Sec. 4.
(a) All
measurements of air quality that are expressed as mass per unit volume, other
than for the particulate matter (PM2.5) standards
contained in subsection (b)(8) and lead (Pb) standards contained in subsection
(b)(6), must be corrected to a reference temperature of twenty-five (25)
degrees Celsius and a reference pressure of seven hundred sixty (760)
millimeters of mercury (one thousand thirteen and two-tenths (1,013.2)
millibars), as micrograms per cubic meter
(µg/m3). Measurements of
PM2.5, for purposes of comparison to the standards
contained in subsection (b)(8), and Pb, for purposes of comparison to the
standards contained in subsection (b)(6), must be reported based on actual
ambient air volume measured at the actual ambient temperature and pressure at
the monitoring site during the measurement period.
(b) Ambient air quality standards are as
follows:
(1) Sulfur oxides as sulfur dioxide
(SO2) requirements are as follows:
(A) For the primary one (1) hour ambient air
quality standard, the maximum permissible ambient air quality level is
seventy-five (75) parts per billion (ppb). The one (1) hour standard is
attained when the three (3) year average of the annual ninety-ninth percentile
of the daily maximum one (1) hour average concentration is less than or equal
to seventy-five (75) ppb, as determined in accordance with 40 CFR 50, Appendix
T* and measured in the ambient air as SO2 by a reference
method based on 40 CFR 50, Appendix A-1* or 40 CFR 50, Appendix A-2*, or an
equivalent method designated in accordance with 40 CFR 53 *.
(B) For the secondary standard, the following
value represents the maximum permissible ambient air quality level: one
thousand three hundred (1,300) µg/m3
(five-tenths (0.5) ppm) maximum three (3) hour concentration not to be exceeded
more than once per year. The three (3) hour averages must be determined from
successive nonoverlapping three (3) hour blocks starting at midnight each
calendar day and must be rounded to one (1) decimal place (fractional parts
equal to or greater than five-hundredths (0.05) ppm must be rounded up). Sulfur
oxides must be measured in the ambient air as SO2 by the
reference method described in 40 CFR 50, Appendix A-1* or 40 CFR 50, Appendix
A-2*, or by an equivalent method designated in accordance with 40 CFR 53 *. To
demonstrate attainment, the second-highest three (3) hour average must be based
upon hourly data that are at least seventy-five percent (75%) complete in each
calendar quarter. A three (3) hour block average is considered valid if:
(i) all three (3) hourly averages for the
three (3) hour period are available; or
(ii) only one (1) or two (2) hourly averages
are available, but the three (3) hour average would exceed the level of the
standard when zeros are substituted for the missing values, subject to the
rounding rule of this clause. In all cases, the three (3) hour block average
must be computed as the sum of the hourly averages divided by three
(3).
(C)
SO2 values may be converted to ppm using the conversion
factor two thousand six hundred twenty (2,620) µg/m3
= one (1) ppm.
(2) Total suspended particulates (TSP)
requirements are as follows:
(A) For primary
standards, the following values represent the maximum permissible ambient air
quality levels:
(i) Seventy-five (75)
µg/m3 annual geometric mean.
(ii) Two hundred sixty (260)
µg/m3 maximum twenty-four (24) hour average
concentration not to be exceeded more than one (1) day per year.
(B) For secondary standards, the
following value represents maximum permissible ambient air quality levels: one
hundred fifty (150) µg/m3 maximum twenty-four
(24) hour average concentration not to be exceeded more than one (1) day per
year.
(3) Carbon
monoxide (CO) requirements are as follows:
(A)
For primary and secondary standards, the following values represent the maximum
permissible ambient air quality levels:
(i)
Ten (10) milligrams per cubic meter (mg/m3) (ten
thousand (10,000) µg/m3) (nine (9) ppm)
maximum eight (8) hour average concentration not to be exceeded more than once
per year.
(ii) Forty (40)
mg/m3 (forty thousand (40,000)
µg/m3) (thirty-five (35) ppm) maximum one (1)
hour average concentration not to be exceeded more than once per
year.
(B) CO values may
be converted to ppm using the conversion factor one thousand one hundred
forty-five (1,145) µg/m3 = one (1)
ppm.
(4) Ozone
(O3) requirements are as follows:
(A) For the one (1) hour ozone standards, the
level of the one (1) hour primary and secondary ambient air quality standards
for ozone measured by a reference method based on 40 CFR 50, Appendix D* and
designated in accordance with 40 CFR 53 * is twelve-hundredths (0.12) ppm (two
hundred thirty-five (235) µg/m3). The standard
is attained when the expected number of days per calendar year with maximum
hourly average concentrations above twelve-hundredths (0.12) ppm (two hundred
thirty-five (235) µg/m3) is equal to or less
than one (1) as determined by 40 CFR 50, Appendix H*.
(B) For the eight (8) hour ozone standards,
the:
(i) level of the eight (8) hour primary
and secondary ambient air quality standards for ozone, measured by a reference
method based on 40 CFR 50, Appendix D*, as amended by 80 FR 65453, and
designated in accordance with 40 CFR 53 *, as amended by 80 FR 65460, is
seventy-thousandths (0.070) ppm, daily maximum eight (8) hour average; and
(ii) eight (8) hour primary and
secondary ozone ambient air quality standards are met at an ambient air quality
monitoring site when the three (3) year average of the annual fourth highest
daily maximum eight (8) hour average ozone concentration is less than or equal
to seventy-thousandths (0.070) ppm as determined in accordance with 40 CFR 50,
Appendix U*, as added by 80 FR 65458.
