# TechnicalSupportDocument Application for a Permit to Install ProposedModification to an Existing Decorative Chromium Plating Operation Lapeer, Michigan

for 

# DottIndustries, Inc. - DecoPlateManufacturing 395DeMilleRoad Lapeer, MI 48446

submittedby Horizon Environmental Corporation 4595BroadmoorSE, Suite 200 GrandRapids,Michigan 49512 January 

### 8, 2001

### • ,I TABLE OF CONTENTS 1. INTRODUCTION ................................................................................................................................................... 1 2. DESCRIPTION OFPROCESS AND PROPOSED CHANGES.......................................................................3 2.1 PROCESS DESCRIP110NAND PROPOSED CHANGES................................................................................................3 2.2 AlREMISSIONS CONTROLEQUIPMENT..................................................................................................................4 2.3 PROPOSED PROCESS CHANGES..............................................................................................................................6 3. ESTIl\IATION OF El\fi"SSIONS ............................................................._ .............................................................9 3.1 CHROME ELECTROPLATING TANK. ........................................................................................................................9 3.1.1 Chromium (VI) Emissions...........................................................................................................................9 3.1.2 SulforieAcidEmissions ............................................................................................................................ 10 3.1.3 Cumulative System 1Emissions Summary................................................................................... ............ 10 3.1.4 RegulatoryStatusjortheProposed Chrome Plating Tank..................................................................... 11 3.2 BRIGHTACID COPPERTANK ............................................................................................................................... 11

. 3.2.1 Sul.furicAcidEmissions ............................................................................................................................ 11 3.2.2 Cumulative System 2Emissions Summary............................................................................................... 12 3.2.3 RegulatoryStatus for the ProposedBrightAcid Copper Tank ................................................................ 13 3.3 COPPERINICKEL STRIPTANK .............................................................................................................................. 13 3.3.1 CumulativeSystem 4 Emissions Summary................................................................................ ............... 14 3.3.2 RegulatoryStatus fortheProposed CopperlNickelStrip Tank............................................................... 14 3.4 PRE-cQNDmONERTANK..................................................................................................................................... 15 3.4.1 Amino-SaturatedButrolactoneEmissions................................................................................................ 15 3.4.2 Cumulative System 5 Emissions Summary............................................................................................... 16 3.4.3 RegulatoryStatus forthePreconditioner Tank........................................................................................ 16 3.5 SEMI-BRIGHTNICKELANDBRIGHTNICKELTANKS ........................................................................................... 17 3.6 EMISSION SUMMARYANDCOMPARISON TO FACILITY'S CURRENTROP LIMITS ............................................... 18 4. APPLICABLE REGULATORY REQUIREMENTS..................._ .............................................._ ...............20 4.1 MICHIGAN AIRQUAJ.JTY REQUIREMENTS..........................................................................................................20 4.1./ MAR 201 - Permits to Install....................................................................................................................20 4.1.2 MAR 2J6 - Modifications to Renewable Operating Permits ................................................................... 21 Dott Iodustrfes, Inc:. Pennit to Install Application Lapeer, Michigan 

### -iHorizoD Environmental Corporadon Technical Support Document October3,2000·1 4.1.3 MAR 225 - Health-BasedScreeningLevelRequirement forNeworModifiedSources of Air Toxies ... 21 4.2 NATIONAL EMISSIONS STANDARDS FOR HAzARDOUS AIRPOLLur ANTS ...........................................................22 S. Al\mIENTAIR QUALITY Il\fP ACT ANALYSIS...........................................................................................24 5.1 DESCRIPTION OF SITEAREA ...........................................:....................................................................................24 5.1.1 Land Use Classijication............................................................................................................................24 5.1.2 Topography.................................................................... ...........................................................................25 5.2 DISPERSION MODEL.............................................................................................................................................26 5.2.1 BUilding Downwash Effects........................................................................... ........................................... 27 5.3 DATABASES USED IN AIR QUALITY IMPACTANALySiS......................................................................................27 5.3.1 MeteorologicalData......................................................................... ........................................................28 5.3.2 ReceptorPoints............................................................................................,............................................ 28 5.3.3 Emission Inventory..................................................................... ...............................................................29 5.5 AIRQUAUTY IMPACT..........................................................................................................................................29
TABLE OFCONTENTS (CONT'D)
FIGURES 1 Bun.OING PROJECllONS IN RELATION TO EMISSION POINTS 2 RECEPTOR GRID

TABLES lA SULFURIC ACID EMISSIONS FROM THENEW BRIGHT ACID COPPERTANK (SYSTEM #2) 1 B SYSTEM #2 - SULFURIC ACID EMISSIONS FROM COPPER STRIKE AND ACID COPPER TANKS 2A SULFURIC ACID EMISSIONS FROM THE NEW COPPERINICKEL STRIP TANK (SYSTEM 

### #4) 2B SYSTEM 

### #4 - NITRIC ACID EMISSIONS FROM NITRIC STRIP TANKS (PROPOSED TANK AND TANK#39) 2C SYSTEM 

### #4 - HYDROCHLORIC ACID EMISSIONS FROM NEUTRALIZER TANK (TANK #5) Dott IDdustrles, Inc. Permit to Install Application Lapeer, Michigan - 11 - Horizon EDvironmental CorporatloD Technical Support Document October3, 2000 

# ,.) 

### 3A AMINO-SATURATED BUTROLACTONE EMISSIONS FROM THE NEW PRECONDITIONER TANK (SYSTEM 5) 3B SYSTEM #5 - CHROME VI EMISSIONS FROM PRE-ETCH AND ETCH TANKS (TANKS #1, #2A, AND #2B) 3C SYSTEM #5 - SULFURIC ACID EMISSIONS FROM PRE-ETCH AND ETCH TANKS (TANKS #1, #2A, AND#2B) 4 

### SUMMARY OF AIR POLLUTANTS EMISSIONS FROM THE MODIFIED PLATING PROCESS 5 AVER LAND USE CLASSIFICATION SCHEME 

### 6 

### COMPARISON OF PREDICTED HEXAVALENT

### CHROMIUM IMPACTS 

### TO MAR

### 225 SCREENING LEVELS

APPENDICES A PERMIT TO INSTALL APPLICATION 

### FORM B FACfl..I1Y 

### PLOT PLANS 

### C RELEvANT

### MA1ERlAL

### SAFE1Y DATA 

### SHEETS D DISPERSION MODELING 

### INPUT/OUTPUTFll..ES (DISKETIE)

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan - 1I1 - Horizon Environmental Corporation Technical Support Document October 3, 2000

