Section 112 requires us to establish a minimum baseline or ``floor'' for standards. For new sources, the standards for a source category or subcategory cannot be less stringent than the emission control that is achieved in practice by the bestcontrolled similar source. The standards for existing sources can be less stringent than the standards for new sources, but they cannot be less stringent than the average emission limitation achieved by the bestperforming 12 percent of existing sources for categories and subcategories with 30 or more sources. For categories and subcategories with fewer than 30 sources, the standards cannot be less stringent than the average emission limitation achieved by the bestperforming five sources.

Section 112(d) allows us to distinguish among classes, types, and sizes of sources within a category or subcategory. For example, we can establish two classes of sources within a category or subcategory based on size and establish a different emission standard for each class.

For NESHAP developed to date, we have used several different approaches to determine the MACT floor for individual source categories depending on the type, quality, and applicability of available data. These approaches include determining a MACT floor based on: (1) emissions test data that characterize actual HAP emissions from presently controlled sources included in the source category; (2) existing federallyenforceable emission limitations specified in air regulations and facility air permits applicable to the individual sources comprising the source category; and (3) application of a specific type of control technology for air emissions currently being used by sources in the source category or by sources with similar pollutant stream characteristics.

To select the MACT standard, we evaluate several alternatives (which may be different levels of emission control or different levels of applicability or both) to select the one that best reflects the appropriate MACT level. The selected alternative may be more stringent than the MACT floor, but the control level selected must be technically achievable. In selecting an alternative, we consider the achievable HAP emission reduction (and possibly other pollutants that are co controlled), cost and economic impacts, energy impacts, and other environmental impacts. The objective is to achieve the maximum degree of emission reduction without
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unreasonable economic or other impacts. The regulatory alternatives selected for new and existing sources may be different, and separate regulatory decisions may be made for new and existing sources.

We then translate the selected regulatory alternative into a proposed rule. The public is invited to comment on the proposal during the public comment period. Based on an evaluation of these comments, we reach a final decision and promulgate the standard.

C. What Source Category Is Affected by This Proposed Rule?

Section 112 of the CAA requires us to list all categories of major HAP emitting sources and to promulgate regulations for their control. An initial list of source categories and accompanying schedules for regulation were published on December 3, 1993 (58 FR 63941). Friction materials manufacturing was not among the initially listed source categories. A subsequent notice published on June 4, 1996 (61 FR 28197) added friction products manufacturing to the list of major source categories scheduled for regulation by November 15, 2000. The listing was based on information obtained in a 1992 survey of the industry from which we concluded that some facilities that manufacture friction products have the potential to be major sources of HAP emissions. Friction products manufacturing includes facilities that manufacture, assemble, or rebuild friction products such as brakes or clutches. Based on additional information obtained during the development of this proposed rule, we have determined that only facilities that manufacture friction materials have the potential to emit HAP at major source levels. As such, this proposed rule will affect only friction materials manufacturers. The next revision to the source category list under section 112, which is published in the Federal Register, will remove the friction products manufacturing source category and add the friction material manufacturing source category.

D. What Is Friction Materials Manufacturing?

Friction materials manufacturing is a subset of friction products manufacturing. Broadly speaking, the friction products manufacturing industry includes any facility that manufactures or remanufactures friction products such as brakes and clutches. Friction products are used in a number of market segments, including automotive, aerospace, railroad, heavy equipment, industrial, appliance, and lawn and garden. We know of 147 domestic friction products manufacturing facilities. Of these, 16 only assemble new products, 78 rebuild or otherwise recondition products, and 53 manufacture friction materials (e.g., brake and clutch linings). Assemblers purchase new friction materials from other manufacturers and attach it to new backing plates or shoes. Rebuilders purchase new friction materials from other manufacturers and attach it to reconditioned brake shoes or clutch plates. None of these facilities manufacture friction materials and none are major sources of HAP. Consequently, none of these facilities would be regulated under today's proposed rule.

Friction materials manufacturers make brake and clutch linings and, in most cases, assemble finished products. They can be classified into three classes based on the friction materials manufactured: sintered material, carbonbased material, and resinbased material.

Two facilities manufacture sintered friction materials. Both use high temperature processes to fuse nonHAP metal and mineral ingredients into a consolidated product. Neither facility is believed to be a major source of HAP, and, therefore, neither would be regulated under today's proposal.

Four facilities manufacture carbonbased friction products in which carbon is impregnated into a synthetic mesh to create a friction material. Hydrogen cyanide is the only HAP known to be emitted in the process. All four existing facilities have federally enforceable control requirements that limit hydrogen cyanide emissions to well below the major source threshold of 10 tpy. In addition, we do not anticipate that any new carbonbased facilities will be built. As a result, manufacturers of carbonbased friction products will not be regulated under today's proposed rule.

Fortyseven facilities manufacture resinbased friction materials. At these facilities, friction ingredients are mixed with resins which, when cured, bind the friction ingredients together. In most cases, mixing can be done without the aid of a solvent. However, for some friction materials, solvents are needed to enhance mixing and as a process aid in later stages. Of the 47 facilities that manufacture resinbased friction materials, only four use solvents to mix friction materials. All four are believed to be major sources of HAP due to air releases of the solvents used. The HAPcontaining solvents used include nhexane, toluene, and trichloroethylene.

