TECHNICAL SUPPORT DOCUMENT

Department of the Environment 

COMAR 26.11.17 Nonattainment 

Provisions for Major New Sources and 

Major Modifications

Purpose of the Amendments 

The purpose of this action is to establish requirements for the construction of new major 

sources and major modifications in areas designated as nonattainment that are compatible 

with federal requirements. 

This action will be submitted to the U.S. Environmental Protection Agency as a revision 

to Maryland's State Implementation Plan (SIP). 

Background 

COMAR 26.11.17 establishes requirements for the construction of new major sources 

and major modifications at major sources that apply in ozone nonattainment areas. 

Because Maryland is in the Ozone Transport Region, the nonattainment New Source 

Review (NSR) requirements apply statewide. Generally, the regulations require affected 

sources to install state-of-the-art controls, referred to as to the lowest achievable emission 

rate (LAER), and to offset emissions by a specific offset ratio depending on the location 

of the source. In 2002, the Environmental Protection Agency (EPA) amended its New 

Source Review provisions and established different procedures to determine emission 

increases when modifying an existing facility and set forth different procedures for 

electric generating units (EGUs) and non-EGU major sources. These regulations were 

challenged by environmental groups and states, including Maryland. The courts upheld 

most of EPA’s new rule, but struck down certain provisions. 

States are required to establish regulations that are at least as restrictive as EPA’s. The 

substantive requirements for new sources, however, remain unchanged. The 

Department’s proposed amendments adopt all the federal definitions and include 

procedures that are nearly identical to the EPA procedures, except for the period used to 

calculate a source’s emissions increase following a modification. Under EPA’s rule, the 

non-EGU source could use a 24-month period to calculate emissions within the past ten 

years, while MDE’s regulations would allow the source to select the 24 month baseline 

period from the previous five years, absent a demonstration that another period was more 

representative of normal operations. 

The amendments also include specific requirements for the creation, banking and transfer 

of emissions reduction credits (ERCs). 

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Expected Emission Reductions 

The amendments apply to new or modified sources and set forth the criteria for issuing 

permits to construct in nonattainment areas. The amendments do not affect existing 

unmodified sources and therefore there is no expected emission reduction from existing 

sources. There is an overall benefit to the environment, however, because New Source 

Review requires state-of-the-art pollution controls for new and modified sources subject 

to the rule. 

Sources Affected 

These amendments apply statewide and affect new sources in the Baltimore/Washington 

areas that will have emissions of 25 tons per year or more of VOC or NOx and new 

sources in the rest of the state with emissions of 50 tons per year of VOC or 100 tons per 

year of NOx. Major modifications in the rest of the State will affect major sources that 

will have emission increases of 40 tons per year or more. 

Requirements of the Amendments 

The regulations maintain the same major source thresholds and offset ratios as the current 

regulations and contain the following changes: 

1. Current regulations require a source to use the average emissions of the previous 2 

years or another 2-year period that is more representative of normal operations as the 

baseyear from which increases are determined. Except for EGUs, EPA now allows a 

source to choose a 24-month period using a 10-year look-back. The proposed regulations 

require a 5-year look-back unless the regulated entity can establish that another 24-month 

period within the prior 10 years is more representative of normal operations. 

2. The current regulations contain a contemporaneous period that extends back 5 years 

from the date of a complete permit application. It now extends back in time five years 

from the date of the complete permit application and forward in time to the date when the 

new source commences operation. 

3. A new term “projected actual emissions” is added that allows an existing source to 

consider emissions that the unit could have accommodated during the 24-month period in 

determining whether the increase in emissions is “significant.” As a result of the use of 

this term, a source could use a higher baseline and become exempt from these 

requirements even though there is a significant emissions increase. 

4. In lieu of meeting applicable requirements an existing source may request a “plantwide applicability limit (PAL)” which establishes a five-year cap on the total plant 

emissions. Under a PAL, the units at the source could increase and decrease emissions if 

the cap is not exceeded. 

