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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION III

1650 Arch Street

Philadelphia, Pennsylvania 19103

Date: April 5, 2016

Subject: Technical Support Document – Revisions and Amendments to Continuous Opacity 

Monitoring (COM) and Continuous Emissions Monitoring (CEM) Requirements in 

COMAR 26.11.01 and Addition of Quality Assurance Requirements for COMs in 

COMAR 26.11.31

 

From: Marilyn Powers, Environmental Engineer /s/ April 5, 2016

 Office of Air Program Planning (3AP30)

To: File

Thru: Cristina Fernandez, Associate Director /s/ April 10, 2016

 Office of Air Program Planning (3AP30)

I. Background

On November 24, 2015, the Maryland Department of the Environment (MDE) 

submitted a state implementation plan (SIP) revision revising COMAR 26.11.01 General 

Administrative Provisions and adding COMAR 26.11.31 Quality Assurance Requirements for 

Continuous Opacity Monitors (COMs). The submission includes a series of revisions and 

amendments to Maryland’s existing regulations as detailed in section II of this technical support 

document (TSD). 

On February 26, 2016, MDE supplemented its November 24, 2015 submittal to clarify 

that certain provisions of COMAR 26.11.01 are excluded from the submittal.

The federally enforceable requirements for COMs and CEMs are contained in COMAR 

26.11.01.10 Continuous Emission Monitoring (CEM) Requirements, which was approved into 

the Maryland SIP on February 28, 1996 (61 FR 6418). COMAR 26.11.01.10 required fuelburning equipment burning coal or fuel oil with a rated heat input capacity of 250 million Btu 

per hour or greater, with certain exceptions, to install and operate CEMs for opacity. This 

regulation established installation and certification schedules for CEMs, how CEMs data is to 

be used, and record keeping and reporting requirements for CEMs downtimes and CEMs data. 

This regulation refers to CEMs and COMs (“an opacity CEM” and “a CEM to measure and 

record opacity”) interchangeably. MDE has been in the process of establishing unique 
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requirements for COMs, separate from the requirements for CEMs, and previously broke out 

the requirements into separate COMAR regulations. The revised COMAR regulations were not 

submitted to EPA for approval into the SIP for years, until after MDE completed the series of 

revisions to them. It is this series of regulatory changes that MDE has submitted as part of its

November 24, 2015 submittal.

COMAR 26.11.01.10 also required that opacity monitors meet the quality assurance 

procedures contained in MDE’s Technical Memorandum (TM) 90-01 Continuous Emission 

Monitoring (CEM) Policies and Procedures, which was incorporated by reference in EPA’s 

February 28, 1996 rulemaking. TM 90-01 established levels of enforcement actions for visible 

emissions exceedances based on a source’s operating time during a calendar quarter, and 

allowed exceedances to occur up to 10 percent of a source’s operating time in addition to an 

existing 6 minute exclusion. It established enforcement action based on the number of 

exceedances during the quarter as well as for sources with repeated exceedances during 

consecutive calendar quarters. 

MDE had used TM 90-01 as its enforcement policy for COMs opacity violations and 

COMs data availability violations since 1991. In the past few years, MDE has been working 

toward tightening the compliance demonstration criteria for the State’s visible emissions

limitations for sources required to operate COMs by removing provisions requiring the use of 

TM 90-01.

 

II. Description of Revision

On November 24, 2015, MDE submitted a SIP revision for approval into the Maryland 

SIP. The submission is comprised of four State actions pertaining to the requirements for 

COMs and CEMs in COMAR 26.11.01.01, COMAR 26.11.01.10, new COMAR 26.11.01.11,

and new COMAR 26.11.31, as follows:

1. Amendments to COMAR 26.11.01 General Administrative Provisions adopted on 

April 14, 2010

In the Maryland SIP, the COMs and CEMs requirements for fuel-burning equipment are 

contained in COMAR 26.11.01.10 which, as noted previously, do not distinctly 

differentiate between COMs requirements and CEMs requirements. To establish 

separate regulations for COMs and CEMs, the April 14, 2010 action amended COMAR 

26.11.01.01 Definitions to add a new definition for COMs and to clarify the definition 

for CEMs, repealed COMAR 26.11.01.10 in its entirety and replaced it with a new 

regulation for COMs entitled Continuous Opacity Monitoring Requirements, and added 

new COMAR 26.11.01.11 Continuous Emissions Monitoring Requirements. The action 

also amends COMAR 26.11.01.05 Records and Information for administrative changes 

to reporting and recordkeeping requirements.
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Revised COMAR 26.11.01.10 establishes requirements for COMs and applies to fuelburning equipment burning coal, fuel oil, tars, or waste combustible fluid at any time 

that has a rated heat input capacity of 250 million Btu per hour or greater, 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, cement kilns, fluidized bed combustors of any size, and municipal waste 

combustors with a burning capacity greater than 35 tons per day. The regulation 

establishes general requirements for installation of COMs, certification and quality 

assurance procedures, and record keeping and reporting requirements. COMAR 

26.11.01.10F removes the requirements for fuel-burning equipment subject to the COM 

requirements in COMAR 26.11.09.05 to meet TM 90-01, but retains the requirement 

that the COMs on these sources meet the quality assurance and quality control (QA/QC) 

requirements contained in Part II of TM 90-01. Likewise, COMAR 26.11.01.10C(5) 

requires the COMs on these sources to meet the QA/QC procedures for COMs in 

accordance with TM 90-01. As noted below, the QA/QC requirements were 

subsequently revised to remove the reference to TM 90-01, and instead refer to newly 

codified QA/QC requirements.

