AQ_F_0400061_20210818_PRMT_PmtRvw

NORTH CAROLINA DIVISION OF Region: Fayetteville Regional Office
AIR QUALITY County: Anson
Application Review NC Facility ID: 0400061
Inspector's Name:
Date of Last Inspection:
Issue Date:08/18/2021 Compliance Code:
Facility Data Permit Applicability(this application only)
Applicant(Facility's Name): Catawba Biogas,LLC SIP:
NSPS:
Facility Address: NESHAP:
Catawba Biogas, LLC PSD:
1133 Blewett Falls Rd. PSD Avoidance:
Lilesville,NC 28091 NC Toxics:
112(r):
SIC: 1311 /Crude Petroleum&Natural Gas Other:
NAICS: 211111 /Crude Petroleum and Natural Gas Extraction
Facility Classification: Before: Small After: Small MODIFICATION
Fee Classification: Before: Small After: Small
F- Contact Data Application Data
Facility Contact Authorized Contact Technical Contact Application Number: 0400061.21A
Ted Niblock Ted Niblock Ted Niblock Date Received: 06/07/2021
Manager Manager Manager Application Type: Modification
[phone] [phone] [phone] Application Schedule: State
1200 18th St.NW 1200 18th St.NW 1200 18th St.NW Existing Permit Data
Washington,NC 20036 Washington,NC 20036 Washington,NC 20036 Existing Permit Number: 10593/R00
Existing Permit Issue Date: 10/16/2019
Existing Permit Expiration Date: 09/30/2027
Review Engineer: Jeffrey D. Cole Comments/Recommendations:
Issue 10593/R01
Review Engineer's Signature: Date: Permit Issue Date: 08/18/2021
Permit Expiration Date: 09/30/2027
C4
'Ar- 11r1Z 0 11
1. Purpose of Application:
Catawba Biogas, LLC is a greenfield biogas production operation located in Lilesville,Anson
County. The company is requesting a modification to their existing permit to address their
facility's potential to exceed the daily TPER emission limit for hydrogen sulfide(H2S)as defined
in 15A NCAC 02Q .0711(b). The company proposes to limit the daily volume of biogas flared to
ensure that the H2S emission limit will not be exceeded.
The facility is classified as small, as none of the potential emissions before controls exceed the
Title V threshold.
There was one pink sheet item to address which is discussed in Section 6.
The application did not contain any confidential information.

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Permit R01 Review
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The facility contact for the permit application is Ted Niblock(215-932-8017). The facility
utilized a consultant to prepare the permit application. The contact at the consultant, Cavanaugh
&Associates, P.A. International of Wilmington,NC, is Benjamin Cauthen, E.I. (877-557-8923
ext. 303).
2. Facility Description
Catawba Biogas, LLC is a yet to be constructed biogas production operation located in Lilesville,
Anson County. The facility will receive used poultry bedding from surrounding farms to use as
feedstock for an anaerobic digester system to produce biogas. The facility will utilize
fermentation to remove nitrogen from the used poultry bedding prior to anaerobic digestion.
During normal operation(Scenario 1),the biogas will leave the anaerobic digesters and flow
through a fixed bed media vessel containing activated carbon media known as the Carbon
Adsorber Hydrogen Sulfide Removal System. The biogas will be upgraded to natural gas quality
and injected into an existing natural gas pipeline. The undesirable non-methane constituents of
the biogas(i.e.,tail gas)will be combusted using a shrouded biogas flare utilizing natural gas as
the pilot fuel. The biogas flare(which is vertical and unobstructed)will be used to combust the
raw biogas on-site during initial facility startup and at times when the upgrading system is
temporarily out of operation (defined as Scenario 2).A natural gas-fired boiler will be used to
produce process heat. A storage bunker capable of storing a five-day supply of used poultry
bedding will be used to receive solid material at the facility. The used poultry bedding will be
treated in three receiving pits that act to homogenize the material. The used poultry bedding will
then enter a biomass liquefaction system where it is mixed with hot water and large inorganic
particles are removed. The used poultry bedding will be heated prior to introduction into the
fermenters to minimize the heating that is needed in the fermenters. The gases from the biomass
liquefaction system,which will include ammonia,will be collected and routed to the natural gas-
fired boiler's intake which will control emissions from the biomass liquefaction system when
used as a thermal oxidizer.
The plant is expected to operate under"normal operations"for—8;30,0 hours per year. Normal
operations(i.e., Scenario 1)are defined as the biogas production equipment, including the poultry
litter handling and preparation equipment,the fermentation system, and the anaerobic digestion
system, and gas upgrading equipment operating properly, as designed.
ed. During normal
rmal operation,
biogas will be separated into product as and tail as b the as upgrading system. The product
g g Y g PgT g Y
gas will be compressed, injected into the existing natural gas pipeline as renewable natural gas,
and utilized off-site. The tail gas will be routed through the biogas flare so any remaining
constituents that are not carbon dioxide will be oxidized, even though the tail gas will primarily
be carbon dioxide. The natural gas boiler will operate to provide process heat to the facility
during normal operations. When the Carbon Adsorber Hydrogen Sulfide Removal System's
media is saturated it has to be removed and replaced. This action usually takes approximately
one day and during that maintenance period the biogas generated is sent instead to the biogas
flare.
The potential emissions before controls/limits in the permit application show the potential
emissions if the facility combusted biogas in the flare for an entire year,however,the facility will
never realistically combust raw biogas in the flare for an entire year.
Combusting raw biogas in the flare will not occur for prolonged periods. It would not be
economically feasible to continue operating the facility if biogas cannot be upgraded to renewable
natural gas and utilized off-site. As noted above, combustion of raw biogas without gas

