DEPARTMENT OF ENVIRONMENTAL CONSERVATION 

Standard Operating Permit Condition XIII – Coal Fired 

Boilers 

Permit Condition for Air Quality Permits 

Adopted by Reference in 18 AAC 50.346 

April 1, 2002 

Revised August 20, 2008 
Standard Operating Permit Condition XIII – April 1, 2002 

Coal Fired Boilers 

Revised August 20. 2008 1 

Standard Operating Permit Condition XIII – Coal Fired Boilers 

Stationary Source Categories This Condition Applies to: Coal fired boilers in 

operation before July 1, 1972. 

The department will use standard permit condition XIII in an operating permit unless the 

department determines that emission unit or stationary source specific conditions more 

adequately meet the requirements of 18 AAC 50. 

Circumstances where emission unit or stationary source 

specific conditions more adequately meet 18 AAC 50 include:

1. the permittee demonstrates that Continuous Opacity Monitoring System 

(COMS) operation and audit procedures that are specific to the COMS unit 

being used and that differ from this standard permit condition XIII are more 

appropriate. 

Permit Wording: 

1. Coal Fired Boiler Visible Emissions Monitoring – Procedures for Operation of a 

COMS. The following procedure applies to monitoring visible emissions using a 

Continuous Opacity Monitoring System (COMS): 

1.1 the COMS must meet the performance specifications in 40 C.F.R. 60, Appendix B, 

Performance Specification 1, adopted by reference in 18 AAC 50.040(a);

1.2 operate and maintain the COMS in accordance with the manufacturer’s written 

requirements and recommendations; 

1.3 except during COMS breakdowns, repairs, calibration checks, and zero and upscale 

adjustments, complete one cycle of sampling and analyzing for each successive 10-

second period of emission unit operation; from this data, calculate and record the 

average opacity for each successive one-minute period; 

1.4 at least once daily, conduct a zero and upscale check in accordance with 40 C.F.R. 

60.13(d), adopted by reference in 18 AAC 50.040(a), and a written procedure; adjust 

whenever the zero or upscale drift exceeds four percent opacity in a 24-hour period; 

1.5 conduct performance audits as follows: 

a. for a COMS that was new, relocated, replaced, or substantially refurbished on 

or after April 9, 2001, perform an audit that includes the following elements as 

described in the department's Performance Audits for COMS, adopted by 

reference in 18 AAC 50.030, at least once in each 12 months: 

(i) optical alignment; 
Standard Operating Permit Condition XIII – April 1, 2002 

Coal Fired Boilers 

Revised August 20. 2008 2 

(ii) zero and upscale response assessment; 

(iii) zero compensation assessment; 

(iv) calibration error check; and 

(v) zero alignment assessment; 

b. for a COMS that was new, relocated, replaced, or substantially refurbished 

before April 9, 2001, perform the same audits required under condition 

XIII.1.5a, except that condition XIII.1.5a(i) - XIII.1.5a(iv) must be performed 

at least quarterly; this frequency may be reduced if 

(i) the permittee demonstrates, by applying measurable criteria to the results 

of quarterly audits, that quarterly audits are not necessary; and 

(ii) the department gives written approval for the reduction in frequency. 

2. Coal Fired Boiler Particulate Matter (PM). The permittee shall not cause or allow 

particulate matter (PM) emitted from <identify emission units> to exceed 0.1 grains per 

cubic foot of exhaust gas corrected to standard conditions and averaged over three hours. 

(18 AAC 50.055(b)) 

2.1 Coal Fired Boiler PM Monitoring and Recordkeeping. The permittee shall do the 

following. 

a. at least once every 12 months, for each boiler that has operated 90 days or 

more during that period, inspect the exhaust duct work and the internal 

components of the dust collector for the presence of leaks; prior to restarting 

the boiler, repair all leaks in the exhaust ductwork and all leaks that would 

allow dirty gas to pass into the clean gas side of the dust collector; 

b. conduct source tests for particulate matter as follows: 

(i) conduct the tests and report the results in accordance with conditions 

<insert conditions’ numbers that address the requirements of 18 AAC 

50.220 and that reiterate 18 AAC 50.345(l) - (o)>; for tests required under 

condition XIII.2.1b(iii), submit the test plan as required by <insert 

condition number that reiterates 18 AAC 50.345(m)> and at least 60 days 

before the deadline for the next test under condition XIII.2.1b(iii); 

(ii) conduct an initial test on each boiler within 8760 operating hours or two 

calendar years, whichever is sooner, after the issue date of the initial 

operating permit; 
Standard Operating Permit Condition XIII – April 1, 2002 

Coal Fired Boilers 

Revised August 20. 2008 3 

(iii) conduct additional tests on each boiler according to the following schedule 

where each test means a three hour average consistent with 18 AAC 

50.220(f): 

