Permit No.: 22-8041-ST-01 Application No.: 27822 Page 1 of 14 ~ Standard AIR CONTAMINANT DISCHARGE PERMIT N REVIEW REPORT Department of Environmental Quality i I] =<•1 Western Region State ofOregon Departmentof Envlronmental Quality Source Information: 3369 Source Categories B56, C3 SIC I (Table 1 Part, code) NAfCS 331528 Public Notice Category II
C ompmnceI' an dE m1ss10ns' . M omtormg. R eq uirements: FCE Source test [date(s)]
Compliance schedule COMS
Unassigned emissions CEMS
Emission credits PEMS
Special Conditions Ambient monitoring
R epo rfmg R eqmremen t s Annual report 1 Mar Monthly report (due date) (due dates)
Quarter!y report Excess emissions report X (due dates) Other (specify)
Air Programs Synthetic Minor (SM) NSR
SM-80 X PSD
NSPS (list subparts) IIII RACT NESHAP (list subparts) zzzz TACT X
Part 68 Risk Management Other (specify)
CFC
Se/met 15 Pennit No.: 22-8041-ST-0l Application No.: 27822 Page 2 of 14
TABLE OF CONTENTS
PERMITTING ...... 3 SOURCE DESCRIPTION ...... 3 COMPLIANCE ...... 7 EMISSIONS ...... 7 TITLE V MAJOR SOURCE APPLICABILITY ...... 8 ADDITIONAL REQUIREMENTS ...... 9 PUBLIC NOTICE ...... I 0
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PERMITTING
PERMITTEE IDENTIFICATION
1. Selmet, Inc. established a foundry at 33992 SE Seven Mile Lane in Albany in 1994.
PERMITTING ACTION
2. The proposed permit is a renewal of an existing Air Contaminant Discharge Permit (ACDP) that was issued on 1/1/2010 and was originally scheduled to expire on 10/1/2014. The existing ACDP remains in effect until the proposed permit is issued because the permittee submitted a timely and complete application for renewal. A permit addendum was issued on 3/9/2010 to correct emission factor units for the cyclones.
OTHER PERMITS
3. Other permits issued or required by the DEQ for this source include: a. WPCF water quality permit #101350, File #74550 b. Hazardous waste large quantity generator ORD009421579
ATTAINMENT STATUS
4. The source is located in an attainment area for all pollutants.
SOURCE DESCRIPTION
OVERVIEW
4. The permittee owns and operates a titanium casting facility producing parts for the aerospace, medical, auto, and recreational industries by investment casting. Raw materials used in the various processes include commercially pure and alloyed titanium metal, waxes, ceramic materials, and ethanol. Additionally, scrap pieces of titanium are re-melted after being cleaned in a chemical milling process.
The investment casting process starts out with the creation of wax patterns in accurate metal dies in the wax department. Acid soluble wax fillers are incorporated into the pattern so a void will be left in the wax pattern once the soluble filler is dissolved by a citric acid solution. The wax patterns are touched up by hand before serving as the core for the creation of the shell molds.
The ceramic shell molds arn built up around the wax pattern by alternately dipping the pattern (or group of patterns) into a slurry and rotating it within a drum or fluidized bed sander. The first dip consists of a tungsten-zirconium acetate solution, which is then
Se/met 15 Pennit No.: 22-8041-ST-01 Application No.: 27822 Page 4 of 14
sprinkled with zirconium oxide sand. In the second dip, the slurry consists of milled ceramic particles, ethanol and ethyl silicate, and the sanders dispense aluminum oxide sand. In any further dips, aluminum silicate sand is used instead of aluminum oxide. Wire mesh and other reinforcements are added to the shell as it is built up, so the shell will withstand the centrifugal forces during casting. After the shell has set up, the wax is melted out of the shells using steam in the autoclave.
The company is using more and more a water-based investing material rather than the ethanol based material for certain dips, thus reducing VOC emissions. Approximately 70% of the investment material currently used is water-based.
Most of the residual wax remaining after the autoclave de-waxing process is melted out of the shells in the bake-out furnaces. After bake-out, the shell molds are tempered in kilns called shell-firing furnaces where any remaining residual wax is burned out. The shells are held in the shell-firing furnaces for a specific time period before they are ready for the casting operation.