# ..
1. INTRODUCTION Dott Industries, Inc. - Deco Plate Manufacturing ("Dott" ) owns and operates a metallic plating process for applying a chrome finish on plastic parts at their facility located at 395 DeMille Road, Lapeer, Michigan. The plating process is comprised ofa number ofstages (i.e., 

### tanks) that include pre-etching, etching, and activator/accelerator 

### tanks fOT preparing parts for plating, and subsequent copper, nickel, and chrome plating tanks, which are used in differing combinations to provide the desired swface finish. The plating process also contains copper/nickel strip and chrome strip tanks used to clean the parts racks following removal ofthe plated plastic parts. The plant operates in accordance with the terms and conditions of State of Michigan Renewable Operating Permit ("ROP") Number 199600451, issued by the Air Quality Division (" AQD" ) ofthe Michigan Department of Environmental Quality ("MDEQ" ) on June 2, 1999. Dott proposes to make a change at the facility, by installing additional 

### tanks to increase the capacity and efficiency ofthe plating process. The proposed tanks include: one (1) two-bay preconditioner tank; two (2) two-bay semi-bright nickel plating 

### tanks; one 

### (l) single-bay bright nickel plating tank; one (1) two-bay acid copper plating 

### tank; one 

### (l) single-bay chrome plating 

### tank; and one (1) single-bay copper/nickel strip tank. Only the chrome plating 

### tank installation is required to obtain an air use permit for construction. The rest of the proposed tanks are considered exempt from permitting according to Rules 285(r)(vii) and 290 ofMichigan's Administrative Rules ("MARs" ) for Air Pollution Control (PA 451 of 1991). Pursuant to Rule 201 of MAR for Air Pollution Control (PA 451 of 1991), a Permit to Install covering the proposed chrome plating 

### tank must be issued by the AQD prior to installation. This technical support document constitutes the Permit to Install application package for the proposed chrome plating tank for the Dott facility. Infonnation necessary

Dott Industries, Inc. Pennit to Install Application Lapeer, Michigan 

### - 1 - Horizon Environmental Corporation Technical Support Document October3, 2000to demonstrate compliance with a11 applicable air quality requirements, as specified in MAR 203, is presented within this document. An analysis of the proposed operation, including a description ofthe process, emissions control devices, and equipment specifications, is presented in Section 2.0 ofthis document. Applicable state and federal air quality requirements are introduced in Section 3.0, while Section 4.0 summarizes emissions estimates. Ambient air quality dispersion modeling analyses demonstrating that potential toxic 

### air contaminant ("T AC" ) emissions due to the proposed modification will not exceed applicable MAR225health-based screening levels is presented in Section 5.0. The required Pennit to Install application form is submitted as Appendix A to this document. Detailed facility plot plans are submitted with this docwnent as Appendix B. Relevant Material Safety Data Sheets are provided in Appendix C and dispersion modeling input/output files (in electronic fonnat) are submitted as Appendix D.

Dott indUstries, Ine. Pennit to Install Application Lapeer, Michigan -2- Horizon Environmental Corporation Technical Support Document October3, 2000

# '.

2. DESCRIPTION OF PROCESS AND PROPOSED CHANGES Dott proposes to make a change at its Lapeer facility, by installing an additional chromeplating 

### tank to increase the capacity ofthe plating process. The facility is located at 395 DeMille Road, in the City of Lapeer, Lapeer County, Michigan. A description of the plating process, emissions controls, and proposed changes is provided below. 2.1 PROCESS DESCRIPTION AND PROPOSED CHANGES The plating process is a multiple stage operation, consisting of a number of sequential 

### tanks, which is utilized in producing a metallic coating on plastic parts. Depending on the coating desired, differing sequences of the surface preparation and plating 

### tanks may be used. This process description covers all 

### tank stages in the sequence. The initial stages in the plastic part plating process deal with preparation ofthe substrate to beplated (i.e. the plastic parts). Preparatory stages include pre-etch (Tank I), etch (Tank 2), neutralizer (Tank 5), activator (Tank 7), and accelerator (Tank 9) tanks, and intennediate water rinse 

### tanks. Each ofthese stages generally contain a solution ofacids and reducing agents designed to prepare the plastic parts to better accept the metallic plating. Dott proposes to add an additional preconditioner

### tank to the surface preparation 

### tank group. The next 

### tank grouping in the plating process is comprised ofthose tanks that are used for application ofa copper base coat. The stages include electro less copper (Tank 11), copper strike (Tank 14), and bright acid copper (Tanks 15, 16, 17, 18, 19) 

### tanks, and intennediate water rinse tanks. Dott proposes to add one additional bright acid copper

### tank to the copper plating 

### tank group. The next 

### tank grouping in the plating process is comprised ofthose 

### tanks that are used for application ofa nickel intermediate coat. The stages include semi-bright nickel (Tanks 24, Dott IDdustries, Inc. Permit to Install Application Lapeer, Michigan 

### -3- Horizon Environmental Corporation Technical Support Document October3, 200025,26), bright nickel (Tank 28), microporosity nickel (Tanks 29, ?), and pearl nickel (Tank ?) tanks, and intennediate water rinse tanks. Dott proposes to add two additional semibright nickel and one additional bright nickel tank to the nickel plating tank group. The following tank grouping in theplating process is comprised ofthose tanks that are used for application ofa chrome surface coat. The stages include a chrome plating tank (Tank 32), and final parts water rinse tanks. Dott proposes to add one additional chrome tank to the chromeplatingtank group. The final tank grouping in the plating process is comprised ofthose tanks that are used for removal ofthe metallic plating accumulated on the racks utilized to hold the plastic parts to be plated. The stages include chrome strip (Tank 37) and copper/nickel strip (Tank 39) tanks, and intermediate water rinse 

### tanks. Dott proposes to add one additional copper/nickel strip tank to the rack cleaning tank group. 2.2 AIREMISSIONS CONTROL EQUIPMENT Chemical fume suppressants containing wetting agents are utilized in all plating tanks at the Dott facility. The fume suppressants minimize emissions ofmetals and acid mists to the atmosphere by maintaining the surface tension ofthe plating baths at low levels at all times during operation ofthe plating tanks In addition, emissions from the plating process are captured and controlled by one offive existing emission control systems. Each control system is designed to remove aerosol emissions ofacids and metals released from the surface oftheplating 

### tanks. Capture ofthe aerosol emissions is accomplished by use ofpush-pull lateral exhaust hoods at the edges of plating 

