1

PRELIMINARY DETERMINATION.

ANALYSIS, PRELIMINARY DETERMINATION AND DRAFT PERMIT

FOR

THE RENEWAL OF OPERATION PERMIT NUMBER 122049950-P02

FOR

SCOT INDUSTRIES, INC

LOCATED AT

810 NEBRASKA

MUSCODA, 

GRANT COUNTY, WISCONSIN

ON THE OPERATIONS OF

EXISTING

CHROMIUM PLATING, HONING, AND METAL CLEANING

This review was performed by the Wisconsin Department of Natural Resources in accordance with Sections 285.60 

to 285.66, Wis. Stats. and Chapter NR 407, Wis. Adm. Code. This review is for a Part 70 source located in an area 

which is designated attainment/unclassified for all criteria pollutants.

Air Pollution Control Operation Permit:

Air Pollution Control CONOP: 

122049950-P10

Analysis, Preliminary Determination 

and Draft Permit prepared by: /s/ Yonggang (Y.) Su Date: 12/21/2005

Approval Element Initials and Date

Preliminary Determination Document (including calculations) /s/ YSu for BNP 12/21/05

Applicable Requirement /s/ YSu for BNP 12/21/05

Compliance Documentation Methods

(compliance inspector concurrence) /s/ YSu for MaH 12/21/05

Compliance Plan and Schedule /s/ YSu for MaH 12/21/05

Federal Enforceability of Permit Conditions

(synthetic minor conditions) /s/ TJR

Approved for Public Review and Comment: /s/ Thomas Roushar Date: 12/21/05

cc: WDNR BAM (AM/7) Files – FOP Renewal

Muscoda Public Library, 206 N. Wisconsin Ave., Muscoda, WI 53573-0038

Maria Hill / Files – WDNR South Central Region Air Program, Dodgeville Service Center 
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 2 of 22

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1. Introduction

INTRODUCTION

Sources which are not exempt from the operation permit requirements under Section 407.03, Wis. Adm. Code, that 

were issued an operation permit from the Department of Natural Resources, are required to obtain a renewed air 

pollution control operation permit. Sources subject to the requirements must submit a permit renewal application to 

the Department by the date set forth in Sections 285.66(3)(a), Wis. Stats., and NR 407.04(2), Wis. Adm. Code. The 

renewal application is then reviewed following the provisions set forth in Sections 285.62, 285.63 and 285.64, Wis. 

Stats., and Chapter NR 407, Wis. Adm. Code.

Subject sources are to be reviewed for their air pollution control technology and for their impact upon the air quality. 

This is to insure compliance with all applicable rules and statutory requirements. The review will show why the 

source(s) operation should be approved, conditionally approved, or disapproved. It will encompass emission 

calculations and air quality analysis using US EPA models, if applicable. Emissions from volatile organic 

compound (VOC) sources and small sources whose emissions are known to be insignificant are normally not 

modeled. As a precautionary note, the emission estimates may be based on US EPA emission factors (AP-42) or 

theoretical data and can vary from actual stack test data.

This review is based on information contained within the renewal application submitted for an air pollution control 

operation permit. A renewed operation permit may be issued if the criteria set forth in sections 285.63, 284.64 and 

285.66, Wis. Stats., are met.

A final decision on the renewal will not be made until the public has had an opportunity to comment on the 

Department's analysis, preliminary determination and draft permit. The conditions proposed in the draft permit may 

be revised in any final permit issued based on comments received or further evaluation by the Department.

2. General Application Information

GENERAL APPLICATION INFORMATION

Owner/Operator: Scot Industries

810 Nebraska Street

Muscoda, WI 53573

Responsible Official: Robert B Anderson, Plant Manager

608-739-3171

Application Contact Person: Tim J. DeBruin, Project Manager

608-739-3171

Application Submitted By:

Date of Administratively Complete Application: May 30, 2003

Dates of Submittal: May 1, 1997; July 1, 1998; December 1, 1998, and May 30, 2003 

3.
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 3 of 22

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SOURCE DESCRIPTION

Scot Industries, Inc. (Scot) manufactures honed and hard chromium (Cr) plated steel tubing as well as hard 

chromium plated steel bar to serve the hydraulic and pneumatic industries. Its main operations and processes are 

chromium plating, honing, and metal cleaning.

All the chromium plating, honing and metal cleaning will initially be housed in three different buildings. Scot 

Industries plans to eventually house the chromium plating and honing operations in two new buildings (Phase II 

building and Phase III building) which have been constructed. The phase II building will contain 10 hard chromium 

plating tanks and will exhaust emissions from plating tanks to two exhaust stacks (five tanks per stack). Each stack 

will exhaust 25,000 CFM. The Phase III building will contain 23 hard chromium plating tanks and will be 

exhausted through a single stack.

VOC fugitive emissions will be generated from 16 honing machines. There will be a small area for hand cleaning 

steel tubes which have been honed.

The maximum theoretical emissions of chromium compounds is above the major source definition listed pursuant to 

section 112(b) of the Clean Air Act, but the applicant has elected permit conditions restricting potential emissions 

rates to less than the major source definition in NR 407.02(4)(a), Wis. Adm. Code.

The existing and previous air permits #122049950-P02, #122049950-P01, and #98-GDB-906 for this facility were 

issued in 1999. These three permits covered operations of 35 hard chromium plating tanks, 16 honing machines, 

one boiler, and one metal cleaning process. The construction permit #98-GDB-906 was issued as both an after-thefact (AtF) construction permit (CO) for then-existing units and an initial construction permit for then-to-beconstructed units. During the 10/18/2005 site meeting with Tim Debruin and Robert Anderson from Scot Industries, 

Maria Hill and Y. Su from WDNR, the following main changes occurred since 1999 have been recognized and 

clarified:

1. In Phase I building, the significant emissions unit S12/P12 (S02/P02 in OP #122049950-P02) has been 

removed and phased out. Another significant emissions unit S11/P11 (S06/P06 in OP #122049950-P02) is

still in operation currently, but would be removed and phased out eventually in future.

2. Two new Boilers S01/B01 (S15/B15 in 5/2003 submitted Application Forms, 0.085 MMBtu/hr, Natural Gas 

Fueled Only, Uncontrolled, installed 1/18/2001) and S03/B03 (S35/B35 in 5/2003 Application, 0.3 

MMBtu/hr, Natural Gas Fueled Only, Uncontrolled, installed 1/7/2002) and two fugitive processes S14/F14-

Metal Cleaning (S04/P04 in 5/2003 Application) and S33/F33-Honing (S33/P33 in 5/2003 Application)

were not included in the 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02, but have been 

constructed and are currently in operation. 

3. The twenty-seven (27) Hard Chromium Plating Tanks, P20-P24, P25-P27, P30-P46, P50, and P52 were 

included in the 1999 issued #122049950-P01/#98-GDB-906 and #122049950-P02. And, their installation 

have been completed and are currently in operation.

4. Six Processes P28, P29, P47, P48, P49, and P51 - Hard Chromium Plating Tanks were included in the 1999 

issued #122049950-P01/#98-GDB-906/#122049950-P02. Their installation, however, has not been 

completed yet as of the 10/18/2005 site meeting.

5. After 1999, the revised ch. NR 445, Wis. Adm. Code has been effective since July 1, 2004. Also, US-EPA’s 

National Emission Standards for Hard and Decorative Chromium Electroplating and Chromium Anodizing 

Tanks; Final Rule; amendments were promulgated on Federal Register, Vol. 69, No. 137, July 19, 2004. As 

such, a new hazardous air pollutant (HAP) emissions review is needed for this renewal. 

Most parts in this renewal review and preliminary determination (PD) will focus only on the 

change/update/revisions from the 1998/1999 review and their documents for the air permits #122049950-

P02/#122049950-P01/#98-GDB-906. Additionally, several administrative revisions will be made for this PD and 

DP (draft permit), e.g., deleting overlapped parts and a CP format to an OP one based on the available documents

and the 10/18/2005 site meeting. Other than the changes, many parts contained in the previous documents for air 

permits #122049950-P02/#122049950-P01/#98-GDB-906 may remain unchanged and/or un-presented for the 

review of this renewal.
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 4 of 22

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The following sections will present a detailed description of this review and its results.