Based on our review, we believe that solvent mixing is the only significant HAP emission source associated with friction material manufacturing.\1\ As such, today's proposed rule establishes emission limitations for HAP emissions only for solvent mixers at new and existing sources that manufacture resinbased friction materials. \1\ Two additional resinbased manufacturers are believed to be major sources. However, both are major due primarily to HAP emissions from ancillary surface coating and degreasing operations, which either are or will be regulated under other NESHAP. These two resinbased manufacturers have no solvent mixers, and as such, are not included in the MACT floor analysis for solvent mixers.

The principal operations used in the manufacture of resinbased friction materials can be classified into four general areas: raw material preparation, forming, curing, and assembling and finishing.

In the raw material preparation area, raw materials (reinforcement material, property modifiers, resins, solvents, and other additives) are blended and made ready for subsequent processing. Process units in the raw material preparation area include mixers, granulators, and dryers. Mixing is accomplished in discrete batches. Doublearm mixers are the most common type of mixer used. A typical batch includes between 300 to 1000 pounds of friction ingredients and takes between 20 minutes and 1 hour to mix. Batches of mixed friction material may then be processed further through a granulator which extrudes the material through a \1/4\ to \1/2\ inch die, and then cuts the extruded material into \1/2\ to 1 inch lengths. Some facilities also dry the friction material after mixing, but before the forming step, to remove any remaining solvent from the material mix. The dryer is typically an indirect type which dries the material mix by contact and heat transfer through the dryer wall. Typical drying temperatures are on the order of 150 deg.F.

The blended and prepared friction material is then transferred from the raw material preparation area to the forming area, where the material is formed into shapes. Forming equipment includes extruders, roll machines, and hot presses. Extruders are used to form tapes and pellets of friction material. Pellets are formed by forcing the moist friction material through perforations in a metal die and cutting the continuously formed strands to a predetermined length. Tapes are formed by forcing the friction material through a metal die with an appropriatelyshaped slot in a heated extruder head. Roll machines are used to form flat, pliable tapes, similar
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to those produced by an extruder, and are also used to produce wider sheets of friction material. The moist friction material is metered between a series of rollers which form a continuous strip of friction material with a preset width and thickness. Hot presses are used to form disc brake pucks, integrallymolded disc brake pads, brake segments, and brake blocks. Hot presses apply heat and pressure over time to consolidate the friction mix into a solid product. Premeasured quantities of friction mix are poured into each press cavity. As heat and pressure are applied, the material is partially cured.

After the friction shapes are formed, they are cured in a curing oven or post bake oven. Curing times and temperatures vary with product size and composition. Curing times range from 1 hour to 2 days, but typically run about 12 hours. Oven temperatures ramp up and then down over the curing cycle and range from 180 to 500 deg.F. Once the friction material is formed and cured, it is finished and subsequently assembled with some type of metal backing. Finishing operations bring the friction product to final specifications. These operations include machining, painting, and edge coding. Assembly operations include steel preparation (i.e, degreasing), adhesive application, oven bonding, riveting, and attachment of hardware (e.g., mounting brackets, wear sensors, and noise suppressors).
E. What HAP Are Emitted From Friction Materials Manufacturing Facilities?

The nature and quantity of HAP emissions from the manufacturing of friction materials is driven almost entirely by whether HAP containing solvents are used in mixing. The primary HAP emitted from the major source friction materials manufacturing facilities are HAP solvents from mixing operations. Currently, these include nhexane, toluene, and trichloroethylene. The main sources of these HAP emissions are the solvent mixers themselves. Other potential sources of HAP solvent emissions include granulators, dryers, extruders, roll machines, hot presses, and ovens.

Emissions from mixers can occur as solvent is added to the mixer, during the mixing cycle, and as fugitive emissions when the mixed material is transferred from the mixer to the next and subsequent process operations. The type and quantity of organic HAP emissions from solvent mixers varies depending on the type of solvent used, the amount of solvent used per batch, the configuration of the mixer, and the presence or absence of a solvent recovery system. Three of the seven solvent mixers are equipped with solvent recovery systems designed to minimize HAP emissions and to reclaim solvent for reuse. For these mixers, the solvent is removed from the mixed material by vacuum evaporation and collected in either a condenser or a carbon adsorber. The reclaimed solvent is recycled and reused in the process or sold as reclaimed solvent.

Residual solvent that is not recovered or emitted at the solvent mixer can be emitted in subsequent processes as the friction material is processed through extruders, roll machines, granulators, dryers, hot presses, and ovens. The potential for emissions from these downstream processes is proportional to the quantity of residual solvent retained in the friction material after mixing.

Small amounts of phenol and formaldehyde (HAP components of phenolic resins) are emitted from hot presses and curing ovens or otherwise subject to methods of emission reductions. At the four major HAP sources, phenol and formaldehyde emissions account for less than 5 percent of the total HAP emitted. None of the existing hot presses or curing ovens at the four major sources are equipped with HAP emission controls. Available test data indicate that the phenol and formaldehyde emissions are on the order of 5 parts per million (ppm) or less, which is well below the level which can effectively be controlled by add on controls or any other methods of emissions reductions.
F. What Are the Health Effects Associated With Emissions From Friction Materials Manufacturing Facilities?

The primary HAP that would be addressed by this proposed rule include nhexane, toluene, and trichloroethylene. Each are associated with a variety of adverse health effects, including chronic health disorders (e.g., reproductive and developmental effects, and effects on the central nervous system (CNS)), and acute health disorders (e.g., irritation of the lung, skin, and mucus membranes and effects on the CNS, liver, and kidneys).

