# COMMONWEALTH of 

# VIRGINIA DEPARTMENT OF ENVIRONMENTAL QUALITY 

### STATIONARY SOURCEPERMITTO OPERATE This pel'mit implements the requil'ements for BestAvailable RetrofitTechnology (BART)

for PM, S02 and NO. in the Vallcy ofVirginia Intrastatc Ail' Ouality Control Region. In compliance withthe Federal CleanAirAct and the Commonwealth ofVirginia Regulations for the Control and Abatement ofAir Pollution,

is authorized to operate

located at O-N Minerals (Chemstone) Company Post Office Box 71 Strasburg, Virginia 22657 RegistrationNo,: 80252

a rotary kiln and a calcimatic kiln

1696 Oranda Road Strasburg, Shenandoah County in accordance with the Conditions ofthis permit. Approved on

Permit consists of 16 pages, Permit Conditions I to 48, Source Testing Report Format

# (X.~~ 

# 1-6 /

# 2001

# ~.,/,,~PURPOSE O-N Minerals (Chemstone) Company Registration Number: 80252 Page 2

This permit (i) is for the purpose ofimplementing the "best available retrofit technology" (BART) requirements ofArticle 52 (9 VAC 5-40-7550 etseq.) of9 VAC 5 Chapter40 ofthe Regulations ofthe Board and (ii) establishes control technology and otherrequirements for the control ofvisibility-impairingpollutants from the O-N Minerals (Chemstone) CompanyStrasburg Facility in the Valley ofVirginia Intrastate Air Quality Control Region. These BART requirements shallbethe legal and regulatorybasis for control ofvisibility-impairing pollutants from this facility. INTRODUCTION This permit approval is based on the permit application dated February21,2007, including supplemental information dated April 27, 2007, May 31, 2007, July 12, 2007, August 30, 2007, September 27,2007, November 12, 2007, December 5, 2007, December 14, 2007, January 7, 2008, March 17, 2008, July 15, 2008, May 8, 2009, June 4, 2009, and August 27,2009. Any changes in the permit application specifications or any existing facilities which alter the impact ofthe facility on air quality mayrequire a permit. Failure to obtain such a permitprior to construction mayresult in enforcement action. Words ortelms used in this permit shall have meanings as provided in 9 VAC 5-10-10 and 9 VAC 5-40-7570 C ofthe State Air Pollution Control BoardRegulations for the Control and Abatement ofAir Pollution. Theregulatory reference or authority for each condition is listed in parentheses 

## 0 after eachcondition. Annual requirements to fulfill legal obligations to maintain current stationary source emissions data will necessitate a promptresponse bythe permittee to requests bythe DEQ or the Boardfor information to include, as appropriate: process and production data; changes in control equipment; and operating schedules. Such requests for information from the DEQ will be either in writing orbypersonal contact. The availability ofinformation submitted to the DEQ orthe Board will be governed by applicable provisions ofthe Freedom ofInformation Act, §§ 2.2-3700 through 2.2-3714 ofthe Code ofVirginia, § 10.1-1314 (addressing information provided to the Board) ofthe Code of Virginia, and 9 VAC 5-170-60 ofthe State AirPollution Control Board Regulations. Informationprovided to federal officials is subject to appropriate federal law and regulations governing confidentiality ofsuch information.PROCESS REOUIREMENTS O-N Minerals (Chemstone) Company RegistrationNumber: 80252 Page 3



### I. EquipmentList

- Equipment subject to this permit at this facility consists ofthe following: Equipmentpermitted prior to the date ofthis permit ReferenceNo. Equipment DescriJltion Rated Capacity US Rotarykiln 25 tons lime/hr' Ul2 Calcimatic kiln 8 tons lime/hI'



### .. SpeCIficatIOns mciuded m the permIt under thIS CondItIOn are for informational purposes only and do not form enforceable terms or conditions ofthepermit. (9 VAC 5-80-850 and 9 VAC 5-40-7550) 2. Emission Controls: Rotary Kiln-Nitrogen oxides (NOx) emissions from the rotarykiln (U5) shall be controlled by good combustionpractices and byuse ofan indirect firing system. The indirect firing system shall beprovided with adequate access for inspection and shall be in operation when the rotarykiln is operating. (9 VAC 5-80-850 and 9 VAC 5-40-7580) 3. Emission Controls: Rotary Kiln

