metal HAP emissions as a percent of the PM emissions. We evaluated metal HAP emissions to project the range of metal HAP emissions as a percent of PM associated with the performance of the type of control system used by the unit identified as the MACT floor emissions unit. That is, by normalizing the HAP emissions data by the PM emissions and aggregating these data for the various emissions sources being regulated, we calculated a reasonable estimate of the magnitude and variability of the HAP content as a percent of PM for these sources. By applying this information to the specific system that established the MACT floor PM emissions limits for each source type, we developed a total metal HAP emissions limit for each source type that is based on the performance of the MACT floor unit. Each total metal HAP limit is equivalent to the corresponding MACT floor PM emissions limit. We used this calculation to develop alternative limits for total metal HAP for melting furnaces and pouring operations.
The basis of this alternative emissions limit is the MACT floor determination for PM emissions. Because we lack sufficient test data for metal HAP, we could not otherwise derive a metal HAP emissions limit without first identifying the MACT floor unit on the basis of its PM emissions performance. Therefore, we concluded that this total metal HAP emissions limit is an alternative to the PM emissions limit, and not an additional MACT floor requirement.
We developed a distribution of the PM emissions for each emissions source based on the actual performance of the unit identified as the 6th percentile unit and the same 0.4 relative standard deviation used to determine the MACT floor performance limits. A separate distribution based on the available metal HAP emissions data was developed to characterize the total metal HAP content of the emitted PM. Using Monte Carlo techniques, 5,000 randomizations were generated for each of these distributions and the projected metal HAP emissions were calculated for each of the 5,000 randomizations. This is a common statistical approach for establishing a distribution for a parameter that is dependent on multiple, variable parameters.
As with the MACT floor determination of PM emissions performance, we selected the 99th percentile metal HAP concentrations determined from these distributions. These metal HAP emissions limits were equivalent to approximately 8 percent of the 99th percentile PM emissions limit (i.e., the MACT floor PM emissions limit) for each of the emissions sources. That is, this analysis indicated that the total metal HAP emissions limit that is equivalent to the MACT floor PM emissions limit can be calculated by multiplying the PM emissions limit by 0.08 (i.e., assuming the PM is 8 percent metal HAP). The final metal HAP emissions limits were rounded to one significant digit in keeping with the relative accuracy of the assessment.
As the identification of the unit that represents the MACT floor is solely dependent on the PM emissions performance, these metal HAP emissions limits do not represent a separate MACT floor that must be met at all emissions sources, but rather an alternative emissions limit that is equivalent to the MACT floor PM emissions limit. The alternative metal HAP emissions limits provide foundry operators with more flexibility in meeting the metal HAP emissions limits (for example, by adopting a scrap program that is more stringent than the MACT requirement, in conjunction with PM emissions controls to further reduce metal HAP emissions). This alternative also avoids, in some cases, the need for replacing wellperforming venturi wet scrubbers with high efficiency baghouses to achieve a required PM emissions reduction when other measures might be used to achieve the desired metal HAP emissions reduction. The alternative also accommodates facilities that may have disproportionate PM emissions but low HAP emissions, as in the case for dry scrubbers used to control sulfur dioxide.
Comment: More than twenty industry commenters opposed the proposed carbon monoxide (CO) emissions limit for cupolas (200 ppmv). Several of these commenters stated that CO data from CEMS and CO monitors show that the limit cannot be achieved. They explained that the cupola operation is a dynamic process that is affected by changes in the melt rate and iron chemistry, which requires the CO combustor to adjust and seek a new equilibrium; CO concentrations are highly variable even in the best afterburner systems. The material being melted, coke sources, and seasonal adjustments also affect CO emissions. One vendor stated that his company could not guarantee equipment that can meet the 200 ppmv CO emissions limit. The commenters also suggested that the CO limit is based on the Illinois emissions standard, which was found to be improperly derived and never enforced.
Five commenters stated that EPA failed to provide sufficient data that maintaining a CO concentration of 200 ppmv is an effective surrogate for organic HAP destruction, while two commenters supported the use of CO as a surrogate for HAP. One commenter asked why VOC was not used as the surrogate for organic HAP emissions from the cupolas.