Both the process of melting the titanium electrodes and scrap, and the pouring of molten titanium into the mold are conducted in a vacuum (backfilled with argon gas) inside the casting furnaces. In the centrifugal casting process, the mold assembly is placed on a turntable inside the furnace in order to spin the part during the pour. After the poured molds have been removed from the furnaces, the lmockout, cleaning, and finishing departments use various methods to remove the shells and clean up the cast parts. These methods include the use of water blasting, jack hammers, sandblasting, shot-blasting, and abrasive grinding. A natural gas heated caustic bath is used to assist in the removal of residual shell material from the cast parts. Unwanted appendages are removed from the parts by torch cutting, band sawing, or belt grinding.
Th:e oxygen emiched layer on the surface of the castings is removed by an acid solution in the chem mill department. The dimensions of the castings are checked and modifications made to bring them within specs using a press, inert gas welding, and grinding. Final steps include both surface penetrant and x-ray inspections, as well as heat treating in an electrical vacuum heat treatment furnace.
6. The following changes have been made to the facility since the last permit issuance:
a. 2010 - Installation of a mold firing furnace (NC# 024336) b. 2011 - Device ventilation changes from exhausting internally to externally; downdraft tables, two wet scrubbers, and one cast parts oven (NC # 026098) c. 2012 - Installation of an air dehumidifier on a parts oven, categorically insignificant (NC# 026895) d. 2013 - Replacement of Chem Mill and Tri-Mer acid scrubbers (NC # 027334) e. 2014 - Installation of a 25 hp water tube boiler, which is categorically insignificant (no NC submitted). f. 2015 - Installed a new Goff steel shot blaster and baghouse
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PROCESS AND CONTROL DEVICES
6. Existing air contaminant sources at the facility consist of the following:
a. Three chem mill baths containing nitric and hydrofluoric acids with emissions controlled by three wet scrubbers. b. Two rainfall sanders with cyclone emission controls. c. One steam-heated autoclave with no emission controls. d. Two Ajax boilers rated at 1.5 MMBtu/hr fired solely on natural gas, manufactnred 1996, installed 1996. e. One Weil McLain boiler rated at 1.3 MMBtu/hr fired solely on natural gas, manufactured 1994, installed 1994. f. One Cleaver Brooks boiler rated at 1.75 MMBtu/hr fired solely on natnral gas, manufactured 1995, installed 1995. g. Four natural gas fired balce-out ovens and shell mold firing furnaces with no emission controls. h. One natural gas heated caustic bath with no emission controls. 1. Three torch cutting stations with two baghouse emission controls. J. One abrasive cutoff wh~el with cyclone and baghouse emission controls. k. Various shot and tumble blasters with four baghouse emission controls.· J I. Various abrasive blasters with cyclone and baghouse emission controls. 1 m. Belt grinding with cyclone emission controls. n. Fugitives from facility paved roads. o. Usage ofVOC containing materials. p. IRAM air stripper. q. Wire wheel dust collector. r. Grinding booth down draft table with a baghouse.