- Particulate matter having an aerodynamic diameter less than or equal to ten micrometers (PM-lO) emissions from the rotary kiln (U5) shall be controlled by a muiticycione and fabric filters. The multicyclone and fabric filters shall each beprovided with adequate access for inspection and shall each be in operation when the rotarykiln is operating. (9 VAC 5-80-850 and 9 VAC 5-40-7580) 4. Emission Controls: Rotary Kiln- No later than September lO, 2010, sulfur dioxide (S02) emissions from the rotary kiln (U5) shall be controlled to achieve the S02 limits in Condition 23. Unless the Director, Valley Regional Office, approves inherentprocess scrubbing as an alternative control technology by September 10,2011, a wet scrubber shall be installed by August 1, 2012. The wet scrubber orother technology employed to meet the S02 limits shall beprovided with adequate access for inspection and shall be in operation when the rotary kiln is operating. (9 VAC 5-80-850, 9 VAC 5-40-7580, 9 VAC 5-40-7590 and 9 VAC 5-40-7650) 5. Emission Controls: CalcimaticKiln

- NOxemissions from the calcimatic kiln (U12) shall be controlled bygood combustion practices. (9 VAC 5-80-850 and 9 VAC 5-40-7580) 6. Emission Controls: Calcimatic Kiln

- PM-10 emissions from the calcimatic kiln (Ul2) shall be controlled by a muiticycione and Ventnri scrubber. Themulticyclone and Ventnri scrubber shall each beprovided with adequate access for inspection and shall each bein operation when the calcimatic kiln is operating. (9 VAC 5-80-850 and 9 VAC 5-40-7580)O-N Minerals (Chemstone) Company Registration Number: 80252 Page 4
7. Emission Controls: Calcimatic Kiln

- Sulfur dioxide (S02) emissions from the calcimatic kiln 

### (Ul2) shall be controlled byVenturi scrubber. The Venturi scrubber shall beprovided with adequate access for inspection and shall be in operation when the calcimatic kiln is operating. (9 VAC 5-80-850 and 9 VAC 5-40-7580) 8. MonitoringDevices: Fabric Filter

- Each fabric filter serving the rotary kiln (U5) shall be equipped with devices to continuously measure the differential pressure across the filter. Each monitoring device shall be installed, maintained, calibrated or verified, and operated in accordance with approvedprocedures which shall include, as a minimum, the manufacturer's written requirements orrecommendations. Each monitoring device shall beprovided with adequate access for inspection and shall be in operation when the rotarykiln is operating. (9 VAC 5-80-850 and 9 VAC 5-40-7670) 9. MonitoringDevices: Wet Scrubber

- Ifa wet scrubber is used to meet the S02limits in Condition 23, it shall be equipped with devices to continuously measure and record liquid flow rate and the differential pressure across the scrubber. Each monitoring device shall be installed, maintained, calibrated and operated in accordance with approved procedures which shall include, as a minimum, the manufacturer's written requirements orrecommendations. Each monitoring device shall beprovided with adequate access for inspection and shall be in operation when the scrubber is operating. (9 VAC 5-80-850 and 9 VAC 5-40-7670) 10. MonitoringDevices: Venturi Scrubber

- The Venturi scrubber serving the calcimatic kiln (UI2) shall be equipped with devices to continuously measure the scrubber liquid flow rate, the exit gas temperature, and the differential pressure across the scrubber. Each monitoring device shall be installed, maintained, calibrated orverified, and operated in accordance with approved procedures which shall include, as a minimum, the manufacturer's written requirements orrecommendations. Each monitoring device shall beprovided with adequate access for inspection and shall be in operation when the calcimatic kiln is operating. (9 VAC 5-80-850 and 9 VAC 5-40-7670) II. BARTMonitoring Plan- The permittee shall prepare and implement, for eachkiln (U5 and UI2), a written BARTmonitoring plan. The permittee shall submit the plan to the Director, ValleyRegional Office, for review and approval within 180 days ofpermit issuance. Any subsequent changes to theplan must be submitted to the Director, Valley Regional Office, for review and approval. Pending approval bythe Director, Valley Regional Office, ofan initial or amended plan, the permittee shall comply with the provisions ofthe submitted plan. Each plan shall contain the following information: a. Process and control device parameters to be monitored to determine compliance with NOx emission limits and good combustion practices, along with established operating limits orranges, as applicable, for each kiln (U5 and UI2). b. A monitoring schedule for each kiln (U5 and UI2).O-N Minerals (Chemstone) Company Registration Number: 80252 Page 5

