ENGINEERING SUMMARY SHEET AIR RESOURCES DIVISION

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1 AFS #: Application #: FY DATE: 9/2/05 Page 1 of 4 DATE APPLICATION RECEIVED: November 25, 2003 PROJECT DESCRIPTION (A-Plus) submitted an application for the renewal of their State Permit to Operate, FP-S-0067 which expired on December 31, The existing permit covers RTAP and HAP emissions that are controlled by a wet scrubber. PROCESS DESCRIPTION A-Plus operates a job-shop for plating, etching and polishing various metal components. The chemical products used vary based on the workload of the facility. Chemical products used in the process consist of acidic and basic surface treatments, plating baths, ammonia and solvents. Attachment A lists the baths that were evaluated for this application. EMISSION CALCULATIONS A-Plus submitted data on chemical usage and estimated emissions for calendar year 2003 (actual purchases through 10/31/03 prorated to 12 months). The facility was also inspected in November 2003 by Alan Moulton who requested chemical purchasing records for the previous five years. All of this data was evaluated to determine the source s compliance status and applicability requirements. As an initial, conservative review, it was assumed that all of the chemicals purchased in a year are emitted. The details of this are in the spreadsheet h:\permitting\source Files\\ \A-Plus_ _Eng Sum(excel)_ Only the data for 2003 is printed and attached to this summary. The total VOC and HAP usage rates were added and are summarized below: Chemical Usage Rates (tpy) VOCs HAPs Estimating the potential emissions from the facility is difficult due to the nature of the operations (job-shop). The facility operates for 8 hr/day and 250 day/yr (2000 hr/yr). If one takes the highest annual usage rate and scales the number to 8760 hr/yr, the potential usage rate for VOCs would be 7.98 tpy and for HAPs it would be 9.86 tpy. These numbers are well below the major source thresholds for these compounds, and therefore it is concluded that this facility is a true minor source. The 2003 chemical usage rates were also compared to the de minimus emission rates listed in Env-A In most cases the daily usage rate was determined by taking the annual rate and dividing by 250 day/yr. For daily rates followed by an *, the rates listed in the table are based on expected maximum emission rates. There are eleven chemicals that had usage rates or emissions greater than the de minimus emission rates. The following discusses the assumptions and calculations made for these 11 chemicals to determine their emission rates. Two of the chemicals are solid metal compounds, barium and nickel sulfate. The usage rates are for the solid compound which is dissolved in a chemical bath and then plated onto the products. A-Plus utilizes electroless plating and the baths are not agitated in any way. It is assumed that the metals will not be emitted from the process; therefore these compounds are in compliance with Env-A Sodium hydroxide is used in relatively large quantities. This chemical is used in the wet scrubber as a means of neutralizing acid emissions. It is also used as part of a waste treatment system to neutralize liquid acid wastes. It is not expected that sodium hydroxide, as it is used by A-Plus, will be emitted into the air, therefore this compound is in compliance with Env-A Potassium Hydroxide is an alkali chemical used in one of the baths (Metex 662SE). Due to the low vapor pressure of this compound it is not expected to be emitted into the air, therefore this compound is in compliance with Env-A Hydrochloric and acetic acids are both volatile acids. For conservatism, it is assumed that 100% of these chemicals are emitted. All of the acetic acid is exhausted to a wet scrubber. The exhaust flow rate is 7500 acfm (7500/2119 = 3.54 m 3 /sec). The uncontrolled, adjusted in-stack concentrations of this acid is: 0.27 lb/hr * 10 6 /7.94 = μg/sec