New COMAR 26.11.01.11 requires CEMs for fuel-burning equipment burning coal that 

has a rated heat input capacity of 100 million Btu per hour or greater, municipal waste 

combustors with a burning capacity greater than 35 tons per day, fluidized bed 

combustors, kraft pulp mills, and any owner or operator that is required to install a CEM 

under any federal requirement. This new regulation establishes general requirements for 

the installation of CEMs for each of the applicable source categories, quality assurance 

provisions, and monitoring and compliance requirements. COMAR 26.11.01.11D(3)

requires enforcement in accordance with TM 90-01, which may have been an oversight 

in MDE’s efforts to remove the requirements of TM 90-01, however, MDE’s July 29, 

2011 action included in this submittal removes the TM requirements from the COMAR 

regulation (see action 4 below). 

2. New COMAR 26.11.31 Quality Assurance Requirements for Continuous Opacity 

Monitors (COMs) adopted on May 16, 2011

COMAR 26.11.31 is a new regulation comprised of the QA/QC procedures for COMs. 

In the existing SIP, the required QA/QC procedures for COMs were found in a section of 

TM 90-01 that was incorporated by reference in the Maryland SIP. As part of MDE’s 

efforts to remove the applicability of TM 90-01 from the Maryland SIP, the May 16, 

2011 action codified the QA/QC requirements into COMAR 26.11.31, and incorporated 

by reference, in COMAR 26.11.31.03, two federal performance and design specification 

requirements for the operation of opacity monitoring: Performance Specification 1 under 

40 CFR part 60 Appendix B, and Performance Audit Procedures for Opacity Monitors, 

EPA 450/4-92-010 dated March 1992. 
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3. Revisions to COMAR 26.11.01 General Administrative Provisions adopted on 

July 29, 2011 

The July 29, 2011 action amends COMAR 26.11.01.10 and .11 previously adopted on 

April 14, 2010 (described in Action 1). The amendments revise COMAR 

26.11.01.10A(1)(e) and .11A(1)(b) to correct the size of municipal waste combustors

required to install continuous monitors (from greater than 35 mmBtu per hour to 35 

mmBtu or greater), COMAR 26.11.01.10C(5) to remove the requirement to meet TM 

90-01 for QA/QC procedures and instead point to the newly established QA/QC 

requirements in COMAR 26.11.31 (described in Action 2), and COMAR 

26.11.01.11B(3) to clarify the pollutants to be continuously measured for municipal 

waste combustors, Kraft pulp mills, and fluidized bed combustors. The action also adds 

COMAR 26.11.01.10E for recordkeeping and reporting requirements for CEMs. 

4. Revisions to COMAR 26.11.01 General Administrative Provisions adopted on 

July 29, 2011

This action further amends COMAR 26.11.01.10 and .11 (described in Action 1). The 

requirements for QA/QC procedures to meet TM 90-01 in COMAR 26.11.01.10F is 

removed and replaced with the requirement to instead meet new COMAR 26.11.31 

(described in Action 2). Also, the requirement to meet TM 90-01 for enforcement 

purposes in COMAR 26.11.01.11D(3) is removed. 

It is noted that MDE’s April 14, 2010 and July 29, 2011 actions (actions 1 and 3 above) 

also adopted changes to COMAR 26.11.09 Control of Fuel-Burning Equipment, Stationary 

Internal Combustion Engines, and Certain Fuel-Burning Installations, which are not included 

in the November 24, 2015 submittal. The submittal letter explicitly excludes changes made to 

COMAR 26.11.09 from this SIP revision, as MDE states that these regulations must undergo 

further revisions before being separately submitted for inclusion into the State’s SIP.

On February 26, 2016, MDE provided a supplemental submission excluding some 

additional portions of its November 24, 2015 SIP submittal. In addition to the exclusion of the 

changes to COMAR 26.11.09.01 and .05 from the submittal, as noted above, MDE is also 

excluding several provisions in COMAR 26.11.01.10 that refer to sections or subsections of 

COMAR 26.11.09 that are not yet in the State’s SIP. The additional excluded sections or 

subsections are COMAR 26.11.01.10A(4), B(4), D(2)(c), and F. MDE plans to submit the 

COMAR 26.11.09 revisions along with these related provisions for approval into the SIP at a 

later date.
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III. EPA’s analysis of Maryland’s Submittal

Many of the revisions in Maryland’s November 24, 2015 submittal consist of 

realignment of requirements that are already in the Maryland SIP. The separate regulations for 

COMs and CEMs in COMAR 26.11.01.10 and .11, respectively, provide clarifications and new 

requirements for COMs and CEMs, which were previously referred to interchangeably in the 

existing SIP-approved regulation. The removal of TM 90-01, which contained enforcement 

exclusions related to the number of violations and data availability from COMs, will strengthen 

enforcement of the State’s visible emissions standards. The additional exclusions identified in

MDE’s February 26, 2016 supplemental submission are acceptable because they point to 

provisions that have not yet been submitted for inclusion into the SIP.

IV. Conclusion/ Recommendation

The SIP revision strengthens the Maryland SIP. It is recommended that a Notice of 

Proposed Rulemaking be published proposing approval of Maryland’s November 24, 2015 

submittal, as supplemented on February 26, 2016, as a revision to the State’s SIP.