SUPPORT DOCUMENT 

FOR 

COMAR 26.11.01 AND COMAR 26.11.31 

SIP Revision #15-05 

STANDARDS AND PROCEDURES 

FOR 

CONTINUOUS OPACITY MONITORS 

AND 

CONTINUOUS EMISSION MONITORS 

 

PREPARED BY 

AIR QUALITY PLANNING PROGRAM 

January 10, 2011 

Revised September 29, 2015, and November 20, 2015
Introduction

The purpose of this document is to explain the changes that are proposed to the opacity or 

visible emissions requirements in Maryland as part of State Implementation Plan (SIP) 

Revision #15-05. The purpose of SIP Revision #15-05 is to incorporate into the SIP, 

various actions adopted by Maryland between 2010 and 2011. These actions added new 

definitions, aligned requirements and created unique regulations for both continuous 

opacity monitors (COMs) and continuous emission monitors (CEMs), and adopted 

quality assurance procedures which incorporated and replaced procedures outlined in 

Technical Memorandum 90-01 (TM). The opacity standards adopted by Maryland in 

1991remain unchanged. This document presents an explanation of the changes in the 

regulations and a demonstration that these changes remain equivalent to the current SIP. 

The opacity regulations were developed by EPA and incorporated by Maryland in the 

1970s and 80s and generally state that emissions visible to the human observer are 

prohibited throughout the Baltimore/Washington metropolitan areas, whereas rural areas 

are subject to a 20% opacity standard. The opacity requirements prior to 2010 were 

generally under COMAR 26.11.01.10 and previously approved by EPA through the 

1990s. During the 1990s, the method used to determine compliance with the opacity 

standard was an observation using the human eye, known as Method 9. With the advent 

of automated equipment that could continuously gauge and report opacity levels and 

could determine opacity levels below what the human eye could read, it became 

necessary to develop a policy to transition enforcement of the regulations from a focus on 

manual technologies to automated technologies. 

The proposed regulations introduce a continuous method for monitoring opacity in 

addition to the compliance process of Method 9. Although Maryland now has additional 

regulations under the Healthy Air Act and the Particulate Matter PM2.5 SIP to control fine 

particulate, the opacity requirements are important, especially in attainment areas, to limit 

particulate levels. Although there is no national policy regarding opacity and states have 

a patchwork of stringency levels, the Department has worked closely with EPA Region 3 

to ensure that the SIP is strengthened and not relaxed. 

The proposed regulations for approval in this SIP Revision #15-05 were developed 

through four separate actions in the Maryland regulation development process. As noted 

in the Table of contents there are four proposed and final actions that affect COMAR 

26.11.01, 26.11.09 and 26.11.31. Additional explanation and a detailed chart are included 

with this summary document. 

Important note – As Maryland prepared to assemble this opacity SIP package and 

coordinate several pieces with EPA in 2015, it became apparent, due to evolving EPA 

guidance and regulations, that Maryland would need to revise opacity requirements 

established for Portland cement plants, municipal waste incinerators and fuel burning 

equipment prior to SIP submittal. The Department has amended regulations for Portland 

cement plants and municipal waste incinerators to conform to new EPA policies and will 

be submitting these actions in a separate SIP submittal. (A public hearing is scheduled 

for March 9, 2016 for the COMAR regulations) The Department will also need to amend 
opacity requirements for fuel burning equipment to comply with EPA policies, Therefore, 

Maryland is submitting this SIP package, but not including COMAR 26.11.09.01 and .05 

regulations as part of the package. 

 

Background

Under existing regulations, fuel burning equipment, as well as other sources located in 

the Baltimore/Washington metropolitan areas, is subject to a no visible emissions (VE) 

requirement. In the rest of the state, sources are subject to a 20% opacity requirement 

unless other source-specific requirements are applicable. The VE of stacks can be 

measured by a person trained to use the observational procedures in the EPA Test 

Method 9. The VE can also be measured using COMs in the stack. Whether the stack is 

equipped with a continuous opacity monitor or not, a Method 9 observational test can be 

performed. Maryland has revised regulations to incorporate technologies that were 

developed through the 1990s and new monitoring technologies. 