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Permit RO1 Review
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upgrading is anticipated to occur primarily during initial facility startup and during repairs to the
gas upgrading system. The anaerobic digesters are designed to allow at least one day of biogas
storage at the maximum production rate. The feedstock supply to the digester system will be
promptly reduced during gas upgrading system or hydrogen sulfide removal system downtime to
decrease the biogas production rate. The feedstock supply to the digester system will be carefully
managed and controlled at the facility using a series of processing steps. The heated digesters
used at the facility should respond quickly to changes in feedstock supply, and considerable
changes in biogas production begin to occur within hours after the feedstock feed rate is changed.
This type of response is expected for mixed, heated digester systems that are designed for high-
rate feedstock conversion using shorter retention times. Additionally, digester effluent will be
drained from the system each day and can be drained from the digesters to provide additional
headspace for biogas storage. To significantly reduce biogas production, digester effluent can
also be drained from the tanks while the feedstock feed rate is reduced, which would provide
significantly increased biogas storage capacity(several days to over a week) and reduced biogas
production. Scheduled preventative maintenance activities for the gas upgrading system will be
used to prevent prolonged system downtime and to minimize the volume of biogas that is flared
at the facility by aligning repairs with reduced feedstock supply to the system. Any off
specification product gas(i.e., not pipeline quality)generated by the facility will be flared.
Of the biogas constituents 55% CHa 44.95% CO2 0.25% H2S and 0.05%NH3 , nearly all of the
g ( ) Y
methane will be separated to be utilized as renewable natural gas off-site and nearly all of the
hydrogen sulfide will be captured in the media vessel. The remaining as that is discharged from
the gas upgrading system, referred to as tail gas,will consist primarily of carbon dioxide.
The facility will be staffed full-time,24 hours per day, 7 days per week, by a trained operator.
The operator will monitor operations, including biogas production and the biogas flare,to ensure
the facility is operating within acceptable operating limits.
The biogas composition values included in the original permit application(R00)were derived
from the Ductor pilot plant operations, including the demonstration plant at Tuorla in Finland,
and similar anaerobic digester facilities using poultry litter or poultry manure as a feedstock. For
anaerobic digester operation in general,biogas composition varies with feedstock composition
and environmental factors such as temperature and pH. The biogas composition for the Catawba
Biogas facility will vary slightly depending on the source of poultry litter and operating j
conditions, but the composition listed in the air permit application (2,500 ppmv)represents the
expected average.
The natural gas-fired boiler will operate whenever the other equipment at the facility is operating.
The boiler is required for fermenter and anaerobic digester heating, and thus is required for biogas
production. The boiler will not operate at maximum capacity for the entire year. The heating
required for the fermenters and anaerobic digesters will be less when ambient temperatures are
higher during the summer months and greater when ambient temperatures are lower during the
winter months. Due to this,the boiler will operate at a slightly greater capacity during the winter
months than other times throughout the year.