SIGNIFICANT EMISSIONS UNITS

BOILERS AND PROCESSES FOR CHROMIUM PLATING, HONING, AND METAL CLEANING 

Stack/Process No. 

(Based on Existing Documents and 

10/2005 #122049950-P10 Meeting)

Process Description Emission Controls Remarks

#122049950-P10*

(2003 Form 102A

#122049950-

P02

01. S01/B01 

(S15/B15)

(Not included 

in -P02)

Cast Iron Hot Water Boiler (<1 

MMBtu)

None

NR 406.04(1)(a)5. & 

407.05(4)(c)10, 

W.A.C.

02. S02/B02 

(S25/B25)

E. S01/B01 Hot Water Boiler (4 MMBtu) None

03. S03/B03 

(S35/B35)

(Not included 

in -P02) Cast Iron Hot Water Boiler (<1 

MMBtu)

None

A. S11/P11 A. S06/P06 Hard Chromium Plating (Tank?) C11: 4- Stage 

Composite Mesh Pad 

Scrubber

B. S13/F13 

Fugitive

C. S03/P03 

Fugitive Honing Operations None

C. S14/F14 S04/P04 (?) Metal Cleaning Not found in -P02. 

D. S21/P20, P21, 

P22, P23, P24

B. S21/P20, 

P21, P22, P23, 

P24

Hard Chromium Plating 

Processes / Tanks

4-Stage Composite 

Mesh Pad Scrubbers 

for each tank, then 

vented to a common 

HEPA filter C01 and 

Stack S21

D. S22/P25, P26, 

P27

B. S22/P25-

P29

Hard Chromium Plating 

Processes / Tanks

4-Stage Composite 

Mesh Pad Scrubbers 

for each tank, then 

vented to a common 

HEPA filter C02 and 

Stack S22

P28 and P29 have 

NOT been installed 

yet.

E. S31/P30-P35, 

P36-P50, P51, and 

P52

B. S31/P31 Hard Chromium Processes / 

Tanks

A 4-Stage CompositeMesh-Pad-Scrubber 

(C31), followed by a 

HEPA filter (C03).

P47, P48, P49, and 

P51 have NOT been 

installed yet.

F. S33/F33 

Fugitive

S33/P33 

Fugitive Honing None Not found in -P02.

G. S34/F34 D. S34/P34 Metal Cleaning None

Notes:

* The numbering in the documents for this PD (Preliminary Determination) and enclosed DP (Draft Permit) is 

based on the facility’s request.

The significant emissions sources at Scot Industries, Inc. are listed in the above table. Detailed parameters for the 

boilers and processes in the permit application are summarized in the following:
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 5 of 22

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01. STACK INFORMATION

Stack Identification Number: S01 (S15 in 5/2003 Application Forms)

Exhausting Unit(s): B01 (B15 in 5/2003 Application Forms)

This stack has an actual exhaust point: YES

A. Emission Unit Information

Process number : B01 (B15 in 5/2003 Application Forms)

Unit description: Cast Iron Hot Water Boiler, fired with natural gas only

Maximum heat continuous rating: 0.085 mm BTU/hr

Control technology status: Uncontrolled

Date of construction or last modification: 1/18/2001

Construction Permit (CP): Exempted under s. NR 406.04(1)(a)5, Wis. Adm. Code

Fuel and firing conditions: (based on 5/2003 Renewal Application Form 4530-104, Item 11.)

Primary Fuel Backup Fuel

Fuel name/type Natural Gas None

Higher heating value 1,050 BTU/CF

Maximum sulfur content (wt. %) Negligible

Maximum ash content (wt. %) Negligible

Excess combustion air (% O2) 15%

Moisture content (as fired) (%) 8.4%

Maximum hourly consumption 50 therms

Actual yearly consumption Unknown

02. STACK INFORMATION

Stack Identification Number: S02 (S25 in 5/2003 Application Forms or S01 in 1999 

#122049950-P01/#98-GDB-906/#122049950-P02)

Exhausting Unit(s): B02 (B25 in 5/2003 Application Forms or B01 in 1999 

#122049950-P01/#98-GDB-906/#122049950-P02)

This stack has an actual exhaust point: YES

A. Emission Unit Information

Process number : B02 (B25 in 5/2003 Application Forms or B01 in 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02)

Unit description: Hot water boiler, fired with natural gas only

Maximum heat continuous rating: 4 mm BTU/hr (shown in 5/2003 Application Form 104, and clarified

by Scot Industries during the 10/18/2005 site meeting, but shown with 

5.0 MMBtu/hr in 1999 issued #122049950-P02/-P01/#98-GDB-906.)

Control technology status: Uncontrolled

Date of construction or last modification: 4/5/2001

Construction Permit (CP): Exempted under s. NR 406.04(1)(a)5, Wis. Adm. Code

Fuel and firing conditions: (based on 5/2003 Renewal Application Form 4530-104, Item 11.)

Primary Fuel Backup Fuel

Fuel name/type Natural Gas None

Higher heating value 1,050 BTU/CF

Maximum sulfur content (wt. %) Negligible

Maximum ash content (wt. %) Negligible

Excess combustion air (% O2) 15%
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 6 of 22

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Primary Fuel Backup Fuel

Fuel name/type Natural Gas None

Moisture content (as fired) (%) 8.4%

Maximum hourly consumption 50 therms

Actual yearly consumption Unknown

03. STACK INFORMATION

Stack Identification Number: S03 (S35 in 5/2003 Application Forms)

Exhausting Unit(s): B03 (B35 in 5/2003 Application Forms)

This stack has an actual exhaust point: YES

A. Emission Unit Information

Process number : B03 (B35 in 5/2003 Application Forms)

Unit description: Cast Iron Steam or Hot Water Boiler, fired with natural gas only

Maximum heat continuous rating: 0.3 mm BTU/hr

Control technology status: Uncontrolled

Date of construction or last modification: 1/7/2002

Construction Permit (CP): Exempted under s. NR 406.04(1)(a)5, Wis. Adm. Code

Fuel and firing conditions: (based on 5/2003 Renewal Application Form 4530-104, Item 11.)

Primary Fuel Backup Fuel

Fuel name/type Natural Gas None

Higher heating value 1,050 BTU/CF

Maximum sulfur content (wt. %) Negligible

Maximum ash content (wt. %) Negligible

Excess combustion air (% O2) 15%

Moisture content (as fired) (%) 8.4%

Maximum hourly consumption 50 therms

Actual yearly consumption Unknown

4. * STACK INFORMATION

Stack Identification Number: S11 (S11 in 5/2003 Application Forms or S06 in 1999 

#122049950-P01/#98-GDB-906/#122049950-P02)

Exhausting Unit(s): P11 (P11 in 5/2003 Application Forms or P06 in 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02)

This stack has an actual exhaust point: Yes

Discharge height above ground level (ft): 25

Inside dimensions at outlet (ft): Circular - 2

Exhaust flow rate (ACFM): 7,700 (Normal)

Exhaust gas temperature (Normal) (0

F): 90

Exhaust gas discharge direction: Up

Stack equipped with any obstruction: No

A. Emission Unit Information

Process number: P11 (P11 in 5/2003 Application Forms or P06 in 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02)

Comment [BNP1]: These numbers are based 

on general outline formatting and are not 

intended to correlate to the stack number.
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 7 of 22

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Unit description: Hard chromium plating tank

Control technology status: Controlled

Maximum continuous rating: 10,000 amps (for P06 in the 12/1998 signed PD for 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02, but 32,000 amps in 

5/2003 Application Form 126 enclosure for P11?)

