AQ_F_1300129_20220105_CMPL_CAV-Rpt

NORTH CAROLINA DIVISION OF Mooresville Regional Office
AIR QUALITY Stevenson-Weir/Southern,LLC-Concord Plant
NC Facility ID 1300129
Inspection Report County/FIPS: Cabarrus/025
Date: 01/04/2022
Facility Data Permit Data
Stevenson-Weir/Southern,LLC-Concord Plant Permit n/a
2807 Armentrout Drive Issued n/a
Concord,NC 28025 Expires n/a
Lat: 35d 22.6710m Long: 80d 34.6030m Class/Status Permit Exempt
SIC: 3273/Ready-Mixed Concrete Permit Status Inactive
NAICS: 32732/Ready-Mix Concrete Manufacturing Current Permit Application(s)None
Contact Data Program Applicability
Facility Contact Authorized Contact Technical Contact SIP
Gary Barnhardt Stuart Stevenson Shannon Houck
Plant Manager President Environmental Manager
[phone] [phone] [phone]
Compliance Data
Comments:
Inspection Date 01/04/2022
Inspector's Signature: Danny eook J993t Inspector's Name Donna Cook
Operating Status Operating
Compliance Status Compliance-inspection
Date of Signature: 01/05/2022 Action Code FCE
Inspection Result Compliance
Total Actual emissions in TONS/YEAR:
TSP S02 NOX VOC CO PM10 *HAP
2011 0.4200 --- 0.1200 0.0100 0.1000 0.1900 4.21
2006 1.33 --- 0.0100 --- --- 0.6100 0.3700
*Highest HAP Emitted(in pounds)
Five Year Violation History:None
Date Letter Type Rule Violated Violation Resolution Date
Performed Stack Tests since last FCE:None
Date Test Results Test Method(s) Source(s)Tested

Stevenson-Weir/Southern,LLC -Concord Plant
(Formerly Southern Concrete Materials—Concord Plant)
January 4,2022
Page 2
Type Action: _Full Compliance _Partial Compliance _Complaint X Other: Compliance Assurance Visit
Evaluation Evaluation/Reinspection Investigation CAV
Data Tracking: X Date submitted for initial review 01/05/2022 _IBEAM WARNING/OB,NOD,NOV,NRE
X IBEAM Document
X IBEAM Inspection,list date inspected IBEAM LAT/LONG,Facility Locked
X IBEAM Inspection,list date draft is submitted X IBEAM LAT/LONG,Coordinates checked
X IBEAM Inspection,pollutants/programs checked IBEAM Complaint
X IBEAM Planning,Next Inspection Date 01/01/2024
Directions: From Mooresville Regional Office to Concord,travel via Highway 3 South;turn right on
Odell School Road;turn right at the stop light onto Poplar Tent Road due to the no left turn;make a U
turn at the next stop light;turn right on Highway 601/29 (referred to as Concord Parkway);turn left on
Highway 601 Bypass (Warren C. Coleman Boulevard)toward Monroe for approximately 2 1/2 miles;turn
right onto Armentrout Drive; and 0.2 mile on the right is this facility. The street address is 2807
Armentrout Drive.
Safety Equipment: This company requires that steel toe shoes,hard hat, safety glasses and safety vest be
worn by the inspector at this facility.
Safety Issues: The inspector should be cautious of vehicle traffic and the frontend loader at this facility.
Lat/Long Coordinates: A review of the "Facilities Regulated by Air Quality" on the DAQ web site
indicates the facility's latitude and longitude coordinates are accurate. No changes to the latitude and
longitude coordinates of this facility are needed in IBEAM. The latitude and longitude coordinates of this
facility are not locked in IBEAM.
Email Contacts: The emails for the facility, authorized and technical contacts were verified by Mr. Gary
Barnhardt,plant manager. I changed the facility contact to Mr.Barnhardt; authorized to Stuart Stevenson,
president; and the technical contact to Ms. Shannon Houck, environmental manager, in IBEAM.
COVID-19 Information:
Mr. Gary Barnhardt,plant manager of this company, and I discussed the COVID-19 restrictions at this
facility. Mr. Barnhardt stated that this facility has no coronavirus restrictions. The on-site inspection was
conducted by me outside of the concrete batch plant with no coronavirus restrictions.