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3. Discussion of Requested Permit Modification Approach
Using data from the company's greenfield permit application, DAQ has determined that the
facility has the potential to exceed the daily TPER emission limit for H2S (i.e., 5.1 lbs of H2S/day)
as defined in 15A NCAC 02Q .0711(b)when the company is combusting unprocessed biogas that
has not been treated using their hydrogen sulfide removal system(Scenario 2 as described in
Section 2 above).
Catawba Biogas, LLC proposes to limit the volume of unprocessed biogas flared to less than
1,130,400 standard cubic feet(scf)/day,which they equate to 5.0 lbs of H2S/day. Their equation
is based on the estimated H2S concentration of H2S in their unprocessed biogas(2,500 ppmv)
which was taken from analysis of unprocessed biogas at another similar pilot facility. The
company also proposed to monitor and record the total volume of unprocessed biogas combusted
in the flare each day to ensure that the proposed daily volume of gas mentioned above is not
exceeded and that the biogas being directed to the flare will be halted automatically when the
volume of unprocessed biogas flared equals 1,130,400 scf/day. The company stated in their
updated permit application that controlling the rate of feedstock supply to the digester system will
be used to reduce biogas production during gas upgrading system downtime and allow the facility
to comply with the daily limitation on the volume of biogas combusted in CD-1 when the
hydrogen sulfide removal system is not operational. To accomplish the monitoring,
recordkeeping, and reporting of this limitation,the company proposes to install a flowmeter on
the bypass line that takes the unprocessed biogas to flare CD-1 directly.
After reviewing the company's proposed modifications listed above,the DAQ/FRO believes that
a more accurate method of determining the daily H2S emissions from the biogas flare is required.
Similar to permitting actions taken in recent Align RNG, LLC (3100179; R00 permit and Optima
TH (0900096; R00)(action),the new permit will include a requirement to analyze hourly the H2S
content and biogas flow and then to sum the flare's daily H2S emissions from the
biogas/tailgas/off specification gas stream entering the Shrouded Biogas Flare(CD 1). If the
daily H2S emissions from the flare-exceed the 5.1 lb/day limit the facility wilt bye considered in
violation of 15A NCAC 02Q .0711(b).
4. Zoning
Zoning was not affected by this permit action.

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5. Application Chronology:
06/07/21 The FRO received the permit modification including the"Form A"and the required$400
fee. There was no request to keep any information confidential. The application
appeared to be complete for processing.
06/08/21 The FRO sent the facility a letter acknowledging receipt of the permit application.
06/15/21 Mr. Jeffrey Cole and Heather Carter of FRO held a teleconference with Mr. Gus
Simmons and Mr. Ben Cauthen of Cavanaugh&Associates. Mr. Cole and Ms. Carter
noted two concerns with the permit modification application for Catawba Biogas, LLC.
• FRO noted that the permit modification application requested a limit on the daily
amount of biogas flared in the shrouded biogas flare(CD-1)when the H2S
scrubber/gas upgrading system is being bypassed and all biogas is being flared.
This limit on flare operation was requested in order to stay under the 02Q
.0711(b) limit of 5.1 lbs of H2S per day for vertically oriented, unobstructed
stacks. However, CD-1 is a shrouded biogas flare(i.e., obstructed) and thus
would have to comply with the 02Q .0711(a) limit of 1.7 lbs of H2S per day
under all operational conditions.
• FRO requested a detailed explanation on how the 02Q .0711(a) limit of 1.7 lbs of
H2S per day will be met on a continuous basis during biogas generation but when
the H2S scrubber/gas upgrading system is down for an extended period of time.
The FRO requested that the facility submit an updated permit application addressing
these issues.
PERMIT APPLICATION CLOCK OFF
06/24/21 The facility submitted an updated permit application answering the questions asked in the
6/15/21 meeting.
• The company provided evidence,through manufacturer certification,that the
shrouded biogas flare(CD-1)will actually be unobstructed and vertically
oriented and thus its toxic emissions should be compared to the limits under 02Q
.0711(b)not 02Q .0711(a).
• The company provided a detailed explanation on how the 02Q .0711(b) limit of
5.1 lbs of H2S per day will be met on a continuous basis when biogas is being
generated but when the H2S scrubber/gas upgrading system is down for an
extended period of time.
PERMIT APPLICATION CLOCK ON
08/06/21 FRO sent a draft copy of the permit to Mr. Ted Niblock, Mr. Simmons and Mr. Cauthen
for their review.
08/10/21 Mr. Cauthen sent an email to Mr. Cole listing comments that the company had with the
draft permit.