c. Procedures for the proper operation and maintenance ofeachkiln (U5 and U12) and each air pollution control device used to meet the applicable emission limitations in Conditions 22,23 and 24. d. Procedures for the proper installation, operation, and maintenance ofmonitoring devices or systems used to determine compliance or good combustion practices, including: 1. Calibration and celtification ofaccuracy ofeach monitoring device; 11. Perfotmance and equipment specifications for the sample interface, parametric signal analyzer, and the data collection and reduction systems; 111. Ongoing operation and maintenance procedures; and IV. Ongoing data quality assurance procedures.
e. Procedures for monitoring process parameters indicative ofgood combustion practices and control device parameters indicative ofproper control device operation. f. Corrective actions to betaken when process or operatingparameters oradd-on control deviceparameters deviate from the values identified in Condition 11e. g. A maintenance schedule for eachkiln (U5 and U12) and control device that is consistent with the manufacturer's insttuctions and recommendations for routine and long-term maintenance. (9 VAC 5-80-850 and 9 VAC 5-40-7670) 12. Monitoring Devices/Observations

- Process parameters indicative ofgood combustion practices for the rotarykiln (U5) and the calcimatic kiln (UI2) shall be monitored in accordance with the BART monitoringplan required byCondition 11. (9 VAC 5-80-850 and 9 VAC 5-40-7670) 13. MonitoringDevice Observation: Fabric Filter

- To ensure good performance, the fabric filter monitoring device used to continuouslymeasure differential pressure shall be observed bythe permittee with a frequency ofnot less than once per operating day. Thepermittee shall keep a log ofthe measurements ofthe fabric filter monitoring device. (9 VAC 5-80-850 and 9 VAC 5-40-7670) 14. MonitoringDevice Observation: Wet Scrubber

- Ifa wet sctubber is used to meet the S02 limits in Condition 23, the monitoring devices used to continuouslymeasure liquid flow rate and pressure drop for the wet sctubber shall be observed bythe permittee with a frequency of not less than once per operating day. Thepermittee shall continuouslyrecord measurements from the wet sctubber monitoring devices. (9 VAC 5-80-850 and 9 VAC 5-40-7670)O-N Minerals (Chemstone) Company Registration Number: 80252 Page 6
15. Monitoring Device Observation: Venturi Scrubber

- To ensure good performance, the magnahelic gauge used to continuously measure pressure drop across the Venturi sClUbber, the flow meter used to monitor sClUbber liquid flow rate, and the thermocouple used to measure exit gas temperature shall eachbe observed bythe permittee with a frequency ofnot less than once per operating day. The permittee shall keep a log ofthe measurements from the magnahelic gauge, the flow meter, and the thermocouple. (9 VAC 5-80-850 and 9 VAC 5-40-7670) 16. Monitoring: Rotary and CalcimaticKilns

- The combustion apparatus on the rotary and calcimatic kilns (U5 and U12) shall each be inspected at least annually orat the earliest shutdown following one year from the previous inspection. During the inspection, each apparatus shall be adjusted as necessary or tuned to ensure optimization such thatNOx emissions are minimized. (9 VAC 5-80-850 and 9 VAC 5-40-7670) OPERATINGLIMITS 17. Fuel: Rotary Kiln

- The approved fuels for the rotarykiln (U5) are coal, distillate oil, and natural gas. A change in the fuel mayrequire a permitto modify and operate. (9 VAC 5-80-850) 18. Fuel: Calcimatic Kiln

- The approved fuels for the calcimatic kiln (UI2) are distillate oil, natural gas, and recycled oil. A change in the fuel mayrequire a permit to modify and operate. (9 VAC 5-80-850) 19. Fuel: Rotary Kiln

- The coal and distillate oil shall meet the specifications below: COAL: Maximum sulfur contentper shipment: 1.0% as determined byASTM D3177, D4239, or a DEQ-approved equivalentmethod DISTILLATE OIL which meets the ASTM D396 specification for numbers 1 or 2 fuel oil: Maximum sulfur content per shipment: 0.5% (9 VAC 5-80-850 and 9 VAC 5-40-7580) 20. Fuel: Calcimatic Kiln

- The distillate oil and recycled oil shall meet the specifications below: DISTILLATE OIL which meets the ASTM D396 specification for numbers 1 or 2 fuel oil: Maximum sulfur contentper shipment: 0.5%O-N Minerals (Chemstone) Company RegistrationNumber: 80252 Page 7
RECYCLED FUEL OIL which meets the following specifications: Maximum sulfur content per shipment: 0.5% (9 VAC 5-80-850 and 9 VAC 5-40-7580) 21. Fuel Certification