Response: The proposed CO emissions limit was based upon the
emissions source test data for CO emissions from cupolas; it was not
based upon the Illinois CO emissions limit. Two of the CO emissions
tests used to develop the 200 ppm CO emissions limit were from
foundries located in New Jersey, where CO CEMS are required. Therefore,
EPA requested CO CEMS emissions data from these foundries to verify the
performance of these systems and to better understand the variability
associated with the process. Data were received from one of these
foundries which supported the assertion that the 200 ppmv limit did not
adequately accommodate the variability in the process operations and
control device performance. Additionally, emissions test data were [[Page 21914]]
also received from a cupolaafterburner system that measured CO and VOC
(minus methane) emissions concurrently. For the individual runs of this
test, the average outlet CO concentrations were 701, 1470, and 849
ppmv, while the average VOC emissions were 3.4, 4.2 and 5.1 ppmv as
propane. This limited data supports the industry commenters' assertion
that organic HAP emissions (as indicated by VOC emissions) are not well
correlated, although there is a limited range of CO and VOC emissions considered in this single emissions test.
As discussed in the preamble to the proposed rule, CO is an indicator of good (complete) combustion, but, at some lower level of CO, further reductions in CO concentrations do not necessarily result in further reductions of organic HAP. That is, we recognize that CO is not a perfect surrogate for organic HAP emissions from the best performing units, but it is a surrogate for which emissions data were available and one that provides a reasonable indication of adequate combustion characteristics. However, based on the comments and the additional data received, we agree that we do not have sufficient data to support the establishment of a specific CO concentration limit as a surrogate for the organic HAP emissions performance of a cupola afterburner system.
We reviewed the submitted data and other data in the docket for VOC and organic HAP for the bestcontrolled cupolas (those using afterburners). These data are too limited to identify the level of performance of the bestperforming units or to establish a specific organic HAP or VOC emissions limit. Therefore, we rely on our experience with the performance of thermal destruction systems such as these afterburners. This experience clearly indicates that these units should be able to meet a 98 percent destruction efficiency or an outlet concentration of 20 ppmv (as the chemical emitted), whichever is less stringent. However, due to safety issues associated with typical equipment configurations, sampling between the cupola chamber and the afterburner is impracticable and unsafe. Therefore, we provide only the 20 ppmv exhaust concentration alternative. The limited available data on organic HAP emissions from cupola afterburners suggest that the 20 ppmv emissions limit is achievable and reflects the level of performance of the best controlled units, and that the 98 percent reduction alternative is not needed for this application.
Furthermore, we establish this emissions limit as the sum of all volatile organic HAP (or VOHAP) emitted, thereby eliminating the need to select a surrogate. However to provide flexibility in conducting the performance tests, we are providing compliance alternatives to allow for demonstration of compliance using test methods to measure TGNMO or TOC concentrations (in ppmv as hexane). These test method alternatives will measure both HAP and nonHAP compounds, and will, therefore, ensure that a unit is meeting an emissions level as stringent or more stringent than the VOHAP emissions limit. However, these test methods are cheaper and easier to perform, and therefore, these options may be desirable for some sources. Hexane was selected for the concentration equivalency because the primary HAP expected to be emitted are C6 hydrocarbons or higher (e.g., benzene, toluene, and xylenes).
Comment: While one commenter supported the proposed rule requirement for direct measurement of CO emissions from cupolas using a CEMS, many industry commenters were opposed. They argued that the final rule should include an operating limit for the afterburner temperature measured by a CPMS. According to the commenters, a CO CEMS is not technically feasible or reliable because of the harsh conditions of the gas stream, and it is costly while achieving minimal benefit.