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6. Changes in Equipment,Emissions and Regulations and PE Review Requirements
• There is no requirement for a P.E.review of this permit application.
• No additions were made to the permitted equipment list.
• The facility had one pink sheet note which stated that the 02Q .0711 "TOXIC AIR
POLLUTANT EMISSIONS LIMITATION REQUIREMENT," stipulation should be
added at the next opening of the permit.
The following additions were made to permit conditions:
• Added a 02Q .0309"NOTIFICATION REQUIREMENT"stipulation requiring a written
notice to the Regional Supervisor,DAQ within 15 days after start-up of the Biogas
Production Equipment(ID No. ES-2)becoming operational.
• Added a 02Q .0711 "TOXIC AIR POLLUTANT EMISSIONS LIMITATION
REQUIREMENT, stipulation.
• Added a separate AdHoc 02Q .0711 "TOXIC AIR POLLUTANT EMISSIONS
LIMITATION REQUIREMENT," stipulation to address monitoring and recordkeeping
requirements to ensure compliance with the H2S emission limit of 5.1 lbs/day.
The facility's permitted emission sources and controls are as follows:
Emission Emission Source Control Control System
Source ID Description System ID . Description
ES-1 Iv atural gas-fired Boiler N/A N/A
(NSPS) (19.02 mmBtu./hr maximum heat input)
Shrouded Biogas Flare
CD-1 (using natural gas for pilot flame with a
Biogas Production Equipment 28.06 mmBtu/hr maximum heat input)
ES-2 (consisting of three(3)identical 70,629 W
fermenters and two(2)identical and and
2.28 million-gallon anaerobic digesters)
CD-2 Carbon Adsorber Hydrogen Sulfide
Removal System*
ES-3 Biomass Liquefaction System N/A Natural gas-fired Boiler(ID No.ES-1)
used as a thermal oxidizer

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*Note that the Shrouded Biogas Flare(CD-1)is always operational in one of three modes(except when undergoing
maintenance). During normal operation(known also as Scenario 1),the biogas generated by the Biogas Production
Equipment(ES 2)flows through the Hydrogen Sulfide Removal Vessel(CD-2)and through the gas upgrading
system and is injected into the natural gas pipeline. During this time,the Shrouded Biogas Flare is used to combust
the undesirable constituents of the biogas after gas upgrading has occurred(i.e.,tail gas). However,during facility
start-up and when the facility's gas upgrading system is not operating,the hydrogen sulfide removal vessel is
bypassed and the shrouded biogas flare combusts the full flow of biogas(known also as Scenario 2). The third
mode(known also as Scenario 3)is when the facility's hydrogen sulfide removal vessel and/or gas upgrading
system is not operating to specification and the facility is generating off specification gas that is not off pipeline
quality. Under this scenario the off specification gas and the tail gas are both flared.
The facility's Insignificant/Exempt Activities are as follows:
Source Regulation Exemption Source of Source of Title
P TAPS? V Pollutants?
IES-1
Two Lean Ammonia Water Pits 02Q .0102(g)(14)(B) Yes No I
(each 3,770 ft3 in volume)
Rich Ammonia Water Tank 02Q .0102 (g)(4) Yes No
equipped with Activated Carbon Filter
7. NSPS,NESHAP,PSD,Attainment Status,and 112(r)
• NSPS
✓ The Natural gas-fired Boiler(19.02 mmBtu/hr maximum heat input)
(ID No. ES-1) is subject to NSPS Subpart Dc.
• NESHAP
✓ The Natural gas-fired Boiler(19.02 mmBtu/hr maximum heat input)(ID No. ES-1) is
not subject to NESHAP Subpart JJJJJJ"Industrial, Commercial, and Institutional
Boilers Area Sources" since it is a gas-fired boiler, only capable of firing gaseous
fuels.
• PSD—The potential emissions do not exceed PSD threshold limits;therefore,this facility
does not trigger a PSD review. PSD minor-source increment tracking has not been triggered
in Anson County.
• — n County is in attainment
Attainment Status Anson ty
• 112(r)—The facility does not store any of the subject materials at or above the 112r threshold
quantity and is not required to maintain a written Risk Management Plan(RMP).
q ty q