CATEGORlCALLY INSIGNIFICANT ACTIVITIES
5. Per OAR 340-200-0020(23), the following activities have not been addressed in the permit.
• Constituents of a chemical mixtnre present at less than 1% by weight of any chemical or compound regulated under OAR Chapter 340, Divisions 200 through 268, excluding Divisions 248 and 262, or less than 0.1 % by weight of any carcinogen listed in the U.S. Department of Health and Human Service's Annual Report on Carcinogens when usage of the chemical mixtnre is less than 100,000 pounds/year • Evaporative and tail pipe emissions from on-site motor vehicle operation • Distillate oil, kerosene, and gasoline fuel burning equipment rated at less than or equal to 0.4 million Btu/hr • Natnral gas and propane bnrning equipment rated at less than or equal to 2.0 million Btu/hr • Office activities
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• Food service activities • Janitorial activities • Groundskeeping activities including, but not limited to building painting and road and parking lot maintenance • On-site laundry activities • Instrument calibration • Maintenance and repair shop • Air cooling or ventilating equipment not designed to remove air contaminants generated by or released from associated equipment • Refrigeration systems with less than 50 pounds of charge of ozone depleting substances regulated under Title VI, including pressure tanks used in refrigeration systems but excluding any combustion equipment associated with such systems • Bench scale laboratory equipment and laboratory equipment used exclusively for chemical and physical analysis, including associated vacuum producing devices but excluding research and development facilities • Temporary construction activities • Warehouse activities • Accidental fires • Air vents from air compressors • Air purification systems • Electrical charging stations • Instrument air dryers and distribution • Process raw water filtration systems • Fire suppression • Routine maintenance, repair, and replacement such as anticipated activities most often associated with and performed during regularly scheduled equipment outages to maintain a plant and its equipment in good operating condition, including but not limited to steam cleaning, abrasive use, and woodworking • Electric motors • Storage tanks, reservoirs, transfer and lubricating equipment used for ASTM grade distillate or residual fuels, lubricants, and hydraulic fluids • Natural gas, propane, and liquefied petroleum gas (LPG) storage tanks and transfer equipment • Pressurized tanks containing gaseous compounds • Storm water settling basins • Fire suppression and training • Health, safety, and emergency response activities • Emergency generators and pumps used only during loss of primary equipment or utility service due to circumstances beyond the reasonable control of the owner or operator, or to address a power emergency as determined by DEQ • Non-contact steam vents and leaks and safety and relief valves for boiler steam distribution systems • Non-contact steam condensate flash tanks
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• Non-contact steam vents on condensate receivers, de-aerators and similar equipment • Boiler blowdown tanks • Industrial cooling towers that do not use chromium-based water treatment chemicals COMPLIANCE
7. DEQ inspected the facility on 8/11/2011 and documented violations of three permit conditions. See next item. DEQ inspected the facility on 7/30/2014 and documented compliance with all permit conditions.
8. Following the August, 2011 inspection DEQ issued a Warning Letter with Opportunity to Correct to Selmet. Corrective actions required the following documentation:
a. Verification that procedures are in place to address documentation and actions taken when wet scrubbers are out of the normal operating range for pH levels; b. Each baghouse has a functioning pressure drop gauge and the manufacturer's specified operating range for each baghouse; and, c. Monthly emissions calculations are being completed.
Selmet submitted the required documentation for the above items within the time allotted resolving the violation. DEQ verified compliance at the next inspection.
9. During the prior permit period the Department received two complaints about smoke from this facility. The complaint received in 2011 could not be substantiated. Selmet identified the complaint received in 2013 as a process upset condition. This resulted in a minor process change at the plant.
EMISSIONS
10. Proposed PSEL information:
Netting Basis Plant Site Emission Limits (PSEL) Baseline Previous Proposed PSEL Emission Previous Proposed PSEL PSEL Increase Pollutant Rate (tons/yr) (ton:s/yr) (tons/yr) (tons/yr) (tons/yr) (tons/yr) PM 7 7 7 24 24 0 PM10 6 6 6 14 14 0 PM2.s n/a n/a 4 n/a 9 9 NOx 5 5 2 39 39 0 co 1 1 1 99 99 0 voe 62 62 62 99 99 0
GHG (C02e) n/a n/a n/a n/a 74,000 n/a
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a. The baseline emission rates were established in previous permitting actions and there is no new information that effects the previous determinations. b. PM2.5 is a fraction of PM10, and following federal law was deemed a criteria pollutant of air quality in Oregon in May 2011. The above table does not represent an actual emissions increase, but recognition of the separate sizes of particulate matter. A baseline rate will not be established for PM25. c. Greenhouse gas emissions (GHG) emissions, collectively, have been designated a regulated pollutant by EPA. The facility's GHG potential to emit emissions are above the de minimis level of2,500 metric tons, therefore the GHG generic PSEL is established in this permit for the first time. d. SO2 emissions are negligible. No PSEL has been set for SO2. e. The netting basis is equal to the baseline emission rate minus emission reductions required by rule plus emission increases approved in accordance with OAR 340, Division 224 (NSR rules). f. The previous PSEL is the PSEL in the last permit. g. Refer to the attached emissions calculations. h. The PSEL is a federally enforceable limit on the potential to emit.
SIGNIFICANT EMISSION RATE ANALYSIS
11. For each pollutant, the proposed Plant Site Emission Limit is less than the Netting Basis plus the significant emission rate, thus no further air quality analysis is required.
OTHER INFORMATION
12. Data submitted to EPA's toxic release inventory included in the permit application was reviewed. Data reported to EPA included compounds not addressed under Oregon law.