### tanks requiring control. The five capture and control systems are currently configured to control emissions from multiple tanks, as follows:

Dott Industries, Inc. Pennit to Install Application Lapeer, Michigan -4- Horizon Environmental Corporatfon Technical Suppon Document October3, 2000System 1: Emissions captured from one chrome electroplating tank (Tank 32) and treated by a water-washed mesh pad mist eliminator with a rated aerosol control efficiency of99 percent. The air contaminant controlled by the mesh pad mist eliminatoris hexavalent chromium. System 2: Emissions captured from one copper strike tank (Tank 14) and five bright copper tanks (Tanks 15 through 19) and treated by six cyclonic mist eliminators with a rated aerosol control efficiency of 40 percent. The 

### air contaminant controlled bythe cyclonic mist eliminator is sulfuric acid. System 3: Emissions captured from one activator 

### tank (Tank 7), one accelerator 

### tank (Tank 9) and one electroless coppertank (Tank 11) and treated by a packed-bed water scrubber with a rated aerosol control efficiency of 96 percent. The air contaminants controlled by the packed-bed scrubber are hydrochloric acid and fonnaldehyde. System 4: Emissions captured from one neutralizer tank (Tank 5) and one copper/nickel strip 

### tank (Tank 39) and treated by a packed-bed water scrubber with a rated aerosol control efficiency of96 percent. The air contaminant controlled by the packed-bed scrubberishydrochloric 

### acid System 5: Emissions captured from one pre-etch tank (Tank 1) and one etch tank (Tank 2) and treated by a dry mesh pad scrubber with a rated aerosol control efficiency of 99 percent. The air contaminants controlled by the 

### dry mesh pad scrubber are hexavalent chromium and sulfuric acid. All other 

### tanks included in the plating process, including the chrome strip 

### tank, and all water rinse tanks, do not require capture and control of their emissions and are vented directly into the general building air space.

Dott Industries, Ine. Permit to Install Application Lapeer, Michigan 

### - 5- Horizon Environmental Corporation Technical Suppon Dccument October3, 2000"

... 2.3 PROPOSED PROCESS CHANGES As noted in Section 2.1, Dott proposes to install seven additional tanks to the existing plating process. The following section provides a description ofthe proposed new tanks. 

### NewPreconditioner Tank (1)
• Dimensions: 108" x 72" x 68" (LxWxD) • Solution Temperature: 103-165 0 F • Surface Tension: 50 dynes/em • 15%

### MicroEtch etching solution; balance is water • Equipped with air agitation system for mixing (0.35 

### ft3 air/min-fil) • Emissions collected and treated by Control System 5 The new preconditioner 

### tank will act as an additional substrate preparation step prior to plating ofthe plastic parts. The active ingredient in the tank will be

### MicroEtch, produced by CRT, Inc ofOkemos, Michigan. A MSDS for the material is presented as Appendix C. 

### NewBrightAcidCopper Tank (1)
• Dimensions: 108" x 72" x 68" (LxWxD) • Solution Temperature: ambient • SurfaceTension: 55 dynes/em • 25 ozJgal copper sulfate; 15 ozJgal sulfuric acid; balance is water • Equipped with air agitation system for mixing (0.35 

### ft3 air/min-fill • Emissions collected and treated by Control System 2 The new bright acid copper 

### tank will operate in the same manner as existing Tanks 15 through 19. 

### NewSemi-BrightNickel Tanks (2)
• Dimensions: 108" x 72" x 68" (LxWxO) • Solution Temperature: 145 0 F • Surface Tension: Uncontrolled Dott Industries, Inc. Pennit to Install Application Lapeer, Michigan 

### -6- HorizoD Environmental Corporation Technical Support Document October3, 2000• 10 ozJgal nickel metal; 6.5 ozJgal boric acid; balance is water • Equipped with air agitation system for mixing (0.35 Wair/min-fil) • Emissions vented to general building airspace The new semi-bright nickel tanks will operate in the same manner 

### as existing Tanks 24 through 26. 

### NewBrightNickel Tanks (1)
• Dimensions: 108" x 42" x**68'~** (LxWxD) • Solution Temperature: 145 0 F • Surface Tension: Uncontrolled • 10 ozJgal nickel metal; 6.5 ozJgal boric acid; balance is water • Equipped with air agitation system for mixing (0.35 Wair/min-fil) • Emissions vented to general building airspace The new bright nickel tank will operate inthe samemanner as existing Tank 28. 

### New Chrome Tank (1)
• Dimensions: 108" x 42" x 68" (LxWxD) • Solution Temperature: 1100 F • Surface Tension: 40 dynes/em • 40 ozlgal chromic acid (crO); 0.13 ozlgal sulfuric acid; balanceis water • No air agitation • Emissions captured and treated by Control System 1. Thenew chrome tank will operate inthe same manner as existing Tank 32. 

### New CopperlNickelStrip Tank (1)
• Dimensions: 108" x 42" x 68" (LxWxD) • Solution Temperature: 1300 F • Surface Tension: Uncontrolled • 20 ozlgal total metals (copper and nickel); 10 N nitric acid; balance is water • Equipped with air agitation system for mixing (0.35 Wair/min-fil) • Emissions captured and treated by Control System 4.

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan - 7 - HorizoD Environmental Corporation Technical Support Document October3, 2000 •

### The new copper/nickel strip tank 

### will operate inthe same manner as existing Tank 39.

Dott Industries, IDe. Permit to Install Application Lapeer, Michigan 

### -8- Horizon Environmental Corporadon Technical SupportDocument October3, 2000

### 3. ESTIMATION OF EMISSIONS This section presents emission estimates of toxic air pollutants from the proposed tanks. Based on emission levels and/or type ofprocess, a determination is made ofwhether a 

### tank is exempt from permitting or subject to the permitting requirements ofMAR Rule 201.
3.1 CHROME ELECTROPLATINGTANK This tanks composition will be 40 oz.lgal 

### er03 and 0.14 oz.lgal H2

### S0 4, The surface tension will be maintained at a maximum of40 dynes/em. The 

### tank will be vented through Control System 1 consisting ofa mesh pad mist eliminator and a control efficiency of99%. 

### 3.1.1 Chromium (VI) 

### Emissions According to the US EPA publication 

### "Compilation of AirPollutant Emission Factors, AP42, Fifth Edition, Volume 

### 1: Stationary Point andArea Sources" ("AP-42" ), Chapter 12, Table 12.20-1, the chromium (VI) ("Cr (VI)" ) emission factor for decorative chromium electroplating with fume suppressant is 1.2·10-6 grains/dscf. Using this emission factor, Cr (VI) emissions from the new chrome tank is equal to: 1.2.10-6