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8. 15A NCAC 02D .0516 Compliance Review
For the 15A NCAC 02D .0516 review, I calculated the following based on Catawba Biogas,
LLC's original greenfield permit application:
...... ,.r � . .. ....; Biogas Tail Gas 3 ,
Flow rate to flare 926.97 scf/minute 425.91 scf/minute
Heating Value 504.5 Btu/scf 28 Btu/scf
This equates to: 467,656 Btu/minute 11,925 Btu/minute
Which equates to: I 28,059,382 Btu/hr 715,529 Btu/hr
Which equates to: 28.06 mmBtu/hr 0.716mmBtu/hr
S02 Emission Rate 22.57 lbs S02/hr 0.45 lbs S02/hr
This equates to: 80 lbs of S02/mmBtu 0.63 lbs of S02/mmBtu
9. Facility Emissions Review:
Expected Actual Potential Emissions Potential Emissions
Pollutant Emissions Before Controls After Controls
(tons/yr) (tons/yr) (tons/yr) ;
PM 0.08 � 0.17 0.08
PMIo 0.03 0.14 0.07 A
PM2.5 0.07 0.14 ; 0.07 i
l
S02 1.91 98.90 1.91
NOx 16.51 32.73 ; 16.52
CO 13.71 27.32 13.71 "
VOC 0.90 1.79 0.90
The emissions listed in the table above are taken from the R00 permit review.
Note that this permit modification contains requirements to ensure that the facility remains under
the TPER emission limit for H2S as defined in 15A NCAC 02Q .0711(b). This is accomplished
by monitoring H2S emissions as explained in Section 9 below.

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10. Facility Wide Air toxics:
acetaldehyde I 6.72 x 10' lb/hr 28.43 lb/hr o
acrolein 7.96 x 10-' lb/hr 0.08 lb/hr j No
ammonia 0.0166 lb/hr 2.84 lb/hr No
benzene 0.686lb/yr 11.069lb/yr No
benzo(a)pyrene 3.92 x 10-4 lb/yr 3.044 lb/yr I No
formaldehyde 3.32 x 10' lb/hr 0.16 lb/hr No
hydrogen sulfide 5.91b/day 5.1 lb/day Yes
---
n-hexane 1.911b/day 46.31b/day No
toluene x 10' lb/day 197.96 lb/day No
toluene 1.5 x 10-4 lb/hr 5 8.97 lb/hr No
Toxic pollutant emissions from the facility operations are detailed in the table above. Facility
wide toxics were,evaluated in the.R00 permit review against the 02Q .0711(al.toxic limits as the
Shrouded Biogas Flare(CD-1)emission release point was assumed to be obstructed. The
company has since provided manufacturer information that CD-1 will actually be unobstructed
and vertically oriented and thus its toxic emissions are actually subject to the 02Q .0711(b)toxic
limits.
There is one toxic pollutant whose emissions exceed the toxic air pollutant permitting emissions
rates(TPERs). In this permit application,the company chose to not model H2S emissions but
rather requested a limit on the volume of unprocessed biogas flared to keep their facility-wide
emissions of H2S under 5.1 lbs/day based on an estimated H2S content in their biogas. DAQ does
not agree with this approach and instead chose to address H2S emissions from the biogas flare in
a similar manner to permitting actions taken in recent Align RNG, LLC (3100179; R00)and
Optima TH(0900096; R00)permits actions by including a requirement to monitor the hourly H2S
content and biogas flow rate and then to sum the biogas flare's daily H2S emissions. If the daily
H2S emissions from the biogas flare exceed the 5.1 lb/day limit the facility will be considered in
violation of 15A NCAC 02Q .0711(b).
There will be no 02D .1100 toxics condition in the permit as no modelling was performed;
however there will be two separate 02Q .0711 toxics conditions in the permit. One of these two
conditions will account for all toxics that were estimated to be below their TPER limits. The
second, an AdHoc 02Q .0711 toxics condition,will list operational, monitoring and
recordkeeping requirements to ensure compliance with the H2S emission limit of under
5.1 lbs/day. The following AdHoc 02Q .0711 toxics condition,which acts as a 02D .1100
avoidance condition,will be inserted into the new permit:
15A NCAC 2Q.0711 "TOXIC AIR POLLUTANT EMISSIONS LIMITATION REOUIREMENT"-Pursuant
to 15A NCAC 2Q.0711 "Emission Rates Requiring a Permit,"for each of the below listed toxic air
pollutants(TAPs), the Permittee has made a demonstration that facility-wide actual emissions, where all
emission release points are unobstructed and vertically oriented, do not exceed the Toxic Permit Emission
Rates (TPERs) listed in 15A NCAC 2Q.0711(b). The facility shall be operated and maintained in such a