Acute inhalation exposure of humans to high levels of hexane causes mild CNS effects, including dizziness, giddiness, slight nausea, and headache. Chronic exposure to hexane in air causes numbness in the extremities, muscular weakness, blurred vision, headache, and fatigue. One study reported testicular damage in rats exposed to hexane through inhalation. No information is available on the carcinogenic effects of hexane in humans or animals. We have classified hexane in Group D, not classifiable as to human carcinogenicity.

Acute and chronic inhalation exposure to trichloroethylene can affect the human CNS, producing symptoms such as dizziness, headache, confusion, euphoria, facial numbness, and weakness. High, shortterm exposures to humans by inhalation have also been associated with effects on the liver, kidneys, gastrointestinal system, and skin. Human evidence is not adequate to establish a causal link between trichloroethylene exposure and cancer, but animal inhalation studies have reported increases in lung, liver, and testicular tumors. We have classified trichloroethylene as intermediate between probable and possible human carcinogen (Group B/C). We are currently reassessing its potential carcinogenicity.

Acute inhalation of toluene by humans may cause effects to the CNS, such as fatigue, sleepiness, headache, and nausea, as well as irregular heartbeat. Adverse CNS effects have been reported in chronic abusers exposed to high levels of toluene. Symptoms include tremors, decreased brain size, involuntary eye movements, and impaired speech, hearing, and vision. Chronic (longterm) inhalation exposure of humans to lower levels of toluene also causes irritation of the upper respiratory tract, eye irritation, sore throat, nausea, dizziness, headaches, and difficulty with sleep. Studies of children whose mothers were exposed to toluene by inhalation or mixed solvents during pregnancy have reported CNS problems, facial and limb abnormalities, and delayed development. However, these effects may not be attributable to toluene alone. We have classified toluene in Group D, not classifiable as to human carcinogenicity.
II. Summary of the Proposed Rule

A. What Is the Affected Source?

The affected source is each existing and new solvent mixer at a friction materials manufacturing facility that is, or is part of, a major source of HAP emissions. A new affected source is one constructed or reconstructed after October 4, 2001. An existing affected source is one constructed or reconstructed on or before October 4, 2001. B. What Is the Emission Limitation?

The proposed rule would require owners and operators of both new and existing affected solvent mixers to limit emissions of total organic HAP discharged to the atmosphere to 15
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percent or less of that loaded into an affected solvent mixer, based on a 7day block average.
C. What Are the Initial and Continuous Compliance Requirements?

Initial compliance would be determined by measuring and recording the weight of solvent added to each affected mixer and the weight of solvent recovered for each mix batch over the first 7 consecutive days after the compliance date. Initial compliance is demonstrated if the average amount of solvent discharged to the atmosphere recorded for each mix batch over the 7day period does not exceed 15 percent. The proposed rule also includes performance specifications for the weight measurement device as well as procedures for conducting the measurements and computing the results. To demonstrate continuous compliance, owners and operators would be required to continue to weigh and record the percent of solvent emitted for each mix batch and to maintain each 7day block average at or below 15 percent.
D. What Are the Notification, Recordkeeping, and Reporting Requirements?

The proposed notification, recordkeeping, and reporting requirements rely on the NESHAP General Provisions in 40 CFR part 63, subpart A. Table 1 in the proposed rule shows each of the requirements in the General Provisions (Secs. 63.2 through 63.15) and whether they apply.

Under today's proposed rule, owners or operators subject to these standards must submit each of the notifications contained in the General Provisions that applies to them. These include an initial notification of applicability, which for existing sources is required within 120 days of the promulgation date; and a notification of compliance status, which must be submitted before the close of business on the 30th calendar day following the completion of the initial compliance demonstration.

In addition, owners or operators subject to these standards would need to prepare and maintain all records required by the General Provisions to document compliance with each enforceable provision of the proposed rule. Records needed to show continuous compliance with the emission limitation in the proposed rule are to be kept for 5 years.

We are also requiring owners and operators of all affected sources to submit semiannual compliance reports which highlight any deviations from the emission limitation and other provisions of the proposed rule. Each report would be due no later than 30 days after the end of the reporting period. If no deviations occurred, owners and operators are only required to submit a statement that there were no deviations from the emission limitation during the reporting period. More detailed information would be required, as specified in the proposed rule, if a deviation occurred or there was a startup, shutdown, or malfunction event. Owners and operators must submit an immediate report if they undertake actions during a startup, shutdown, or malfunction that are inconsistent with the procedures in their approved startup, shutdown, and malfunction plan, required by Sec. 63.6(e)(3) of the General Provisions. Deviations that occur during a period of startup, shutdown, or malfunction are not violations if the owner or operator demonstrates to our satisfaction that the affected source was operating in accordance with the startup, shutdown, and malfunction plan. E. What Are the Compliance Deadlines?

Existing sources must comply within 2 years of the date of publication of the final rule. New or reconstructed sources must comply at startup, or upon the date of publication of the final rule, depending on their startup date.
III. Rationale for Selecting the Proposed Standards

A. How Did We Select the Source Category?

We added the friction products manufacturing source category to the list of major sources to be regulated under Title III on on June 4, 1996 (61 FR 28197) because we believed that a number of friction products manufacturers had the potential to emit HAP at major source levels. Friction products manufacturing includes facilities that manufacture, assemble, or rebuild friction products such as brakes or clutches. Based on additional information obtained during the development of this proposed rule, we have determined that only facilities that manufacture friction materials have the potential to emit HAP at major source levels. As such, we have selected friction materials manufacturing as the source category to regulate. B. How Did We Select the Affected Source?

