16

PERMIT MEMORANDUM 2005-203-TVR

OKLAHOMA DEPARTMENT OF ENVIRONMENTAL QUALITY

AIR QUALITY DIVISION

MEMORANDUM February 13, 2006

TO: Dawson F. Lasseter, Chief Engineer, Permits Section

THROUGH: Grover Campbell, P.E., Existing Source Permits Section

THROUGH: Phil Martin, P.E., New Source Permits Section

THROUGH: Peer Review

FROM: David Schutz, P. E., New Source Permits Section

SUBJECT: Evaluation of Permit Application No. 2005-203-TVR

U. S. Silica Company, Mill Creek North Plant

Industrial Sand Processing Facility

Mill Creek, Johnston County

SECTION I. INTRODUCTION

The U. S. Silica Company has requested renewal of their current Part 70 operating permit for their Mill Creek North Plant (SIC 1446). The plant is currently operating under Permit No. 99-108-TV (M-1) issued December 13, 2004. The North Plant is one of two plants operated in the area by U. S. Silica; they are located approximately 6 miles from each other.

Since the facility emits more than 100 TPY of a regulated pollutant, it is subject to Title V permitting requirements. Emission units (EUs) have been arranged into Emission Unit Groups (EUGs) in the following outline.

SECTION II. PROCESS DESCRIPTION

Sand is removed from the quarry hydraulically. The quarry face is sprayed with a high-pressure water stream which loosens uncemented or weakly-cemented sand grains from each other. (No acids are used.) This water stream results in a slurry of 75% water and 25% sand. The slurry is pumped to a screen where oversized material is removed from the materials that are transported to the plant for further processing. Screened sand is pumped to a wet stockpile or to the raw sand tank. The wet stockpile stores sand for when the quarry is not operating but the rest of the plant is, supplying the plant with sand feed. When the quarry is inactive, front-end loaders are used to move sand from the wet stockpile to a screening tank; there, the sand is slurried with water and pumped to the raw sand tank.

16

PERMIT MEMORANDUM 2005-203-TVR

Wet sand from the raw sand tank is transferred to various slurry tanks and/or hydrosizers depending on product size desired. Sized wet sand slurries are pumped to two vacuum filter tables for preliminary dewatering, after which bucket elevators transfer sand to damp sand storage bins.

There are two drying circuits, designated No. 1 and No. 2. Each consists of a belt conveyor, fluidized bed dryer, and a bucket elevator. The dryers are each rated at 31 MMBTUH apiece. Exhausts from the No. 1 dryer are processed by a cyclonic separator and a wet scrubber prior to discharge, while exhausts from the No. 2 dryer are processed by a wet scrubber. Dried sand is moved by bucket elevator to two dry screening operations. The No. 2 dryer was authorized under Permit No. 79-087-O to burn liquid fuel and became subject to NSPS Subpart UUU under Permit No. 99-108-TV (M-1) by removal of a cyclone prior to the wet scrubber.

The screening operations sort dried sand into various size ranges. Sorted (“graded”) sand is moved by bucket elevator to “Whole Grain” storage silos or to the sand cooler. Air emissions from the screening operations are vented to Drying Circuit No. 1’s wet scrubber. “Whole Grain” sand is moved by belt conveyor to the railcar loading station. Loading snorkles are used to conduct the sand from bins into railcars. Displaced air from railcar loading is vented to a wet scrubber with a PM emissions control efficiency of 95%. In addition to the railcar loading, there are units for loading trucks. Fines materials are conveyed to the No. 4 silo for “OK-100 Fines”, and to Whole Grain Silos 2 and 3.

No crushing or grinding of sand/sandstone is conducted at the facility. All sand-handling operations prior to the drying, screening and loading units are wet. The facility has a maximum annual process rate of 3,241,200 tons per year sand.