- The permittee shall obtain a celtification from the fuel supplierwith each shipment ofcoal, distillate oil and recycled oil. Each fuel supplier certification shall include the following:
a. The name ofthe fuel supplier; b. The date on which the coal, distillate oil or recycled oil was received;
c. The quantity ofcoal, distillate oil or recycled oil delivered in the shipment; d. A statement that the distillate oil complies with the American Society for Testing and Materials specifications (ASTM D396) for numbers 1 or2 fuel oil;
e. The sulfur content ofthe coal, distillate oil, orrecycled oil; f. The methods used to determine the sulfur content ofthe coal. Details ofthe content ofcertifications shall be arranged with the Director, Valley Regional Office. Fuel sampling and analysis, independent ofthatused for certification, as maybe periodicallyrequired or conducted byDEQ, maybeused to determine compliance with the fuel specifications stipulated in Conditions 19 and 20. Exceedance ofthese specifications may be considered credible evidence ofthe exceedance ofemission limits. (9 VAC 5-80-850 and 9 VAC 5-40-7580) EMISSION LIMITS 22. Process Emission Limits: Rotary Kiln

- Emissions from the operation ofthe rotarykiln (US) shall not exceed the limits specified below. The PM and PMlO limits shall be effective 180 days after the permit effective date. Particulate Matter (PM) PMlO Nitrogen Oxides (as N02) tsf= tons stone feed 0.12 lbs/tsf 6.0lbs/hr 0.12 lbs/tsf 6.0lbs/hr

1.74lbs/tsf 87.01bslhrO-N Minerals (Chemstone) Company Registration Number: 80252 Page 8 Hourly emission limits represent averages for a three-hour sampling period. Compliance with these emission limits may be determined as stated in Conditions 2, 3, II, 19,21,27,30, and 31. Compliance with the Ib/tsflimits shall be based on the most recent DEQ-approved stack test. Compliance with the Ib/hr limits shall be calculated monthly (as a monthly average) based on the Ib/tsffactor determined in the mostrecent DEQ-approved stacktest, the monthly limestone feed input, and kiln operating hours for the month. (9 VAC 5-80-850 and 9 VAC 5-40-7580) 23. Process Emission Limits: Rotary Kiln

- No later than September 10,2010, emissions from the operation ofthe rotary kiln (U5) shall not exceed the limits specified below: Sulfur Dioxide 0.29 lbs/tsf 14.7lbs/hr tsf= tons stone feed Hourly emission limits represent averages for a 24-hour sampling period. The lbs/tsflimit shall apply at all times except during startup. The lbslhr limit shall apply at all times, including startup. Statiup is defined as the period commencing when fuel begins to flow to the burner and ending when any productis discharged to the cooler discharge weigh belt. For compliance purposes, emissions shall be calculated based on CEMS data and daily limestone feed input and using a DEQ-approved methodology. (9 VAC 5-80-850 and 9 VAC 5-40-7580) 24. Process Emission Limits: Calcimatic Kiln

- Emissions from the operation ofthe calcimatic kiln (UI2) shall not exceed the limits specified below: Patiiculate Matter (PM) PM-I0 Nitrogen Oxides (as N02) Sulfur Dioxide tsf= tons stone feed 0.60 Ibs/tsf 9.6lbs/hr 0.60 lbs/tsf 9.6lbs/hr 0.61lbs/tsf 9.8lbslhr
0.16 Ibs/tsf 2.6lbs/hr
Hourly emission limits represent averages for a three-hour sampling period. Compliance with these emission limits may be determined as stated in Conditions 5, 6, 7, II, 20,21,29,30 and 31. Compliance withthe lb/tsflimits shall be based onthe most recent DEQ-approved stack test. Compliance with the lbllu'limits shall be calculated monthly (as aO-N Minerals (Chemstone) Company RegistrationNumber: 80252 Page 9 monthly average) based on the lb/tsffactor determined inthe most recent DEQ-approved stack test, the monthly limestone feed input, and kiln operating hours for the month. (9 VAC 5-80-850 and 9 VAC 5-40-7580) 25. Emission Testing

- The rotary and calcimatic kilns (U5 and U12) shall eachbe constructed so as to allow for emissions testing upon reasonable notice at any time, using appropriate methods. This includes constructing the facility/equipment suchthatvolumetric flow rates and pollutant emission rates can be accurately determined by applicable test methods and providing a stack or duct that is free from cyclonic flow. Sampling POlts shall beprovided when requested at the appropriate locations and safe sampling platforms and access shall be provided. (9 VAC 5-80-880, 9 VAC 5-80-850 and 9 VAC 5-40-7660) RECORDS 26. On Site Records