### ~ X 453.6.106 

### pg Cr (VI) Emissions 

## = x dscf 7,000 

### gr 1 

### ft3 IIg 

## = 2.75 -""-'3 0.0283 m3 m The rated control efficiency for the mesh pad is 99%. However, for a control efficiency was used in the calculation for conservatism. Using an actual control efficiency of 97%, the controlled Cr(VI) emissions are equal to:

Dott IDdustrles, IDe. Pennitto Install Application Lapeer, Michigan 

### -9- Horizou EDviroDmentaJ CorporadoD Technical Support Document October3,2000Controlled Cr (VI) Emissions 

## = 2.75

## ,u~ x (I - 0.97) 

## = 0.082

## ,u~ m m 3.1.2 SulfuricAcid Emissions According to AP-42, the majority of the emissions consist of Cr (VI). Sulfuric acid emission is considered negligible since the 

### H2

### S04 concentration in the plating tanks is low (0.13 oz.lgal) 

### as compared to erO) concentration of40 oz./gal. 3.1.3 Cumulative System 1 Emissions Summary System 1 will consist oftwo chrome electroplating tanks (#32 and the new chrome tank). Both tanks are exhausted through a mesh pad mist eliminator with a rated control efficiency of99%. Chrome VIEmissions Chrome VI emissions from the existing chrome tank (Tank 32) is equivalent to new tank's emissions, so the total chromium emissions from System 1 are double the emissions from the new tank, or0.164 Jlglml

. SulforicAcidEmissions Sulfuric acid emission is considered negligible since the H2S04 concentration in the plating tanks is low (0.13 oz./gal) 

### as compared to erO) concentration of40 oz./gal.

Dott Industries, Inc. Pennit to Install Application Lapeer. Michigan - 10- Horizon Environmental Corporation Technical Support Document October 3. 2000

### 3.1.4 Regulatory Status for the Proposed Chrome Plating Tank Since Chrome emissions from this tank are not released into the general in-plant environment and the corresponding IRSL is less than 0.04 mglm3, the proposed chrome tank 

### is not considered exempt per MAR Rules 284r)(vii) and 290(a)(ii) and 290(a)(iii). Therefore, the proposed chrome plating 

### tank is subject to permitting requirements under Rule 201. 

### 3.2 BRIGHTACID COPPERTANK 

### This tanks composition will be 25 oz.lgal CuS0 4 

### and 15 oz.lgal H2

### S0 4• 

### Nonnal operating surface tension is 55 dynes/em. The tank will be vented through Control System 2 consisting ofa cyclonic mist eliminators and an aerosol control efficiency ofa minimum of 40%. Potential emission from this tank 

### is expected to only consist ofsulfuric acid mist. 

### 3.2.1 SulfuricAcid Emissions Sulfuric acid emissions from the new acid copper tank 

### is due to: 1) electrical current loss, and 2) air agitation. Since the process cathode efficiency is approximately 98%, current loss is negligible; consequently sulfuric acid mist emissions due to electrical current loss is considered to be negligible. Mist generated due to air agitation can be estimated using Equation 4, AP-42, Section 12.20.2.

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan - 11 - Horizon Environmental Corporation Technical Suppan Document October 3, 2000E misl 

## = x [(1 - 2a 

### + 9a2

# t 5 

### + (a - 

### 1)

# ]°
05 

### (I 

### + 3a) - (1 - 2a 

### + 9a2

## )005 where: Emist 

## = Mist emission factor in grains 

### I ft3 ofaeration air; Rb 

## = Average bubbleradius, in. 

## = 0.25 inches (j 

## = Surface tension ofbath, lb r 1ft a 

## = 0.072 x S.G. x**R~** (j S. G. = Specific gravity ofthebath This correlation allows the calculation of the mist emission rate generated due to air agitation. The mist composition is considered to be the same 

### as the bath composition. Using this equation, total controlled sulfuric acid emissions from the new bright acid copper tank are calculated at 5.2'10'" lblhr, 3.8'10'\ lb/month, and 5.2 J.1g/m3• The calculation details 

### are presented in Table 1 A. 

### 3.2.2 Cumulative System2 Emissions Summary System 2 will consist ofone copper strike tank (# 14) and six bright acid copper

### tanks (# 15 through #19 and the new bright acid copper tank), The tank solutions used 

### in each ofthe existing bright acid copper 

### tanks (Tank #15 through #19) are identical to the new tank composition. All 

### tanks are exhausted through a cyclone. The control efficiency is conservatively estimated at 40%. Cumulative SulforicAcidEmissions Sulfuric acid emissions from System 2 

### are calculated at 3.1'10-3 Iblhr, 2.3 lb/month, and 31.8 llg/m3, Thecalculation details are presented in Table 1 B.

Dott Industries, Inc. Pennit to Install Application Lapeer, Michigan - 12- Horizon Environmental Corporation Technical Support Docwnent October3,2000

### · 3.2.3 Regulatory Status for the Proposed BrightAcid CopperTank Based on sulfuric acid (ITSL 

## = 10 J.1g!m3, 

### 8-hour average) emission levels, the proposed bright acid coppertank is exempt from pennittingperRule 290(a)(ii)(A) which state: 

### "(a) An emission unit which meets any of the following criteria: (i) ... (ii) 

### Any emission unit that the total uncontrolled or controlled emissions of air contaminants are not more than 1,000 or 500poundsper month, respectively. and all of the following criteria are met: (A) For noncarcinogenic air contaminants, excluding noncarcinogenic volatile organic compounds and noncarcinogenic materials which are listed in R 336.1122(f) as not contributing appreciably to theformation of ozone, with inilialthreshold screening levels greater than or equal to 2.0 microgramsper cubic meter, the uncontrolled or controlled emissions shall not exceed J,

### 000 or 500poundspermonth, respectively. JJ 

### 3.3 COPPERINICKEL STRIPTANK 

### This tank's composition 

### will be made up of nitric acid and water. The nitric acid bath concentration 

### will be maintained at a nonnality equal 

### to 

### ION. The tank 

### will be vented through Control System 

### 4 consisting of a packed bed scrubber having a rated control efficiency of 96% (For purposes of conservative emission calculations, a 95% control efficiency was used). Only nitric acid mist is expected to be emitted released from this new copper/nickel strip tank. Emissions ofnitric acid from the new copper/nickel strip tank are mainly due to air agitation. The nitric acid emissions are calculated using the approach described above for sulfuric acid (Section 3.2.1). Using this approach, nitric acid emissions from the new tank are calculated at 1.8'10-4 Iblhr, 1.3'10,1 lb/month, and 4.4 