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manner that emissions of any listed TAPS from the facility, including fugitive emissions, will not exceed
TPERs listed in 15A NCAC 2Q.0711(b).
a. A permit to emit any of the below listed TAPS shall be required for this facility if actual emissions
from all sources will become greater than the corresponding TPERs.
b. PRIOR to exceeding any of these listed TPERs, the Permittee shall be responsible for obtaining a
permit to emit TAPS and for demonstrating compliance with the requirements of 15A NCAC 2D
.1100 "Control of Toxic Air Pollutants".
c. In accordance with the approved application, the Permittee shall maintain records of operational
information demonstrating that the TAP emissions do not exceed the TPERs as listed below:
oe
01
Hydrogen sulfide(7783-06-4) 5.1
d. Monitoring
i. The Permittee shall monitor and record, hourly, both the total biogas/tail gas/off
specification gas flow(in scf) and the H2S concentration (in ppmv)for the biogas/tail
gas/off specification gas stream entering the Shrouded Biogas Flare(CD-1).
ii. The Permittee shall calculate the daily facility wide emission rate(lbs/day) of H2S when
the ES-2 (Biogas Production Equipment) is in operation. Note that an operating day is
defined as any calendar day between 12:00 AM to 11:59 PM.
The following equation shall be used to calculate the hourly H2S emission rate(lb/day):
[(60)(MWH2S)(P) * [(V) PPMV * 0.02
�LhrH2s = (R)(T) 1,000,000
)]
Total H2S Emissions per day(lb/day):
mhrH2s =H2S emission rate from facility per hour
60 = conversion factor = 60 min/hr
MWH2S =molecular weight of H2S(lb/lbmol) = 34.08 lb/lbmol
P =standard pressure = 14.7 psia
R =gas constant = 10.73 (psia*ft)/(lbmol*R)
T=standard temperature = 491.67 R
V= hourly calculated biogas/tail gas/off specification gas volumetric flow rate (scfm)
0.02 =assuming 98%conversion of H2S to S02
PPMV=measured hourly biogas/tail gas/off specification gas H2S concentration (ppmv)
24
M daily H25= mhr H2S
i=1
iii. The Permittee shall record all periods, including date and duration, when the flare is not
in operation.

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iv. The Permittee shall record all periods of H2S analyzer and biogas/tail gas/off
specification gas flow meter downtime:
A. For both the H2S analyzer and biogas/tail gas/off specification gas flow meter,
required in A.15.d above, the downtime for each monitor:
1. shall not exceed 5.0 percent of the operating time in a calendar
quarter;
II. shall be calculated using the following equation:
Total Monitor Downtime l
%MD = 100
[Total Source Operating Time1 *
Where:
%MD is the percent monitor downtime.
"Total Monitor Downtime"is the number of hours during a calendar quarter where an
emission source was operating but data from the associated monitors are invalid, not
available, and/or substituted per the DAQ approved data substitution procedure.
"Total Source Operating Time"is the number of hours in a calendar quarter where the
biogas/tail gas/off specification gas is being vented from the Biogas Production
Equipment(ID No. ES-2).
"Quarterly period"is defined as the three-month periods between January and March or
April and June or July and September or October and December of each calendar year.
Missing Data Substitution Procedure:see A.15.d.viii. below.
V. If the total daily H2S emissions from the biogas flare exceed the 5.1 lb/day limit the
facility will be considered in violation of 15A NCAC 02Q.0711(b).
vi. By 9:00 a.m. Eastern time of the Division's next business day of becoming aware of an
exceedance of the H2S daily emission limit in the table above, the Permittee shall notes
and submit the results of the calculation in A.15.d.ii to the Division of Air Quality.
vii. Within 15 days of the issuance of all purchase contracts signed by the Permittee with air
pollution control equipment vendors and parametric monitoring and data recording
equipment vendors, the Permittee shall provide written notification of the last signed
contract.
viii. A written inspection, maintenance, calibration and audit plan shall be submitted by the
facility to the DAQ within 30 days of the issuance of the final purchase contracts by the
facility to vendors of any air pollution control equipment,parameter monitors, and data
recording equipment. Once approved by the DAQ, a copy of the written plan shall be
kept onsite at all times and made available to DAQ personnel upon request.
ix. A written data substitution procedure shall be submitted by the facility to the DAQ by the
date of startup of the facility. Once approved by the DAQ, a copy of the written plan shall
be kept onsite at all times and made available to DAQ personnel upon request.

