35 Ill. Adm. Code 217.850
Emissions Monitoring
Section 217
Section 217.850 Emissions
Monitoring
a) The owner or operator of an emission reduction source shall
install, calibrate, maintain, and operate during the control period on each NO
x
emission unit at the source subject to the NO
x
emission cap a
continuous emission monitoring system (CEMS), or an alternative approved by the
Agency and included in a federally enforceable permit condition, for measuring
NO
x
emissions to the atmosphere.
b) The CEMS shall be operated and data recorded during all
periods of operation of the emission unit at the source during the control
period, except for periods of CEMS breakdowns and repairs as provided in
subsection (e) of this Section.
c) CEMS quality assurance data must be recorded during
calibration checks and zero and span adjustments.
d) The 1-hour average NO
x
emissions measured by the CEMS
shall be:
1) Expressed in lbs/hr or in lbs/mmbtu and heat input;
2) Calculated using the data points required under 40 CFR 60.13,
as incorporated by reference in Section 217.104 of this Subpart; and
3) Calculated using at least two data points separated by a
minimum of 15 minutes (where the unit operates for more than one quarter of an
hour) if data are unavailable as a result of the performance of calibration,
quality assurance, or preventive maintenance activities.
e) The procedures under 40 CFR 60.13, as incorporated by
reference in Section 217.104 of this Subpart, shall be followed for
installation, evaluation, and operation of each CEMS.
f) For monitoring systems measuring NO
x
in lbs/hr, if
NO
x
emission data are not obtained because of CEMS breakdown,
repairs, calibration checks, or zero and span adjustments, NO
x
emission data shall be obtained by using the data substitution procedures
contained in 40 CFR 75, subpart D, incorporated by reference in Section 217.104
of this Part.
g) For monitoring systems measuring NO
x
in lbs/mmbtu,
if NO
x
emission data are not obtained because of CEMS breakdown,
repairs, calibration checks, or zero and span adjustments, NO
x
emission data shall be obtained by using the rolling hourly average of emission
data recorded for the previous 30 day period of operation if the data capture
for such period is 95% or greater and the period of missing data is equal to or
less than 24 consecutive hours. If the data capture for such previous 30 day
period is less than 95% or the period of missing data is greater than 24
consecutive hours, the data shall be obtained by using the highest hourly
average recorded during the previous 30 days of operation.
h) The CEMS shall be subject to the quality assurance procedures
and requirements of 40 CFR 60, Appendix F, incorporated by reference in Section
217.104 of this Part.