---
kind: "section"
citation: "40 C.F.R. § 63.5545"
title: "40"
number: "63.5545"
heading: "What are my monitoring installation, operation, and maintenance requirements?"
url: "https://uscodex.org/cfr/40/63.5545"
---

# §63.5545. What are my monitoring installation, operation, and maintenance requirements?

- (a) For each CMS required in this section, you must develop and make available for inspection by the permitting authority, upon request, a site-specific monitoring plan that addresses the provisions in [paragraphs (a)(1) through (3)](#a-1..a-3) of this section.
  - (1) Installation of the CMS sampling probe or other interface at a measurement location relative to each affected process unit such that the measurement is representative of control of the exhaust emissions (e.g., on or downstream of the last control device);
  - (2) Performance and equipment specifications for the sample interface, the pollutant concentration or parametric signal analyzer, and the data collection and reduction system; and
  - (3) Performance evaluation procedures and acceptance criteria (e.g., calibrations).
- (b) In your site-specific monitoring plan, you must also address the provisions in [paragraphs (b)(1) through (3)](#b-1..b-3) of this section.
  - (1) Ongoing operation and maintenance procedures in accordance with the general requirements of §§ [63.8(c)(3)](/cfr/40/63.8.md?p=c-3) and [(4)(ii)](/cfr/40/63.8.md?p=4-ii), [63.5515(b)](/cfr/40/63.5515.md?p=b), and [63.5580(c)(6)](/cfr/40/63.5580.md?p=c-6);
  - (2) Ongoing data quality assurance procedures in accordance with the general requirements of [§ 63.8(d)(2)](/cfr/40/63.8.md?p=d-2); and
  - (3) Ongoing recordkeeping and reporting procedures in accordance with the general requirements of §§ [63.10(c)](/cfr/40/63.10.md?p=c), [(e)(1)](/cfr/40/63.10.md?p=e-1), [(e)(2)(i)](/cfr/40/63.10.md?p=e-2-i) and [63.5585](/cfr/40/63.5585.md).
- (c) You must conduct a performance evaluation of each CMS in accordance with your site-specific monitoring plan.
- (d) You must operate and maintain the CMS in continuous operation according to the site-specific monitoring plan.
- (e) For each continuous emissions monitoring system (CEMS), you must meet the requirements in [paragraphs (e)(1) through (6)](#e-1..e-6) of this section.
  - (1) Each CEMS must be installed, operated, and maintained according to the applicable performance specification (PS) listed in [paragraphs (e)(1)(i) through (iv)](#e-1-i..e-1-iv) of this section:
    - (i) PS-7 of [40 CFR part 60](/cfr/40/part60.md), appendix B, for CEMS used to measure hydrogen sulfide emissions;
    - (ii) PS-8 of [40 CFR part 60](/cfr/40/part60.md), appendix B, for CEMS used to measure volatile organic compound emissions;
    - (iii) PS-9 of [40 CFR part 60](/cfr/40/part60.md), appendix B, for CEMS that use gas chromatography to measure organic HAP emissions; and
    - (iv) PS-15 of [40 CFR part 60](/cfr/40/part60.md), appendix B, for CEMS that use Fourier transform infrared spectroscopy to measure organic HAP emissions.
  - (2) You must conduct a performance evaluation of each CEMS according to the requirements in [§ 63.8](/cfr/40/63.8.md), Procedure 1 of [40 CFR part 60](/cfr/40/part60.md), appendix F, and according to the applicable performance specification listed in [paragraphs (e)(1)(i) through (iv)](#e-1-i..e-1-iv) of this section.
  - (3) As specified in [§ 63.8(c)(4)(ii)](/cfr/40/63.8.md?p=c-4-ii), each CEMS must complete a minimum of one cycle of operation (sampling, analyzing, and data recording) for each successive 15-minute period.
  - (4) The CEMS data must be reduced to operating data averages computed using valid data from at least 75 percent of the hours during the averaging period. To have a valid hour of data, you must have four or more data points equally spaced over the 1-hour period (or at least two data points during an hour when calibration, quality assurance, or maintenance activities are being performed), except as specified in [paragraph (e)(5)](#e-5) of this section.
  - (5) The CEMS data taken during periods in which the control devices are not functioning in controlling emissions, as indicated by periods of no flow for all or a portion of an affected source, must not be considered in the averages.
  - (6) Determine the daily average of all recorded readings for each operating day during the semiannual reporting period described in Table 8 to this subpart.
- (f) For each continuous parameter monitoring system (CPMS), you must meet the requirements in [paragraphs (f)(1) through (9)](#f-1..f-9) of this section.
  - (1) Satisfy all requirements of performance specifications for CPMS upon promulgation of such performance specifications.
  - (2) Satisfy all requirements of quality assurance (QA) procedures for CPMS upon promulgation of such QA procedures.
  - (3) The CPMS must complete a minimum of one cycle of operation for each successive 15-minute period.
  - (4) To calculate a valid hourly average, there must be at least four equally spaced values for that hour, excluding data collected during the periods described in [paragraph (f)(6)](#f-6) of this section.
  - (5) **Have valid hourly data for at least 75 percent of the hours during the averaging period.**
  - (6) The CPMS data taken during periods in which the control devices are not functioning in controlling emissions, as indicated by periods of no flow for all or a portion of an affected source, must not be considered in the averages.
  - (7) Calculate a daily average using all of the valid hourly averages for each operating day during the semiannual reporting period.
  - (8) **Record the results of each inspection, calibration, and validation check.**
  - (9) Except for redundant sensors, any device that is used to conduct an initial validation or accuracy audit of a CPMS must meet the accuracy requirements specified in paragraphs [(f)(9)(i)](#f-9-i) and [(ii)](#f-9-ii) of this section.
    - (i) The device must have an accuracy that is traceable to National Institute of Standards and Technology (NIST) standards.
    - (ii) The device must be at least three times as accurate as the required accuracy for the CPMS.
- (g) If flow to a control device could be intermittent, you must install, calibrate, and operate a flow indicator at the inlet or outlet of the control device to identify periods of no flow.

## Notes

### Amendments

[67 FR 40055, June 11, 2002, as amended at 70 FR 46693, Aug. 10, 2005; 85 FR 39995, July 2, 2020]

### Source

Source: 67 FR 40055, June 11, 2002, unless otherwise noted.

### Authority

Authority: 42 U.S.C. 7401 et seq.

### Source

Source: 57 FR 61992, Dec. 29, 1992, unless otherwise noted.

### Amendments

[67 FR 40055, June 11, 2002, as amended at 70 FR 46693, Aug. 10, 2005; 85 FR 39995, July 2, 2020]