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.

(Source:  Added at 25 Ill. Reg. 5914, effective April 17, 2001)