Affected source means the collection of equipment and processes in the source category or subcategory to which the emission limitation and other regulatory requirements apply. The affected source may be the same collection of equipment and processes as the source category or it may be a subset of the source category. For each rule, we must decide which individual pieces of equipment and processes warrant separate standards in the context of the CAA section 112 requirements and the industry operating practices.

We considered two approaches for designating the affected source for friction materials manufacturingthe entire facility or individual emission sources. We concluded that designating individual solvent mixers as the affected source is the most appropriate approach. The solvent mixer is the only significant source of HAP emissions at the four major sources, and controlling individual solvent mixers is consistent with the approach to control applied at all four major sources. The affected source definition we selected is the same for both new and existing sources. We decided not to identify hot presses and curing ovens as affected sources because HAP emissions from these sources are very low, none of the existing hot presses and curing ovens are equipped with HAP controls, and we do not believe that hot presses and curing ovens at friction materials manufacturers can effectively be controlled by add on controls.

C. How Did We Select the Pollutants?

The HAP solvents currently used at the friction materials manufacturing facilities estimated to be major sources include n hexane, toluene, and trichloroethylene. Whether these specific solvents will continue to be used or whether they might in the future be replaced with other HAP solvents is uncertain. As such, we believe that establishing separate standards for individual solvents would be unwise. Consequently, we have selected HAP solvent emissions as a surrogate for the individual HAP compounds nhexane, toluene, and trichloroethylene.
D. How Did We Determine the Basis and Level of the Proposed Emission Limitation for Solvent Mixers?

As reported previously, we surveyed the entire friction materials manufacturing industry and determined that four facilities with solvent mixers emit HAP in excess of the major source levels. Combined, these four facilities (referred to here as Plants A, B, C, and D) operate a total of seven solvent mixers, of which three are equipped with air pollution controls, and four have no control.

Plant A operates one solvent mixer and uses toluene as the solvent. [[Page 50773]]
According to information on air releases reported by the plant to the 1998 Toxics Release Inventory (TRI), air emissions of toluene are on the order of 45 tons per year. After mixing, solvent is drawn out of the mixer under a strong vacuum. Data collected by plant personnel indicate that typically more than 95 percent of the solvent is removed from the mixed material, with less than 5 percent remaining in the mix. The evacuated solvent vapors are then condensed in a noncontact condenser, which cools the vapors to 32 deg.F. Liquid condensate is collected and recycled to the process, and uncondensed vapor is exhausted to the atmosphere through a stack.

Plant A has a State operating permit which requires that the facility collect at least 85 percent (by weight) of the solvent that is added to the mixer, averaged over a calender week. The percent solvent recovery is determined for each individual mix batch by weighing the amount of solvent loaded into the mixer and weighing the amount of solvent recovered by the condenser. Plant A began collecting solvent recovery data for each batch in January 1999. We reviewed the solvent recovery records from January 1999 through October 1999 and found that the 85 percent solvent recovery limit has been consistently achieved on a weekly, or 7day block average, basis.

Plant B has four solvent mixers that use nhexane as the solvent. Again, based on selfreported emissions data to TRI for 1998, Plant B emits approximately 450 tons of hexane annually. Three of the four mixers have no air pollution controls. All of the solvent added to these mixers is emitted to the atmosphere. The fourth mixer has a solvent recovery system similar to the one described for Plant A. Solvent is drawn out of the mixed material by vacuum. The solvent vapors are then collected by a noncontact condenser, which cools the solvent vapor to 60 deg.F. Once a quarter, Plant B performs a solvent mass balance for one batch to evaluate the performance of the solvent recovery system. The amount of solvent added to the mixer is measured using a calibrated flow meter and the amount of solvent recovered by the condenser is weighed. The results of these measurements indicate that approximately 70 percent of the solvent is recovered by the solvent recovery system on average. A moisture analysis is also performed on a sample of the mixed material to determine how much solvent remains in the mix. Using these data and the overall system efficiency, plant personnel have determined that approximately 90 percent of the solvent is removed from the mix by the solvent recovery system, and that the condenser removes approximately 80 percent of the solvent vapors.

Plant C has one solvent mixer that uses trichloroethylene as the solvent. Based on the selfreported emissions data to TRI for 1998, Plant C emits approximately 30 tons of trichloroethylene per year. As with the other two controlled mixers, solvent is removed from the mixer under vacuum. No data are available on how much of the solvent is removed from the mixed friction material by the vacuum system. The solvent vapors are combined with the emissions from a solvent degreaser, and the comingled vapors are collected in an activated carbon adsorber. The adsorbed solvent is recovered daily by steam stripping the adsorber bed, and the recovered solvent is sold. Performance data based on a single inlet/outlet emissions test conducted in 1996 indicate that the subject adsorber is capable of achieving 94 percent control. It should be noted that control efficiency does not equate to solvent recovery since it does not account for the residual solvent content remaining in the mixed material. If one assumes that the residual solvent content is similar to that achieved at Plants A and B (i.e., between 5 and 10 percent), the corresponding percent of solvent recovered would be on the order of 85 and 90 percent.