5. A new section is added that sets forth requirements for creating and using ERCs as 

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offsets. The ERCs are created by overcontrol or shutting down installations that were 

included in the Department’s most recent State Implementation Plan. The new section 

also establishes a ten year life for ERCs. 

Economic Impact 

The proposed action has no economic impact. These amendments will not increase the 

cost of compliance. Recent changes to the federal NSR program made the federal rule, 

under some conditions, less stringent. Maryland, however, is proposing changes to its 

current NSR program that incorporate some but not all of the federal changes. This 

makes the Maryland regulations more stringent than the federal rule. 

The amendments do not change the substantive portions of the regulations that require 

state-of-the-art controls and offsets based on Maryland's fully approved 1-hour Ozone 

State Implementation Plan. As with the existing regulations, the cost of compliance varies 

depending upon the size of the source, control costs, and the cost of offsets. 

Comparison to Federal Standards 

In compliance with Executive Order 01.01.1996.03, this proposed regulation is more 

restrictive or stringent than corresponding federal standards as follows: 

(1) Regulation citation and manner in which it is more restrictive than the applicable 

federal standard:

40 CFR 51.165 

COMAR 26.11.17.01B(2-1) defines the term “Baseline actual emissions.” This 

regulation establishes the procedures used to identify a historic emissions baseline from 

which emission increases are calculated. Whether or not emissions have increased is a 

major factor in determining whether or not this regulation applies to a proposed 

modification of an existing facility. If an emission increase is significant, this regulation 

would require use of state-of-the-art controls and costly offsets. The federal rule permits 

calculation of the baseline emissions using a 24-month period that occurred up to ten 

years ago. It is the Department’s position that the older baseline emissions would not 

necessarily be representative of more current emissions and we question the accuracy of 

emissions that are based on data and records that are up to ten years old. 

The Department’s regulations allow a source to choose a baseline emissions period from 

emission records up to five years old. For affected facilities, the MDE believes that a five 

year look back of emissions would best represent normal or typical emissions and would 

be more accurate. The Department’s selected five year period is also consistent with the 

duration of the facility’s operating permit and its five year reporting requirement. 

Allowing a facility to choose an emissions baseline from an earlier period could mean 

that a facility would not be subject to New Source Review even though it proposes a 

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significant modification and increase in emissions. 

(2) Benefit to the public health, safety or welfare, or the environment:

The Department’s use of a five year period from which to select baseline emissions is 

beneficial to the environment and to public health because a greater number of 

modifications will be subject to the restrictive requirements in this regulation. Although 

nearly all proposed increases of emissions would be subject to some existing regulation 

under COMAR, this regulation would require state-of-the-art controls and emissions 

offsets of up to 130 percent of the new emissions. 

(3) Analysis of additional burden or cost on the regulated person:

These amendments will not increase the cost of compliance. Recent changes to the 

federal NSR program made the federal rule less stringent. Maryland, however, is 

proposing changes to its current NSR program that incorporate some but not all of the 

federal changes. This makes the Maryland regulations more stringent than the federal 

rule. 

The amendments do not change the substantive portions of the regulations that require 

state-of-the-art controls and offsets based on Maryland's fully approved 1-hour Ozone 

State Implementation Plan. Maryland’s regulation, however, will require more sources to 

be subject to the more restrictive requirements in this chapter.

(4) Justification for the need for more restrictive standards:

The Department, over the years, has regulated nearly all existing emission sources that 

contribute to the pollutants that cause Maryland to fail to meet the federal health related 

ambient air quality standards for ozone. In order for Maryland to show progress in 

meeting the standards, we must continue to require state-of-the-art pollution controls on 

new large facilities and modifications of existing facilities. 

Additionally, nitrogen oxides (NOx), which would be subject to pollution control 

measures under these regulations, is a precursor to the formation of ozone. It is also a 

contributor to our nonattainment status for the federal fine particulates ambient standard. 

The EPA has already set 2010 attainment dates for Maryland to meet the ambient 

standards for both ozone and fine particulates. 

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