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a. Recordkeeping
i. A log book or electronic record of the biogas flare's operational status, hourly flow rates,
hourly H2S concentrations and the daily facility wide H2S emission rate shall be kept on
site and made available to DAQ personnel for inspection upon request.
b. Reporting
i. The Permittee shall submit a semiannual summary report of monitoring and
recordkeeping activities postmarked on or before January 30 of each calendar year for
the preceding six-month period between July and December, and on or before July 30 of
each calendar year for the preceding six-month period between January and June. This
report shall include:
A. A list of any daily H2S emission rate exceedances(in lbs/day),
B. An identification of all periods, including date and duration, during which data
from the H2S analyzer and biogas/tail gas/off specification gas flowmeter
monitors are invalid, not available, and/or substituted per the DAQ approved
data substitution procedure.
C. Results of the percent monitor downtime calculation listed in A.1 S.d.N.H.
11. Facility Compliance Status:
N/A This is a greenfield facility and has no previous compliance history. The facility has
not commenced construction.
12. Stipulat
ion n Review:
P
The following regulations are applicable to this facility:
......
Emission Limit
pan 1 Wei a urces,egu a� .._
M Requiremen t
15A NCAC 02D.0202 Facility-wide Permit Renewal and Emission Inventory Requirement
15A NCAC 02D.0503 Boiler PM<0.47 lb/mmBtu
ES-1
E=4.10*(P)0-67 for P<30 tons/hr
15A NCAC 02D.0515 ES-2 and ES-3
I _ E=55 *(P)0-1—40 for P>30 tons/hr
Facility-wide-15A NCAC 02D.0516 ty wide S02<_2.3 lb/mmBtu
15A NCAC 02D.0521 Facility-wide 20%opacity
Boiler requirements
15A NCAC 02D.0524 Boiler Recordkeeping
NSPS Subpart Dc ES-1 Notification of initial startup
within 15 days of startup
Monthly Fuel Usage
15A NCAC 02D.0535 Facility-wide Notification requirement
15A NCAC 02D.0540 Facility-wide S Fugitive Dust Control Requirement
1 4

Catawba Biogas, LLC
Permit RO1 Review
Page 13 of 15
. _. Emission Limit
tegufat on Affected Sources
or Requirement
Biogas Flare Requirements
! I&M as well as periodic calibrations and audits per
15A NCAC 02D.0611 Biogas Flare Manufacturer's Recommendations for Biogas Flare,HzS
CD-1 Monitor(s)and Flow meter(s),Annual Inspection of Biogas
Flare, Daily visual inspection of Biogas Flare, Recordkeeping
Carbon Adsorber Requirements
Hydrogen Sulfide I&M per Manufacturer's Recommendations
15A NCAC 02D.0611 Removal Vessel
CD-2 Annual Inspection, Develop operational plan for periodic
replacement of the carbon media,Recordkeeping
Permittee shall implement the following management practices
I for minimizing odor from poultry litter:
• Use of covered trucks
• Utilize on-site fuel handling and management practices to
minimize emissions and spillage of the poultry litter
15A NCAC 02D.1806 Facility-wide • Perform loading and off-loading procedures inside a
Avoidance
poultry litter storage area in an expeditious manner;
• Reasonably utilize the"first in,first out" (FIFO)
method for processing and using poultry litter
- • Not storing any poultry litter on site for more than 90 '
( days. _._________ __ m
Prior to construction or operation of the facility under this
15A NCAC 02D.0304 permit,the Permittee shall comply with all lawfully adopted
Zoning Specific Condition Facility-wide local ordinances that apply to the facility at the time of
I construction or operation of the facility
Within 15 days after start-up of the Biogas Production
Biogas Production Equipment(ID No. ES-2)becoming operational,the Permittee
15A NCAC 2Q.0309 Equipment shall provide written notice of the start-up to the Regional
ES-2
Supervisor, DAQ.
15A NCAC 2Q.0711 Facility-Wide ? Permitting required if toxic emission rate exceeds TPER