SIP Amendments to Existing COM/CEM Requirements in COMAR 26.11.01

The existing SIP’d regulations .10 and .11 in this chapter use Continuous Opacity 

Monitors (COMs) and Continuous Emission Monitors (CEMs) interchangeably. The 

proposed SIP revisions distinguish the two types of monitoring and separate the 

requirements. The existing COMAR regulations.10 & .11 were repealed and replaced 

with new language addressing COMs in COMAR 26.11.01.10 and CEMs in COMAR 

26.11.01.11, treating each separately, although the substantive requirements remain the 

same. 

The current regulation .10 and the Technical Memorandum (TM) were submitted to EPA 

as a State Implementation Plan (SIP) revision and were approved into the SIP. The 

existing regulation .11 was not submitted to EPA for inclusion in the SIP. 

As part of this SIP #15-05, both the revised regulations .10 and .11 are submitted to EPA 

for approval. Also included in this SIP are the definition changes under regulation .01 

and the reporting additions under regulation .05. For convenience, contact information for 

reporting test results was added in 26.11.01.05, but each of the affected sources has an 

assigned premise engineer. 

The Department may use the COM data or the observational procedures in Method 9 to 

determine compliance or non-compliance with opacity standards. 

Amendments to COMAR 26.11.09 – NOT PART OF THIS SIP REVISION

Due to evolving EPA guidance and regulations, the Fuel Burning Equipment opacity 

requirements will need to be revised before SIP approval. Therefore, Maryland is 

submitting this package but not including COMAR 26.11.09.01 and .05 regulations as 

part of this SIP. Changes to 26.11.09 happened in the same action as some of the other 

COMAR revisions thus it is mentioned here. MDE has provided the current effective 

COMAR text and struck out this language with redline to indicate that this part of the 

action is not to be included in the SIP. 
Units with Flue Gas Desulfurization Installed 

In 2010, 9 of the 17 affected large fuel burning units installed flue gas desulfurization 

equipment (scrubbers). These scrubbers reduced particulate matter and opacity. If the 

owner of the units that install scrubbers demonstrates that the saturated plume from the 

scrubber interferes with accurate measurement of VE, the owner can install a CEM for 

particulate matter. If the CEM provides accurate measurement for particulate matter, the 

source may discontinue use of the COM and provide quarterly data for particulate matter 

emissions with approval from the Department. The source must provide an alternative 

plan for demonstrating compliance with VE requirements to the Department when the 

CEM is not generating data that includes a schedule for monthly Method 9 observations. 

As noted earlier, sources subject to COM requirements have computer programs to 

manage the copious data generated by COMs. These programs assess compliance with 

the opacity standards continuously throughout the quarter and a quarterly report is issued 

to the Department. Under COMAR 26.11.01.07 (part of early SIP documents), any 

excess emissions or malfunctions lasting more than 1 hour must be reported immediately 

to the Department. 

SIP Amendments to COMAR 26.11.31

The existing COMAR regulations for small business pollution compliance loan funds 

were repealed and replaced with new language addressing quality assurance (QA) and 

quality control (QC) procedures for COMs. References to 90-01 TM are no longer 

needed. 

SIP Amendments to Remove the Technical Memorandum 90-01 (TM)

The proposed SIP actions remove the need for the 90-01 TM. (The TM was part of SIP 

91-04). The 90-01TM will be proposed for removal from the SIP, when the last reference 

to the TM is removed in 2016.
SIP EQUIVALENCY TABLE SUMMARY 

COMAR 26.11.01.01, .05, .10 & .11 

The SIP Equivalency Table compares the additions to existing COMAR 26.11.01 to the 

total proposed amendment actions for COMAR 26.11.01 relating to opacity (through 

November 2015). The existing regulations are those prior to May 2010. 

As stated earlier in the document, the existing regulation 26.11.01.10 is in the approved 

SIP while existing regulation 26.11.01.11 is not. The existing regulations comingle 

requirements for continuous emission monitors (CEMs) and continuous opacity monitors 

(COMs). For clarity, requirements for continuous emission monitors are transferred to 

new 26.11.01.11 and requirements for continuous opacity monitors are retained in new 

26.11.01.10. 