### J-lg/m3, 

### The calculation details are presented in Table 2A.

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan 

### - 13 - Horizon Environmental Corporadon Technical Suppon Document October3, 20003.3.1 Cumulative System 4 Emissions Summary System 4 will consist ofone neutralizer 

### tank (#5) and two copper/nickel strip 

### tanks (#39 and the new strip tank). The solution used in Tank 5 contains hydrochloric acid and the solution used in Tank 39 and the new 

### tank contains nitric acid. Potential 

### air emissions consist ofhydrochloric acid from Tank 5 and nitric acid from Tanks #39 and the new tank. The tanks are exhausted through a packed bed scrubberhaving a rated control efficiency of 96% (For purposes of conservative emission calculations, a 95% control efficiency was used). Cumulative NitricAcidEmissions Nitric acid emissions from System 4 are calculated at 3.6·10-4 lblhr, 2.6·}0. 1 lb/month, and 8.8 fJglml

. The ca1culation details are presented in Table 2B. CumulativeHydrochloricAcidEmissions Hydrochloric acid emissions from System 4 are calculated at 2.9·10-6 Iblhr, 2.1 .10-3 Ib/month, and 0.07 fJglm3• The calculation details are presented in Table 2e. 3.3.2 Regulatory Status for the Proposed CopperlNickel StripTank Based on nitric acid (ITSL 

## =50 fJglm3, 8-hour average) emission levels, the proposed bright copper/nickel strip 

### tank is exempt from permitting per Rule 290(a)(ii)(A) which state: "(a) An emission unit which meets any of the follOWing criteria: (i) ..: Dolt Industries, IDCo Permit to Install Application Lapeer, Michigan - 14- HorizoD EDvironmental CorporatioD Technical Support Document October 3, 2000(ii) 

### Any emission unit that the total uncontrolled or controlled emissions of air contaminants are not more than 1,000 or 500poundsper month, respectively, and all of the following criteria are met: (A) For noncarcinogenic air contaminants, excluding noncarcinogenic volatile organic compounds and noncarcinogenic materials which are listed in R 336.JJ22(f) as not contributing appreciably to theformation of ozone, with initial threshold screening levels greater than or equal to 2.0 microgramsper cubic meter, the uncontrolled or controlled emissions shall not exceed 1,000 or 500poundspermonth, respectively. .. 3.4 PRE-CONDITIONER

### TANK 

### This tank's composition will be made up of 15% 

### MicroEtch etching solution and the balance is water. Nonnal operating surface tension for this tank 

### will be 55 

### dynes/em. The MicroEtch Solution contains amino-saturated butrolactone. Potential air 

### emissions from this tank 

### consist ofamino-saturated butrolactone which makes 100% 

### ofthe MicroEtch Solution. The tank will be vented through Control System 5 consisting ofa dry mesh pad mist eliminator having a rated control efficiency of 99% (For purposes of conservative emission calculations, a 97% control efficiency was used). 3.4.1 Amino-Saturated ButrolactoneEmissions 

### Emissions of amino-saturated butrolactone from the new preconditioner tank 

### are mainly due to air agitation. The amino-saturated butrolactone emissions are calculated using the approach described above for sulfuric acid (Section 3.2.1). Using this approach, aminosaturated butrolactone emissions from the new preconditioner tank are calculated at .1.9'10'" 

### lblhr, 1.4'10'\ 

### lb/month, and 3.77 J.1g1m3• 

### The calculation details are presented in Table 3A.

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan 

### - 15- Horizon Environmental Corporation Technical Support Document October3, 2000

### 3.4.2 Cumulative System 5 Emissions Summary System 5 will consist of one pre-etch tank (#1), two etch tanks (#2A and #2B), and one preconditioner tank (new). The tank solutions used in Tanks 1, 2A, and 2B consist of a mixture of chromic acid and sulfuric acid. The solution in the new preconditioner 

### tank contains amino-saturated butrolactone. Potential air emissions from these tanks include Cr (VI), sulfuric acid, and butrolactone. The tanks are exhausted through a 

### dry mesh pad mist eliminatorhaving a rated control efficiency of99% (For purposes ofconservative emission calculations, a 97% control efficiency was used). Cumulative Chrome VI Emissions Chrome VI emissions from System 5 are calculated at 

### 1.0·10-4 Iblhr, 

### 7.5.10-2 

### Ib/month, and 2.2 J-lglm3• The calculation details are presented inTable 38. Cumulative SulforicAcid Emissions Sulfuric acid emissions from System 

### 5 are calculated at 

### 2.0·10-4 Iblhr, 

### 1.4.10-1 Ib/month, and 4.3 J-lglm3• The calculation details are presented in Table 3C. Cumu/atiyeAmino-SaturatedButro/actone Emissions Amino-saturated butrolactone emissions from the new preconditioner

### tank are calculated at 

### 1.9·10-4 lblhr, 

### 1.4.10-1 lb/month, and 

### 3.77 J.1g1ml • The calculation details are presented in Table 3A. 

### 3.4.3 Regulatory Status for the PreconditionerTank

Dott Industries, Inc. Pennitto Install Application Lapeer, Michigan 

### - 16- Horizon Environmental Corporation Technical Support Document October 3, 2000Based on amino-saturated butrolactone (ITSL 

## = 0.1 J,lglml, annual trace level) emission levels, the proposed bright copper/nickel strip tank is exempt from permitting per Rule 290(a)(ii)(A) which state: 

### "(a) An emission unit which meets any of the following criteria: (i) ... 

### (U) Any emission unit that the total uncontrolled orcontrolled emissions of air contaminants are not more than 1.000 or 500poundsper month. respectively, and all of the following criteria are met: (B) For noncarcinogenic air contaminants. excluding noncarcinogenic volatile organic compounds and noncarcinogenic materials which are listed in R 336.1122(f) as not contributing appreciably to theformation of ozone, with initial threshold screening levels greater than or equal to 0.04 microgramsper cubic meter and less than 2.0 microgramsper cubic meter. the uncontrolled or controlled emissions shall not exceed 20 or 10 pounds per month. respectively . .. 3.5 SEMI-BRIGHT NICKELAND BRIGHT NICKELTANKS As stated in Section 

### ??? the semi-bright and bright nickel tanks are used for application ofa nickel intennediate coat. 

### Air emissions associated with these 

### tanks are considered negligible and released into the general in-plant environment. Per MAR Rule 285(r)(vii), these 

### tanks are exemtp from thepermitting requirements ofRule 201. Rule 285(r)(vii) states: 

### "(r) Equipment used for any of thefollowing metal treatmentprocesses 

### if theprocess emissions are only released into the general in-plant environment:

(vii) Electrolytic stripping orelectrolyticplating . ..