2 AFS #: Application #: FY DATE: 9/2/05 Page 2 of / 3.54 / 400 = μg/ m 3 This is less than 50% of the 24-hr and annual AALs of 126 μg/ m 3 and 84 μg/ m 3, respectively. Therefore, this chemical is in compliance without the use of controls. Hydrochloric acid is used in five baths at the facility. Three of the baths are exhausted to the wet scrubber (removal efficiency 90%) and the remaining two have no exhaust. Because some of the emissions are fugitive, an in-stack calculation could not done for this pollutant. See the discussion below on modeling. The emissions of nitric acid were calculated by using a mass balance. Nitric acid is shipped off-site as a hazardous waste. Emissions are assumed to be equal to the usage rate minus the amount sent out as waste, 280 lbs/yr 106 lbs/yr = 174 lbs/yr. The estimated maximum daily emission rate is 8.4 lb/day. These numbers are greater than the de minimus emission rates. Nitric acid is used in a number of the baths at A-Plus. Some of these baths are exhausted to the wet scrubber (removal efficiency 70%) and some are not vented (fugitive emissions). Because of the fugitive emissions, an in-stack calculation for compliance determination is not possible. See the discussion below on modeling. The emission rates for sulfuric and phosphoric acids were determined by the source with an experiment to determine evaporation rates. It was determined that sulfuric acid evaporates at a rate of 0.19 g/ft 2 /hr (0.04 lbs/hr) and phosphoric acid evaporates at a rate of 0.23 g/ft 2 /hr (0.05 lbs/hr). (Note: these emission rates were compared to emission rates calculated from mass transfer equation for evaporation rates based on chemical properties see Attachment B for calculations. The emission rates used by A-Plus were higher and thus more conservative). If the baths were used for the maximum operating time of 8 hr/day, the emissions would exceed the de minimus emission rate. Like hydrochloric and nitric acids, some of the emissions of these acids are fugitive making an in-stack calculation invalid. See the discussion below on modeling. Methyl ethyl ketone (MEK) is a Volatile Organic Compound (VOC). It is assumed that all of the MEK used in the process is emitted into the air. MEK is emitted as a fugitive emission source; therefore an in-stack calculation is not possible See the discussion below on modeling. MODELING/DETAILED EMISSION ESTIMATES Various iterations of modeling was conducted for this source. Modeling was conducted during the previous permit renewal, in This modeling had all the acid emissions controlled and exhausted out of the scrubber stack. Since this is not how the facility actually operates, an updated modeling analysis was required. As an initial check, modeling was requested to be conducted on uncontrolled emissions. If the source was able to meet the AALs without controls, then no permit would be required. The results of this modeling showed that the impacts using uncontrolled emission rates were well above the AALs (the results of this preliminary modeling are not included in the modeling memo). During site visits to the facility, the amount of acid emitted through the exhaust vents was questioned. Due to the configuration of the ventilation systems for the process baths, a capture efficiency of less than 100% would be expected. A qualitative test was conducted using a smoke tube to estimate the capture efficiency of the baths. This test showed that the ventilation had a very good capture efficiency, but because of the qualitative nature of the test, an exact number was not determined. To be conservative, it is assumed that the capture efficiency of the exhaust system is 80%. During the summer months (when the weather is hot), the facility opens its overhead door to increase cross-ventilation through the process area. The smoke test for capture efficiency was conducted with the door open and with the door closed. No significant difference was noticed when the door was opened. As a conservative assumption, modeling was conducted for two scenarios: 1 the overhead door is open and all fugitive emissions are exhausted out of the door; and 2 the door is closed and there are no fugitive emissions out of the building (only emissions captured by the exhaust system were evaluated). Subsequent modeling was also done assuming all the fugitive emissions are eventually captured by the exhaust system and sent out the vent stack. In order to determine the emission rates of the various acids through the different exhausts, a more detailed picture of the facility was needed. The attached table, Detailed Acid Emission Calculations, lists the bath # s (corresponding with the updated facility plan submitted on April 5, 2005), the acids used in each bath and the proportional usage (see sample calculation at the bottom of the table). The proportional usage number was used to divide up the total emissions between the exhaust systems and fugitive emissions, as applicable. For baths that have ventilation an 80% capture efficiency was used, and for emissions through the scrubber, the

3 AFS #: Application #: FY DATE: 9/2/05 Page 3 of 4 appropriate removal efficiency was used. The following tables show the emission rates used as inputs to the dispersion modeling. Emission Rates for Existing Conditions Scrubber Stack Vent Stack Fugitive Annual (lb/hr) Daily (lb/hr) Annual (lb/hr) Daily (lb/hr) Annual (lb/hr) Daily (lb/hr) Nitric Acid Hydrochloric Acid Phosphoric Acid Sulfuric Acid Ammonia Methyl Ethyl Ketone A third, proposed scenario was also evaluated based on fugitive emissions exhausting out of the door and all captured acid emissions controlled and exhausted through the scrubber. Also, for this third scenario the emission rate for hydrochloric acid was decreased using an assumption that only 10% of the total usage is emitted (this is more realistic based on the volatility of acids. Using the mass transfer equation would give an approximate emission rate equal to 3% of the total usage). Emission Rates for Proposed Conditions All bath exhausts directed to scrubber only 10% HCl emitted Scrubber Stack Vent Stack Fugitive Annual (lb/hr) Daily (lb/hr) Annual (lb/hr) Daily (lb/hr) Annual (lb/hr) Daily (lb/hr) Nitric Acid Hydrochloric Acid Sulfuric Acid Results of the modeling analysis are detailed in a memo dated April 13, Basically, the results show that the source can meet the AALs as long as no fugitive emissions are allowed to exhaust through the overhead door. Additional modeling was completed in May In this analysis it was assumed that all the fugitive emissions are exhausted out the vent stack. This scenario showed predicted exceedances of the 24-hr AAL for sulfuric acid. If all the exhausted emissions are controlled and vented through the scrubber with the fugitives exhausting out of the vent stack, then the AALs are met. The source is planning on changing the exhaust configuration of its baths so that all baths with sulfuric acid are exhausted to the scrubber. REVIEW OF REGULATIONS State Regulations Env-A 600 Permitting (effective 7/28/04) (n) NO The facility is a true minor source (v) YES A permit is required for RTAPs because controls are required for compliance with AALs. Env-A 1200 Prevention, Abatement and Control of Stationary Source Air Pollution (effective 10/31/02) NO Potential VOC emissions are less than 50 tpy. Env-A 1400 Regulated Toxic Air Pollutants (effective 6/11/04) 1402 YES Facility able to show compliance with actual, controlled emissions using either the de minimus emission rate or modeling (see discussion above). At the time of permit issuance, the RTAPs in Attachment C were reviewed and determined to be in compliance. Env-A 2100 Particulate Matter and Visible Emissions Standards (effective 11/24/04) YES TSP emissions shall be limited according to the formula stated in ((b) YES visible emissions shall not exceed 20% Federal Regulations Not applicable