The left side of the table contains relevant existing regulations 26.11.01.01, .05, and .10. 

After each existing regulation or portion of the regulation, the location of the comparable 

requirement in the proposed amendments is given in red. 

The right side of the table contains the text of the proposed SIP amendments. Equivalent 

requirements from existing as relocated are not always opposite each other in the table. 

Additionally the creation of 26.11.01.10 (COMS) & .11(CEMS) happened over 3 

proposed actions to COMAR. Thus; 

o The text that existed prior to the first proposal is shown in black. 

o The text as added from the first proposal (January 29, 2010) is in green 

highlight. Eff 5/17/10 

o The text from the second proposal (January 14, 2011) is in yellow 

highlight. Eff 8/22/11 

o The text from the third proposal (April 22, 2011) is in blue highlight. Eff 

8/22/11 

Special Note: 

(1) 26.11.01.10 (F) Fuel burning equipment reference pointing to 26.11.31, QA for 

COMs, is included with this SIP. Other details for Fuel burning equipment COMs 

under 26.11.09 are not part of this SIP package. Those actions will be part of a 

separate SIP. 

(2) An additional change to COMAR 26.11.01.10.A(5) & F (COMS) has been 

adopted and is in effect as of 7/20/15, and is included with SIP 15-04 (Cement 

Plants Controls). This text is shown in orange for reference only. 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.01 Definitions. 

B.(9) "Continuous emission monitor (CEM)" means a 

system of instruments installed, operated, and calibrated 

in accordance with the procedures in this subtitle to 

continuously measure and record the opacity, emission 

rate, or concentration of a substance in a gas stream. This 

definition is in our existing regulations but was not formerly part of the 

SIP. The word opacity was removed from before the words emission 

rate.

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.01 Definitions. 

(9) "Continuous emission monitor (CEM)" means a 

system of instruments installed, operated, and calibrated 

in accordance with the procedures in this subtitle to 

continuously measure and record the emission rate or 

concentration of a substance in a gas stream. 

(9-1) "Continuous opacity monitor (COM)" means a 

system of instruments installed, operated, and calibrated 

in accordance with the procedures in this subtitle to 

continuously measure and record the opacity of emissions 

as six-minute averages of not greater than 15 second 

increments. This definition is new and its purpose is to clarify the 

difference in handling between continuous emission monitors and 

continuous opacity monitors.

.05 Records and Information. 

C. Whenever a provision in this subtitle requires 

submission or reporting of test results, reports, or other 

information to the Department, unless otherwise 

specified, the information shall be submitted to: 

Program Manager 

Air Quality Compliance Program 

Maryland Department of the Environment 

1800 Washington Boulevard, Suite 715 

Baltimore, Maryland 21230 

410-537-4225 

D. Unless otherwise specified, all records, documentation 

or other information required by this subtitle, shall be 

maintained on-site and made available to the Department 

upon request. The requirement to submit reports to the Department 

exists. The identification of a specific entity to receive the report is 

new.
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Emission (CEM) 

Monitoring Requirements. 

The requirements of this regulation must be maintained in the SIP. 

Currently this regulation applies to both CEMs and COMs. The 

CEM requirements must be transferred to regulation .11 (now the 

CEM regulation being submitted for approval into the SIP). The 

current COM requirements must be retained in regulation .10. 

A. Applicability and Exceptions. 

(1) The provisions of this regulation apply to a person 

that owns or operates any fuel burning equipment burning 

coal or fuel oil that has a rated heat input capacity of 250 

million Btu per hour or greater. Maintained CEM requirement 

in 26.11.01.11A(1)(a) which lowers the applicability threshold to be 

more inclusive. Revision maintains COM requirement in revised 

26.11.01.10A(1)(a). 

(2) A person subject to this regulation may also be 

subject to the requirements of 40 CFR 60 which is 

incorporated by reference, and 40 CFR 75. Maintained CEM 

requirement in 26.11.01.11A(2). Revision maintains COM requirement 

in revised 26.11.01.10A(2).