Plant D operates one solvent mixer that uses toluene as the solvent. Based on the selfreported emissions data to TRI for 1998, Plant D emits about 40 tons of toluene annually. Plant D has no air pollution controls on its mixer, and 100 percent of the solvent used is emitted to the atmosphere.

Selection of MACT

We have determined that the MACT floor for existing mixers is a solvent recovery system with a 70 percent solvent recovery efficiency, and the MACT floor for new mixers is a solvent recovery system with a 85 percent solvent recovery efficiency. We have also determined that it is both technically and economically feasible for existing mixers to achieve better than the floor level of control and are, therefore, establishing MACT for both new and existing solvent mixers at 85 percent solvent recovery efficiency. The following paragraphs describe how we determined the MACT floors, and our rationale for going beyond the floor for existing mixers.

Because there are only seven solvent mixers (fewer than 30 sources), the MACT floor for existing solvent mixers is based on the best performing five sources. The available information does not allow for a floor calculation based on actual emissions data or State limits. However, ranking the sources by the estimated performance of the control technology applied allows for a floor determination based on the median of the best performing five sources, i.e., the third best performing source.

Each of the three mixers with control is equipped with a solvent recovery system comprised of two components: a vacuum system to remove the solvent from the mixed material, and a control device that recovers the solvent from the exhaust. The overall performance of these systems is determined by the performances of the individual components, i.e., the efficiency of the vacuum system at removing solvent from the mixed material, and the efficiency of the control device in removing the solvent vapors from the vacuum exhaust.

Plants A and B both use a condenser to recover the solvent vapors. Based on the available data, Plant A's recovery system performs better than the recovery system used at Plant B. Plant A's vacuum system removes 95 percent of the toluene from the mixer, and the condenser removes 90 percent of the solvent vapor, resulting in an overall solvent recovery efficiency of 85 percent. Plant B's vacuum system is estimated to remove 90 percent of the hexane from the mixer, and the condenser removes 80 percent of the hexane vapors from the vacuum exhaust, resulting in an overall solvent recovery efficiency of 70 percent.

Plant C uses a carbon adsorber to recover the trichloroethylene solvent vapors contained in the vacuum exhaust coming from the mixer. The 94 percent control efficiency estimated for the carbon adsorber is the highest of the three control devices applied. However, as stated previously, we have no information from which to assess the effectiveness of the vacuum system at removing the solvent from the mixed material. Without this information, we cannot determine the overall solvent recovery efficiency achieved by the vacuum system and carbon adsorber at Plant C. However, we believe that it is reasonable to assume that the vacuum system at Plant C is comparable to the systems at Plants A and B. Therefore, for the purpose of determining the MACT floor, we have assumed that the vacuum system at Plant C is 90 percent efficient at removing the solvent from the mixed material (the lesser of the two known efficiencies), and have assigned an 85 percent solvent recovery efficiency for the overall system (vacuum system and carbon adsorber). Our assumption
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regarding Plant C's vacuum system efficiency does not impact the MACT determination for existing sources since the floor, as selected below, is ultimately based on Plant B, and since we have decided to establish MACT at a level beyond the floor.

The ranking of the five best sources for purposes of the floor determination is as follows: 85 percent for Plants A and C, 70 percent for Plant B, and zero percent recovery for any two of the remaining mixers. The third best performing source and, thus, the MACT floor for existing solvent mixers is the mixer at Plant B with 70 percent solvent recovery. The MACT floor for new mixers is based on the best performing solvent recovery system. We have determined that Plant A has the best performing solvent recovery system and have set the MACT floor for new mixers at an 85 percent solvent recovery efficiency.

Next we evaluated options that would be more stringent than the floor. Clearly requiring existing mixers to meet an 85 percent solvent recovery efficiency is an option for existing mixers. We looked at the volatility of the three different solvents used at the existing solvent mixers to determine if the volatility of the solvents could limit the vacuum system efficiency such that for certain solvents an 85 percent solvent recovery efficiency could not be achieved. Vacuum systems remove solvent from the mixed material by evaporation at low pressure. Consequently, the higher the volatility of the solvent, the more easily it can be removed by a vacuum system. Of the three solvents used, hexane is the most volatile, while toluene is the least volatile. Based on the available data, Plant A's vacuum system efficiency of 95 percent is the best of the existing systems. Since Plant A also uses the least volatile solvent (i.e., toluene) it is clear that a vacuum system efficiency of 95 percent can be achieved for all three of the solvents used at the existing plants.

We then evaluated the condenser used at Plant B, the poorer performer of the sources with condensers, to determine if improvements to condenser efficiency are possible. The key parameter that determines condenser performance for a given solvent is the outlet temperature of the condenser. The lower the outlet temperature of the condenser, the more solvent will be condensed, and the higher the condenser efficiency will be. For Plant B, the condenser outlet temperature is 60 deg.F. This compares to an outlet temperature of 32 deg.F at Plant A. Condenser outlet temperatures of 32 deg.F can be obtained with either a glycolcooled condenser, or a Freoncooled condenser. The vapor pressure of hexane, the solvent used at Plant B, is estimated to be approximately 100 millimeters of mercury (mm of Hg) at 60 deg.F. At 32 deg.F, the vapor pressure of hexane is estimated to be approximately 50 mm of Hg. This indicates that the penetration (the amount of solvent that is not condensed) would be halved by lowering the condenser outlet temperature at Plant B from 60 deg.F degrees to 32 deg.F. Since the current condenser is estimated to be 80 percent efficient, we would predict that a condenser with a 32 deg.F outlet temperature would achieve 90 percent efficiency for this gas stream. If Plant B were to install both an improved vacuum system and an improved condenser, we predict the overall solvent recovery would be 85 percent (0.95 x 0.90 x 100 percent = 85 percent). Based on the above analysis, we believe that it is technically feasible to achieve 85 percent solvent recovery on each existing solvent mixer used at friction materials manufacturing facilities.