TITLE V MAJOR SOURCE APPLICABILITY
CRITERIA POLLUTANTS
13. A major source is a facility that has the potential to emit (PTE) 100 tons/yr or more of any criteria pollutant. Although the source has the capacity to emit VOC above the Title V major source threshold levels, the permittee has elected not to obtain an Oregon Title V Operating Permit by requesting a PSEL below the major source threshold levels. The PSEL is a federally enforceable limit on PTE.
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HAZARDOUS AIR POLLUTANTS
14. A major source is a facility that has the potential to emit 10 tons/yr or more of any single HAP or 25. tons/yr or more of combined HAPs. This source is not a major source of hazardous air pollutants. Provided below is a surmnary for HAP emissions.
Hazardous Air Pollutant Potential to Emit (tons/year) Hydroquinone 1.02 Methanol 6.61 Methyl isobutyl ketone (MlBK) 1.98 Toluene 0.51 All others 0.12 Total 10.24
ADDITIONAL REQUIREMENTS
NSPS APPLICABILITY
15. 40 CFR Subpart De is not applicable to the facility's boilers because they all have a heat input rating ofless than 10 MMBtu/hour.
NESHAPS/MACT APPLICABILITY
16. 40 CFR 63, Subpart 6-G for Primary Nonferrous Metals (zinc and beryllium) does not apply. 40 CFR 63, Subpart 6-Z for Aluminum, Copper, and Other Nonferrous Foundries does not apply. This facility does not process nor emit any of the target metal HAPs.
I 7. 40 CFR 63, Subpart 4-Z and 40 CFR 60, Subpart 4-I for Reciprocating Internal · Combustion Engines (RICE) applies to the emergency generator at the site. It is a 600 kW Generac Industrial Power engine fired on low-sulfur diesel. The NESHAP under Part 63 refers to the NSPS under Part 60. Maintenance and record keeping requirements are added in this permit.
RACT APPLICABILITY
18. The RACT rules are not applicable to this source because it is not in the Portland AQMA, Medford AQMA, or Salem SKATS.
TACT APPLICABILITY
19. The source is meeting the states TACT/Highest and Best Rules by using baghouses and wet scrubbers to minimize pollutant emissions.
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PUBLIC NOTICE
20. Pursuant to OAR 340-216-0066(4)(a)(A), issuance of Standard Air Contaminant Discharge Permits require public notice in accordance with OAR 340-209-0030(3)(b), which requires DEQ to provide notice of the proposed permit action and a minimum of 30 days for interested persons to submit written comments. The public notice was emailed/mailed on Jnly 20, 2015, and the comment period was schednled to end on August 24, 2015. During the public comment period DEQ discovered that the generic greenhouse gas Plant Site Emission Limit was inadve1iently omitted in the draft permit. DEQ reissued the corrected permit and extended the public comment period. The public notice for the c01Tected permit was emailed/mail on August 14, 2015, and the comment period ended on September 18, 2015. No public comments were received. ka:kwf
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1976 Baseline Emissions
Emission Unit Pollutant Annual Emission Factor Emissions Operations Rate Reference (tons/year)
Caustic bath PM 8,000 dscfin 0.01 gr/dscf Reg. Limit 3.0 hood vent PM10 100%ofPM DEQEst. 3.0 PM2.s 50% ofPM10 DEQ Est. 1.5 1 Baghouses (2) PM10 34,192 lb dust 99.9%eff. Dust Study ·" 0.3 casting cleaning PM2.s 100% ofPM10 0.3 Cyclone PM 15,227 Ib dust 80% eff. Dust Study 1.5 PM10 100%ofPM DEQ Est. 1.5 PM2.s 50%ofPM AQ-EF08j 0.75 Torch Cutoff PM 3,879 lb dust 0%removal Dust Study 1.9 PM10 100%ofPM DEQ Est. 1.9 PM2.s 50%ofPM10 DEQ Est. 0.95 Bake-out ovens PM 264MMdscf 0.01 gr/dscf PCC" 0.2 PM10 100% of PM DEQ Est. 0.2 PM2.s 50% ofPM10 AQ-EF08 0.1 voe 1,995 lb 0.31 lb/lb PCC 0.3 residual wax residual wax Autoclave De- voe 66,489 lb wax 0.0003 lb/lb PCC Neg!. waxmg wax Natural gas usage PM10 24.343 MMCF 2.5 lb/MMCF AQ-EF05" 0.03 PM2.s 2.5 lb/MMCF 0.03 co 84lb/MMCF 1.0 SO2 1.7 lb/MMCF Neg!. NOx 100 lb/MMCF 1.2 voe 5.5 lb/MMCF 0.1 Chem mill NOx 0.81 lb/hr 8,760 hrs Eng. Est. 3.5 Facility-wide usage voe Co. Est. 61.8 j Dust study by Selmet and SECOR Int ' I. See SM application received 5/25/99. 2 PM from baghouses has been removed; baghouses emit the smaller particulates. 3 DEQ emission factor sheet. 4 Precision Cast Parts permit, 26-1867, 3/15/95. 5 PM emissions from natural gas combustion are the smaller PM fractions. 6 A Netting Basis, not a Baseline rate, has been set for PM2.s per Departinent directive. 7 PM emissions from roadways are ½ ton/year and were originally included only for SM considerations.