Response: We have deleted the requirement for a CO CEMS from the final rule because the CO limit has been replaced by a limit for VOHAP emissions. The autoignition temperature of the organic HAP present in the cupola exhaust stream (primarily benzene, toluene, and xylenes) is lower than the autoignition temperature of CO, which is 1,300 [deg]F. Therefore, an adequately designed afterburner operating at a minimum of 1,300 [deg]F will effectively ensure combustion of the organic HAP. Once a performance test indicates that the cupola afterburner is sufficiently engineered (in terms of excess air flow, residence time and mixing) to achieve the required VOHAP emissions limit, then continuous monitoring of combustion zone temperature will provide adequate assurance of continuous compliance. Therefore, we require foundry operators to install and operate a CPMS for combustion zone temperature, and we require that the 15minute average combustion zone temperature must not fall below 1,300 [deg]F. Periods when the cupola is off blast and for 15 minutes after going on blast from an off blast condition are not included in the 15minute average.
Comment: Several industry commenters objected to the proposed VOC emissions limit for scrap preheaters (20 ppmv as propane or 98 percent reduction). The commenters contended that the VOC limit based on afterburning technology does not meet the requirements for determining the MACT floor because only 4 or 5 of 169 preheaters nationwide (3 percent) currently use afterburners. The commenters stated that there is no basis for the proposed limit, there are no data indicating the presence of organic HAP in preheater emissions, and improvements in direct flame preheaters have made the afterburners an outdated technology. Commenters also stated the existing units cannot achieve 20 ppmv because of process variability and the likely presence of uncombusted methane from the preheater, which can contribute significantly to the VOC concentration, especially when measured as propane.
Response: Based on the information available at the time the proposed rule was developed, it appeared that more than 6 percent of the scrap preheaters were controlled by afterburners. However, we have confirmed that, as the commenters suggested, one foundry that had reported using afterburners had subsequently upgraded their material handling system and installed direct flame preheater systems. With this change, the median of the top 12 percent of units is no longer a unit using an afterburner, but a unit using a direct flame preheater.
There are two basic types of preheater designs: direct flame contact preheaters and hot gas flow preheaters. Direct flame contact preheaters primarily use gasfired burners where the flame impinges on the scrap. The primary heating mechanism for direct flame contact preheaters is the burner flames contacting the scrap. Hot gas flow preheaters may use gasfired burners or electricity to heat air and the hot air (and combustion gases from the burner, if applicable) is used to preheat the scrap. In hot gas flow preheaters, the scrap is not heated by direct contact with a high temperature flame. Preheaters are used primarily to remove water and organic contaminants that could cause explosions or other hazards when the scrap is melted in induction furnaces. Although both types of preheaters are effective for this purpose, the different preheater designs have different HAP emissions potentials.
For preheaters generally, we require a scrap selection and
inspection program to limit, to the extent practicable, the amount of
organic HAP precursors (i.e., oils and other organic liquids) entering [[Page 21915]]
a scrap preheater, and we are establishing a work practice standard to
require either preheaters with direct flame contact or application of
an afterburner. Because the scrap selection and inspection program
cannot completely exclude the potential presence of tramp organic
materials, scrap preheaters are a potential source of organic HAP
emissions. Furthermore, we could not identify specific scrap selection
and inspection programs for these types of scrap materials that would
be more effective than those proposed. Therefore, the primary variable
affecting the organic HAP emissions from scrap preheaters is the
pr
FOR FURTHER INFORMATION CONTACT Kevin Cavender, Metals Group (C439-
02), Emission Standards Division, Office of Air Quality Planning and
Standards, U.S. EPA, Research Triangle Park, NC 27711, telephone number
(919) 5412364, electronic mail (email) address,
cavender.kevin@epa.gov.
Common CFR Searches
14 CFR Part 39 40 CFR Part 52 14 CFR Part 71 33 CFR Part 165 50 CFR Part 679 26 CFR Part 1 40 CFR Part 180 47 CFR Part 73 50 CFR Part 17 33 CFR Part 117 44 CFR Part 67 50 CFR Part 648 14 CFR Part 97 33 CFR Part 100 40 CFR Part 63 50 CFR Part 622 26 CFR Part 301 39 CFR Part 111 40 CFR Part 300 50 CFR Part 660 44 CFR Part 65 40 CFR Parts 52 and 81 40 CFR Part 271 47 CFR Part 64 50 CFR Part 665 47 CFR Part 76 50 CFR Part 229 14 CFR Part 23 14 CFR Part 25 21 CFR Part 522