We also believe it is economically feasible to achieve 85 percent solvent recovery on each existing solvent mixer. The incremental costs to install and operate a solvent recovery system that achieves 85 percent over that of a system that would achieve 70 percent are minimal. Nationwide capital for the abovethefloor alternative increases by $92,000 over the floor level. However, because more solvent is recovered under the abovethefloor alternative, the annual costs decrease by $29,000 per year.

We also evaluated and rejected an option that would prohibit the use of HAP solvents altogether. The HAP solvent usage has declined significantly as friction materials manufacturers develop formulations and processes that either use nonHAP solvents or need no solvents in the mixing process (i.e., dry mixing). Personnel at Plants B and C are actively working to identify alternatives to the HAP solvent they currently use. Plant B uses a dry mixer to mix many of the formulations it currently makes, but must use hexane to mix those formulations where the dry mixing process cannot meet the performance characteristics needed. They have also investigated several nonHAP solvents, but have not yet identified an acceptable alternative to hexane. Plant C uses nonHAP solvents to mix many of the friction materials they manufacture, but still have a number of formulations that require the use of trichloroethylene to achieve the necessary characteristics. While it may be possible in the future to eliminate the use of HAP solvents from all friction materials manufacturing, we believe it is not feasible currently to eliminate HAP solvent usage from all friction materials manufacturing.

Selection of the Standards

The CAA requires us to set numerical emission limitations unless the setting or enforcement of a numerical emission limitation is infeasible, in which case a design, equipment, work practice, or operational standard can be set. Consequently, we have selected a format for the standards that expresses the goal of 85 percent solvent recovery as an emission limit based on the amount of solvent loaded into the mixer and the amount recovered. Specifically, the proposed standards would limit the HAP solvent emissions to the atmosphere to no more than 15 percent of that loaded into the solvent mixer.

We also evaluated several averaging times to determine an appropriate averaging time for the standards. We determined that a long averaging time (such as a 30day or annual average) would not be appropriate because it would allow for long periods of under performance by the solvent recovery system. In addition, one deviation from a 30day or annual average would put the plant at risk of being determined to be out of compliance for the entire period. We determined that requiring compliance on a per batch basis (i.e. no averaging) would also be inappropriate since it would not accommodate normal variability in the residual solvent requirements for different product mixes. The use of a 7day block average provides time to detect and correct problems (e.g., individual mix batches not achieving the emission limitation) without the risk of the longer averaging periods. A 7day block average is also consistent with the existing State operating permit requirements for Plant A.
E. How Did We Select the Initial and Continuous Compliance Requirements?

We selected the initial and continuous compliance requirements based on a combination of the generic requirements in the General Provisions (subpart A, 40 CFR part 63) and specific requirements tailored to the friction materials manufacturing source category.

We are requiring owners or operators of all affected sources to demonstrate initial compliance with the emission limitation for solvent mixers within 2 years of the date of publication of the final rule. We feel that 2 years should provide sufficient time for the affected facilities to purchase and install control
[[Page 50775]]
equipment capable of meeting the standards. We feel that a compliance date of less than 2 years may not be long enough due to the potential need for process modifications and product testing to accommodate solvent recovery.

To demonstrate initial compliance with the emission limitation for solvent mixers, owners or operators would be required to demonstrate that the percent of HAP solvent discharged to the atmosphere during the first 7 days after the compliance date, expressed as a 7day block average, does not exceed 15 percent of that loaded into an affected solvent mixer. In order to demonstrate continuous compliance, owners and operators would be required to show on an ongoing basis that the percent of HAP solvent discharged to the atmosphere for each successive 7day period does not average more than 15 percent of that loaded into an affected mixer. We selected a 7day block averaging period as part of the standards to accommodate necessary variations in residual solvent in some product mixes.

Testing requirements include the weighing of solvent loaded into each affected solvent mixer and the weighing of solvent recovered for each mix batch. Compliance is then determined against the average recovery achieved for each mix batch over each 7day block period. Requirements of the weight measurement device include a minimum accuracy and requirements for calibration and inspection.

We selected weighing as the means for determining compliance based on our strong belief that each affected facility will elect to comply with the HAP solvent emission limit by installing and operating a condenserbased solvent recovery system over other control measures such as carbon adsorption or incineration. Weighing precludes the need for costly emissions testing and provides continuing compliance assurance on a weekly basis. If an owner or operator elects to use a control device other than a condenserbased solvent recovery system, they would be allowed to petition the Administrator for approval to use an alternative means of demonstrating initial and continuous compliance with the emission limitation for solvent mixers.
F. How Did We Select the Notification, Recordkeeping, and Reporting Requirements?