Compliance Assurance Visit:
1. General Information:
The purpose of this site visit was to conduct a routine compliance assurance visit (CAV). This
facility is a truck mix concrete batch plant rated at 125 cubic yards per hour. This company
operates this plant from 7 a.m. to 4 p.m., 5 days per week, 50 weeks per year. The operational
schedule of this facility is dependent upon weather conditions and customer orders. Mr. Gary
Barnhardt,plant manager,accompanied me during the CAV.

Stevenson-Weir/Southern,LLC -Concord Plant
(Formerly Southern Concrete Materials—Concord Plant)
January 4,2022
Page 3
I phoned Ms. Shannon Houck, environmental manager of this company, to discuss the ownership
and name change that occurred in August 2021. Ms. Houck informed me that Southern Concrete
Materials was acquired by Stevenson-Weir, Inc. to form Stevenson-Weir/Southern, LLC only in
the Charlotte Division. The name of this facility is Stevenson-Weir/Southern, LLC — Concord
Plant.
3. Compliance history file review:
No problems have been noted in the last five years by DAQ prior to the CAV.
4. Source Observations:
The truck mix concrete batch plant is comprised of the following air emission sources and
associated control devices:
• one bagfilter(1500 square feet of filter area) installed on one cement silo (1000 barrel or 188
tons); one flyash silo (380 barrel or 56 tons) and cement/flyash weigh batcher (44 tons per
hour maximum capacity) and a truck loadout.
The above referenced sources were in operation during the CAV. The differential pressure gauge
installed on the bagfilter located at ground level read 7 inches of water. The only source of visible
emissions occurred when the cement and flyash were gravity dropped from the weigh batcher into
the mixer truck. The visible emissions from the truck loadout process ranged from 0% to 15%
opacity. The visible emissions limitation of 20% opacity when averaged over a six-minute period
was not being exceeded.
The tanker trucks unload cement and flyash into the respective silos.No tanker truck unloading
of cement or flyash into the respective silos was occurring during the CAV.Mr. Barnhardt stated
that this company receives 0 to 6 loads per month(25 tons per load)of cement and 0 to 2 loads
per month(25 tons per load) of flyash.
One portable auxiliary cement silo (45 tons) and its associated bagfilter (165 square feet of filter
area; 18 bags) are used in emergency situations as indicated by Mr. Barnhardt. The portable
auxiliary cement silo and associated bagfilter were not in operation during the CAV. A tanker
truck pumps cement into the portable auxiliary cement silo. Then the cement is pneumatically
blown from the auxiliary cement silo into the cement silo (1000 barrel or 188 tons). Mr.
Barnhardt informed me that the portable auxiliary cement silo is currently not in use by this
company.
From the stock piles, a front end loader places the aggregate and sand in a hopper. Then the
aggregate and sand are conveyed to four compartment storage bins (50 tons each or 200 tons
total). Then the aggregate and sand are weighed in the batcher(weigh scale)and then conveyed
through a rubber chute(boot)into mixer trucks. I observed no visible emissions from the
aggregate and sand transfer process.
The liquid concrete admixtures(water reducers, accelerators,retarders,plasticizers, and air
entraining) and water are fed into the mixer trucks along with cement, flyash, sand and aggregate
to form the concrete product. The admixtures are stored in plastic tanks.No visible emissions
observed or odors detected by me from the admixture process.

Stevenson-Weir/Southern,LLC -Concord Plant
(Formerly Southern Concrete Materials—Concord Plant)
January 4,2022
Page 4
The natural gas-fired water heater(manufacturer,Bradford White;year, 1998; 3.08 million Btu
per hour maximum heat input and 1.54 million Btu per hour minimum heat input)is used to heat
the mix water and keep the aggregate bins/scale and its associated conveyor from freezing
during cold weather at this plant. The natural gas-fired water heater was in operation with no
visible emissions observed by me at the time of the CAV.
This company has one aboveground diesel tank(12,000 gallon capacity)that is used to fuel the
front end loader and mixer trucks at this plant. The aboveground storage tank is exempt per 15A
NCAC 2Q .0102 (g)(4).
This office has not received any fugitive dust emissions complaints regarding this facility. This
company has paved and unpaved areas at this facility. Mr. Barnhardt stated that a tote containing
water on the forks of a front end loader could be used to wet the unpaved areas of this facility.
During the CAV,I observed no fugitive dust from this facility. I asked Mr. Barnhardt if any
excess emissions had occurred at this facility since the last CAV on October 9, 2019. Mr.
Barnhardt stated that no excess emissions had occurred at this facility.