4 AFS #: Application #: FY DATE: 9/2/05 Page 4 of 4 CHANGES FROM PREVIOUS PERMIT The previous permit detailed calculations that the source could perform to show compliance with Env-A These calculations are not applicable to the current conditions at the facility and will not be included in the updated permit. The previous permit had specific emission limitations for various acids. These limits are no longer applicable to the source. The permit will require the source to maintain compliance with Env-A It has been shown that the emission rates listed in Attachment A are in compliance (note that these emission rates are different than the limits in the previous permit). The previous permit state the following operating conditions for the wet fume scrubber: gas throughput of 7500 acfm at 75 F; minimum pressure drop of 1 inch of water; minimum recycle rate of 4 gal/min of a 1% sodium hydroxide solution; and input solution ph range of 8.5 to 9.0. According to the source, there is currently no continuous monitoring done on the scrubber. The ph is measured with a meter and ph adjustment is performed by the manual addition of sodium hydroxide solution. The new permit will contain conditions to monitor and record ph readings and maintain the ph between 8.5 and 9.5. SUMMARY AND CONCLUSIONS In summary, the operations as applied for (based on 2003 chemical usage) will be capable of meeting all regulations and standards for air quality with the use of pollution control. A State Permit to Operate has been drafted.

5 ATTACHMENT A List of Process Baths Bath # Process/Chemistry Exhaust 1 Multikleen 1602 sodium hydroxide Vent 2 Rinse Vent 3 Rinse None 4 Rinse None 5 ElectroKleen SP sodium hydroxide Vent 6 Hydrochloric acid 20% Scrubber 7 Hydrochloric acid 20% Scrubber 9 Rinse None 10 Hydrochloric acid 10% Scrubber 12 Electrogleam-55 sulfuric and phosphoric acids 50% each Scrubber 14 Rinse None 16 Nitric acid 5% None 17 Rinse Vent 18 Nickel Strike nickel chloride in solution None 19 Rinse None 20 Rinse None 21 Rinse None 22 Nitric acid 20% and sodium dichromate 5% Scrubber 23 Nitric acid 20% Scrubber 24 Sulfuric acid 5% Scrubber 25 Rinse None 26 Hydrochloric acid 10% None 27 Nitric acid 10% None 29 Black Oxide sodium hydroxide Vent 30 Rinse None 31 Rinse None 32 Ultra-Black 407 sodium hydroxide Vent 35 Isoprep 44 proprietary soap solution Vent 36 Isoprep 35 sodium hydoxide Vent 37 Rinse None 38 Di-Oxide NC-9 nitric, sulfuric and hydrofluoric acids None 39 Rinse None 40 Nitric acid 10% and ammonium fluoride 5% Scrubber 41 Rinse None 42 Rinse None 43 ZA-3-L sodium hydroxide None 44 Rinse None 45 Zincate Strip nitric acid 20% None 46 Electroless Nickel nickel sulfate solution Scrubber 47 Rinse None 48 Electroless Nickel nickel sulfate solution Scrubber 49 Rinse None 50 Rinse None 54 Nickel Strip nitric acid 35% Scrubber 55 NiStrip 900P ammonium hydroxide solution Vent 56 Rinse Vent 57 Iridite 57A chromic acid solution None The following baths were not in use at the time of this application: 8, 11, 13, 15, 33, 34, and 51. Numbers 52 and 53 are not associated with process baths and are therefore not listed above.

6 ATTACHMENT C List of RTAPs and Emission Rates Evaluated RTAP CAS # Emission Rate (lb/day) Emission Rate (lb/yr) Compliance Determination Method Acetic Acid In-Stack Acetone De minimus Ammonia Modeling Dipropylene Glycol Monomethyl Ether De minimus Ethylenediamine De minimus Hydrochloric Acid Modeling Methyl Ethyl Ketone Modeling Nitric Acid Modeling Phosphoric Acid Modeling Propylene Glycol Monomethyl Ether De minimus Sulfuric Acid Modeling Notes: 1. The RTAPs listed in bold print are required to be controlled. The emission rates listed above show the controlled emission rates where controls are required in order to show compliance. 2. Annual emissions were evaluated based on actual operation of the Facility. 3. CAS = Chemical Abstract Service.