Date of construction or last modification: 12/1996 (but 1972 in the 12/1998 signed PD for 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02)

Construction Permit: #98-GDB-906

a. Control devices associated with this emissions unit

Emission unit controlled: P11

Control device number: C11

Date of installation: 12/96

Description of device: 4 Stage composite mesh pad scrubber

Pollutant(s) controlled Chromic acid mist

Efficiency (%) 99.9 

Pressure drop:

5. S12/P12 (S12/P12 in 5/2003 Application Forms or S02/P02 in 1999 #122049950-P01/#98-GDB906/#122049950-P02, but this process has been removed according to a clarification from Scot 

Industries’ Tim DeBruin during the 10/18/2005 site meeting with DNR staff)

6. STACK INFORMATION

Stack Identification Number: S13 (S13 in 5/2003 Application Forms or S03 in 1999 

#122049950-P01/#98-GDB-906/#122049950-P02)

Exhausting Unit(s): F13 (F13 in 5/2003 Application Forms or P03/04 in 1999 

issued #122049950-P01/#98-GDB-906/#122049950-P02)

This stack has an actual exhaust point: NO

A. Emission Unit Information

Process number: F13 (F13 in 5/2003 Application Forms or P03 in 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02)

Unit description: Honing operation

Control technology status: Uncontrolled

Date of construction or last modification: 1/30/2000

Construction Permit: #98-GDB-906

Diesel Fuel (coolant) Usage: 5,320 (Average) / 6,840 (Maximum) gal/yr.

Sulfurized Lard Oil (coolant) Usage: 852 (Average) / 1,095 (Maximum) gal/yr.

Honed Steel Tubing Products: 8,000 (Average) / 14,000 (Maximum) Ft./wk.

7. STACK INFORMATION

Stack Identification Number: S14 (S14 in 5/2003 Application Forms or S04 in the 12/1998 signed 

PD for 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02)

Exhausting Unit(s): F14 (F14 in 5/2003 Application Forms or P04/05 in the 12/1998 signed 

PD for 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02)

This stack has an actual exhaust point: NO

A. Emission Unit Information

Process number: F14 (F14 in 5/2003 Application Forms or P04/05 in the 12/1998 signed 

PD for 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02)

Unit description: Manual cleaning of metal parts with shop rags and mineral spirits

Control technology status: Uncontrolled

Date of construction or last modification: 0/0/1970

Construction Permit (CP): Exempt from the CP requirement since the construction date

was before the effective date of the air pollution control permit program in 1980.
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 8 of 22

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Mineral Spirits Usage: 2,160 (Average) / 2,700 (Maximum) lb./yr.

8. STACK INFORMATION

Stack Identification Number: S21

Exhausting Unit(s): P20, P21, P22, P23, P24

This stack has an actual exhaust point: Yes

Discharge height above ground level (ft): 22

Inside dimensions at outlet (ft): Circular - 3.33

Exhaust flow rate (Normal) (ACFM): 25,000

Exhaust gas temperature (Normal) (°F): 90

Exhaust gas discharge direction: Up

Stack equipped with any obstruction: No

A. Emission Unit Information

Process numbers: P20, P21, P22, P23, P24

Unit description: Five Hard Chromium Plating Tanks

Control technology status: Controlled

Date of construction or last modification: 8/27/2002 (5/2003 Application Form 109 for P20-P24)

Construction Permit: #98-GDB-906

 Maximum installed rectifier capacity: 198,000 amps (5/2003 Form 126 Enclosure for P20-P24)

a. Control devices associated with this emissions unit

Emission units controlled: P20-P24

Control device number: C20-C24 for P20-P24 respectively, then C01 for all P20/C20-P24/C24

combined

Date of installation: Unknown

Description of device: C20-C24 – Five 4-Stage composite mesh pad scrubbers, C01 - HEPA filter.

Pollutant(s) controlled Chromic acid mist

Scrubber Efficiency (%) 99.99 

Pressure drop: Not provided

9. STACK INFORMATION

Stack Identification Number: S22

Exhausting Unit(s): P25, P26, P27

This stack has an actual exhaust point: Yes

Discharge height above ground level (ft): 22

Inside dimensions at outlet (ft): Circular - 3.33

Exhaust flow rate (Normal) (ACFM): 25,000

Exhaust gas temperature (Normal) (°F): 90

Exhaust gas discharge direction: Up

Stack equipped with any obstruction: No

 

A. Emission Unit Information

Process numbers: P25 through P29

Unit description: Five Hard Chromium Plating Tanks

Control technology status: Controlled

Date of construction or last modification: Between 1998 and 10/18/2005, except uninstalled yet P28 and 

P29, according to Tim DeBruin’s clarification during the 

10/18/2005 meeting at Scot Industries

Construction Permit: #98-GDB-906

 Maximum installed rectifier capacity: 180,000 amps (5/2003 Form 126 Enclosure for P25-P29) 

a. Control devices associated with this emissions unit

Emission units controlled: P25 through P29

Control device number: C25-C29 for P25-P29 respectively, then C02 for all P25/C25-P29/C29 

combined

Date of installation: Unknown
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 9 of 22

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Description of device: C25-C29 – Five 4-Stage composite mesh pad scrubbers, C02 - HEPA filter.

Pollutant(s) controlled Chromic acid mist

Scrubber Efficiency (%) 99.99

Pressure drop: Not provided

10. STACK INFORMATION

Stack Identification Number: S31

Exhausting Unit(s): P30 through P52

This stack has an actual exhaust point: Yes

Discharge height above ground level (ft): 29 (but 25 ft in the 12/1998 signed PD for 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02)

Inside dimensions at outlet (ft): Circular - 3.00

Exhaust flow rate (Normal) (ACFM): 15,000

Exhaust gas temperature (Normal) (°F): 90

Exhaust gas discharge direction: Up

Stack equipped with any obstruction: No

A. Emission Unit Information

Process number: P30 through P52

Unit description: 23 Identical Hard Chromium Plating Tanks

Control technology status: Controlled

Date of construction or last modification: between 1998 and 10/18/2005, except P47, P48, P49, and P51 

that were not installed yet, according to Tim DeBruin’s

clarification during the 10/18/2005 meeting at Scot Industries

Maximum installed rectifier capacity: 68,000 amps (5/2003 Form 126 Enclosure for P30-P52) 

a. Control devices associated with these emissions units

Emission unit controlled: P30-P52

Control device number: C31

Date of installation: 12/2001

Description of device: 4-Stage composite mesh pad scrubber

Pollutant(s) controlled Chromic acid mist

Scrubber Efficiency (C31) 99.99 % for Cr (VI)

Pressure drop:

b. Control devices associated with these emissions units

Emission unit controlled: P30-P52

Control device number: C03

Date of installation: 12/2001

Description of device: HEPA Filter

Pollutant(s) controlled Chromic acid mist

HEPA Filter Efficiency (C03) 99.97 % for Cr (VI)

Pressure drop:

11. STACK INFORMATION

Stack Identification Number: S33 (S33 in 5/2003 Application Forms or S03 in 1999 

#122049950-P01/#98-GDB-906/#122049950-P02)

Exhausting Unit(s): F33 (F33 in 5/2003 Application Forms or P33/34 in 1998 

signed PD, but not in 1999 issued #122049950-P01/#98-GDB906/#122049950-P02)

This stack has an actual exhaust point: NO
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 10 of 22

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A. Emission Unit Information

Process number: F33 (F33 in 5/2003 Application Forms or P33/34 in 1998 signed PD, but not in 

1999 issued #122049950-P01/#98-GDB-906/#122049950-P02)

Unit description: Honing operation

Control technology status: Uncontrolled

Date of construction or last modification: 1/2/2000

Construction Permit: #98-GDB-906

Diesel Fuel (coolant) Usage: 13,500 (Average) / 17,200 (Maximum) gal/yr.

Sulfurized Lard Oil (coolant) Usage: 1,800 (Average) / 2,300 (Maximum) gal/yr.

Honed Steel Tubing Products: 27,000 (Average) / 40,000 (Maximum) Ft./wk.

12. STACK INFORMATION

Stack Identification Number: S34

Exhausting Unit(s): P34

This stack has an actual exhaust point: NO

A. Emission Unit Information

Process number: F34 (F34 in 5/2003 Application Forms or P34 in 1999 issued #122049950-

P01/#98-GDB-906/#122049950-P02)

Unit description: Manual cleaning of metal parts with shop rags and mineral spirits

Control technology status: Uncontrolled

Date of construction or last modification: 3/15/2002

Construction Permit: #98-GDB-906

Mineral Spirits Usage: 3,240 (Average) / 4,050 (Maximum) lb./yr.