(3) A CEM is not required for fuel burning equipment 

that: 

(a) Burns only distillate fuel oil or a mixture of gas and 

distillate fuel oil; 

(b) Is able to comply with the applicable particulate 

matter and opacity regulations without utilization of 

particulate matter control equipment; and 

(c) Has never been found in a final order to be in 

violation of any visible emission standard. Revision 

maintains COM requirement in revised 26.11.01.10A(3).

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Opacity Monitoring 

Requirements. 

A. Applicability and Exceptions. 

(1) The provisions of this regulation apply to: 

(a) Fuel burning equipment burning coal, fuel oil, tars, or 

waste combustible fluid at any time and that has a rated 

heat input capacity of 250 million Btu per hour or 

greater; 

(b) Fuel burning equipment burning coal with a rated heat 

input capacity of 100 million Btu per hour or greater but 

less than 250 million Btu per hour and was constructed 

on or before June 19, 1984; 

(c) A cement kiln; 

(d) A fluidized bed combustor of any size; and 

(e) A municipal waste combustor with a burning capacity 

[greater than] of 35 tons or greater per day. 

(2) The owner or operator of an installation subject to this 

regulation may also be subject to the requirements of 40 

CFR Parts 60 and 75, as amended. 

(3) This regulation does not apply to fuel burning 

equipment that: 

(a) Burns only distillate fuel oil or a mixture of gas and 

distillate fuel oil; 

(b) Is able to comply with the applicable particulate 

matter and opacity emission limitations without using 

particulate matter control equipment; and
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Emission (CEM) Monitoring 

Requirements. 

B. Monitoring Requirements. 

(1) Except as provided in § A of this regulation, a person 

owning or operating fuel burning equipment with a heat 

input capacity of 250 million Btu per hour or greater and 

burning coal or fuel oil shall install and operate a CEM to 

measure and record opacity. Requirement now established in 

revised 26.11.01.10A(1). 

(2) Any CEM that is required by this regulation shall be 

operated, maintained, and calibrated to provide 

continuous valid data for each operating day, except that 

data is not required to be provided during: 

(a) The time required under an approved quality 

assurance plan to perform adjustments, checks, 

calibrations, and scheduled maintenance; and 

(b) CEM equipment malfunctions lasting not more than 

2 hours per operating day. Maintained CEM requirement in 

26.11.01.11B(4). Revision maintains COM requirement in revised 

26.11.01.10D(1)(c).

(3) Except as otherwise approved by the Department, a 

person who reports a CEM system downtime in 

accordance with § G(1) of this regulation may be 

required to use an alternative monitoring method 

approved by the Department. Maintained CEM requirement in 

26.11.01.11B(4). Revision maintains COM requirement in revised 

26.11.01.10D(1)(c).

C. General CEM Installation Requirements. 

(1) A person subject to this regulation shall submit a 

CEM plan containing the CEM design specifications, 

proposed location, and a description of the proposed 

alternative measurement method required by Regulation 

.11B(7) of this chapter to the Department for approval 

before installation of the CEM. Maintained CEM requirement 

in 26.11.01.11B(1). Revision maintains COM requirement in revised 

26.11.01.10B(1)(b).

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Opacity Monitoring 

Requirements. 

 (c) Has never been found in a final order to be in 

violation of any visible emissions standard. 

(4) The owner or operator of fuel burning equipment 

subject to this regulation may, with approval by the 

Department, discontinue use of a COM only in 

accordance with the provisions in COMAR 

26.11.09.05C. 

(5) The owner or operator of a cement manufacturing 

installation may discontinue use of a COM when a PM CPMS 

is installed and operated in accordance with the requirements 

of COMAR 26.11.30. Text EFFECTIVE 7/20/15 with SIP 

15-04 (Cement Plants) 

B. General Requirements for COMs. 

(1) The owner or operator of an installation subject to this 

regulation shall: 

(a) Install and continuously operate a COM that complies 

with a plan approved by the Department and EPA in 

accordance with §B(1)(b) of this regulation; and 

(b) Before installing a COM, submit to the Department 

for approval, a plan containing the COM design 

specifications, proposed location, and a description of a 

proposed alternative measurement method consisting of a 

schedule for utilizing the EPA Reference Method 9 

observational procedures. 