5. NSPS/NESHAP Review:
The exempt natural gas-fired water heater rated at 3.08 million Btu per hour maximum heat input
is not subject to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for
Industrial, Commercial, and Institutional Boilers Area Sources (40 CFR Part 63, Subpart JJJJJJ or
6J), since the rule does not apply to a water heater that is gas-fired.
The exempt natural gas-fired water heater is not subject to 40 CFR Part 60,New Source
Performance Standards(NSPS), Subpart Dc-"Standards of Performance for Small Industrial-
Commercial-Institutional Steam Generating Units." The applicability of NSPS Subpart Dc to a
water heater is constructed after June 9, 1989 with a maximum heat input capacity greater than
10 million Btu per hour. The water heater is rated 3.08 million Btu per hour maximum heat input
and was manufactured in 1998.
This company has no emergency generators,peak shaving generators,fire pump engines or
gasoline storage tanks at this facility.
6. Exemption Qualification:
The truck mix concrete batch plant with controls emits PM10 and HAPs/TAPS emissions.The
combustion of natural gas from the hot water heater emits PMIO, SO2,NOx,VOC, CO and
HAPs/TAPs emissions. This facility can be exempt from air quality permitting if the facility-wide
actual emissions of PM10, S02,NOx,VOC, CO,HAPs and TAPs,each are less than five tons per
year and the total actual aggregate emissions of these pollutants are less than ten tons a year per the
exemption rule, 15A NCAC 2Q .0102(d).
This company provided five years of concrete production records during the permit exemption
process. The highest concrete production occurred in 2015 calendar year. MRO DAQ permitting
determined using the concrete batch plant emissions calculator spreadsheet that 0.41tons of actual
PMIO emissions were emitted based on 42,107 cubic yards of concrete produced by this plant. The
total HAPs/TAPs emissions from this concrete plant were 0.00027 tons.

Stevenson-Weir/Southern,LLC -Concord Plant
(Formerly Southern Concrete Materials—Concord Plant)
January 4,2022
Page 5
This company reported 2.34 million cubic feet of natural gas in the 2011 emissions inventory. MRO
DAQ permitting determined that the amount of natural gas used based on 42,107 cubic yards was
estimated at 5 million standard cubic feet(scf)per year. The natural gas emissions calculator was
used by MRO DAQ permitting to calculate the following emissions from the natural gas combustion
of 5 million standard cubic feet(scf)per year were 0.019 PM10; 0.0015 tons S02; 0.25 tons NOx;
0.014 tons VOC; 0.21 tons CO; and 0.013 tons HAPs/TAPS. The total aggregate emissions from the
truck mix concrete batch plant and natural gas-fired water heater were 0.91 tons per year(0.41 +
0.50=0.91 tpy).
The concrete batch plant emissions calculator spreadsheet indicated that the truck mix concrete batch
plant with controls would emit 4.971 tons PM10 if this plant produced 515,890 cubic yards of
concrete in a year. The total PM10 emissions from the concrete batch plant and natural gas-fired
water heater would still not exceed 5 tons per year(4.971 +0.019=4.99 tpy).
This office sent a letter dated July 13,2016 exempting this facility from permitting since the actual
PM10, S02,NOx,VOC, CO,HAPs and TAPS emissions, each are less than five tons and the total
aggregate emissions are less than ten tons per year.
During this visit,I reviewed the concrete production records. The records indicated that this facility
produced the following concrete: 24,609 cubic yards in 2019;26,215.25 cubic yards in 2020;
22,275.25 cubic yards in 2021 and 27.5 cubic yards from January 1 to January 4,2022. This facility
still qualifies for exemption. In addition,no changes or modifications have been made to the
equipment since the last visit. The ownership and name of this company changed from Southern
Concrete Materials—Concord Plant to Stevenson-Weir Southern, LLC—Concord Plant in August
2021.
7. Compliance determination:
Based on my observations, this facility appeared to be in compliance with the air quality rules
(213 .0515-particulates from miscellaneous industrial processes; 2D .0521-visible emissions; 2D
.0535-excess emissions; 2D .0540-fugitive dust emissions and 2D .1806-odorous emissions). The
CAV checklist is attached on page 6.