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Baseline Summary Pollutant Emissions (tons/year) PM 6.9 PMw 6.2 SO2 Neg!. co 1.0 NOx 4.7 . voe 62.2
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Proposed Emissions
Emission Unit Pollutant Annual Emission Factor Emissions
. Operations Rate Reference (tons/year) Caustic bath PM 628 dscfm 0.027 lb/hr Engr. Est.' 0.1 Hood vent PM10 l00¾ofPM DEQ Est. 0.1 PM2.s 50%ofPM DEQ Est. 0.05 Baghouses (2) PM10 793,131 lb dust 99.9% eff. Dust Study-·" 0.4 Casting cleaning PM2s inlet 100% ofPM10 0.4 Belt Grinder PM 6,908 lb dust 80% eff. Dust Study" 0.7 Cyclones (3) PM10 inlet l00¾ofPM DEQ Est. 0.7 PM2.s 50% ofPM10 AQ-EF03' 0.35 Rainfall Sander PM 10,400 lb dust 80% eff. Dust Study' 1.0 Cyclones (2) PM10 inlet 50%ofPM DEQ Est. 0.5 PM2.s 50%ofPM10 AQ-EF05'. 0.25 Bake-out ovens PM 281 MM dscf 0.046 Pee• 0.2 PM10 l00¾ofPM DEQ Est. 0.2 PM2.s 50% ofPM10 DEQ Est. 0.1 voe 6,330 lb residual 0.31 lb/lb pee• 1.0 wax (3% of wax) residual wax Autoclave De- voe 66,489 lb wax 0.0003 lb/lb PCC' Neg!. waxing wax Natural gas usage PM10 55MMCF 2.5 lb/MMCF AQ-EF05' 0.06
PM2.s 2.5 lb/MMCF . 0.06 co 84 lb/MMCF 2.3 SO2 1.7 lb/MMCF Neg!. NOx 100 lb/MMCF 2.8 voe 5.5 lb/MMCF 0.2 Chem mill NOx 885,760 lb Ti 0.02 lb/lb NOxStudy0 8.8 Scrubbers (3) poured IRAM Air Stripper voe 26,300,000 gal 5.45E-5 lb/gal Source Test 0.7 Agg. Insignificant voe All sources 1.0 Facility-wide usage voe Co. Est. 96.0 1
1 Estimate of 0.005 gr/dscf was converted to lb/hour. 2 Dust study by Selmet and SECOR Int'!. The majority of the molten salt PM condenses onto the hood. See SM application received 5/25/99. 3 PM from baghouses has been removed; baghouses normally emit the smaller particulates. 3 DEQ emission factor sheet. 4 Precision Cast Parts permit, 26-1867, 3/15/95, converted to lb/hour. 5 PM emissions from natural gas combustion are the smaller PM fractions. 6 Selmet study; results reported with NC 27334, 6/5/13, shows lower emissions with new chem. mill scrubbers. 7 Company estimate at completion of expansion in progress at 8,112 production hours per year.
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Proposed Emissions Summary Pollutant Emissions (tons/year) PM 1.9 PM10 2.0 PM2.s 1.2 SO2 Neg!. co 2.3 NOx 11.6 voe 98.9 GHG 3,308
Note: GHG emissions are calculated using DEQ's E-Z Filer program and are based on the usage of 55 MM ft3 of natural gas. Reporting is required at 2,756 short tons actual GHG emissions.
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