(2) The Department shall submit the plan to EPA for 

review and approval. 

(3) A COM shall comply with the applicable 

requirements in 40 CFR Part 51, Appendix P, Sections 

3.3—3.9, as amended, which is incorporated by 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Emission (CEM) Monitoring 

Requirements. 

(2) A person who is required by this regulation to install 

a CEM shall comply with the applicable requirements in 

40 CFR Part 51, Appendix P, § 3.3--3.8, which is 

incorporated by reference, and if an alternative procedure 

is to be used, in § 3.9. Alternative procedures shall be 

submitted to the U.S. EPA for approval. Revision maintains 

COM requirement in revised 26.11.01.10B(3). In this case CEM only 

refers to COM. 

D. CEM Installation and Certification Schedules. 

(1) A person subject to this regulation or Regulation .11 

of this chapter shall have all required CEM equipment 

installed, operating, maintained, calibrated, and certified 

not later than 12 months after the effective date of this 

regulation unless an alternative date is specified in an 

approved plan for compliance. Earlier compliance date has 

passed. 

(2) Except as provided in §D(4) of this regulation, all 

certification testing, including certification performance 

tests and audits, shall be performed in accordance with 40 

CFR Part 60, Appendix B, which is incorporated by 

reference. Maintained CEM requirement in 26.11.01.11C. Revision 

maintains COM requirement in revised 26.11.01.10C(1).

(3) All certification testing, including certification 

performance tests and audits, for sources subject to 42 

U.S.C. 7401-----7671q, shall be performed in accordance 

with 40 CFR Part 75, Appendix A. Revision maintains COM 

requirement in revised 26.11.01.10C(2).

(4) A person required to perform a certification 

performance test shall: 

reference. 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Opacity Monitoring 

Requirements. 

(4) The owner or operator of fuel burning equipment that 

is required by this regulation to install and operate a 

COM is subject to the provisions in COMAR 

26.11.09.05. 

C. Certification and Quality Assurance Procedures. 

(1) All certification testing, including certification 

performance tests and audits, shall be performed in 

accordance with 40 CFR Part 60, Appendix B, as 

amended, which is incorporated by reference. 

(2) For fuel burning equipment subject to the federal 

Acid Rain Program, all certification testing, including 

certification performance tests and audits, shall be 

performed in accordance with 40 CFR Part 75, Appendix 

A, as amended. 

(3) Certification testing shall be repeated when the 

Department determines that the data are invalid because 

of component replacement or other conditions that affect 

the accuracy of generated data. 

(4) The owner or operator that is required to perform a 

certification performance test shall: 

a) At least 60 days before the test, submit a test protocol 

to the Department for review and approval; 

(b) Schedule the test at a reasonable time and notify the 

Department at least 10 days before the test is to be 

conducted; and
 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Emission (CEM) Monitoring 

Requirements.

(a) Submit a test protocol to the Department at least 60 

days before the test for review and approval by the 

Department; 

(b) Schedule the test at a reasonable time and notify the 

Department at least 10 days before the test is to be 

conducted; and 

(c) Submit the test results to the Department not later 

than 45 days after the completion of the test. Maintained 

CEM requirement in 26.11.01.11C. Revision maintains COM 

requirement in revised 26.11.01.10C(4). 

E. Quality Assurance Procedures for Opacity Monitors. 

An opacity monitor required by this regulation or 

Regulation .11 of this chapter shall meet the quality 

assurance procedures established in the Department's Air 

Management Administration Technical Memorandum 90-

01 "Continuous Emission Monitoring (CEM) Policies 

and Procedures" (October, 1990), which is incorporated 

by reference. Replaced TM with 26.11.31 and requesting removal 

of the TM from the SIP. 

F. Use of CEM Data. Except as provided in Regulation 

.11D(1) of this chapter, an opacity CEM installed 

pursuant to this regulation shall be used as an indication 

of whether proper maintenance and operating procedures 

are being utilized by source operators to maintain 

emission levels at or below emission standards. Maintained 

CEM requirement in 26.11.01.11D(1).

G. Record Keeping and Reporting Requirements. 

(1) CEM System Downtime Reporting Requirements. 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Opacity Monitoring 

Requirements. 