DLC:Ims
c: MRO File
https://ncconnect.sharepoint.com/sites/DAQ-MRO/Counties/CABARRUS/00129/INSPECT 20220104_CAV.docx

Stevenson-Weir/Southern,LLC -Concord Plant
(Formerly Southern Concrete Materials—Concord Plant)
January 4,2022
Page 6
Compliance Assurance Visit Checklist rev.11/03/16
Facility Name:Stevenson-Weir/Southern,LLC-Concord Plant
Physical Site Address:2807 Armentrout Drive
City: Concord Zip Code: 28025 County: Cabarrus
Facility Contact:Gary Barnhardt Title: Plant Manager
Phone No.:[phone]
Mai I i ng Address:2807 Armentrout Drive,Concord,NC 28025
Facility Contact Email Address:[e-mail]
Is the facility contact the person that you met?If not,fill out the following:
Contact Name: Title:
Phone No.:
Mailing Address:
Email Address:
Safety requirements:safety shoes(yes/no)-safety glasses(yes/no)-hearing protection(yes/no)-hardhat(yes/no)-
safety vest(yes/no) other(please describe)
Normal operating schedule(hr/d,d/wk,wk/yr):7 am-4 pm;9 hr/d,5 d/wk,50 wk/yr
Opacity(%)-indicate any non-zero opacities observed: 5%to 15%opacity from truck Ioadout
Odors-indicate if any objectionable odors were detected beyond the property boundary: None
Fugitive dust-indicate whether fugitive dust was observed leaving property boundary:None
Since last inspection,have there been any changes in equipment or operation? None
Throughput and/or fuel usage with units: 125 cubic yards per hour maximum capacity at truck Ioadout
Control device(s)(list): Bagfilter(1500 square feet of filter area)installed on cement silo(1000 barrels or 188
tons);flyash silo(380 barrels or 56 tons);cement and flyash weigh batcher(44 tons per hour maximum capacity)and truck
Ioadout.Portable auxiliary cement silo(45 tons)and its associated bagfilter(165 square feet of fitler area;18 bags).
Properly operated and maintained?Yes
For a permit exempt facility found to be improperly operating or maintaining plant equipment:1)provide compliance
assistance as a first option;2)initiate enforcement action in egregious/repeat cases;3)re-evaluate facility's emissions
using more representative control efficiency/emission factor;4)If re-evaluated actual emissions result in a classification/
registration change,follow enforcement guidelines for operation without a permit/registration;and 5)increase compliance
visit frequency.
Notes or calculation space:
Permit Exemption:
•Actual emissions from the previous year(s)(and projected actual)of PM10,S02,NOx,VOCs,CO,HAPs,and TAPS
are each<5 tpy and whose actual total aggregate of these emissions are<10 tpy
•Can be subject to 40 CFR Part 63(MACT or GACT)and 40 CFR Part 60(NSPS)
•Cannot be subject to Rule 2Q.0315(Synthetic Minor Facilities)or2Q.0500(Title V Procedures)
Concrete Batch Plant:
Actual annual production(cy/yr): Concrete production in cubic yards:27.5 from Jan.Ito Jan.4,2022;22,275.25 in 2021;
26,215.25 in 2020 and 24,609 in 2019.
Truck mix or Central mix plant?: Truck/Central Mix (circle one) Controls?Bagfilter/Cycl one/N one
Boilers: #1 #2 #3 #4
ID No. 1
Installed or last modified date 1998
Size(mmBTU heat input) 3.08 max.1.54 min.
Primary/backup fuel: Natural Gas
Fuel used(annual) Potential<5tons
NSPS Subpart Dc subject? No
NSPS Subpart Dc boiler if>10 mmBtu/hr and<100 mmBtu/hr i nstal led or modified after June 9,1989. Yes/No/NA
Gas only Dc subject boilers:have they submitted initial notification(only requirement)? Yes/No/NA
Gas/fuel oil Dc subject boilers:records kept of each fuel type and startup notification for each fuel? Yes/No/NA
Fuel oil certification required for Dc subject boilers(0.5%max S content).Are copies kept? Yes/No/NA
If fuel oil Dc subject boiler>30 mmBtu/hr,was opacity testing performed on schedule based on results?'
2If VE=O%then done annually,<=5%done semiannually,<=10%done quarterly,>10%done every45 days. Yes/No
GACT O Gas Curtailment option claimed? Yes/No/NA
If no,has a one-time energy assessment been performed. Yes/No/NA
If no,are tune-ups being done biennially(25 months since last tune-up)? Yes/No/NA
If yes,are records kept for natural gas curtailment and testing less than 48 hours per year.