(a) if the most recent source test exceeded 90 percent of the emission 

standard, conduct a source test within 8760 operating hours of the 

previous test; 

(b) if the most recent source test exceeded 75 percent of the emission 

standard, conduct a source test within 17520 operating hours of the 

previous test; and 

(c) within five years of the previous source test, conduct a test of each 

boiler operated during that time; 

(iv) for any boiler with a steam production limit that the operator wishes to 

change, the operator may operate in excess of the steam limit to perform 

source tests on which a new limit would be based; the operator may use a 

new limit based on the source testing if 

(a) the permittee submits a source test plan and the department 

approves the plan in writing; 

(b) the permittee conducts source testing according to the source test 

plan and consistent with condition <insert conditions’ numbers 

that address the requirements of 18 AAC 50.220>; 

(c) the permittee submits the results to the department; 

(d) the test results show compliance at the requested new steam 

production rate; and 

(e) the department concurs with the new limit in writing, after finding 

that 

i) the test results will be representative of normal operation; and 

ii) the new limit does not cause the facility to be subject to 

permitting under 18 AAC 50.300(h); 

(v) during each test, measure and record visible emissions and steam 

production rates; submit the records with the source test report; 

determine visible emissions consistent with monitoring methods of 

condition <insert applicable condition number from this permit> for the 

duration of each one hour run; 
Standard Operating Permit Condition XIII – April 1, 2002 

Coal Fired Boilers 

Revised August 20. 2008 4 

c. measure and record steam production as follows: 

(i) operate and maintain a device to measure and record steam production in 

accordance with the manufacturer’s written requirements and 

recommendations; 

(ii) except during breakdowns, repairs, calibration checks, and zero and span 

adjustments of the device, complete at least one cycle of sampling and 

analyzing for each successive 15-minute period of boiler operation; from 

this data, calculate and record the average steam production rate for 

successive one-hour periods; maintain this data at the facility and make it 

available to the department upon request; 

(iii) within one year after the effective date of this permit and at such times as 

the department may require, determine the relative accuracy of each 

monitoring device required by condition XIII.2.1c(i); 

(iv) keep sufficient written records to show compliance with the requirements 

of this condition XIII.2.1; in addition, keep records of the date and time 

identifying each period during which a device required by this permit is 

inoperative, except for zero and span checks, and records of the nature of 

device repairs and adjustments; upon request of the department, submit 

copies of the records. 

2.2 Coal Fired Boiler PM Reporting. The permittee shall 

a. submit a report in accordance with <insert standard permit condition number 

concerning excess emissions and permit deviation reports> whenever any of 

the following situations occur: 

(i) when steam production exceeds a permit limit; 

(ii) when the results of a source test exceed the particulate matter emission 

limit; 

(iii) if a steam production monitoring device malfunctions or becomes 

inoperable for four or more consecutive hours; in the report, identify the 

boiler, the cause of failure, and the anticipated time required to repair the 

device; 

b. include in each operating report under condition <insert standard permit 

condition number concerning operating reports>: 

(i) the results of each particulate matter source test; 
Standard Operating Permit Condition XIII – April 1, 2002 

Coal Fired Boilers 

Revised August 20. 2008 5 

(ii) for any boiler with a steam production limit, the limit and averaging 

period, the highest steam production rate for the period covered by the 

report (averaged over the same averaging period as the limit), and 

identification of any periods exceeding the limit; and 

(iii) the results of any relative accuracy determination of steam monitoring 

equipment. 

3. Sulfur Compound Emissions. The permittee shall not cause or allow sulfur compound 

emissions, expressed as sulfur dioxide, from emission units <identify coal fired boilers> to 

exceed 500 parts per million averaged over a period of three hours. (18 AAC 50.055(c)) 

3.1 CFB Sulfur Compound Emissions Monitoring. The following applies to sulfur 

compound emission monitoring:

a. upon receipt of each shipment of fuel at the stationary source, the permittee 

shall 

(i) obtain a signed statement from the supplier with the following 

information: 

(a) the percent sulfur by weight of the coal; 

(b) the method of analysis; and 

(c) a statement that the analysis was representative of the coal shipped; 

(ii) if valid representative results are not available from the supplier, analyze a 

representative sample of the fuel to determine the sulfur content using 

ASTM D2492-90 for coal, adopted by reference in 18 AAC 50.035(c), or 

another method approved in writing by the department for coal or other 

fuels; and 

(iii) if the coal contains more than 0.4 percent sulfur by weight, calculate the 

three hour exhaust concentration expected to result from combusting each 

shipment of fuel using the following equation: 

SO2-concentration, PPM = 1.00 X 106

 X mol-SO2 / (mol-SO2 + molCO2 + mol-O2 + mol-N2) 