Dott Industries, InCo Permit to Install Application Lapeer, Michigan 

### - 17- Horizon Environmental Corporadon Technical Support Document October3, 2000

# .. 3.6 EMISSION SUMMARY AND COMPARISON TO FACILITY'S CURRENT

### ROP LIMITS 

### According to the facility's RO Pennit No. 199600451, emission limits for hexavalent chromium, sulfuric acid, hydrochloric acid, and fonnaldehyde are either specified by an emission unit consistent with an existing Control Systems, or by a flexible grouping consisting ofseveral Control Systems. Thebreakdown is as follows: EMISSION LIMITS BY RENEWABLE OPERATING PERMIT GROUP 

### ID ROP Control Chrome (VI) H2SO4 HCI Formaldehyde GroupID Systems Limit Limit Limit Limit Included (J.Lglml) (mglml) (mglml) (mglml) E-l.3 System I 2.9 

### NA NA NA F-l.l System 2 (contains E-1.4, System 3 

### NA 4.65 4.65 1.02

E-l.S, E-1.6) System 4 E-l.7 System 5 11.5 6.05 

### NA NA All emission limit values are corrected to 70 degrees F and 29.92 inches ofmercury. Therefore, the estimated air pollutant concentrations were calculated, on a per pollutant basis, for each ofthe three applicable ROP groups. For Group ID numbers E-l.3 and E-l.7, the emissions were consistent with those estimated previously for Control Systems I and 5, respectively. Air pollutant concentrations from Group ID F-l.l were calculated by summing the mass emission rate ofthe individual pollutants from each applicable control system and dividing by the corresponding total airflow through the applicable systems. For example, sulfuric acid mass emissions from Control Systems 2,3, and 4 are added together and divided by the sum of the volumetric airflow rates for Control Systems 2, 3, and 4. This calculation is shown in Table 4.

Dott Industries, Inc:. Pennit to Install Application Lapeer, Michigan 

### - 18- Horizon Environmental Corporation Technical Support Document October 3, 2000The final ROP group emissions including the proposed equipment are as follows: ESTIMATED EMISSION CONCENTRAnONS BY RENEWABLE OPERATING PERMIT GROUP 

### ID ROP Control Chrome (VI) H2SO4 HCl Fonnaldehyde GroupID Systems Emissions Emissions Emissions Emissions Included ijlg/ml) (mg/ml) (mglml) (mglml) E-l.3 System 1 0.164 NA NA NA F-l.l System 2 NO (contains E-1.4, System 3 NA 0.032 0.00003 PROPOSED

E-1.S, E-1.6) System 4 Changes E-l.7 System 5 

### 2.2 0.004 NA NA

As shown in this table which include emission increases due to the proposed modification, chromium (VI) emissions, sulfuric acid emissions, and hydrochloric acid emissions are in compliance with the corresponding emission limits specified in RO Pennit No. 199600451.

Dott Industries, Inc:. Pennit to Install Application Lapeer, Michigan - 19- Horizon Environmental Corporation Technical Support Document October3, 2000

### 4. APPU,CABLE REGULATORY REQUIREMENTS The proposed chrome plating tank installation will be subject to certain state and federal air quality regulations. Requirements applicable to the proposed modification are summarized below.

4.1 MICmGAN AIR QUALITY REQUIREMENTS Michigan's Administrative Rules for AirPollution Control set forth requirements for new or modified sources ofair contaminants, including sources ofTACs. As described below, the proposed installation

### has been designed to comply with all applicable 

### MARs.

4.1.1 

### MAR 201- Permits to Install Pursuant to MAR 201.**'~person** shallnot install, construct. reconstruct. relocate, alter, or modify anyprocess orprocess equipment, including control equipmentpertaining thereto, which may emit an aircontaminant, unless apermitto install which authorizes such action is issued 

### bythe department." Theproposed addition ofa chrome plating 

### tank constitutes a modification; consequently, a Permit to Install must be issued by the AQD prior to the installation and trial operation of the proposed modification. This technical support document constitutes the Permit to Install application for the proposed modification. In accordance with MAR 203 (Information Required), the Pennit to Install application form (Appendix A) and supporting documentation for the proposed installation are included 

### in this submittal.

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan - 20- Horizon Environmental Corporation Technical Support Document October 3,2000

### • 4.1.2 MAR216 - Modifications to Renewable OperatingPermits The Dott facility is classified as a major stationary source pursuant to MAR 21 1 (a)(ii) 

### (Renewable OperatingPermitApplicability). The AQD has issued a Renewable Operating Pennit ("ROP" ) for the facility. The tenns and conditions ofa Pennit to Install issued after receipt of

### an ROP must be incorporated into the ROP. Ofthe 

### three possible procedures for modifying an ROP, as provided for in MAR 216 and described 

### in detail 

### in AQD Operational Memorandum No.2, a Minor Permit Modification will be applicable to the requested Pennit to Install. Dott will comply with all applicable Minor Permit Modification submittal requirements. 

### 4.1.3 MAR 225 - Health-Based Screening Level Requirement for New or Modified Sources ofAirToxies 

### MAR 225 presents emission limitations and control technology requirements for all new or modified sources ofTACs. MAR 225 states: (1) ':.4 

### person who is responsible for any proposed new or modified emission unit ...which emits a toxic air contaminant (l' 

### AC) 

### shall not cause or allow the emission of the toxic air contaminant ...in excess o/themaximum allowable emission rate which results in a predicted maximum ambient impact that is more than the initial thresholdscreening level or the initial riskscreening level. orboth... As required under MAR 225, a conservatively based ambient air quality impact analysis was conducted demonstrating compliance with applicable health-based screening levels. Theresults ofthe impact analysis are summarized in Section 5.0.