Stack Parameter Summary.

Stack ID Actual Exhaust 

Point or Fugitive

Circular or 

Rectangular

Diameter or 

Width (if 

rect.)

Length (if 

rect.) Discharge

Direction

Exhaust

Obstacle Height Temp.

Normal 

Flow Rate

Maximum 

Flow Rate

ft (m) ft (m) U, D, H True/False ft (m) °F ACFM ACFM

S01/B01 

(S15/B15)

Yes Circular 1 ft. Up Yes 22.75 ft. 196

S11/P11 Yes Circular 2 ft. Up No 25 ft. 90 7700 7700

S13/F13 No Room

S14/F14 No Room

S02/B02 

(S25/B25)

Yes Circular 1.67 ft. Up Yes 44 ft. 196

S21/

P20-P24

Yes Circular 3.33 ft. Up No 22 ft. 90 25000 25000

S22/

P25-P29

Yes Circular 3.33 ft. Up No 22 ft. 90 25000 25000

S31/

P30-P52

Yes Circular 2.33 ft. Up No 29 ft. 90 8000 8000

S33/F33 No Room

S34/F34 No Room

S03/B03 

(S35/B35)

Yes Circular 0.67 ft. Down No 10 ft. 196

INSIGNIFICANT EMISSION UNITS (IEUs)

Group 1 IEUs, which were listed in the 2003 Renewal Application Form 102B:

Maintenance of Grounds, Equipment, and Bldg. 

Boiler, Turbine, and HVAC System Maintenance

Pollution Control Equipment Maintenance 

Int Comb Eng Used for Warehouse and Mat Trans

Fire Control Equipment 

Janitorial Services 

Office Activities 
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 11 of 22

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Convenience Water Heating 

Convenience Space Heating ( < 5 mil BTU/hr ) 

Sanitary sewer and plumbing venting

Group 2 IEU, which was listed in the 12/8/1998 signed PD for #122049950-P01 and also clarified by Scot 

Industries’ Tim DeBruin during the 10/18/2005 site meeting, but NOT listed in the 2003 Renewal Application Form 

102B:

Boiler clean operation

Group 3 IEUs, which are new insignificant emission units verified in the following Section of SOURCE 

SPECIFIC APPLICABLE REQUIREMENTS AND EMISSION CALCULATIONS

01. Boiler B01/S01 (B15/S15 in Scot Industries’ 5/2003 Application), 0.085 MMBtu/hr, Natural Gas 

Fueled Only, Uncontrolled, installed 1/18/2001;

:

02. Boiler B02/S02 (B25/S25 in Scot Industries’ 5/2003 Application and B01/S01 in WDNR’s 1999 issued 

#122049950-P01/#98-GDB-906/#122049950-P02/), 4 MMBtu/hr, Natural Gas Fueled Only, 

Uncontrolled, installed 4/5/2001;

03. Boiler B03/S03 (B35/S35 in Scot Industries’ 5/2003 Application), 0.3 MMBtu/hr, Natural Gas Fueled 

Only, Uncontrolled, installed 1/7/2001.

4. Cross Media Impacts

Material from the chromium (Cr) plating tanks is processed by a filter press and the sediment is disposed of off site.

CROSS MEDIA IMPACTS

LATEST PERMIT HISTORY

May 19, 1999: An operation permit (OP) of #122049950-P01 and a construction permit (CP) of 98-GDB-906 were 

issued by the Wisconsin DNR. 

August 2, 1999: #122049950-P02, a Revision to #122049950-P01, was issued. And the initial OP #122049950-P01

was superseded immediately at the issuance of #122049950-P02. Two changes were made with this revision: 1. The 

cover page of #122049950-P01 was revised for a clarification; 2. A missing page of permit conditions relating to 

reporting and compliance certification was added into the OP #122049950-P02. The OP #122049950-P02 would 

expire on May 19, 2004.

May 30, 2003: The DNR received Scot Industries’ Air Control Operation Permit Renewal Application.

February 10, 2004: The DNR’s NSR-Exemption-Letter #03-POY-133 determined that Scot Industries’ proposed 

construction of chrome plating tanks was exempted from the Air Control Construction Permit requirements per s. 

NR 406.04(1)(rm), Wis. Adm. Code. This is based on that the facility is an area source, which is defined in s. NR 

460.02(5), Wis. Adm. Code, for federal hazardous air pollutants and that the project only involves the construction 

of the chromium electroplating tanks. 

October 18, 2005: A site meeting participated by Tim Debruin and Robert Anderson from Scot Industries, Maria 

Hill and Y. Su from WDNR. During the meeting, Mr. Robert Anderson gave a presentation on Scot Industries. 

Then other three clarified main changes happened since the 1999 issuance of #122049950-P01/98-GDB-906 and

#122049950-P02, and discussed the strategies for this renewal review.

October 19, 2005: WDNR’s Maria Hill distributed a summary for the 10/18/2005 site meeting.

December 8, 2005: The DNR’s NSR-Exemption-Letter #05-POY-337 determined that Scot Industries’ proposed 

construction of two chrome electroplating tanks “is exempt from construction permit requirements as per s. NR 

406.04(1)(rm), Wis. Adm. Code. This is based on that your facility is an area source for federal hazardous air 

pollutants and that the project only involves the construction of the chromium electroplating tanks. Your facility 

may proceed with the construction.

Although this project has been determined to be exempt under ch. NR 406, Wis. Adm. Code, it is still subject to all 

applicable requirements in NR 400 – 499, Wis. Adm. Code and any other applicable federal, state or local 

regulations. In addition, please note that you are required by s. NR 407.04(1)(b)3., Wis. Adm. Code, to submit an 
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 12 of 22

12

operation permit application covering these emissions units prior to commencing construction, if you have not done 

so already.”

EXISTING PERMITS (#122049950-P02)

Scot Industries has an existing Air Control Operation Permit #122049950-P02, which was issued by the DNR on 

08/02/1999.

EXISTING PERMITS ACTIONS

The following permit actions will be done concurrently with the issuance of this operation permit renewal, in 

addition to the administrative changes for an operation permit renewal format:

A CON/OP permit #98-GDB-906-OP will be issued. This will be done so that the construction permit #98-GDB906 can be converted into an operation permit, with several needed changes per s. NR 407.07(3)(c), Wis. Adm. 

Code.

When the operation permit renewal #122049950-P10 is issued, all the permits #98-GDB-906-OP, 

#122049950-P02, #122049950-P01, and #98-GDB-906 will be incorporated/carried over into the integrated 

operation permit #122049950-P10 and be superseded/expired immediately upon the issuance of this

renewal. As such, #122049950-P10 will become the only effective air permit for this facility after its 

soon-coming issuance until the next renewal or Scot Industries applies for another air permit/revision in 

future. 

Most of the limitations included in the permits #98-GDB-906/#122049950-P01/#122049950-P02 will be kept 

unchanged and just be incorporated into the integrated operation permit renewal #122049950-P10, except several 

typos, facility updates, permit language upgrading, integrating/reorganizing, and already completed construction 

permit requirements. Also, several items contained in the existing/previous air permits may be moved into Part II 

GENERAL PERMIT CONDITIONS, as applied. 

SOURCE SPECIFIC APPLICABLE REQUIREMENTS AND EMISSION CALCULATIONS

Boilers: S01/B01, S02/B02, and S03/B03: Natural Gas Fueled Only, Uncontrolled.

The primary criteria pollutant emissions from these boilers are nitrogen oxides and carbon monoxides emissions. 

The natural gas criteria pollutant emissions are calculated using emission factors from the Fifth Edition of AP-42, 

1.4 Natural Gas Combustion. The following tables in this section list the emission factors used and the calculated 

criteria pollutant emissions.

