A. A source operator who is required to install and operate continuous monitoring equipment (Article I of Chapter 17.20) shall comply with the performance specifications established in this article and Article VI of Chapter 17.16.
B. Calibration Gases.
1. For nitrogen oxides monitoring systems installed on fossil-fuel fired steam generators, the pollutant gas used to prepare calibration gas mixtures (Section 2.1, Performance Specification 2) shall be nitric oxide (NO). For nitrogen oxides monitoring systems installed on nitric acid plants, the pollutant gas used to prepare calibration gas mixtures (Section 2.1, Performance Specification 2) shall be nitrogen dioxide (NO 2 ). These gases shall also be used for daily checks under paragraph 3.7 of the Arizona Testing Manual as applicable.
2. For sulfur dioxide monitoring systems installed on fossil-fuel fired steam generators or sulfuric acid plants, the pollutant gas used to prepare calibration gas mixtures (Section 2.1, Performance Specification 2) shall be sulfur dioxide (SO 2 ). Span and zero gases should be traceable to National Bureau of Standards reference gases whenever these reference gases are available. Every six months from date of manufacture, span and zero gases shall be reanalyzed by conducting triplicate analyses using the reference methods as follows:
a. For sulfur dioxide, use EPA Reference Method 6;
b. For nitrogen oxides, use EPA Reference Method 7; and
c. For carbon dioxide or oxygen, use EPA Reference Method 3.
The gases may be analyzed at less frequent intervals if longer shelf lives are guaranteed by the manufacturer.
C. Cycling Times. Cycling times include the total time a monitoring system requires to sample, analyze, and record an emission measurement.
1. Continuous monitoring systems for measuring opacity shall complete a minimum of one cycle of operation (sampling, analyzing, and data recording) for each successive ten-second period.
2. Continuous monitoring systems for measuring oxides of nitrogen, carbon dioxide, oxygen, or sulfur dioxide shall complete a minimum of one cycle of operation (sampling, analyzing, and data recording) for each successive fifteen-minute period.
D. Monitor Location. The control officer shall specify conditions such that each continuous monitoring system or monitoring device is installed in such a manner that representative measurements of emissions or process parameters (i.e., oxygen, or carbon dioxide) from the affected facility are obtained. Additional guidance for location of continuous monitoring systems to obtain representative samples are contained in the applicable performance specifications.
E. Combined Effluents. When the effluents from two or more affected facilities of similar design and operating characteristics are combined before being released to the atmosphere, the same monitoring system may be installed on the combined effluent. When the affected facilities are not of similar design and operating characteristics, or when the effluent from one affected facility is released to the atmosphere through more than one point, the control officer shall specify alternative procedures to implement the intent of these requirements.
F. Zero and Drift. Any owner, lessee, or operator of any continuous monitoring system shall record the zero and span drift in accordance with the method prescribed by the manufacturer of such instruments; shall subject the instrument(s) to the manufacturer's recommended zero and span check at least once daily unless the manufacturer has recommended adjustments at shorter intervals, in which case such recommendations shall be followed; to adjust the zero and span whenever the twenty-four-hour zero drift or twenty-four-hour calibration drift limits of the applicable performance specifications herein are exceeded;
and shall adjust continuous monitoring systems whenever the twenty-four-hour zero drift or twenty-four-hour calibration drift exceed ten percent of the emission standard.
G. Span. Instrument span shall be approximately two hundred percent of the expected instrument data display output corresponding to the emission standard for the source.
H. Alternative Procedures and Requirements. In cases where source operators wish to utilize different, but equivalent, procedures and requirements for continuous monitoring systems, the operator shall provide a description of such alternative procedures for approval by the control officer. Some examples of situations that may require alternatives follow:
1. Alternative monitoring requirements to accommodate continuous monitoring systems that require corrections for stack moisture conditions (e.g., an instrument measuring steam generator SO 2 emissions on a wet basis could be used with an instrument measuring oxygen concentration on a dry basis if acceptable methods of measuring stack moisture conditions are used to allow accurate adjustment of the measured SO 2 concentration to dry basis);
2. Alternative locations for installing continuous monitoring systems or monitoring devices when the owner or operator can demonstrate that installation at alternative locations will enable accurate and representative measurements;
3. Alternative procedures for performing calibration checks (e.g., some instruments may demonstrate superior drift characteristics that require checking at less frequent intervals).
4. Alternative monitoring requirements when the effluent from one affected facility or the combined effluent from two or more identical affected facilities is released to the atmosphere through more than one point (e.g., an extractive, gaseous monitoring system used at several points may be approved if the procedures recommended are suitable for generating accurate emission averages);
5. Alternative continuous monitoring systems that do not meet the special response requirements in Performance Specification 1, but adequately demonstrate a definite and consistent relationship between their measurements and the opacity measurements of a system complying with requirements in Performance Specification 1. Such demonstration must be performed for each affected facility.
(Ord. 1993-128 § 5 (part), 1993)