(c) Submit the test results to the Department not later than 

45 days after the completion of the test. 

(5) The owner or operator of [Fuel] fuel burning 

equipment [subject to the COM requirements in COMAR 

26.11.09] required to install and operate a COM shall 

meet the quality assurance procedures contained in 

[Technical Memorandum 90-01 "Continuous Emission 

Monitoring (CEM) Policies and Procedures," Part II 

Quality Assurance Requirements for Continuous Opacity 

Monitoring Systems] COMAR 26.11.31. 

D. Record Keeping and Reporting Requirements. 

(1) System Downtime Reporting Requirements. 

(a) All COM downtime that lasts or is expected to last 

more than 24 hours shall be reported to the Department 

by telephone before 10 a.m. of the first regular business 

day following the first day on which downtime occurs. 

(b) The COM downtime report shall include the reason, if 

known, for the breakdown and the estimated period of 

time that the COM will be down. The owner or operator 

shall notify the Department by telephone when the COM 

has met performance specifications for accuracy, 

reliability, and durability of acceptable monitoring 

systems, as provided in 40 CFR Part 51 Appendix P, and 

is producing data. 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Emission (CEM) Monitoring 

Requirements. 

(a) All CEM system downtime that lasts or is 

expected to last more than 24 hours shall be 

reported to the Department by telephone before 

10 a.m. of the first regular business day 

following the breakdown. Maintained CEM requirement in 

26.11.01.11E(1)(a). Revision maintains COM requirement in revised 

26.11.01.10D(1)(a).

(b) The system breakdown report required by § G(1)(a) 

of this regulation shall include the reason, if known, for 

the breakdown and the estimated period of time that the 

CEM will be down. The owner or operator of the CEM 

shall notify the Department by telephone when an out-ofservice CEM is back in operation and producing valid 

data. Maintained CEM requirement in 26.11.01.11E(1)(b). Revision 

maintains COM requirement in revised 26.11.01.10D(1)(b). 

(2) CEM Data Reporting Requirements. 

(a) An opacity CEM shall automatically reduce all data 

to 6-minute block averages calculated from 36 or more 

equally spaced data points. Maintained CEM requirement in 

26.11.01.11E(2)(a). Revision maintains COM requirement in revised 

26.11.01.10D(2)(a).

(b) All test results shall be reported in a format approved 

by the Department. Maintained CEM requirement in 

26.11.01.11E(2)(b). Revision maintains COM requirement in revised 

26.11.01.10D(2)(b).

(c) Certification testing shall be repeated when the 

Department determines that the CEM data may be invalid 

because of component replacement or other conditions 

that affect the quality of generated data. Maintained CEM 

requirement in 26.11.01.11E(2)(c). Revision maintains COM 

requirement in revised 26.11.01.10C(3).

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Opacity Monitoring 

Requirements. 

(c) Except as otherwise approved by the Department and 

the EPA, a COM shall operate in compliance with the 

requirements of §B(2) of this regulation and collect data 

for at least 95 percent of the source's operating time 

during any calendar quarter. The alternative measurement 

plan required in §B(1)(b) of this regulation shall be used 

at all times when the COM fails to conform to 

performance standards required by §B(2) of this 

regulation during data collection. 

(2) Data Reporting Requirements. 

(a) A COM shall automatically reduce all data to sixminute block averages calculated from 24 or more 

equally spaced data points. 

(b) All COM data shall be reported in a format approved 

by the Department. 

(c) A quarterly summary report shall be submitted to the 

Department not later than 30 days following each 

calendar quarter. The report shall be in a format approved 

by the Department, and shall include the following: 

(i) The cause, time periods, and the opacity of all 

emissions which exceed the applicable quarterly, daily 

and hourly emission standards as provided in COMAR 

26.11.09.05A(4); 

(ii) The COM and installation downtimes, including the 

time and date of the beginning and end of each downtime 

period, and whether the downtime was scheduled; 

(iii) The cause of all COM downtime; 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Emission (CEM) Monitoring 

Requirements.