- The permittee shall maintain records ofemission data and operating parameters as necessaryto demonstrate compliance with this permit. The content and format ofsuchrecords shall be al1'anged with the Director, ValleyRegional Office. These records shall include, but are not limited to:
a. Annual consumption ofeach fuel used in each kiln, calculated monthly as the sum of each consecutive 12-monthperiod. b. Records necessary to monitor the monthly and annual limestone feed input to eachkiln in accordance with a DEQ-approved protocol. Annual limestone feed input shall be calculated monthly as the sum ofeach consecutive 12-month period.
c. Monthlyhours ofoperation for each kiln. d. All fuel supplier celtifications.
e. Monthly emissions calculations for PM and NO, from the rotarykiln (U5) to verify compliance with the Ibs/hr emissions limitations in Condition 22. f. Beginning on September 10,2010, Continuous Emissions Monitoring System (CEMS) data from the rotarykiln (U5) to verify compliance with the Ibslhr emissions limitation in Condition 23. g. Beginning on September 10,2010, daily emissions calculations for S02 from the rotary kiln (U5) based on CEMS and production data to verify compliance with the Ib/tsf emissions limitation in Condition 23. h. Monthly emissions calculations for PM, S02 and NO, from the calcimatic kiln (UI2) to verify compliance with the lbslhr emissions limitations in Condition 24.O-NMinerals (Chemstone) Company RegistrationNumber: 80252 Page 10

i. Control device monitoring records for the fabric filter serving the rotary kiln (U5) as required in Conditions 8 and 13. j. Beginning onAugust I, 2012, control device monitoring records for the wet sctubber serving therotary kiln (U5) as required in Conditions 9 and 14. k. Control device monitoring records for the Venturi sctubber serving the calcimatic kiln (UI2) as required in Conditions 10 and 15. 

### 1. Copy ofthe BARTMonitoring Planrequired byCondition 11, including any amendments made to the original plan.
m. Records ofmonitoring conducted in accordance with the BARTMonitoring Plan, as required byCondition 12.
n. Records ofrotary and calcimatickilns (U5 and U12) combustion optimization/tuning conducted according to Condition 16.
o. Scheduled andunscheduled maintenance, and operator training. p. Results ofall stack tests, performance evaluations, and CEMS Quality Control Program documentation. These records shall be available for inspection bythe DEQ and shall be current for the most recent five years. (9 VAC 5-80-900 and 9 VAC 5-40-7680) 

### INITIAL COMPLIANCEDETERMINATION 27. StackTest: Rotary Kilu- Initial performance tests shallbe conducted for NOx and PM from the rotarykiln (U5) using EPA Reference Methods 7 or7E and 5 (40 CFR 60 Appendix A), respectively, to determine compliance with the emission limits contained in Condition 22. The tests shall beperformed and demonstrate compliance within 180 days after the effective date ofthepermit. Upon approval bythe Director, ValleyRegional Office, stack testing performed 12 months or less prior to the effective date ofthepermitmay serve to satisfy this condition. Tests shall be conducted and repOlted and data reduced as setforth in 9 VAC 5-40-30 and the testmethods and procedures contained in each applicable section or subpart listed in 9 VAC 5-50-410. The details ofthetests are to be arranged with the Director, Valley Regional Office. Thepelmittee shall submit a test protocol at least 30 days priorto testing. A copyofthe testresults shall be submitted to the Director, ValleyRegional Office, within 60 days after test completion and shall confOlm to the test repOlt format enclosed with this permit. (9 VAC 5-80-850 and 9 VAC 5-40-7660)O-N Minerals (Chemstone) Company Registration Number: 80252 Page 11

28. StackTest: Rotary Kiln

- mitial perfmmance tests shall be conducted for S02 from the rotarykiln (U5) using EPA Reference Method 6 or 6C (40 CFR 60 Appendix A) to determine compliance with the emission limits contained in Condition 23. The tests shall be performed and demonstrate compliance within 60 days after the compliance date in Condition 23. Tests shall be conducted and reported and data reduced as setforth in 9 VAC 5-40-30 and the test methods and procedures contained in each applicable section or subpati listed in 9 VAC 5-50-410. The details ofthe tests are to be arranged with the Director, ValleyRegional Office. The permittee shall submit a testprotocol at least 30 days prior to testing. A copy ofthe test results shall be submitted to the Director, ValleyRegional Office, within 60 days after test completion and shall conform to the testreport format enclosed with this permit. (9 VAC 5-80-850 and 9 VAC 5-40-7660) 29. StackTest: Calcimatic Kiln- mitial performance tests shall be conducted for NO" S02 and PM from the calcimatic kiln (UI2) using EPAReference Methods 7 or 7E, 6 or 6C, and 5 (40 CFR 60 Appendix A), respectively, to determine compliance with the emission limits contained in Condition 24. The tests shall beperformed and demonstrate compliance within the latter of 180 days after the effective date ofthe pelmit or 90 days following resumption of the unit's normal operation. Tests shall be conducted and reported and data reduced as set fmih in 9 VAC 5-40-30 and the test methods andprocedures contained in each applicable section or subpati listed in 9 VAC 5-50-410. The details ofthe tests are to be arranged with the Director, Valley Regional Office. Thepermittee shall submit a testprotocol at least 30 days prior to testing. A copy ofthe test results shall be submitted to the Director, Valley Regional Office, within 60 days after test completion and shall confmmto the test report format enclosed with this permit. (9 VAC 5-80-850 and 9 VAC 5-40-7660) CONTINUING COMPLIANCE DETERMINATION 30. StackTests: PM