The facility includes two large fuel oil storage tanks. The first is 60,000 gallons and was constructed prior to 1972. The second is 100,000 gallons and was also constructed prior to 1972. Since the liquid fuel will have a maximum true vapor pressure of 0.008 psia, these tanks are included as “insignificant activities.”

SECTION III. EQUIPMENT

Equipment was organized into emissions unit groups depending on date of installation and function.

EUG “SCREENING”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

SCREENING

/

8Rotex #1

/

Vibrating screen #1 Type 522A

/

1992

8Rotex #2

/

Vibrating screen #2 Type 522A

/

1992

Emissions from these units are controlled by a Torit Dust Collector, “8TORITDC”, and discharged from Stack 5.

EUG “DRYING1”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

DRYING1

/

8FD1

/

No. 1 fluidized bed dryer

/

Pre-1972

8BC1

/

Feed belt to dryer

/

Pre-1972

8BE2N

/

No. 1 fluid bed dryer discharge elevator

/

Pre-1972

Emissions from these units are controlled by a cyclone and wet scrubber in series, “8SB1” and “8CY1”, and discharged from Stack 1.

EUG “DRYING2”

EU ID

/

Point ID

/

EU Name/Model

/

Construction/

Modification Date

DRYING2

/

8FD2

/

No. 2 fluidized bed dryer

/

2005

8BC1A

/

Feed belt to dryer

/

1979

8BE2A

/

No. 2 fluid bed dryer discharge elevator

/

1979

Emissions from these units are controlled by a wet scrubber and discharged from Stack 4.

EUG “FUGITIVE PRE-1972”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

FUGITIVE1

/

8AUTOMON1

/

Automatic monitor #1 - Stang

/

Pre-1972

8STOCKPILE

/

Wet sand stockpile

/

Pre-1972

8STOCKSCREEN

/

Stockpile screening vat

/

Pre-1972

8FL988B

/

Caterpiller front end loader

/

Pre-1972

8PITSCREEN

/

Tyler screening vat

/

Pre-1972

8RST1

/

Raw sand tank 1100 Ton/Mine

/

Pre-1972

8NSILO3

/

Cool sand tank

/

Pre-1972

8RST2

/

Fines slurry tank

/

Pre-1972

8ST1

/

Slurry tank #1 slide

/

Pre-1972

8VT1

/

Vacuum filter table #1

/

Pre-1972

8DS1

/

Damp sand storage Silo #1

/

Pre-1972

8BE1N

/

Vacuum table discharge elevator #1 side

/

Pre-1972

Emissions from these units are controlled by the wetness of the materials handled.

EUG “FUGITIVE POST-1972”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

FUGITIVE2

/

8 RCT1

/

Rising current tank hydrosizers

/

1995

8HYDRO1

/

Hydrosizer 1

/

1995

8HYDRO2

/

Hydrosizer 2

/

1995

8HYDRO3

/

Hydrosizer 3

/

1995

8ST1A

/

Slurry Tank #2 side

/

1979

8VT1A

/

Vacuum filter Table #2 side

/

1979

8DS1A

/

Damp sand storage silo #2 side

/

1979

8BE1A

/

Vacuum table discharge elevator #2 side

/

1979

Emissions from these units are controlled by the wetness of the materials handled, and some of these operations are completely submerged in liquid.

EUG “LOADOUT”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

LOADOUT

/

8BC2

/

Belt Conveyor #2 Rail Load-out

/

Pre-1972

8TLONLS4

/

North track load-out snorkle #4

/

Pre-1972

8TLONLS5

/

South track load-out snorkle

/

Pre-1972

8NTLONLS1

/

Truck load-out spout #1

/

Pre-1972

8NTLONLS2

/

Truck load-out spout #2

/

Pre-1972

8LTOCOOLSND

/

Cool sand truck load-out spout

/

Pre-1972

The railcar load-out snorkles are vented to “8SB4” and discharged from Stack 3, while the truck load-out snorkles are vented to “8SB3” and discharged from Stack 2. Each stack is equipped with a dry filter.