(d) A quarterly summary report shall be submitted to the 

Department not later than 30 days following each

calendar quarter. The report shall be in a format approved 

by the Department, and shall include the following: 

(i)The cause, time periods, and magnitude of all 

emissions which exceed the applicable emission 

standards; 

(ii) The source downtime including the time and date of 

the beginning and end of each downtime period and 

whether the source downtime was planned or unplanned; 

(iii) The time periods and cause of all CEM downtime 

including records of any repairs, adjustments, or 

maintenance that may affect the validity of emission data; 

(iv) Quarterly totals of excess emissions, installation 

downtime, and CEM downtime during the calendar 

quarter; 

(v) Quarterly quality assurance activities; and 

(vi) Daily calibration activities that include reference 

values, actual values, absolute or percent of span 

differences, and drift status; and 

(vii) Other information required by the Department that 

is determined to be necessary to evaluate the data, to 

ensure that compliance is achieved, or to determine the 

applicability of this regulation. 

(e) All information required by this regulation to be 

reported to the Department shall be retained and made 

available for review by the Department for a minimum of 

2 years from the time the report is submitted. Maintained 

CEM requirement in 26.11.01.11E(2)(d). Revision maintains COM 

requirement in revised 26.11.01.10D(2)(e).

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.10 Continuous Opacity Monitoring 

Requirements. 

 (iv) The total operating time for the quarter, and the total 

time and percent of the operating time during the quarter 

that excess emissions occurred, and the percentage of 

COM downtime, during the calendar quarter; 

(v) Quarterly quality assurance activities; 

(vi) Daily calibration activities that include reference 

values, actual values, absolute or percent of span 

differences, and drift status; 

(vii) Other information that the Department determines is 

necessary to evaluate the data or to ensure that 

compliance is achieved. 

E. All information required by this regulation to be 

maintained or reported to the Department shall be 

retained and made available for review by the 

Department for a minimum of 5 years from the time the 

report is submitted. 

F. Fuel burning equipment subject to the COM 

requirements in COMAR 26.11.09.05 and cement kilns 

subject to the COM requirements in COMAR 26.11.30

are subject to the COM requirements contained in 

COMAR 26.11.31. Text EFFECTIVE 7/20/15 with 

SIP 15-04 (Cement Plants) 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

.11 Additional CEM Installation 

Requirements (NOT IN previous SIP) 

Text not applicable 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.11 Continuous Emission Monitoring 

Requirements. 

A. Applicability and Exemptions. 

(1) The provisions of this regulation apply to: 

(a) Fuel-burning equipment burning coal that has a rated 

heat input capacity of 100 million Btu per hour or greater; 

(b) Municipal waste combustors with a burning capacity 

[greater than] of 35 tons or greater per day; 

(c) Fluidized bed combustors; and 

(d) Kraft pulp mills. 

(2) An owner or operator that is required to install a CEM 

under any federal requirement is also subject to all of the 

provisions of this regulation. 

B. General Requirements for CEMs. 

(1) An owner or operator subject to this regulation shall: 

(a) Before installing a CEM, submit to the Department, 

for approval by the Department and EPA, a plan 

containing the CEM design specifications, proposed 

location, and a description of a proposed alternative 

measurement method; and 

(b) Install and operate a CEM in accordance with the plan 

approved by the Department and EPA under the 

provisions of §B(1)(a) of this regulation. 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.11 Continuous Emission Monitoring 

Requirements. 

(2) The owner or operator of fuel-burning equipment 

burning coal, with a heat input capacity of 100 million 

Btu per hour or greater, shall install CEMs to measure 

and record sulfur dioxide, nitrogen oxide, either oxygen 

or carbon dioxide, and flow. 

(3) The owner or operator of: 

(a) A municipal waste combustor (MWC) shall install [a 

CEM in accordance with the requirements in COMAR 

26.11.08.07 or 26.11.08.08, as applicable] CEMs to 

measure and record SOx, NOx, carbon monoxide 

emissions and either CO2 or oxygen; 

(b) A Kraft pulp mill shall install a CEM to measure and 

record [process total reduced sulfur in accordance with 

COMAR 26.11.14.05] SO2 and flow; and 

(c) A fluidized bed combustor of any size shall install 

CEMs to measure and record sulfur dioxide, nitrogen 

oxide and either oxygen or carbon dioxide. 