- At least once every five years, or upon request bythe DEQ, the permittee shall conduct additional performance tests for PM from the rotary and calcimatickilns (U5 and UI2) to demonstrate compliance with the emission limits contained inthis permit. The details ofthe tests shall be arranged with the Director, Valley Regional Office. (9 VAC 50-80-850 and 9 VAC 5-40-7660) 31. Annual StackTest: NOx - An annual stacktest shall be conducted on the rotarykiln (U5) and onthe calcimatic kiln (UI2) for NO" using EPAReference Method 7 or 7E (40 CFR 60 Appendix A). Each annual stack test shall be conducted no later than 13 months after the previous stack test. The first test ofthe calcimatic kiln (UI2) shall be conducted within 90 days after the unit resumes normal operation. Ifthe calcimatic kiln (UI2) has ceased operation at the time the subsequent annual test is due (13 months after the previous test), testing shall be conducted within 60 days after the unit again resumes normal operation. Tests shall be conducted and reported and data reduced as setforth in 9 VAC 5-40-30 and theO-N Minerals (Chemstone) Company Registration Number: 80252 Page 12

test methods and procedures contained in each applicable section or subpart listed in 9 VAC 5-50-410. The details ofthe tests are to be arranged with the Director, ValleyRegional Office. Thepermittee shall submit a testprotocol at least 30 days prior to testing. Test results shall be submitted to the Director, Valley Regional Office, within 45 days after test completion and shall confotm to the test report format enclosed with this pelmit. (9 VAC 5-80-850 and 9 VAC 5-40-7660) 32. Reduced Stack Testing

- Ifthree consecutive annual stack tests conducted in accordance with Condition 31 for eitherkiln (U5 orU12) demonstrate compliance with theNOx emission limits in Conditions 22 (for U5) or 24 (for UI2), the stack testing frequency required byCondition 31 shall bereduced to once every five years for the kiln. The permittee shall conduct another stack test for each kiln (U5 orU12) within 60 months ofthe date ofthe third consecutive stack test that shows compliance with the emission limits. Thereafter, the permittee must perform stack tests every fifth yearbutno later than 60 months following the previous stack test. Ifthe calcimatic kiln (UI2) has ceased operation at the time the subsequent fifth-year test is due (60 months after theprevious test), testing shall be conducted within 60 days after the unit again resumes notmal operation. Ifa stack test for either kiln (U5 orU12) shows noncompliance withtheNOx emission limits, the permittee shall conduct annual stacktests for the kiln until stack tests over three consecutive years show compliance withthe emission limits. (9 VAC 5-80-850 and 9 VAC 5-40-7660) 33. CEMS