Natural gas, the only fuel combusted in Boilers: S01/B01, S02/B02, and S03/B03, is considered Group 1 Virgin 

Fossil fuel as defined by s. NR 445.02(18), Wis. Adm. Code. Per s. NR 445.07(5)(a), Wis. Adm. Code the 

emissions of hazardous air pollutants from the Group 1 Virgin Fossil fuel combustion, including natural gas, are

exempt from the requirements of the regulatory chapter NR 445, Wis. Adm. Code. Therefore no further NR 445 

review is necessary for the emissions from Natural Gas combustion in Boilers: S01/B01, S02/B02, and S03/B03.

S01/B01 – Boiler, Rated @ 0.085 MMBtu/hr, Natural Gas Fueled Only, Uncontrolled: (S15/B15 in 5/2003 

submitted Application Forms, but not in 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02)

Natural Gas (NG) Combustion Only: 85,000 Btu/hr / 1050 Btu/cf / 1,000,000 = 0.000081 cf6/hr

EF FUEL USE RATES POLLUTANT EMISSION RATES

CFmax CFaa Actual MTE PTE

Pollutant lb/cf6

burned

Max. Fuel 

Use cf6/hr

Actual Fuel

Use cf6/yr

ACTh

lb/hr

ACTa

TPY

MTEh

lb/hr

MTEa

TPY

PTEh

lb/hr

PTEa

TPY
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 13 of 22

13

SO2 0.6 0.000081 Unknown 0.00 0.00 0.00 0.00

NOx 100 0.000081 Unknown 0.01 0.044 0.01 0.044

CO 84 0.000081 Unknown 0.007 0.03 0.007 0.03

VOC 5.5 0.000081 Unknown 0.00 0.00 0.00 0.00

PM 7.6 0.000081 Unknown 0.00 0.00 0.00 0.00

NG: ACTh = EF x CFmax

ACTa = EF x CFaa

MTEh = EF x CFmax

MTEa = EF x CFmax x 8,760 hr/yr x 1 ton/2000 lb

PTEh = EF x CFmax

PTEa = EF x CFmax x 8,760 hr/yr x 1 ton/2000 lb

S02/B02 – Boiler, Rated @ 4.0 MMBtu/hr, Natural Gas Fueled Only, Uncontrolled: (S25/B25 in 5/2003 

submitted Application Forms, or S01/B01 with 5.0 MMBtu/hr in 1999 issued #122049950-P01/#98-GDB906/#122049950-P02. During the 10/18/2005 meeting, Scot Industries’ Tim DeBruin clarified this boiler as 

S02/B02, Rated @ 4.0 MMBtu/hr. The following table has used the updated data to update and revise the 

corresponding part in the 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02 for this renewal OP.)

Natural Gas (NG) Combustion Only: 4,000,000 Btu/hr/1050 Btu/cf / 1,000,000 = 0.00381 cf6/hr

EF FUEL USE RATES POLLUTANT EMISSION RATES

CFmax CFaa Actual MTE PTE

Pollutant lb/cf6

burned

Max. Fuel 

Use cf6/hr

Actual Fuel

Use cf6/yr

ACTh

lb/hr

ACTa

TPY

MTEh

lb/hr

MTEa

TPY

PTEh

lb/hr

PTEa

TPY

SO2 0.6 0.00381 Unknown 0.00 0.01 0.00 0.01

NOx 100 0.00381 Unknown 0.38 1.67 0.38 1.67

CO 84 0.00381 Unknown 0.32 1.40 0.32 1.40

VOC 5.5 0.00381 Unknown 0.021 0.092 0.021 0.092

PM 7.6 0.00381 Unknown 0.029 0.127 0.029 0.127

NG: ACTh = EF x CFmax

ACTa = EF x CFaa

MTEh = EF x CFmax

MTEa = EF x CFmax x 8,760 hr/yr x 1 ton/2000 lb

PTEh = EF x CFmax

PTEa = EF x CFmax x 8,760 hr/yr x 1 ton/2000 lb

S03/B03 - Boiler, Rated @ 0.3 MMBtu/hr, Natural Gas Fueled Only, Uncontrolled: (S35/B35 in 5/2003 

submitted Application Forms, but not in 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02)

Natural Gas (NG) Combustion Only: 300,000 Btu/hr/1050 Btu/cf / 1,000,000 = 0.000286 cf6/hr

EF FUEL USE RATES POLLUTANT EMISSION RATES

CFmax CFaa Actual MTE PTE

Pollutant lb/cf6

burned

Max. Fuel 

Use cf6/hr

Actual Fuel

Use cf6/yr

ACTh

lb/hr

ACTa

TPY

MTEh

lb/hr

MTE

a

PTEh

lb/hr

PTEa

TPY
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 14 of 22

14

TPY

SO2 0.6 0.000286 Unknown 0.00 0.00 0.00 0.00

NOx 100 0.000286 Unknown 0.0286 0.125 0.0286 0.125

CO 84 0.000286 Unknown 0.024 0.105 0.024 0.105

VOC 5.5 0.000286 Unknown 0.002 0.007 0.002 0.007

PM 7.6 0.000286 Unknown 0.0022 0.01 0.0022 0.01

NG: ACTh = EF x CFmax

ACTa = EF x CFaa

MTEh = EF x CFmax

MTEa = EF x CFmax x 8,760 hr/yr x 1 ton/2000 lb

PTEh = EF x CFmax

PTEa = EF x CFmax x 8,760 hr/yr x 1 ton/2000 lb

Emissions Summary from Facility Wide Boilers - S01/B01, S02/B02, and S03/B03

Sub-Total Air Criteria Pollutants Emissions from Facility Wide Boilers - S01/B01, S02/B02, and S03/B03

Air pollutant Actual 

emissions

Maximum theoretical 

emissions (MTE)

Potential to emit 

(PTE)

Maximum 

allowable

5 times NR 407 

inclusion level

TPY TPY TPY TPY TPY

Sulfur dioxide 0.01 0.01 0.01 5.0

Nitrogen oxides 1.84 1.84 1.84 5.0

Carbon Monoxide 1.54 1.54 1.54 5.0

VOCs 0.1 0.1 0.1 5.0

Particulate matters (PMs) 0.14 0.14 0.14 5.0

The Table above shows that MTEs of all the Criteria Pollutants Emissions from all the boilers within the entire 

facility are less than 5 times the corresponding inclusion levels specified in Table 2 or Table 3 in s. NR 407.05, Wis. 

Adm. Code. Therefore, no further discussion for all the Criteria Pollutants Emissions from all the boilers within the 

entire facility will be required, under s. NR 407.05(4)(c)10, Wis. Adm. Code. Also, no further NR 445 review is 

necessary for the emissions from Natural Gas combustion in Boilers: S01/B01, S02/B02, and S03/B03 since all 

these boilers fire natural gas only and natural gas is a Group 1 Virgin Fossil fuel. As such, Boilers: S01/B01, 

S02/B02, and S03/B03 will be listed as insignificant sources in the Section of INSIGNIFICANT EMISSION 

UNITS. 

Honing Operations

Air Pollutant Emissions from S13/F13 (Based on Scot Industries’ 5/2003 Renewal Application Form 128 for 

S13/F13)

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 6.76 25.308 6.76 25.308 25.308
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 15 of 22

15

Air Pollutant Emissions from S33/F33 (Based on Scot Industries’ 5/2003 Renewal Application Form 128 for 

S33/F33)

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 17.00 63.64 17.00 63.64 63.64

Sub-Total Air Pollutant Emissions from Honing Operations within the entire facility (Based on Scot 

Industries’ 5/2003 Renewal Application Form 128s for S13/F13 and S33/F33)

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 23.76 88.948 23.76 88.948 88.948

Hard Chromium Electroplating Processes (in Tanks)

The electroplating plating processes use chromium (VI), water soluble compound. The process is subject 

to the MACT standard which limits emission of total chromium to 0.015 milligrams of total chromium per 

dry standard cubic meter (mg/dscm)(6.6 x 10-6 grain per dry standard cubic foot [gr/dscf]) of ventilation air. 

The flow rates for the electroplating stacks which are the basis of calculating the emission rates of

chromium (VI), water soluble compound, were taken from the permit application. The moisture content is 

assumed to be 4.0%.