(4) Except as otherwise approved by the Department, if 

the owner or operator is unable to obtain emissions data 

from CEMs because of a malfunction of the CEM for 

more than 2 hours in duration, the owner or operator shall 

use the alternative measurement method approved by the 

Department and EPA. 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.11 Continuous Emission Monitoring 

Requirements.

C. Quality Assurance for CEMs. A CEM used to monitor 

a gas concentration shall meet the quality assurance 

criteria of 40 CFR Part 60, Appendix F, as amended, 

which is incorporated by reference, or, if applicable, the 

quality assurance criteria of 40 CFR Part 75, Appendix B, 

as amended. 

D. Monitoring and Determining Compliance. 

(1) General. A CEM required by this regulation is the 

primary method used by the Department to determine 

compliance or non-compliance with the applicable 

emission standards established in any permit or approval, 

administrative or court order, Certificate of Public 

Convenience and Necessity, or regulation in this subtitle. 

(2) Data Reduction. A CEM used to monitor a gas 

concentration shall record not less than four equally 

spaced data points per hour and automatically reduce data 

in terms of averaging times consistent with the applicable 

emission standard. 

(3) Technical Memorandum. Except for fuel burning 

equipment subject to the COM requirements in 

COMAR26.11.09.05, use of COMs and CEMs for 

equipment purposes shall be as specified in the 

Department’s Air Management Administration Technical 

Memorandum 90-01”Continuous Emission Monitoring 

(CEM) Policies and Procedures, “ which is incorporated 

by reference. Added with 5/17/10 action, deleted with 

8/22/11 action 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.11 Continuous Emission Monitoring 

Requirements. 

E. Record Keeping and Reporting Requirements. 

(1) CEM System Downtime Reporting Requirements. 

(a) All CEM system downtime that lasts or is expected to 

last more than 24 hours shall be reported to the 

Department by telephone before 10 a.m. of the first 

regular business day following the breakdown. 

(b) The system breakdown report required by § E(1)(a) 

of this regulation shall include the reason, if known, for 

the breakdown and the estimated period of time that the 

CEM will be down. The owner or operator of the CEM 

shall notify the Department by telephone when an out-ofservice CEM is back in operation and producing data 

that has met performance specifications for accuracy, 

reliability, and durability of acceptable monitoring 

systems, as provided in COMAR 26.11.31, and is 

producing data. 

 (2) CEM Data Reporting Requirements. 

 (a) All test results shall be reported in a format 

approved by the Department. 

(b) Certification testing shall be repeated when the 

Department determines that the CEM data may not meet 

performance specifications because of component 

replacement or other conditions that affect the quality of 

generated data. 

(c) A quarterly summary report shall be submitted to the 

Department not later than 30 days following each 

calendar quarter. The report shall be in a format 

approved by the Department, and shall include the 

following: 

(i) The cause, time periods, and magnitude of all 

emissions which exceed the applicable emission 

standards; 

(ii) The source downtime including the time and date of 

the beginning and end of each downtime period and 

whether the source downtime was planned or unplanned; 

(iii) The time periods and cause of all CEM downtime 

including records of any repairs, adjustments, or 

maintenance that may affect the ability of the CEM to 

meet performance specifications of emission data; 
Existing Regulations in SIP Regulations Incorporating Proposed Changes 

Title 26 DEPARTMENT OF 

THE ENVIRONMENT 

Subtitle 11 AIR QUALITY 

Chapter 01 General Administrative 

Provisions 

.11 Continuous Emission Monitoring 

Requirements. 

 (iv) Quarterly totals of excess emissions, installation 

downtime, and CEM downtime during the calendar 

quarter; 

(v) Quarterly quality assurance activities; 

(vi) Daily calibration activities that include reference 

values, actual values, absolute or percent of span 

differences, and drift status; and 

(vii) Other information required by the Department that 

is determined to be necessary to evaluate the data, to 

ensure that compliance is achieved, or to determine the 

applicability of this regulation. 

(d) All information required by this regulation to be 

reported to the Department shall be retained and made 

available for review by the Department for a minimum of 

2 years from the time the report is submitted.