- No later than September 10, 2010, a Continuous Emission Monitoring Systems (CEMS) shall be installed to measure and record the emissions ofS02 inpounds per hour from the rotarykiln (U5). CEMS for S02 shall be installed, evaluated, and operated according to therequirements of9 VAC 5-40-41. For compliance withthe emission limits contained in Condition 23, S02 data shall bereduced to 24-hourblock averages. (9 VAC 5-80-850, 9 VAC 5-40-40 F and 9 VAC 5-40-7670) 34. CEMS Performance Evaluations - Performance evaluations ofthe S02 continuous monitoring systems shall be conducted in accordance with 9 VAC 5-40-41 B.I and shall take place during the performance tests required by Condition 28 or within 30 days thereafter. One copy ofthe performance evaluation repoti shall be submitted to the Director, Valley Region, within 45 days ofthe evaluation. The continuous monitoring systems shall be installed and operational priorto conducting initial performance tests. Verification of operational status shall, as a minimum, include completion ofthe manufacturer's written requirements orrecommendations for installation, operation and calibration ofthe device. A 30-daynotification, prior to the demonstration ofthe continuous monitoring system's performance, and subsequent notifications shall be submitted to the Director, Valley Regional Office. (9 VAC 5-80-850, 9 VAC 5-40-40 F and 9 VAC 5-40-7670)O-N Minerals (Chemstone) Company Registration Number: 80252 Page 13
35. CEMS Quality Control Program - A CEMS quality control program which is equivalent to the requirements of40 CFR 60.13 and 40 CFR 60, Appendix F shall be implemented for the CEMS. (9 VAC 5-80-850, 9 VAC 5-40-40 F and 9 VAC 5-40-7670) 36. Reports - Thepermittee shall submitreports to the Director, Valley Regional Office, within 90 days after the end ofeach semi-annual period ending June 30 and December 31. Each report shall contain, atminimum, the dates included in the semi-annual period and the following, reported separately for eachunit (rotary kiln (US) and calcimatic kiln (UI2)): Monthly emissions calculations (or summary ofCEMS measurements, as applicable) for PM, S02 and NOx to verify compliance with the lbs/hr and lbs/tsfemissions limitations in Conditions 22, 23, and 24. (9 VAC 5-80-850 and 9 VAC 5-40-7680) BART GENERAL CONDITIONS 37. Relationship to Other Requirements - Except to the extent that conditions in this permit maybemore stringent, this permit does not supersede orreplace any other valid pelmit, regulatory or statutoryrequirement. FUlthermore, this approval to operate shall notrelieve O-NMinerals (Chemstone) Company ofthe responsibility to complywith all other local, state and federal regulations, includingpermitregulations. (9 VAC 5-80-800 D, 9 VAC 5-80-820 F and 9 VAC 5-40-7580) 38. Federal Enforceability - Once the permitis approved by the U.S. Environmental Protection Agency into the Commonwealth ofVirginia State Implementation Plan, the permit is enforceable byEPA and citizens under the federal Clean AirAct. (9 VAC 5-80-800 C.2, 9 VAC 5-80-820 F and 9 VAC 5-40-7580) 39. Permit Modification - The Board mayrevise (modify, rewrite, change or amend) orrepeal this permit with the consent ofO-N Minerals (Chemstone) Company, for good cause shown by O-NMinerals (Chemstone) Company, or on its own motion provided approval ofthe revision orrepeal is accomplished in accordance with Regulations ofthe Board and the Administrative Process Act (§ 2.2-4000 et seq.). Suchrevision or repeal shall notbe effective until the revision orrepeal is approved bythe U.S. Environmental Protection Agencyfollowing the requirements of40 CFRPalt 51 (Requirements for Preparation, Adoption and Submittal ofImplementations Plans). (9 VAC 5-80-960, 9 VAC 5-80-1000 and 9 VAC 5-40-7710)O-N Minerals (Chemstone) Company RegistrationNumber: 80252 Page 14
40. Failure to Comply

- Failure byO-N Minerals (Chemstone) Company to complywith any of the conditions ofthis pelmit shall constitute a violation ofa Pelmit ofthe Board. Failure to complymayresult in a Notice ofViolation and civil penalty. Nothing herein shall waive the initiation ofappropriate enforcement actions or the issuance oforders as appropriate bythe Board as a result ofsuch violations. Nothing herein shall affect appropriate enforcement actions byany other federal, state, or local regulatory authority. (9 VAC 5-80-820 F, 9 VAC 5-80-910, 9 VAC 5-80-1010 and 9 VAC 5-40-7640) 41. BARTDetermination Criteria: Operation and Maintenance

- O-N Minerals (Chemstone) Company shall maintain the control equipment required bythis permit and establish procedures to ensure such equipment is properly operated and maintained. (9 VAC 5-80-800 and 9 VAC 5-40-7590) SOP GENERAL CONDITIONS 42. Right ofEntry

- Thepermittee shall allow authorized local, state, and federal representatives, upon the presentation ofcredentials:
a. To enterupon the permittee's premises on which the facility is located or in which any records are required to be keptunder the terms and conditions ofthis permit; b. To have access to and copy atreasonable times any records required to bekeptunder the telms and conditions ofthis permit or the State AirPollution Control Board Regulations;
c. To inspect at reasonable times any facility, equipment, or process subject to the terms and conditions ofthis permit or the State Air Pollution Control Board Regulations; and d. To sample or test atreasonable times. Forpurposes ofthis condition, the time for inspection shall be deemed reasonable during regularbusiness hours or whenever the facility is in operation. Nothing contained herein shall make an inspection time umeasonable during an emergency. (9 VAC 5-170-130 and 9 VAC 5-80-850)O-N Minerals (Chemstone) Company Registration Number: 80252 Page 15
43. Notification for Facility or Control Equipment Malfunction