Along with the 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02, all the emission calculations 

including the principles and methods for all the electroplating processes within the entire facility have been 

reviewed and commented by the public/facility and approved by the DNR. They covered and included all the 

electroplating processes in this renewal review, plus the already-removed S12/P12 - Hard Chromium Electroplating 

Process (i.e., S02/P02 in 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02). As such, the emission 

calculations for the electroplating processes will not be re-reviewed and re-presented in detail again in this renewal 

review. Please refer to the preliminary determination for air permits #122049950-P01/#98-GDB-906/#122049950-

P02 for a detailed description of the emission calculations for all the electroplating processes within the entire 

facility.

But, many emission results will be presented in this renewal review for further applicable limitation/requirements 

establishing and regulatory analyzing for this preliminary determination (PD).

S11/P11 Hard Chromium Electroplating Process Tank * (i.e., S06/P06 in 1999 issued #122049950-P01/#98-

GDB-906/#122049950-P02)

Pollutant Actual Emissions Maximum Theoretical PTE

Total Chromium 0.0058954 mg/dscm 1.483175 TPY 0.11 lb/yr

Chromium VI (water 

soluble)

0.401693 TPY 0.03 lb/yr

Notes:

* Data in the table are based on Scot Industries’ 5/2003 Renewal Application Form 126.

S21/P20-P24, Five (5) Hard Chromium Electroplating Tanks *

Pollutant Actual Emissions Maximum Theoretical PTE

Total Chromium ** 9.1770143 TPY 0.07 lb/yr

Chromium VI (water 

soluble)

2.485476 TPY 0.02 lb/yr
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 16 of 22

16

Notes:

* Data in the table are based on Scot Industries’ 5/2003 Renewal Application Form 126.

** To be determined with compliance test. Maximum stack emissions must be less than 0.015 mg/dscm to be 

compliance with 40 CFR Parts 9 and 63.

S22/P25-29, Five (5) Hard Chromium Electroplating Tanks *

Pollutant Actual Emissions Maximum Theoretical PTE

Total Chromium ** 8.342857 TPY 0.06 lb/yr

Chromium VI (water 

soluble)

2.259524 TPY 0.02 lb/yr

Notes:

* Data in the table are based on Scot Industries’ 5/2003 Renewal Application Form 126.

** To be determined with compliance test. Maximum stack emissions must be less than 0.015 mg/dscm to be 

compliance with 40 CFR Parts 9 and 63.

S31/P30-P52 - Hard Chromium Plating Process * (S31/P31 - Hard Chromium Plating Tank in #122049950-P02, 

whose specifications were intended to include P30-P52 in #122049950-P10)

Pollutant Actual Emissions Maximum Theoretical PTE

Total Chromium ** 3.151746 TPY 0.000142 lb/yr

Chromium VI (water 

soluble)

0.8535979 TPY 0.000038 lb/yr

Notes:

* Data in the table are based on Scot Industries’ 5/2003 Renewal Application Form 126.

** To be determined with compliance test. Maximum stack emissions must be less than 0.015 mg/dscm to be 

compliance with 40 CFR Parts 9 and 63.

Sub-Total Air Pollutant Emissions from Scot Industries’ All Hard Chromium Plating Processes – S11/P11, 

S21/P20-P24, S22/P25-P29, and S31/P30-P52 *

Pollutant Actual Emissions Maximum Theoretical PTE

Total Chromium ** 22.1547923 TPY 0.240142 lb/yr

Chromium VI (water 

soluble)

6.0002909 TPY 0.070038 lb/yr

Notes:

* Data in the table are based on Scot Industries’ 5/2003 Renewal Application Form 126s.

** To be determined with compliance test. Maximum stack emissions must be less than 0.06 mg/dscm (0.015 

mg/dscm x 4 Stacks) to be compliance with 40 CFR Parts 9 and 63.

Manual Metal Parts Cleaning - S14/F14 and S34/P34:

Air Pollutant Emissions from S14/F14 (Based on Scot Industries’ 5/2003 Renewal Application Form 128 for 

S14/F14, which was constructed or last modified in 1970 according to their 5/2003 Renewal Application Form 109)

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 0.36 1.35 0.36 1.35 1.35

Air Pollutant Emissions from S34/P34 (Based on Scot Industries’ 5/2003 Renewal Application Form 128 for 

S34/F34, which was constructed or last modified in 3/15/2002 according to their 5/2003 Renewal Application Form 

109)
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 17 of 22

17

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 0.54 2.0268 0.54 2.0268 2.0268

Sub-Total Air Pollutant Emissions from Manual Metal Parts Cleaning within the entire facility (Based on Scot 

Industries’ 5/2003 Renewal Application Form 128s for S14/F14 and S34/F34)

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 0.90 3.378 0.90 3.378 3.378

VOC Description: Mineral Spirits (CAS 8052-41-3)

Density: 7.2 lb/gal

Usage: 5,400 lb./yr (Average) and/or 6,750 lb./yr (Maximum) in 5/2003 Form 109s. (2,160 

lb./yr (Average) and/or 2,700 lb./yr (Maximum) for S14/F14 and 3,240 lb./yr (Average) and/or 4,050 lb./yr 

(Maximum) for S34/F34) (but 470 gal/yr in the 12/8/1998 signed PD for the 1999 issued #122049950-

P01/#98-GDB-906/#122049950-P02)

Operating Schedule in 5/2003 Form 109s: 24 hr/day

6 days/week

312 days/year (but 300 days/year in the 12/8/1998 signed PD)

7488 hr/yr

Average VOC Emission Rate: 6,750 lb/yr / 7488 hr/yr = 0.90 lb/hr

0.9014 lb/hr x 24 hr/day = 21.6 lb/day

The honed tubes are cleaned with mineral spirits. The 1999 issued #122049950-P01/#98-GDB-906/#122049950-

P02 covered only one Manual Metal Parts Cleaning process line, S34/P34. The emission rate of mineral spirits from 

S34/P34 was 0.47 lb/hr and 11.28 lb/day. Therefore, S34/P34 was exempt from the requirements of chap. NR 424 

per s. NR 424.03(1)4., Wis. Adm. Code.

This renewal review covers both of the current S14/F14 in Phase Building 1 and S34/F34 in Phase Building 3. 

Since they separately process/manufacture products at two different buildings, a further investigation to each of

current / renamed S14/F14 and S34/F34 is needed as follows.

Process S14/F14 - Manual Metal Parts Cleaning was constructed or last modified in 1970 according to their 5/2003 

Renewal Application Form 109. Therefore, the current S14/F14 is exempt from the requirements of chap. NR 424 

per s. NR 424.03(1)1., Wis. Adm. Code.

The above calculation shows that the maximum theoretical mineral spirits emissions from process S34/F34 - Manual 

Metal Parts Cleaning are 0.54 lb/hr and/or 12.96 lb/day. This is lower than 15 pounds in any day, an exemption 

threshold under s. NR 424.03(1)4., Wis. Adm. Code. Therefore, the current S34/F34 is exempt from the 

requirements of chap. NR 424 per s. NR 424.03(1)1., Wis. Adm. Code.

The above analysis shows that the VOC is the only criteria air pollutant emitted from S14/F14 & S34/F34 - Manual 

Metal Parts Cleaning. General Limitations for VOC emissions in ss. NR 419.03 and NR 419.04, Wis. Adm. Code, 

however, still apply to both of S14/F14 & S34/F34 - Manual Metal Parts Cleaning. And the General Limitations for 

VOC emissions have been included in Permit Part II.C.2.d.-e., September 6, 2005 version, therefore, will not been 

included in the Draft Permit Part I.

MAXIMUM AVAILABLE CONTROL TECHNOLOGY (MACT) and NATIONAL EMISSION 

STANDARDS for HAZARDOUS AIR POLLUTANTS (NESHAPs)
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 18 of 22

18

Chromic acid is used in the hard chromium electroplating plating processes. Chromic acid contains 27% chromium 

(VI), water soluble compound. The hard chromium electroplating tanks are required to meet US-EPA’s MACT 

standards for hard chromium plating. Those standards include a requirement to limit emissions of total chromium to 

0.015 mg/dscm for each affected exhaust source per 40 CFR Part 63, Subpart N, 63.342(c). The latest MACT and 

National Emission Standards for Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks; 

Final Rule; amendments were promulgated on Federal Register, Vol. 69, No. 137, July 19, 2004. 