EUG “LOADOUT2”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

LOADOUT2

/

8NDC5

/

Conveyor for No. 2 truck loadout

/

9/99

8NDC4

/

Truck loadout

/

9/99

The two new truck loadouts (8NDC4 and 8NDC5) are discharged through Stacks 7 and 8, respectively. Each stack is equipped with a dry filter.

EUG “STORAGE1”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

STORAGE1

/

8BE3N

/

#1 Side Rotex Screen discharge elevator

/

Pre-1972

8NSILO#1

/

North whole grain silo

/

Pre-1972

8NSILO#2

/

Middle whole grain silo

/

Pre-1972

Emissions from these units are vented to the No. 1 Dryer wet scrubber, “8SB1”, and discharged from Stack 1.

EUG “STORAGE2”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

STORAGE2

/

8BE3A

/

#2 Side Rotex Screen discharge elevator

/

1995

8NPB1

/

OK-100 product silo

/

1995

8SC3N

/

#3 Dry Sand Storage discharge screw

/

1995

8NSILO#4

/

South whole grain silo

/

1995

8BE4N

/

Cool sand elevator

/

1995

8BC3N

/

Transfer conveyor from BE3A to OK-100 silo

/

1995

8SC2N

/

#2 dry sand storage discharge screw

/

1995

8SC1N

/

Discharge screw

/

1995

8BC4N

/

OK80/90 conveyor atop silos

/

1995

8NTLOOK100

/

Truck load-out for OK-100 silo

/

1995

Emissions from the OK-100 silo are controlled by a dry cartridge dust collector, and discharged from Stack 6.

EUG “ROADS”

EU ID

/

Point ID

/

EU Name/Model

/

Construction Date

FUGITIVE

/

ROADS

/

Unpaved facility roads

/

Pre-1972

EUG “TANKS”: Fuel Storage Tanks

Unit ID

/ Point / EU Description / Capacity / Construction Date
A / Tank 1 / Diesel tank / 60,000 gal. / pre-1972
B / Tank 2 / Diesel tank / 100,000 gal. / 1977
C / Gasoline / Vehicle gasoline tank / 250 gal. / --

SECTION IV. AIR EMISSIONS

Based on U. S. Silica’s measurement and estimate, the maximum process capacity of the facility downstream from raw material unloading is 370 tons/hour. The PM collectors are reported to have an efficiency of at least 99% for PM collection. A 70% control efficiency was claimed for units enclosed in buildings and 50% for outdoor enclosures. Based on 8,760 hours/year continuous operation and AP-42 (1/95), Section 13.2-4 (aggregate handling and storage); and Section 11.19.1 (sand and aggregate transfer to elevated bin), the PM emissions are listed in the following tables.

Dryer emissions shown are worst-case, based on liquid fuel usage except for CO, with emissions calculated from AP-42 (10/98), Section 1.3 (fuel oil combustion), assuming 0.7% by weight sulfur in the liquid fuel used in the No. 2 Dryer and 1.28% by weight sulfur in the No. 1 Dryer. CO emissions were calculated from factors for natural gas in AP-42 (9/98), Section 1.4. PM10 emissions were based on the limits of NSPS Subpart UUU (0.025 gr/DSCF) and a flow of 53,000 SCFM.

There are two operating scenarios for the plant, gas fuel and liquid fuel. Except for CO emissions, liquid fuel constitutes the worst-case emissions. Emissions limitations were established on that basis.