Dott Industries, Inc. Pennillo Install Application Lapeer, Michigan - 21 - Horizon Environmeatal Corporadon Technical Support Documenl October 3, 2000

### • 4.2 NATIONAL EMISSIONS STANDARDS FOR 

### HAzARDous AIR POLLUTANTS 

### The proposed modification is subject to National Emission Standards for Hazardous Air Pollutants (NESHAP) for Chromium Emissions from Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks, Subpart N (40 CFR 63.340). This standard applies to each chromium electroplating or chromium anodizing tank at 

### facilities performing hard chromium electroplating, decorative chromium electroplating, or chromium anodizing. Process 

### tanks associated with chromium electroplating or anodizing, but in which neither chromium electroplating nor anodizing take place, are not subject to the provisions ofthis subpart. The NESHAP requirements listed in Subpart N are summarized as follows:

• §63.342(a) - "Each owner oroperator of an affectedsource subject to theprovisions of this subpart shall comply with these requirements on and after the compliance dates specified in §63.343(a). All affected sources are regulated by applying maximum achievable control technology . .. • §63.342(b)(2) - 

## "If an owneror operator is controlling a group of tanks with a common add-on airpollution control device, the emission limitations of paragraphs (c), 

### (d), and (e) of this section apply wheneveroneaffectedsource is operated. OJ • §63.342(d) - "Standards/or decorative chromium electroplating tanks using a chromic acid bath and chromium anodizing tanks. During tank operation, each owner or operator of an existing, new, or reconstructed affected source shall control chromium emissions discharged to the atmosphere from thataffectedsource by either: (1) Not allowing the concentration oftotal chromium in the exhaust gas stream discharged to the atmosphere to exceed O.O} mg/dscm (4.4x}U6gr/dscf); or (2) 

## Ifa chemicalfUme suppressant containing a wetting agent is used, by not allowing the surface tension of the electroplating or anodizing bath contained

Dott Industries, Ine. Pennitto Install Application Lapeer. Michigan 

### - 22- Horizon EDvironmentai Corporation Technical Support Document October3, 2000

### within the affoctedsource to exceed 

### 45 dynesper centimeter (3.1.xl(JJpoundsforceper foot) at any time during operation of the tank. " • §63.343(b)(2) - 

## "Ifthe owner or operator ofan affected source meets all ofthe following criteria, an initialperformance test is not required to be conductedunder this subpart: (i) The affectedsource is a decorative chromium electroplating tank ora chromium anodizing tank; and (ii) A wetting agent is used in theplating or anodizing bath to inhibit chromium emissions from the affoctedsource; and (iii) 

### The owner or operator complies with the applicable surface tension limit of §63.342(d)(2) as demonstrated through the continuous compliance monitoring requiredbyparagraph (c)(5)(ii) of thissection. " §63.343(c)(5)(ii) states that operation ofthe affected source at a surface tension greater than the value established during a performance test, or at a surface tension ofgreater than 45 dynes/em ifthis default value is utilized, shall constitute noncompliance with the standards. A specific schedule for bath surface tension testing intervals during operation ofthe plating tank is indicated. The standard under §63.342 that applies to the proposed modification is that for surface tension. Previous performance testing of the existing decorative chromium-plating tank surface tension during normal operations has indicated compliance with the listed standard of 45 dynes/em. Since the new decorative chromium-plating 

### tank will use a fume suppressant in the bath, and emissions from the new tank will also be treated by the existing water-washed mesh pad mist eliminator; the facility is anticipated to remain in compliance with the 

### standard following the proposed modification. The proposed chromium-plating tank has been designed to comply with all applicable NESHAPs.
DoH Industries, Inc. Pennit to Install Application Lapeer, Michigan - 23- Horizon Environmental Corporation Technical Suppon Document October3, 20005. AMBIENT AIR QUALI1YIMPACTANALYSIS Ambient air quality dispersion modeling analyses have been conducted in support of the proposed installation of a new chrome plating tank. Utilizing procedures in accordance with 

### MARs 240 and 241, AQD 1, and U.S. EPA guidance2, potential emissions of hexavalent chromium due to the operation ofthe existing and proposed chrome tanks were modeled to demonstrate compliance with applicable MAR 225 health-based screening levels. This section characterizes the area surrounding the Dott facility and presents the dispersion model and modeling databases utilized to demonstrate compliance. Dispersion modeling input and output files are submitted in electronic fonnat (diskette) as AppendixD. 

### 5.1 DESCRIPTION OF SITE AREA Characteristics of the site area surrounding the Dott facility applicable to the air quality impact analysis include land use classification and local topography. A detailed discussion ofeach ofthe aforementioned characteristics is providedbelow. 

### 5.1.1 Land Use Classification Annospheric conditions affecting the downwind dispersion of 

### air contaminants may be influenced by localized land use. Dispersion coefficients have been developed for both rural and urban environments. Based on U.S. EPA guidance, the selection ofeither

### rural or

I Michigan Air Use Permit Manual, Air Quality Division, MDEQ, 1995. 2 Guideline on Air Quality Models (Revised), Appendix W of40 CFR Part 51, U.S. EPA, 1995. Dott Industries, Inc. Permit to Install Application Lapeer, Michigan - 24- Horizon Environmental Corporation Technical Support Document October3, 2000urban dispersion coefficients should follow one of the procedures suggested by Irwin3• These include a land use classification procedure, based on a typing scheme recommended by Auer\ or a population based procedure. Ofthe two methods, the land use classification procedure is considered more definitive. The land use classificationprocedure is conducted as follows: I) Classify the land use within the total area, 

## Ao, circumscribed by a 3 

### Ian radius circle about the source using Auer's land use typing scheme; 2) Ifland use type 11, 12, CI, R2, and R3 account for 50 percent or more of

## Ao, use urban dispersion coefficients; otherwise, use appropriate 

### rural dispersion coefficients. Table 5 summarizes Auer's land use typing scheme. Utilizing a U.S.G.S. topographic projection (Lapeer Quadrangle), land use surrounding the Dott facility has been assessed and can be considered rural. Consistent with previous modeling analyses conducted 

### in support ofthe Dott facility, rural dispersion coefficients were used in the dispersion model simulations.
5.1.2 Topography Elevated terrain features may affect the transport of atmospheric contaminants as well as serve as areas ofpotentially higher pollutant impacts. Where appropriate, terrain features should be included in the modeling analysis. The AQD generally recommends that terrain

3 Proposed Criteria for Selection ofUrban Versus Rural Dispersion Coefficients, Draft Staff Report, 

## u.s. EPA, 1978.

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan 

### - 25- Horizon Environmental Corporation Technical Support Document October 3, 2000elevations exceeding**~** the height of the shortest stack at a facility be included in the modeling analysis. Terrain immediately surrounding the Dott facility may be characterized as relatively flat with few distinguishable terrain features. Consequently, terrain elevations were not included in the dispersion modeling analysis. 