(C) O3 values may be
converted to ppm using the conversion factor one thousand nine hundred
sixty-five (1,965) µg/m3 = 1.0 ppm.
(5) Nitrogen dioxide
(NO2) requirements are as follows:
(A) For the primary one (1) hour ambient air
quality standard, the maximum permissible ambient air quality level is one
hundred (100) ppb, one (1) hour average concentration, measured in the ambient
air as NO2. The one (1) hour standard is attained when
the three (3) year average of the annual ninety-eighth percentile of the daily
maximum one (1) hour average concentration is less than or equal to one hundred
(100) ppb, as determined in accordance with 40 CFR 50, Appendix S*.
(B) For the annual primary standard, the
following value represents the maximum permissible ambient air quality level:
one hundred (100) µg/m3 (fifty-three
thousandths (0.053) ppm) annual average concentration in a calendar year. The
annual primary standard is attained when the annual average concentration in a
calendar year is less than or equal to fifty-three (53) ppb, as determined in
accordance with 40 CFR 50, Appendix S* for the annual standard.
(C) For the annual secondary standard, the
following value represents the maximum permissible ambient air quality level:
one hundred (100) µg/m3 (fifty-three
thousandths (0.053) ppm) annual arithmetic mean concentration in a calendar
year. The secondary standard is attained when the annual arithmetic mean
concentration in a calendar year is less than or equal to fifty-three
thousandths (0.053) ppm, rounded to three (3) decimal places (fractional parts
equal to or greater than five ten-thousandths (0.0005) ppm must be rounded up).
To demonstrate attainment, an annual mean must be based upon hourly data that
are at least seventy-five percent (75%) complete or upon data derived from
manual methods that are at least seventy-five percent (75%) complete for the
scheduled sampling days in each calendar quarter.
(D) NO2 values may be
converted to ppm using the conversion factor one thousand eight hundred eighty
(1,880) µg/m3 = one (1) ppm.
(E) The levels of the standards must be
measured by:
(i) a reference based on 40 CFR
50, Appendix F*; or
(ii) an
equivalent method designated in accordance with 40 CFR 53 *.
(6) Pb: For primary and
secondary standards, the following value represents the maximum permissible
ambient air quality level: fifteen-hundredths (0.15)
µg/m3, arithmetic mean concentration over a
three (3) month period. The standards are attained when the maximum arithmetic
three (3) month mean concentration for a three (3) year period is less than or
equal to fifteenth-hundredths (0.15) µg/m3, as
determined in accordance with 40 CFR 50, Appendix R* and measured in the
ambient air as Pb by either:
(A) a reference
method based on 40 CFR 50, Appendix G*, and designated in accordance with 40
CFR 53 *; or
(B) an equivalent
method designated in accordance with 40 CFR 53 *.
(7) PM10: For primary
and secondary standards, the maximum permissible ambient air quality level is
one hundred fifty (150) µg/m3 maximum
twenty-four (24) hour average concentration. The standards are attained when
the expected number of days per calendar year with a twenty-four (24) hour
average concentration above one hundred fifty (150)
µg/m3, as determined in accordance with 40 CFR
50, Appendix K,* is equal to or less than one (1).
(8) PM2.5 requirements
are as follows:
(A) For the primary annual
standard, the following value represents the maximum permissible ambient air
quality level: twelve (12) micrograms per cubic meter
(µg/m3) annual arithmetic mean concentration.
The standard is attained when the annual arithmetic mean concentration is less
than or equal to twelve (12) µg/m3, as
determined in accordance with 40 CFR 50, Appendix N*, and measured in the
ambient air as PM2.5 by either:
(i) a reference method based on 40 CFR 50,
Appendix L*, and designated in accordance with 40 CFR 53 *; or
(ii) an equivalent method designated in
accordance with 40 CFR 53 *.
(B) For the secondary annual standard, the
following value represents the maximum permissible ambient air quality level:
fifteen (15) micrograms per cubic meter
(µg/m3) annual arithmetic mean concentration.
The standard is attained when the annual arithmetic mean concentration is less
than or equal to fifteen (15) µg/m3, as
determined in accordance with 40 CFR 50, Appendix N*, and measured in the
ambient air as PM2.5 by either:
(i) a reference method based on 40 CFR 50,
Appendix L*, and designated in accordance with 40 CFR 53 *; or
(ii) an equivalent method designated in
accordance with 40 CFR 53 *.
(C) For the primary and secondary 24-hour
standard, the following value represents the maximum permissible ambient air
quality level: thirty-five (35) µg/m3
twenty-four (24) hour average concentration. The standards are attained when
the ninety-eighth percentile twenty-four (24) hour concentration is less than
or equal to thirty-five (35) micrograms per cubic meter
(µg/m3), as determined in accordance with 40
CFR 50, Appendix N*, and measured in the ambient air as
PM2.5 by either:
(i) a
reference method based on 40 CFR 50, Appendix L*, and designated in accordance
of 40 CFR 53 *; or
(ii) an
equivalent method designated in accordance with 40 CFR 53 *.
*These documents are incorporated by reference. Copies may be
obtained from the Government Publishing Office, www.gpo.gov, or are available for review at the
Indiana Department of Environmental Management, Office of Legal Counsel,
Indiana Government Center North, 100 North Senate Avenue, Thirteenth Floor,
Indianapolis, Indiana 46204.