Where: 

mol-SO2 = [wt%Sulfurfuel, %] / 32.06 

mol-CO2 = [wt%Carbonfuel, %] / 12.01 
Standard Operating Permit Condition XIII – April 1, 2002 

Coal Fired Boilers 

Revised August 20. 2008 6 

mol-O2 = MF X (([wt%Nitrogenfuel, %] / 28.01) + (4.76 X mol-SO2) + 

(4.76 X mol-CO2) + (1.88 X mol-H2O) - (3.76 X ([wt%Oxygenfuel, %] / 

32.00)) 

MF = ([vol%O2, exhaust, %] / (100% - 4.76 X [vol% O2, exhaust, %]) 

mol-H2O = [wt%Hydrogenfuel, %] / 2.016 

mol-N2 = ([wt%Nitrogenfuel, %] / 28.01) + (3.76 X mol-SO2) + (3.76 X 

mol-CO2) + (1.88 X mol-H2O) + (3.76 X mol-O2) - ([wt%Oxygenfuel, %] / 

8.51); 

And Where: 

The fuel weight percent (wt%) of carbon, nitrogen, oxygen, and hydrogen 

is obtained from the most recent analysis required by condition XIII.3.1b; 

The volume percent of oxygen in the exhaust (vol% O2, exhaust,) is obtained 

from oxygen meters on a three hour average or from the most recent 

ORSAT analysis at the same boiler load used in the calculation; and 

The fuel weight percent (wt%) of sulfur is obtained pursuant to condition 

XIII.3.1a(i) or XIII.3.1a(ii); 

b. at least once each year, and whenever a shipment of coal contains more than 

0.4 percent sulfur, obtain a representative sample of each fuel that is burned 

using the applicable procedures in 40 C.F.R. 60, Appendix A-7, Method 19, 

Section 12.5.2.1, adopted by reference in 18 AAC 50.040(a); conduct an 

ultimate analysis of the representative sample using ASTM D3176-89 (1997), 

adopted by reference in 18 AAC 50.035(c), or another method approved in 

writing by the department to determine the weight percents, dry basis, of 

carbon, nitrogen, oxygen, and hydrogen; 

c. conduct source tests on at least one coal fired boiler at the stationary source to 

determine sulfur compound emissions while burning each shipment of fuel if 

the calculations of condition XIII.3.1a(iii) show that the exhaust SO2

concentration would exceed 500 ppm. 

3.2 CFB Sulfur Compound Emissions Record Keeping. The permittee shall keep 

records of the sulfur contents of each shipment of fuel, each calculated SO2

concentration averaged over three-hours, and any test results and calculations 

determined under condition XIII.3.1. 

3.3 CFB Sulfur Compound Emissions Reporting. The permittee shall 
Standard Operating Permit Condition XIII – April 1, 2002 

Coal Fired Boilers 

Revised August 20. 2008 7 

a. submit a report in accordance with condition <insert standard permit condition 

number concerning excess emissions and permit deviation reports> whenever 

(i) a three-hour exhaust concentration calculated pursuant to condition 

XIII.3.1a(ii) is greater than 500 ppm; or 

(ii) a source test pursuant to condition XIII.3.1c has not shown compliance; 

b. include in each operating report under condition <insert standard permit 

condition number concerning operating reports> a summary that includes 

(i) sulfur contents of each shipment of fuel; 

(ii) each calculated SO2 concentration averaged over three hours; and 

(iii) any test results and calculations required under condition XIII.3.1. 

The following apply to this standard permit condition: 

1. Opacity. The standard conditions for visible emissions apply only to technical aspects of 

operating the COMS, including audits. The permit will state the applicable opacity limit, and 

emission unit specific conditions will be used for all other aspects of monitoring, record 

keeping, and reporting for the opacity standards of 18 AAC 50.055(a)(1) and (a)(9). 

2. Conditions XIII.2.1b(iv) and XIII.2.1c and the reference to steam production rates in 

condition XIII.2.1b(v) for each coal fired boiler will be used unless the department finds that 

- the boiler does not have a steam production limit; and 

- it is not feasible to operate the boiler at a steam production rate sufficiently higher than 

the rated steam production capacity that the particulate matter standard or opacity 

standard could be violated. 

3. The fuel sulfur threshold in conditions XIII.3.1a(ii) and XIII.0 were calculated for the general 

case based on six percent excess air. That threshold will be used unless the applicant shows 

that the boiler must use a specific higher amount of excess air. 

4. If fuel is burned that has a substantially higher ash content than normal run of mine coal, the 

allowable fuel sulfur must decrease proportionally with the portion of the coal that is 

combustible in order to assure compliance with the 500 ppm SO2 standard. The permit 

should require the calculation under condition XIII.3.1a(ii) if it is foreseeable that the facility 

will burn fuel with an ash content greater than 15 percent and a sulfur content between 0.25 

percent and 0.4 percent.