WISCONSIN HAZARDOUS AIR POLLUTANT (HAP / NR 445) REVIEW

Stoddard Solvent (Mineral Spirits) Emissions from Manual Metal Parts Cleaning - S14/F14 and S34/F34:

Hazardous Air Pollutant Emissions from Manual Metal Parts Cleaning - S14/F14 and S34/F34

Pollutant Stack No.

Maximum 

Theoretical (MTE)

Potential to 

Emit (PTE)

NR 445 de minimus Values

(Table A)

lb/hr / tpy TPY < 25 ft 25 to 

<40 ft

40 to 

<75 ft

≥ 75 ft Unit (Lb/hr or 

Lb/yr)

Stoddard solvent 

(Mineral spirits, 

CAS# 8052-41-3) 

S14/F14 0.36 lb/hr / 

1.35 TPY 1.35 TPY 30.8

Lb/hr

S34/F34 0.54 lb/hr / 

2.0268 TPY 2.0268 TPY

Lb/hr

Sub-Total 0.90 lb/hr / 

3.378 TPY 3.378 TPY

Lb/hr

The facility’s 2003 Application Form 109s for Processes F14 and/or F34 indicate that mineral spirits (Stoddard 

solvent, CAS 8052-41-3) is the only raw material used for these two manual metal cleaning processes. Mineral 

spirits is not a Federal regulated HAP. But the current NR 445, Wis. Adm. Code, which started to be effective on 

July 1, 2004, lists in its Table A de minimis level for Stoddard solvent (mineral spirits) of 30.8 lb/hr for stacks less 

than 25 feet in height (either S14 or S34 has NO an actual stack exhaust point, but serves to identify fugitive 

emissions only). Scot Industries’ 5/2003 Renewal Application Form 128s, however, listed the MTE (maximum 

theoretical emissions) rate for facility wide mineral spirits as 0.90 lb/hr (0.36 lb/hr from S14/F14 and 0.54 lb/hr from 

S34/F34), which is less than the de minimis value in Table A. Therefore, no further analysis for Stoddard solvent 

(mineral spirits) within this facility is required under NR 445, Wis. Adm. Code.

Combined with and based on the analyses and conclusions in the above paragraph for HAPs and at the end of above 

Section of SOURCE SPECIFIC APPLICABLE REQUIREMENTS AND EMISSION CALCULATIONS for 

VOC, the only criteria air pollutant, for S14/F14 and/or S34/F34 - manual metal cleaning processes, no special 

limitation(s) are needed to be included in the Draft Permit Part I for this renewal. One of the reasons for this is that 

the General Limitations for VOC and HAP emissions included in the enclosed Permit Part II are good enough for 

these two manual metal cleaning processes.

Chromium Emissions from all Hard Electroplating Tanks within the Entire Facility:

Since Scot Industries’ hard chromium electroplating tanks are required to meet US-EPA’s MACT standards, their 

NR 445 review and analysis are NOT needed per s. NR 445.01(1)(b), Wis. Adm. Code. 

CONTROL TECHNOLOGY REVIEW

Hard Chrome Electroplating Tanks

The hard chromium electroplating tanks are required to meet the MACT standard for hard chromium plating. That 

standard includes a requirement to limit emissions of total chromium to 0.015 mg/dscm for each affected exhaust 

source. The following table summarizes emission calculations from the SOURCE SPECIFIC APPLICABLE 

REQUIREMENTS AND EMISSION CALCULATIONS section of this preliminary determination (PD). The 

table demonstrates that stacks S11/P11, S21/P20-P24, S22/P25-P29 and S31/P30-P52 will meet the 0.015 mg/dscm 

limitation.
Preliminary Determination, FID No. 122049950, Permit No. 122049950-P10 Page 19 of 22

19

Comparison of Total Chromium PTE and Code Allowable Rate

Stack/Process * EF * CE ** Amax Vstd ** ACTmg *** MACT 

Standard

mg/hr/amp %/100 Amp-hr dscfm/m mg/dscm mg/dscm

S11/P11 (S06/P06) 4.8 0.999 10000 **

(32000 *) 132.9 0.0060 0.015

S21/P20-P24 4.8 0.99975 198000 * 664.6 0.00596 0.015

S22/P25-P29 4.8 0.99975 180000 * 664.6 0.00542 0.015

S31/P30-P52 4.8 0.99975 68000 * 398.8 0.00341 0.015

Notes:

* Based on Scot Industries’ 5/2003 Renewal Application. The numbering in parentheses is based on the 

12/8/1998 signed PD for the 1999 issued #122049950-P01/#98-GDB-906/#122049950-P02.

** Based on WDNR’s 12/8/1998 signed PD for the 1999 issued #122049950-P01/#98-GDB-906/#122049950-

P02.

*** Based on the following formula in WDNR’s 12/8/1998 signed PD for the 1999 issued #122049950-

P01/#98-GDB-906/#122049950-P02: 

ACTmg = EF x (1- CE) x Amax ÷ (Vstd x 60 min/hr)

Control equipment for all tanks in the Phase II building will consist of ten individual 4 stage composite mesh pad 

scrubbers for each tank. Tanks P20-24 and P25-29 will be vented thorough individual four stage composite mesh 

pad scrubbers (C20-C24 and C25-C29), and then be passed through HEPA filters C01 and C02 respectively. In the 

Phase III building, Tanks P30-52 will be vented thorough a 4-Stage Composite-Mesh-Pad-Scrubber (C31), and 

followed by a HEPA filter (C03). These are considered to be T-BACT (Toxic Best Available Control Technology).

Honing Operations (16 machines)

The facility includes 16 honing machines which hone the inside of the steel tubes prior to plating with chromium. 

Kerosene is used as a lubricant to hone 20 foot lengths of pipe. For regulatory purposes it is assumed that 100% of 

the kerosene used is emitted as VOC. Based on emission estimates contained in the Source Specific Emission Limit 

Calculation section of this preliminary determination, VOC emissions from this operation are greater than the de 

minimis amount that would subject this operation to regulation under NR 424, Wis. Adm. Code. The emission rate 

for each honing machine is 370 lb VOC/day. Each machine emits 0.81 lb of VOC/hr. NR 424 requires sources to 

meet 85% control, or if 85% control is infeasible to meet LACT. The infeasibility of meeting 85% control is 

demonstrated by the low PTE 3.4 tons/year/machine) and the impractical nature of collecting emissions from 40 foot 

long honing machine. LACT for this case is limiting use of kerosene to no more than 1914 gallons per month in 

average and not using any other lubricant.

5. Facility Emissions

FACILITY EMISSIONS

Actual emissions are the total emissions generated by the emission sources identified below over the specified time 

period taking into account any reductions made by a control device or technique. Maximum theoretical emissions 

are the quantity of air contaminants that theoretically could be emitted by the emissions sources identified below, 

without considering emission control devices, based on the design capacity of the source. Potential to emit is the 

maximum capacity of the emission sources identified below to emit any air contaminant under its physical and 

operational design. Any physical or operational limitation on the capacity of a source to emit an air contaminant 

shall be treated as part of its design if the limitation is Federally enforceable.

A. Stack Emissions.

Honing Operations

Sub-Total Air Pollutant Emissions from Honing Operations within the entire facility (Based on Scot 

Industries’ 5/2003 Renewal Application Form 128s for S13/F13 and S33/F33)
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Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 23.76 88.948 23.76 88.948 88.948

Hard Chromium Electroplating Processes (in Tanks)

Sub-Total Air Pollutant Emissions from Scot Industries’ All Hard Chromium Plating Processes - S11/P11, 

S21/P20-P24, S22/P25-P29, and S31/P30-P52 *

Pollutant Actual Emissions Maximum Theoretical PTE

Total Chromium ** 22.1547923 TPY 0.240142 lb/yr

Chromium VI (water 

soluble)

6.0002909 TPY 0.070038 lb/yr

Notes:

* Data in the table are based on Scot Industries’ 5/2003 Renewal Application Form 126s.

