B. Terms Defined.
(1) "Acceptable ambient level (AAL)" means a
concentration of a toxic air pollutant in the atmosphere that the Department
determines will provide a margin of safety to protect the public health from
toxic, noncarcinogenic effects that may be caused by the toxic air pollutant
and that is used to evaluate the air quality impacts of all premises within a
5-kilometer (3.1-mile) radius. AALs are listed in COMAR
26.11.16.09 a.
(2) "Allowable emissions" means the maximum
emissions a source or installation is capable of discharging after
consideration of any physical or operational limitations required by this
subtitle or by enforceable conditions included in an applicable air quality
permit to construct, permit to operate, secretarial order, plan for compliance,
consent agreement, or court order.
(3) Best Available Control Technology for
Toxics (T-BACT).
(a) "T-BACT" means control
technology that results in the maximum degree of emission reduction that the
Department determines, on a case-by-case basis, is available for each toxic air
pollutant discharged by the installation, taking into account the potency and
toxicity of each toxic air pollutant and the technical and economic feasibility
of control.
(b) "T-BACT" includes
production, operation, and maintenance procedures, emission control technology,
and other emission reduction technologies or a combination of these
technologies and procedures.
(c)
"T-BACT", as applicable to a MACT source, means:
(i) A requirement that has been adopted by
the US EPA under 40 CFR
63 and that applies to the installation, source, source
category, or subcategory;
(ii) A
new source MACT as established by the Department in accordance with the
provisions of 40 CFR
§§
63.40-
63.44;
(iii) Alternative standard approved by the
EPA Administrator; or
(iv)
Alternative emission limitation approved by the Department in accordance with
40 CFR Part
63, Subpart D.
(4) "Class I toxic air pollutant (Class I
TAP)" means a substance or group of substances that is listed in COMAR
26.11.16.06 a.
(5) "Class II toxic air pollutant (Class II
TAP)" means any substance that is not a Class I TAP, for which there is no
ambient air quality standard under this subtitle, that is not a simple
asphyxiant or nuisance particulate, and that is:
(a) A health hazard as that term is defined
at 29 CFR §
1915.1200 (July 1, 1994); or
(b) Listed in COMAR
26.11.16.07 a B as an existing
source Class II TAP, either individually or as a member of a group of
substances.
(6) "EPA's
Risk Assessment Guidelines" means the U.S. Environmental Protection Agency's
Guidelines for Carcinogenic Risk Assessment, 51 FR
33992 (September 24,
1986).
(7) "Existing installation,
existing source, or existing premises" means an installation, source, or
premises, respectively, constructed before July 1, 1988, or for which the
Department issued an air quality permit to construct before July 1, 1988. Any
existing installation that is modified but that is not reconstructed after July
1, 1988, remains an existing installation.
(7-1) "Hazardous air pollutant (HAP)" means any of the
hazardous air pollutants listed in § 112(b) of the federal Clean Air Act
of 1990, 42 U.S.C.
§§
7401-
7671.
(8) "Insignificant risk concentration (IRC)"
means a concentration of a Class I toxic air pollutant in the atmosphere that
would result in an excess individual lifetime cancer risk of not more than 1 in
100,000 (1 X 10 superscript -5) assuming continuous exposure for 70 years and
using procedures consistent with EPA's Risk Assessment Guidelines. IRCs are
listed in COMAR
26.11.16.09 a.
(9) "Installation" has the meaning given in
COMAR
26.11.01.01 a, except that for
purposes of this chapter, installation does not include air pollution control
equipment as defined in COMAR
26.11.01.01 a.
(9-1) "MACT source" means a NESHAP source that is subject
to the requirements in 40 CFR 63 ;
(9-2) "Maximum achievable control technology (MACT)", as
applicable, means:
(a) MACT emission
limitation for existing sources as defined in
40 CFR §
63.51; or
(b) MACT emission limitation for new sources
as defined in 40 CFR §
63.51.
(10) "New installation, new source, or new
premises" means an installation, source, or premises, respectively, constructed
or reconstructed on or after July 1, 1988, except as provided under §B(7)
of this regulation.
(10-1) "New source MACT" means maximum achievable control
technology (MACT) emission limitation for new sources as defined in
40 CFR §
63.41.
