(a) For each operating parameter that you are required by §63.9020(e) to monitor, you must install, operate, and maintain each CMS according to the requirements in paragraphs (a)(1) through (6) of this section.

(1) You must operate your CMS and collect data at all times the process is operating.

(2) You must collect data from at least four equally spaced periods each hour.

(3) For at least 75 percent of the operating hours in a 24-hour period, you must have valid data (as defined in your site-specific monitoring plan) for at least 4 equally spaced periods each hour.

(4) For each hour that you have valid data from at least four equally spaced periods, you must calculate the hourly average value using all valid data or, where data are collected from an automated CMS, using at least one measured value per minute if measured more frequently than once per minute.

(5) You must calculate the daily average using all of the hourly averages calculated according to paragraph (a)(4) of this section for the 24-hour period.

(6) You must record the results for each inspection, calibration, and validation check as specified in your site-specific monitoring plan.

(b) For scrubber control devices, you may request approval, in accordance with §63.8(f), to monitor parameters other than those specified in §63.9020(e). In accordance with §63.8(f), you must submit a monitoring plan to the Administrator and the plan must meet the requirements in paragraphs (a) and (b)(1) through (3) of this section. You must conduct monitoring in accordance with the plan submitted to the Administrator unless comments received from the Administrator require an alternate monitoring scheme.

(1) Identify the operating parameter to be monitored to ensure that the control or capture efficiency measured during the initial compliance test is maintained.

(2) Discuss why this parameter is appropriate for demonstrating ongoing compliance.

(3) Identify the specific monitoring procedures.

(c) For any other control device, you must ensure that the CMS is operated according to a monitoring plan submitted to the Administrator as required by §63.8(f). The monitoring plan must meet the requirements in paragraphs (a) and (c)(1) through (3) of this section. You must conduct monitoring in accordance with the plan submitted to the Administrator, as amended, unless comments received from the Administrator require an alternate monitoring scheme.

(1) Identify the operating parameter to be monitored to ensure that the control or capture efficiency measured during the initial compliance test is maintained.

(2) Discuss why this parameter is appropriate for demonstrating ongoing compliance.

(3) Identify the specific monitoring procedures.

[68 FR 19090, Apr. 17, 2003, as amended at 71 FR 17745, Apr. 7, 2006; 85 FR 20868, Apr. 15, 2020]