Catawba Biogas,LLC
Permit RO1 Review
Page 14 of 15
f
Toxics limitation for Hydrogen Sulfide<5.1 lb/day
Monitoring and Recordkeeping
Monitor and record,hourly,both the biogas flare's operational
status,H2S flow rate(in scf),H2S concentration(in ppmv)for
the biogas stream entering the Shrouded Biogas Flare(CD-1).
Calculate and record the daily facility wide emission rate
(lbs/day)of H2S when ES-2(Biogas Production Equipment)is
in operation.
If the total daily H2S emissions from the biogas flare exceed the
5.1 lb/day limit the facility will be considered in violation of
15A NCAC 02Q .071 I(b).
Next business day notification of an exceedance of the H2S
daily emission limit.
Within 15 days of the issuance of all purchase contracts signed
by the Permittee with air pollution control equipment vendors
and parametric monitoring and data recording equipment
I vendors,the Permittee shall provide written notification of the
15A NCAC 2Q.0711 Biogas Flare last signed contract.
CD 1 Develop and submit a written inspection,maintenance,
calibration and audit plan as well as a data substitution
procedure 30 days of the issuance of the final purchase
contracts by the facility to vendors of any air pollution control
equipment,parameter monitors,and data recording equipment
for any air pollution control equipment,parameter monitors,
and data recording equipment for approval by DAQ.
Develop and submit a written data substitution procedure to the
DAQ by the date of startup of the facility for approval by DAQ.
Semiannual Reporting to include:
• A list of any daily H2S emission rate exceedances(in
lbs/day),
• An identification of all periods, including date and
duration,during which data from the H2S analyzer and
biogas/tail gas/off specification gas flowmeter
monitors are invalid,not available,and/or substituted
per the DAQ approved data substitution procedure.
• Results of the percent monitor downtime calculation.
13. Conclusions, Comments,and Recommendations:
I recommend that air permit 10593ROI be issued for Catawba Biogas,LLC with the following
modifications to IBEAM Permit Writer:
• Adjusted column widths,bolded and shaded to improve appearance.
• General formatting to correct errors commonly introduced by ad hoc stipulations.
• Added the word"and"as necessary to the permitted sources table. This denotes that the
Sulfide Removal Vessel (ID No. CD 2)can operate, or not operate,but that the Biogas
Flare CD-I is always operational.

Catawba Biogas, LLC
Permit RO1 Review
Page 15 of 15
• Added the following text to the ES-3's control device description, "Natural gas-fired
Boiler(ES-1) used as a thermal oxidizer."
• Added the following text after the emission source table, "*Note that the Shrouded
Biogas Flare (CD-1) is always operational in one of three modes (except when
undergoing maintenance). During normal operation (known also as Scenario 1), the
biogas generated by the Biogas Production Equipment(ES 2)flows through the
Hydrogen Sulfide Removal Vessel(CD-2) and through the gas upgrading system and is
injected into the natural gas pipeline. During this time, the Shrouded Biogas Flare is
used to combust the undesirable constituents of the Biogas after gas upgrading has
occurred(i.e., tail gas). However, during facility start-up and when the facility's gas
upgrading system is not operating, the hydrogen sulfide removal vessel is bypassed and
the shrouded biogas flare combusts the full flow of biogas (known also as Scenario 2).
The third mode (known also as Scenario 3) is when the facility's hydrogen sulfide
removal vessel and/or gas upgrading system is not operating to specification and the
facility is generating off specification gas that is not off pipeline quality. Under this
scenario the off specification gas and the tail gas are both flared."
• Deleted the following text"or from those given in this permit(when applicable)" from
the recordkeeping section of the"CARBON ADSORBER REQUIREMENTS"
stipulation.
• Deleted the"Acute Systemic Toxicants(lb/hr)"column heading for the table in the 15A
NCAC 2Q .0711 "TOXIC AIR POLLUTANT EMISSIONS LIMITATION
REQUIREMENT" Stipulation A.14,as it contained no data.
Review Engineer: Date:
ii
Permit Coordinator: Date: /l6zL0 zt
AQ Supervisor: Cti Date:
J do
cc: FRO Files