(11) "Nuisance particulate" means dust that,
when inhaled, causes a potentially reversible lung tissue reaction in which the
architecture of the lung's air spaces remains intact, and collagen (scar
tissue) is not formed to a significant extent. Examples of nuisance
particulates are listed in COMAR
26.11.16.08 a.
(12) "Premises" means all the installations
or other sources that are located on contiguous or adjacent properties and that
are under the control of one person or under common control of a group of
persons.
(13) "Reconstruct" means
to replace components of an existing installation, or add components to an
existing installation, to such an extent that the fixed capital cost of the new
components exceeds 50 percent of the fixed capital cost that would be required
to construct a comparable entirely new installation. Reconstruct does not
include replacement or additions that do not:
(a) Cause the discharge of different toxic
air pollutants;
(b) Cause
applicable screening levels to be exceeded; and
(c) Increase the ambient concentration of any
Class I toxic air pollutant.
(14) "Screening analysis" means an optional
procedure for demonstrating compliance with Regulation .06 of this chapter that
compares maximum incremental ambient impacts with applicable screening
levels.
(15) "Screening level"
means a concentration of a toxic air pollutant in the atmosphere used to
evaluate the air quality impacts of a single premises. Screening level includes
the following:
(a) "Risk-based screening
level" means a concentration of a Class I toxic air pollutant in the atmosphere
as determined under COMAR
26.11.16.03 a;
(b) "Special screening level (SSL)" means a
concentration of a toxic air pollutant in the atmosphere that replaces a TLV or
threshold-based screening level. Special screening levels are listed in COMAR
26.11.16.09 a;
(c) "TLV-based screening level" means a
concentration of a Class I or Class II toxic air pollutant in the atmosphere as
determined under COMAR
26.11.16.03 a;
(d) "Threshold-based screening level" means a
concentration of a Class I or Class II toxic air pollutant in the atmosphere as
determined under COMAR
26.11.16.03 a when a TAP has
neither a TLV-based nor a special screening level.
(16) "Second tier analysis" means an optional
procedure for demonstrating compliance with Regulation .06 of this chapter
using an acceptable ambient level or an insignificant risk concentration, as
provided in COMAR
26.11.16.02 a, instead of a
screening level.
(17) "Simple
asphyxiant" means a physiologically inert gas or vapor that acts primarily by
diluting atmospheric oxygen below the level required to maintain proper levels
of oxygen in the blood. Examples of simple asphyxiants are listed in COMAR
26.11.16.08 a.
(18) "Threshold limit value (TLV)" means the
airborne concentration of a substance that, according to the American
Conference of Governmental Industrial Hygienists (ACGIH), represents conditions
to which nearly all workers may be exposed without adverse effect and that is
published in the chapter titled "1991-1992 Threshold Limit Values for Chemical
Substances in the Work Environment" (Adopted by ACGIH with Intended Changes for
1991-1992), which is incorporated by reference. This chapter is found in the
TLV booklet, defined in §B(19) of this regulation. TLV includes the
following:
(a) "Ceiling TLV (TLV-C)" means a
concentration that ACGIH indicates should not be exceeded even instantaneously
in a workplace;
(b) "Short term
exposure limit (TLV-STEL or STEL)" means a 15-minute time-weighted average
concentration that ACGIH indicates should not be exceeded at any time during a
workday;
(c) "Threshold limit
value-time weighted average (TLV-TWA)" means a concentration recommended by
ACGIH for a normal 8-hour workday and 40-hour workweek.
(19) "TLV booklet" means "1991-1992 Threshold
Limit Values for Chemical Substances and Physical Agents and Biological
Exposure Indices" (American Conference of Governmental Industrial Hygienists,
1991).
(20) Toxic Air Pollutant.
(a) "Toxic air pollutant (TAP)" means any
Class I or Class II toxic air pollutant, as defined in §B(4) and (5) of
this regulation.
(b) "Toxic air
pollutant" does not include particulate matter and volatile organic compounds
as generic classes of substances, but an individual substance or a group of
substances within either of these classes is a TAP if it meets a criterion in
§B(4) or (5) of this regulation.
(21) "Upper bound unit risk factor" means the
95 percent upper confidence limit of an estimate of the extra risk of cancer
associated with a continuous 70-year exposure to 1 microgram/cubic meter of a
Class I toxic air pollutant.