Generally, we selected the notification, recordkeeping, and reporting requirements consistent with those contained in the subpart A General Provisions. We deleted, however, notifications, records, and reports that relate to performance tests, continuous emissions monitoring systems (CEMS), continuous opacity monitoring systems (COMS), opacity observations or other visible emission (VE) observations since none of these requirements are relevant to the proposed rule. The records and reports required by the proposed rule are the minimum needed to demonstrate continuous compliance. IV. Summary of Environmental, Energy and Economic Impacts

A. What Are the Air Emission Impacts?

Estimates of organic HAP emissions from the use of solvents are based on a mass balance using solvent usage data collected during the industry survey, estimates of solvent recovery efficiencies for existing controls, and the proposed solvent emission limitation of 15 percent or 85 percent recovery. Four currently uncontrolled mixers will need to be fitted with a solvent recovery system, and the solvent recovery system on one existing mixer will need to be upgraded. The remaining two mixers currently meet the proposed standards and as such should require no additional upgrades. We estimate that the proposed rule would reduce organic HAP emissions by approximately 340 tpy from a baseline level of about 670 tpy. Emissions of volatile organic compounds (VOC) would also be reduced by 340 tpy because these HAP are also VOC.

B. What Are the Cost Impacts?

We obtained process and emissions data from the facilities with the bestcontrolled solvent mixers and incorporated these data into the control cost algorithms for condensers in the ``OAQPS Control Cost Manual'' (EPA 450/390006). We then applied these costs to those facilities that we project would be impacted by the proposed standards. As stated above, we project that five mixers located at two facilities would be impacted by the proposed rule. Four existing mixers would need to be equipped with solvent recovery systems, and the existing solvent recovery system on a fifth mixer would need to be upgraded to meet the proposed standards. Both facilities would incur capital costs to install condensers to meet the proposed standards, as well as annual costs to operate and maintain the condensers. Monitoring is also an important component of MACT and the cost estimate. We expect that all four facilities affected by today's proposed rule will incur some additional yearly costs due to the monitoring, recordkeeping, and reporting requirements of this proposed rule.

Implementation of the control and monitoring requirements is expected to result in a nationwide capital cost of about $253,000, with a total annualized cost (without recovery credits) of approximately $206,000 per year. Nationwide total annualized cost, including credits for recovered solvent, is estimated to be about $43,000 per year. C. What Are the Economic Impacts?

Based on the control cost estimates provided above, we believe the economic impacts associated with this proposed rule will be negligible. In 1992, there were 53 facilities manufacturing friction materials. Of these 53 facilities, four are affected by the proposed rule and will incur control and monitoring costs. The total annualized cost of $206,000 per year (without recovery credits) is much less than 1 percent of industry revenues. When we consider the solvent recovery credits along with control technology costs, the total economic impact of this proposed rule is a cost to the industry of $43,000 per year. As a result, the impacts of this rule are substantivally less than 1 percent of total revenues and is not significant enough to alter the market price for friction materials.
D. What Are the NonAir Quality Environmental and Energy Impacts?

Indirect air impacts of today's proposed rule would result from increased electricity usage associated with operation of control devices (i.e., condensers) installed to meet the proposed emission limitation. Assuming that plants will purchase electricity from a power plant, we estimate that the proposed rule would increase secondary emissions of criteria pollutants from power plants by less than 0.5 tpy. These criteria pollutants include particulate matter, sulfur dioxide, nitrogen oxides, and carbon monoxide. The overall energy demand is expected to increase by about 340 million British thermal units per year (MMBtu/yr) nationwide under the proposed rule. This increase in energy demand is based on the electricity required to operate the vacuum and condenser systems needed to comply with the proposed rule.

Because impacted facilities are expected to reuse or sell the solvent recovered by the condensers, we do not anticipate any significant wastewater or solid waste impacts as a result of today's proposed rule.
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V. Solicitation of Comments and Public Participation

We seek full public participation in arriving at final decisions and encourage comments on all aspects of this proposal from all interested parties. You need to submit full supporting data and detailed analyses with your comments to allow us to make the best use of them. Be sure to direct your comments to the Air and Radiation Docket and Information Center, Docket No. A9757 (see ADDRESSES). VI. Administrative Requirements

A. Executive Order 12866, Regulatory Planning and Review

Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA must determine whether the regulatory action is ``significant'' and, therefore, subject to review by the Office of Management and Budget (OMB) and the requirements of the Executive Order. The Executive Order defines ``significant regulatory action'' as one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100 million or more or adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, public health or safety, or State, local, or tribal governments or communities;
(2) Create a serious inconsistency or otherwise interfere with an action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants, user fees, or loan programs, or the rights and obligation of recipients thereof; or
(4) Raise novel legal or policy issues arising out of legal mandates, the President's priorities, or the principles set forth in the Executive Order.

Pursuant to the terms of Executive Order 12866, it has been determined that this rule is not a ``significant regulatory action'' because none of the listed criteria apply to this action. Consequently, this action was not submitted to OMB for review under Executive Order 12866.

B. Executive Order 13132, Federalism

Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 10, 1999), requires EPA to develop an accountable process to ensure ``meaningful and timely input by State and local officials in the development of regulatory policies that have federalism implications.'' ``Policies that have federalism implications'' is defined in the Executive Order to include regulations that have ``substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.''

This proposed rule does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132. None of the affected facilities are owned or operated by State governments, and the rule requirements will not supercede State regulations that are more stringent. Thus, Executive Order 13132 does not apply to this proposed rule.