** To be determined with compliance test. Maximum stack emissions must be less than 0.06 mg/dscm (0.015 

mg/dscm x 4 Stacks) to be compliance with 40 CFR Parts 9 and 63.

Manual Metal Parts Cleaning - S14/F14 and S34/P34:

Sub-Total Air Pollutant Emissions from Manual Metal Parts Cleaning within the entire facility (Based on Scot 

Industries’ 5/2003 Renewal Application Form 128s for S14/F14 and S34/F34)

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY TPY

VOC 0.90 3.378 0.90 3.378 3.378

B. Facility Emissions Summary.

I. Criteria Air Pollutants Emissions *

Pollutant

Actual Emissions Maximum Theoretical 

Emissions (MTE) Potential to Emit (PTE)

Lb/hr TPY Lb/hr TPY Tons per Year

VOC 92.33 92.33 92.33

Notes:

* The data come from Scot Industries’ 5/2003 Renewal Application Form 129.

II. Hazardous Air Pollutant Emissions 

Pollutant Stack No.

Maximum 

Theoretical (MTE)

Potential to 

Emit (PTE)

NR 445 de minimus Values

(Table A)

tpy lb/yr < 25 ft

(c)

25 to 

<40 ft (d)

40 to 

<75 ft

≥ 75 ft

(f)

Unit (Lb/hr or 

Lb/yr)

Stoddard 

solvent (Mineral 

spirits, CAS# 

8052-41-3)

S14/F14 0.36 lb/hr / 

1.35 TPY + 

0.54 lb/hr / 

2.0268 TPY

0.90 lb/hr*

(0.36 lb/hr

(S14) + 0.54

lb/hr (S34))

/ 3.378 TPY

30.8 Lb/hr

S34/F34

Sub-Total 0.90 lb/hr / 

3.378 TPY

0.90 lb/hr / 

3.378 TPY

30.8 Lb/hr

Total Chromium

(Cr)

S11/P11 1.483175 TPY 0.110142 

lb/yr *

Lb/hr

S31/P30-52 3.151746 TPY Lb/hr
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S21/P20-24 9.1770143 TPY 0.13 lb/yr * Lb/hr

S22/P25-29 8.342857 TPY Lb/hr

Sub-Total 22.1547923 TPY 0.240142 

lb/yr Lb/hr

Chromium VI 

(water soluble, 

CAS# 7440-47-

3)

S11/P11 0.401693 TPY 0.030038 

lb/yr * 5.84 Lb/yr

S31/P30-52 0.8535979 TPY

S21/P20-24 2.485476 TPY 0.04 lb/yr * 1.42 Lb/yr

S22/P25-29 2.259524 TPY

Sub-Total 6.0002909 0.070038 

lb/yr

Lb/yr

Notes:

* The PTEs are combined and grouped for each contaminant for all stacks within each of the 4 stack categories 

for comparison with the threshold rates in column (c) or (d) in the NR 445 Table A per s. NR 445.07(6)(b), Wis. 

Adm. Code. Also, the PTE data are based on Scot Industries’ 5/2003 Renewal Application Form 126s.

III. Facility Summary

Pollutant Actual Emissions Maximum Theoretical PTE

lb/hr TPY lb/hr TPY

VOC 92.33 92.33 92.33 TPY

Total Chromium * 22.155 TPY 0.240142 lb/yr

Chromium VI (water 

soluble) 6.0003 TPY 0.070038 lb/yr

** To be determined with compliance test. Maximum stack emissions must be less than 0.06 mg/dscm (0.015 

mg/dscm x 4 Stacks) to be compliance with 40 CFR Parts 9 and 63.

AIR QUALITY REVIEW

Based on the above review and analyses, VOC emissions are the only significant criteria air pollution emitted from 

this facility. There are currently no approved and reliable dispersion modeling programs for VOCs, however, so this 

criteria pollutant cannot be accurately modeled for its impact on air quality. VOCs are precursors to ozone 

formation. VOCs are difficult to model because they interact with other substances in the atmosphere in the 

presence of sunlight to produce ozone. While it is known that this reaction occurs in the atmosphere and sunlight 

acts as a catalyst, scientists are not currently able to predict the amount of ozone that will be created under specific 

conditions. 

Stoddard solvent (Mineral spirits, CAS# 8052-41-3) is listed in Table A and has a de minimis value of 30.8 lb/hr for 

stacks less than 25 feet (both S14 and S34) in height. Based on the above review and analyses, 0.90 lb/hr, the

potential to emit (PTE) of mineral spirits from S14 (0.36 lb/hr) and S34 (0.54 lb/hr) combined are less than the 

corresponding NR 445 Table A threshold value of 30.8 lb/hr. Therefore, a modeling analysis for Scot Industries’ 

Stoddard solvent (Mineral spirits, CAS# 8052-41-3) emissions is NOT needed.

Chromium VI water soluble compound is listed in Table A and has a de minimis value of 5.84 lb/yr for stacks 

equal to 25 feet (S11) or more, but less than 40 feet (S31) in height or 1.42 lb/yr for stacks less than 25 feet (S21 

and/or S22) in height. The potential to emit (PTE) of chrome VI water soluble compound from S11 and S31 is 

0.030038 lb/yr pound per hour, based on MACT standard of 0.015 milligrams of total chromium per dry standard 

cubic meter (mg/dscm). Similarly, the potential to emit (PTE) of chrome VI water soluble compound from S21 and 

S22 is 0.04 lb/yr pound per hour, based on MACT standard of 0.015 milligrams of total chromium per dry standard 

cubic meter (mg/dscm). Each of these PTEs is less than the corresponding NR 445 Table A threshold values and 

thus no modeling is necessary. For the total Chromium, the situation is the same since the PTEs for the total 

Chromium are less than the corresponding NR 445 Table A threshold values for Cr-VI (water soluble) only, i.e., 

0.110142 lb/yr < 5.84 lb/yr for (S11 + S31) and 0.13 lb/yr < 1.42 lb/yr for (S21 + S22) respectively. Here, we have 

used a reasonable assumption that a NR 445 Table A threshold value for Cr-VI (water soluble) should be less than 
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the corresponding NR 445 Table A threshold value for total Chromium, which is the sum of the NR 445 Table A 

threshold value for Cr-VI (water soluble) plus the corresponding NR 445 Table A threshold value for total 

Chromium other than Cr-VI (water soluble). The current NR 445 Table A, however, has not listed yet the 

corresponding NR 445 Table A threshold value for either annual total Chromium emissions (lb/yr) or annual total 

Chromium emissions other than Cr-VI (lb/yr).

As such, a modeling analysis is NOT needed for either criteria air pollutant emissions or hazardous air pollutant 

(HAP) emissions for Scot Industries.

6. The results of the modeling analysis demonstrate that all applicable air quality standards will be satisfied, assuming the emission rates and stack parameters given in the attached source table. Facility Status Under Part 70

FACILITY STATUS UNDER PART 70

The permit issued pursuant to this analysis and determination will be a Part 70 permit because all chromium plating

operations are defined as Part 70 sources per s. NR 407.02(6)(b)7., Wis. Adm. Code. The maximum theoretical 

emissions of particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides, and volatile organic compounds, 

however, are less than 100 tons per year.

COMPLIANCE DEMONSTRATION MONITORING METHODS

In this renewal, the allowable operating parameter for the chrome scrubbers has been changed from + or - 1 inch to 

+ or - 2 inches of water column from the base value measured during the stack test. The range of + or - 2 inches is 

the most recent and governing versions of the Chromium MACT standards.

Other details can be seen in the enclosed DP (draft permit). 

FACILITY COMPLIANCE STATUS

The Department finds that:

1. The source will meet applicable emission limits and other requirements.

2. The source will not cause nor exacerbate a violation of an ambient air quality standard or ambient air increment.

7. Determination

PRELIMINARY DETERMINATION

The Wisconsin Department of Natural Resources (WDNR) has reviewed the permit application and other materials 

submitted by Scot Industries, Inc. and hereby makes a preliminary determination that an operation permit may be 

issued with the following Draft Applicable Limits and Draft Permit Conditions.