### 5.2 DISPERSION

### MODEL U.S. EPA's Industrial Source Complex Model, Version 3 ("ISC3" , Release No. 98356) was utilized in the air quality impact analysis. ISC3 is a steady-state Gaussian plume model recommended by U.S. EPA for assessing pollutant impacts from facilities with emission points influenced bybuilding downwash, such as the Dott facility. ISC3 consists ofa short-term and a long-term model. The short-tenn model utilizes hourly meteorological data while the long-term model processes a frequency distribution ofwind speed, wind direction, and atmospheric stability. In accordance with AQD guidanceS, the short-tenn version ofISC3 was employed in the airquality impact analysis. Major features ofISC3 applicable to this air quality impact analysis include:

• Rural dispersion coefficients; • Concentration estimates for 24-hour and annual averaging times; • Concentration estimates over flat terrain; • Consideration ofbuilding downwash effects; and

4 Correlation of Land Use and Cover with Meteorological Anomalies, Journal ofApplied Meteorology, 1978.

Dott Industries, Inc. Pennit to Install Application Lapeer, Michigan - 26- Horizon Environmental Corporation Technical Suppon Document October3, 2000• Treatment ofcalm wind conditions. 

### 5.2.1 Building Downwash Effects Plumes potentially emitted from the proposed baghouse exhaust stack may be influenced by aerodynamic downwash. Consequently, 

# u.s. EPA's recommended Building Profile Input Program ("BPIP" , Release No. 95086) was utilized to estimate maximum projected lateral and vertical building dimensions on a wind direction-specific basis. Dimensions of all existing structures that could potentially influence emissions from the Control System 1 stack (serving the two chrome electroplating tanks) were input to BPIP. Maximum projected lateral and vertical building dimensions, as estimated by BPIP, were subsequently input to ISC3. Building projections in relation to emission points are illustrated in Figure 1. Input/Output files for the BPIP simulations are submitted in electronic fonnat (diskette) as Appendix D to this document.
5.3 DATABASES USED IN AIR QUALIlY IMPACTANALYSIS Databases required as input to the air quality dispersion model consist ofmeteorological data, receptor points and emission inventory data. A discussion ofthe databases utilized in the ambient air quality impact assessment ispresented below.

SMichigan Air Use Permit Manual, Air Quality Dispersion Modeling, Air Quality Division, 1995. Dott Industries, Inc. Pennit to Install Application Lapeer, Michigan 

### - 27- Horizon Environmental Corporation Technical Support Document October3, 2000

### , 5.3.1 Meteorological Data The AQD generally requires the use of the most spatially and temporally representative one-year meteorological databases when conducting dispersion model simulations in support ofMAR 225 compliance demonstrations. The most spatially representative off-site meteorological database available for general use consists of surface and coincident upper air observations measured at the Flint Bishop Airport located in Flint, Michigan (Station No. 94826). The most recently available year (1991) was obtained from the AQD's web site and subsequently employed in the modeling demonstration. 

### 5.3.2 Receptor Points ISC3-predicted concentrations may be estimated at discrete receptor locations. A discrete receptor grid was designed to identify maximum predicted impacts due to the proposed modification. The following methodology was utilized in designing the receptor grid:

• Receptors were located along property boundaries at distances not exceeding 25 meters; and • Additional receptors were located off-property 10 a manner sufficient to identify maximum impacts. The receptor grid used in the air quality impact analysis extends 

### 800 meters from the Control System 

### 1 stack. Consisting of362 discrete points, the receptor grid is illustrated in Figure 2.

Dott Industries, Inc. Pennit 10 Install Application Lapeer, Michigan 

### - 28- Horizon Environmental Corporation Technical Support Document October 3, 2000, 5.3.3 Emission Inventory Emission inventory data required as input to ISC3 includes emission rate, stack location, stack height, inside diameter, exit temperature, and exit velocity. Potential pound per hour and gram per second hexavalent chromium emissi on rates were derived from emission estimates calculated in Section 3.1.3. Exhaust characteristics ofthe Control System I stack, are summarized as follows: Emission Rate: Stack Location: Stack Height: Inside Diameter: Exit Temperature: Flow Rate: Exit Velocity: 5.5 A IR Q UALtTY IMPAct 0.0000079 pounds per hour 0.000000992 grams per second (13.6 meters easting, 4.4 meters northing) 50.0 rcct (15.24 metcrs) 32.0 inches (0.8 1meters) 90 dcg. Fahrcnheit (305.4 Kelvin) 13,300 actual cubic fect per minute (at stack) 39.6 feet per second (12.07 meters per second)

MAR 225(1} requir es new or modified sources ofTAC emissions to demonstrate that the ambient impact of each regulated TAC emitted is less than its corresponding in itial threshol d screening level (" ITSL"), initial risk screening level (" IRSL" ), or both. The AQD has published a hexavalent chromium ITSL of 8.0 x 10·) yiglm) (24-hour averaging period) and an IRSL of8.3 x 10"**g/ J**  (annual avcraging period) . Utilizing ISC3 over a one-year meteorological database (199 1 Flint/Flint), the Control System 1 stack was modeled and resultant maximum predict ed concentrations compared against the published screening values. Maximum pr edicted hexavalent ehromiwn impacts are summarized in Table 6. As shown in Table 6, the maximum predicted 24-hour average hexavalent chromium impact of2 x 10·' yiglm) is well under the published ITSL of8.0 x 10·

Dott InduS lritS, Inc. PumillO Insm]] Applicalion Lapeer, '\1ichigun - 29- Ilorb.on En"ironmenlal Carponlton Technical Suppon Documenl Oclober 3,20003 J.1g1m3; while, the maximum predicted annual average hexavalent chromium impact of2 x 10-6 Jlg/m3 is well under thepublished IRSL of8.3 x 

### 10·sJlglm3• As described above, the conservatively based dispersion modeling analyses indicate that the proposed modification will not threaten published hexavalent chromium health-based screening levels.

Dott Industries, Inc. Permit to Install Application Lapeer, Michigan 

### - 30- Horizon Environmental Corporation Technical Support Document October 3, 2000

### APPENDIXA Permitto InstallApplication Form

## APPENDIXB 

## FacilityPlotPlans

# ..

APPENDIXC MaterialSafetyData Sheets•



### APPENDIXD Dispersion ModelingInput/Output Files (Diskette)