- Thepelmittee shall fumish notification to the Director, Valley Regional Office, ofmalfunctions ofthe affected facility or related airpollution control equipment that may cause excess emissions for more than one hour, byfacsimile transmission, telephone, or telegraph. Suchnotification shall be made as soon as practicable butno later than four daytime business hours after the malfunction is discovered. Thepermittee shall provide a written statement giving all pertinent facts, including the estimated duration ofthe breakdown, within two weeks ofdiscovery ofthe malfunction. When the condition causing the failure or malfunction has been corrected and the equipmentis again in operation, the pelmittee shall notify the Director, ValleyRegional Office, in writing. (9 VAC 5-20-180 C, 9 VAC 5-80-850 and 9 VAC 5-40-7700) 44. Violation ofAmbientAir Quality Standard

- Thepermittee shall, upon request ofthe DEQ, reduce the level ofoperation or shut down a facility, as necessary to avoid violating anyprimary ambient air quality standard and shall notretnm to normal operation until such time as the ambient air qualitystandard will notbe violated. (9 VAC 5-20-180 I and 9 VAC 5-80-850) 45. Maintenance/Operating Procedures

- At all times, includingperiods ofstart-up, shutdown, and malfunction, the permittee shall, to the extentpracticable, maintain and operate the affected source, including associated air pollution control equipment, in a manner consistent with good airpollution control practices for minimizing emissions. (9 VAC 5-50-20 E and 9 VAC 5-80-850) 46. PermitSuspensionlRevocation

- Thispelmitmayberevoked ifthepermittee:
a. Knowinglymakes material misstatements in thepermit application or any amendments to it; b. Fails to comply withthe terms or conditions ofthis permit;
c. Fails to complywith any emission standards applicable to a permitted emissions unit; d. Causes emissions from this facility whichresult in violations of, orinterferes withthe attainment and maintenance of, any ambient air quality standard;
e. Fails to operate this facility inconformance with any applicable control strategy, including any emission standards or emission limitations, in the StateImplementation Plan in effect atthetime that an application for this permit is submitted; or f. Fails to complywiththe applicable provisions ofArticles 6, 8 and 9 of9 VAC 5 Chapter 80. (9 VAC 5-80-1010)O-N Minerals (Chemstone) Company Registration Number: 80252 Page 16

47. Change ofOwnership

- In the case ofa transfer ofownership ofa stationary source, the new owner shall abide by any currentpermit issued to the previous owner. Thenew owner shall notify the Director, Valley Regional Office, ofthe change ofownership within 30 days ofthe transfer. (9 VAC 5-80-940) 48. Permit Copy

- Thepennittee shall keep a copy ofthis permit on the premises ofthe facility to which it applies. (9 VAC 5-80-860 D)SOURCE TESTING REPORT FORMAT Report Cover 1. Plant name and location 2. Units tested at source (indicate Ref. No. used by source inpermit orregistration) 3. Test Dates. 4. Tester; name, address andrepolt date Certification l. Signed byteam leader/certified observer (include celtification date) 2. Signed byresponsible company official 3. *Signed byreviewer Copy ofapproved test protocol Summary 1. Reason for testing 2. Test dates 3. Identification ofunit tested & the maximum rated capacity 4. *For each emission unit, a table showing: a. Operating rate b. Test Methods c. Pollutants tested d. Testresults for each lUn and the lUn average e. Pollutant standard or limit 5. Summarizedprocess and control equipment data for each lUn and the average, as required bythe test protocol 6. A statement that test was conducted in accordance with the test protocol oridentification & discussion ofdeviations, including the likely impact on results 7. Any other important information Source Operation 1. Description ofprocess and control devices 2. Process and control equipment flow diagram 3. Sampling port location and dimensioned cross section Attached protocol includes: sketch of stack (elevation view) showing sampling port locations, upstream and downstream flow disturbances and their distances from ports; and a sketch ofstack (plan view) showing sampling ports, ducts entering the stack and stack diameter or dimensions Test Results 1. Detailed testresults for eachlUn 2. *Sample calculations 3. *Description ofcollected samples, to include audits when applicable Appendix 1. *Raw production data 2. *Raw field data 3. *Laboratoryreports 4. *Chain ofcustody records for lab samples 5. *Calibration procedures and results 6. Project participants and titles 7. Observers' names (industry and agency) 8. Related cOlTespondence 9. Standardprocedures 

## * Not applicable to visible emission evaluations