EUG “SCREENING”

Discharge Point

/

Unit ID

/

EU Name/Model

/

PM10 Emissions

lb/hr

/

TPY

Stack 5

/

8Rotex #1

/

Vibrating screen #1 Type 522A

/

0.26

/

1.13

8Rotex #2 / Vibrating screen #2 Type 522A

EUG “DRYING1” AND EUG “STORAGE1”

Point ID / Unit ID / PM10 / SO2 / NOx / VOC / CO
lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY
Stack
1 / No. 1 fluidized bed dryer / 11.36 / 49.74 / 41.50 / 181.9 / 12.16 / 53.24 / 0.25 / 1.09 / 2.55 / 11.18
feed belt to dryer
dryer discharge elevator
31 MMBTUH Heater

#1 Side Rotex Screen discharge elevator

North whole grain silo

Middle whole grain silo

The two EUGs share a discharge point. Both EUGs consist of grandfathered equipment.

EUG “DRYING2”

Point ID / Unit ID / PM10 / SO2 / NOx / VOC / CO
lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY / lb/hr / TPY
Stack
4 / Sand Dryer No. 2 / 11.36 / 49.74 / 22.01 / 96.40 / 12.16 / 53.24 / 0.25 / 1.09 / 2.55 / 11.18
Product Silo No. 1
Product Silo No. 2
31 MMBTUH Heater

EUG “FUGITIVE POST-1972”

Discharge Point

/

Point ID

/

EU Name/Model

/

PM10 Emissions

lb/hr

/

TPY

FUGITIVE2

/

8 RCT1

/

Rising current tank hydrosizers

/

0.01

/

0.01

8HYDRO1

/

Hydrosizer 1

/

0.01

/

0.01

8HYDRO2

/

Hydrosizer 2

/

0.01

/

0.01

8HYDRO3

/

Hydrosizer 3

/

0.01

/

0.01

8ST1A

/

Slurry tank #2 side

/

0.01

/

0.01

8VT1A

/

Vacuum filter table #2 side

/

1.07

/

4.70

8DS1A

/

Damp sand storage silo #2 side

/

0.06

/

0.24

8BE1A

/

Vacuum table discharge elevator #2 side

/

0.06

/

0.24

TOTALS

/ / /

1.24

/

5.23

EUG “FUGITIVE PRE-1972”

Point ID

/

Unit ID

/

EU Name/Model

/

PM10 Emissions

lb/hr

/

TPY

FUGITIVE1

/

8AUTOMON1

/

Automatic monitor #1 - Stang

/

0.11

/

0.49

8STOCKPILE

/

Wet sand stockpile

/

0.11

/

0.49

8STOCKSCREEN

/

Stockpile screening vat

/

0.06

/

0.24

8FL988B

/

Caterpiller front end loader

/

0.06

/

0.24

8PITSCREEN

/

Tyler screening vat

/

0.11

/

0.49

8RST1

/

Raw sand tank 1100 Ton/Mine

/

0.06

/

0.24

8NSILO3

/

Cool sand tank

/

0.06

/

0.24

8RST2

/

Fines slurry tank

/

0.06

/

0.24

8ST1

/

Slurry tank #1 slide

/

0.53

/

2.35

8VT1

/

Vacuum filter table #1

/

1.07

/

4.70

8DS1

/

Damp sand storage Silo #1

/

0.06

/

0.24

8BE1N

/

Vacuum table discharge elevator #1 side

/

0.06

/

0.24

TOTALS

/ / / 2.35 / 10.20

EUG “LOADOUT”

Discharge Point

/

Unit ID

/

EU Name/Model

/

PM10 Emissions

lb/hr

/

TPY

Stack 3

/

8BC2

/

Belt Conveyor #2 Rail Load-out

/

0.40

/

1.75

8TLONLS4

/

North track load-out snorkle #4

8TLONLS5

/

South track load-out snorkle

Stack 2

/

8NTLONLS1

/

Truck load-out spout #1

/

0.29

/

1.27

8NTLONLS2

/

Truck load-out spout #2

8LTOCOOLSND

/

Cool sand truck load-out spout

TOTALS

/ / /

0.69

/

3.02

EUG “LOADOUT2”

Discharge Point

/

Unit ID

/

EU Name/Model

/

PM10 Emissions