In the spirit of Executive Order 13132 and consistent with EPA policy to promote communications between EPA and State and local governments, EPA specifically solicits comments on this proposed rule from State and local officials.
C. Executive Order 13175, Consultation and Coordination with Indian Tribal Governments

Executive Order 13175, entitled ``Consultation and Coordination with Indian Tribal Governments'' (65 FR 67249, November 6, 2000), requires EPA to develop an accountable process to ensure ``meaningful and timely input by tribal officials in the development of regulatory policies that have tribal implications.'' ``Policies that have tribal implications'' is defined in the Executive Order to include regulations that have ``substantial direct effects on one or more Indian tribes, on the relationship between the Federal government and the Indian tribes, or on the distribution of power and responsibilities between the federal government and Indian tribes.''

This proposed rule does not have tribal implications. It will not have substantial direct effects on tribal governments, on the relationship between the Federal government and Indian tribes, or on the distribution of power and responsibilities between the Federal government and Indian tribes, as specified in Executive Order 13175. No tribal governments own or operate friction material manufacturing facilities. Thus, Executive Order 13175 does not apply to this proposed rule.
D. Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks

Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any rule that: (1) is determined to be ``economically significant'' as defined under Executive Order 12866, and (2) concerns an environmental health or safety risk that EPA has reason to believe may have a disproportionate effect on children. If the regulatory action meets both criteria, EPA must evaluate the environmental health or safety effects of the planned rule on children, and explain why the planned rule is preferable to other potentially effective and reasonably feasible alternatives that EPA considered.

The EPA interprets Executive Order 13045 as applying only to those regulatory actions that are based on health or safety risks, such that the analysis required under section 5501 of the Executive Order has the potential to influence the rule. This proposed rule is not subject to Executive Order 13045 because it is based on technology performance and not on health or safety risks. No children's risk analysis was performed because no alternative technologies exist that would provide greater stringency at a reasonable cost. Furthermore, this proposed rule has been determined not to be ``economically significant'' as defined under Executive Order 12866.

E. Unfunded Mandates Reform Act of 1995

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public Law 1044, establishes requirements for Federal agencies to assess the effects of their regulatory actions on State, local, and tribal governments and the private sector. Under section 202 of the UMRA, EPA generally must prepare a written statement, including a costbenefit analysis, for proposed and final rules with ``Federal mandates'' that may result in expenditures by State, local, and tribal governments, in the aggregate, or by the private sector, of $100 million or more in any 1 year. Before promulgating an EPA rule for which a written statement is needed, section 205 of the UMRA generally requires EPA to identify and consider a reasonable number of regulatory alternatives and adopt the least costly, most costeffective, or least burdensome alternative that achieves the objectives of the rule. The provisions of section 205 do not apply when they are inconsistent with applicable law. Moreover, section 205 allows EPA to adopt an alternative other than the least costly, most costeffective, or least burdensome alternative if the Administrator publishes with the final rule an explanation why that alternative was not adopted. Before EPA establishes any regulatory requirements that may significantly or uniquely affect small governments, including tribal
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governments, it must have developed under section 203 of the UMRA a small government agency plan. The plan must provide for notifying potentially affected small governments, enabling officials of affected small governments to have meaningful and timely input in the development of EPA's regulatory proposals with significant Federal intergovernmental mandates, and informing, educating, and advising small governments on compliance with the regulatory requirements.

The EPA has determined that this proposed rule does not contain a Federal mandate that may result in estimated costs of $100 million or more for State, local, and tribal governments, in the aggregate, or the private sector in any 1 year. The maximum total annual cost of this proposed rule for any year has been estimated to be less than $206,000. Thus, today's proposed rule is not subject to the requirements of sections 202 and 205 of the UMRA. In addition, EPA has determined that this proposed rule contains no regulatory requirements that might significantly or uniquely affect small governments because it contains no requirements that apply to such governments or impose obligations upon them. Therefore, today's proposed rule is not subject to the requirements of section 203 of the UMRA.
F. Regulatory Flexibility Act (RFA), as Amended by the Small Business Regulatory Enforcement Fairness Act of 1966 (SBREFA), 5 U.S.C. 601 et seq.

The RFA generally requires an agency to prepare a regulatory flexibility analysis for any rule subject to notice and comment rulemaking requirements under the Administrative Procedure Act or any other statute unless the agency certifies that the rule will not have a significant economic impact on a substantial number of small entities. Small entities include small businesses, small organizations, and small governmental jurisdictions.

For purposes of assessing the impacts of today's proposed rule on small entities, small entity is defined as: (1) a small business that has no more than 500 employees for NAICS codes 327999 and 333613 or no more than 750 employees for SIC code 33634; (2) a small governmental jurisdiction that is a government of a city, county, town, school district, or special district with a population of less than 50,0

FOR FURTHER INFORMATION CONTACT For questions about the proposed rule, contact Kevin Cavender, Metals Group, Emission Standards Division (MD 13), U.S. EPA, Research Triangle Park, NC 27711, telephone number (919) 5412364, electronic mail address: cavender.kevin@epa.gov. For questions about the public hearing, contact Cassie Posey, Metals Group, Emission Standards Division (MD13), U.S. EPA, Research Triangle Park, NC 27711, telephone number (919) 5410069, electronic mail address: posey.cassie@epa.gov.