17.8.1505 PERFORMANCE CRITERIA AND EVALUATION FACTORS FOR MONITORING DESIGN
(1) The owner or operator shall design the monitoring to meet the following performance criteria:
(a) specifications that provide for obtaining data that are representative of the emissions or parameters being monitored (such as detector location and installation specifications, if applicable) .
(b) for new or modified monitoring equipment, verification procedures to confirm the operational status of the monitoring prior to the date by which the owner or operator must conduct monitoring under this subchapter as specified in ARM 17.8.1511(1) . The owner or operator shall consider the monitoring equipment manufacturer's requirements or recommendations for installation, calibration, and start-up operation.
(c) quality assurance and control practices that are adequate to ensure the continuing validity of the data. The owner or operator shall consider manufacturer recommendations or requirements applicable to the monitoring in developing appropriate quality assurance and control practices.
(d) specifications for the frequency of conducting the monitoring, the data collection procedures that will be used (for example, computerized data acquisition and handling, alarm sensor, or manual log entries based on gauge readings) , and, if applicable, the period over which discrete data points will be averaged for the purpose of determining whether an excursion or exceedance has occurred.
(i) At a minimum, the owner or operator shall design the period over which data are obtained and, if applicable, averaged consistent with the characteristics and typical variability of the pollutant-specific emissions unit (including the control device and associated capture system) . Such intervals shall be commensurate with the time period over which a change in control device performance that would require actions by the owner or operator to return operations within normal ranges or designated conditions is likely to be observed.
(ii) For all pollutant-specific emissions units with the potential to emit, calculated including the effect of control devices, the applicable regulated air pollutant in an amount equal to or greater than 100% of the amount, in tons per year, required for a source to be classified as a major source, for each parameter monitored, the owner or operator shall collect four or more data values equally spaced over each hour and average the values, as applicable, over the applicable averaging period as determined in accordance with (1) (d) (i) above. The department may approve a reduced data collection frequency, if appropriate, based on information presented by the owner or operator concerning the data collection mechanisms available for a particular parameter for the particular pollutant-specific emissions unit (for example, integrated raw material or fuel analysis data, noninstrumental measurement of waste feed rate or visible emissions, use of a portable analyzer or an alarm sensor) .
(iii) For other pollutant-specific emissions units, the frequency of data collection may be less than the frequency specified in (1) (d) (ii) above, but the monitoring shall include some data collection at least once per 24-hour period (for example, a daily inspection of a carbon adsorber operation in conjunction with a weekly or monthly check of emissions with a portable analyzer) .
(2) In designing monitoring to meet the requirements in ARM 17.8.1504 and (1) above, the owner or operator shall take into account site-specific factors including the applicability of existing monitoring equipment and procedures, the ability of the monitoring to account for process and control device operational variability, the reliability and latitude built into the control technology, and the level of actual emissions relative to the compliance limitation.