Air Emissions Monitoring for Permits

Federal regulations require each major source of air pollutant emissions to obtain an "operating permit" that consolidates all of the air pollution control requirements into a single, comprehensive document covering all aspects of the source's air pollution activities. Air pollution permits are also required for businesses that build new pollution sources or make significant changes to existing pollution sources. These are sometimes referred to as "preconstruction" or "new source review" permits. Operating permits document how air pollution sources will demonstrate compliance with emission limits and with other "applicable requirements" such as work practices (e.g., periodically watering a dirt road to prevent dust emissions). Operating permits also document how air pollution sources will monitor, either periodically or continuously, their compliance with emission limits and all other applicable requirements on an on-going basis. Thus, monitoring requirements are a very important aspect of the operating permit because:

  • Monitoring provides facility owners/operators with information they can use to: (a) self-assess their performance relative to meeting air pollution requirements, and (b) assist them in determining the proper corrective actions, when necessary, and
  • Monitoring provides the basis for most on-going compliance demonstrations and provides documentation to support the compliance certification required of the source owners/operators.

In short, the role of monitoring is to assure compliance with the operating permit conditions and air pollution regulations.

Title V Operating Permits

The Clean Air Act Amendments of 1990 added Title V to the statute, thus establishing the air permitting program for the federal government. Operating permits are legally enforceable documents that permitting agencies issue to air pollution sources. These operating permits are sometimes called part 70 permits because the Federal regulations that establish minimum standards for State permit programs are found in the Code of Federal Regulations at 40 CFR part 70. Most title V permits are issued by State and local permitting authorities. However, the U.S. EPA also issues title V permits in Indian and tribal lands and in other situations, as needed. EPA-issued permits are called part 71 permits because the regulations for these permit programs are found in the Code of Federal Regulations at 40 CFR part 71. Title V permits are federally enforceable which means that EPA and the public can enforce the terms of the permit, along with the State or local permitting authorities. EPA has a website for the title V operating permits program (see link below). Many States, Locals, Tribes, and Regions have made their final permits and permit application materials available on-line (see link below in "State / Local / Tribal Permits Program" section).

EPA Title V Air Permits

Title V Monitoring Requirements

Part 70 identifies the standard permit requirements that each permit shall include. The monitoring and related recordkeeping and reporting requirements are identified in 70.6 (a)(3) which states, in part, that "each permit shall contain the following requirements with respect to monitoring:

A. All monitoring and analysis procedures or test methods required under applicable monitoring and testing requirements, including part 64 [Compliance Assurance Monitoring] ...;

B. Where the applicable requirement does not require periodic testing or instrumental or noninstrumental monitoring (which may consist of recordkeeping designed to serve as monitoring), periodic monitoring sufficient to yield reliable data from the relevant time period that are representative of the source's compliance with the permit..."

Furthermore, the compliance requirements [70.6(c)(1)] state, in part that: "all part 70 permits shall contain the following elements with respect to compliance:

  1. Consistent with paragraph (a)(3) of this section, compliance certification, testing, monitoring, and reporting requirements sufficient to assure compliance with the terms and conditions of the permit..."

Examples of Title V Monitoring

EPA has prepared a technical document that provides some examples of title V monitoring for emission sources without add-on controls.

Title V Technical Monitoring Examples (54 pp, 98 K, About PDF)

Compliance Assurance Monitoring

The EPA promulgated regulations for Compliance Assurance Monitoring (CAM) in 1997; the regulations are codified in 40 CFR part 64. The CAM rule applies to major sources required to have a title V permit; it applies to major emission units at the source that rely on add-on pollution control devices to achieve compliance. The CAM rule requires owners/operators to submit specific information on how monitoring will be conducted (the CAM "Submittal", sometimes referred to as the "CAM Plan"), including a justification for the proposed monitoring [64.4]. The CAM rule also identifies the required permit conditions, including:

  1. the approved monitoring approach, including the indicator(s) of performance to be monitored;
  2. the indicator range such that operation within the range provides a reasonable assurance of compliance;
  3. specifications for the monitoring system and monitoring location to assure data representativeness;
  4. quality assurance & quality control practices to ensure continuing validity of the data; and
  5. the frequency of monitoring, and, if applicable, the data averaging period.

A Technical Guidance Document (TGD) to aid in implementation of the CAM rule has been prepared by EPA. The document further explains the CAM process, monitoring approach submittals, and CAM illustrations, and also supplies technical references for monitoring equipment and instruments. The CAM TGD contains detailed examples of CAM submittals for different combinations of pollutant specific emission units (PSEU) and add-on control devices.

More detailed information on CAM and links to the text of the CAM rule, CAM technical Reference Document and CAM submittal case studies are provided at the following link:

Compliance Assurance Monitoring

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New Source Review Permits

Air pollution permits are also required for businesses that build new pollution sources or make significant changes to existing pollution sources. These permits are sometimes referred to as "preconstruction" or "new source review" permits. These permits are required to ensure that large new emissions sources do not cause significant health or environmental threats and are well-controlled. EPA has a website for the new source review.

New Source Review (NSR) Permitting

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Innovative/Flexible Permits

In continuing to improve the permitting process, EPA has been working on ways to identify and create exemplary and innovative permits. As part of these efforts, EPA has been conducting pilot programs to work with interested companies and their permitting authorities to develop innovative/flexible permits. These innovative permits involve a wide range of industry source categories and types of emissions.

Smart permits may make use of a streamlining analysis. By design, operating permits consolidate all of the air pollution control requirements into a single, comprehensive document covering all aspects of a source's year-to-year air pollution activities. Because a source may be subject to multiple regulations, the consolidation of all requirements into a single document can result in a complex set of requirements. Furthermore, in some cases there may be multiple applicable requirements intended to achieve the same purpose, but with slightly different requirements. One of the objectives of smart permits is to "streamline" requirements; that is to include only the most stringent requirement in the permit. This situation can apply to monitoring requirements. For example, under one regulation, a facility might be required to monitor the operating temperature of a thermal oxidizer used to control Volatile Organic Compounds (VOC) emissions once per operating shift; however, under another applicable requirement established by a newer regulation, the facility might be required to monitor the temperature continuously and calculate and record the 1-hour average temperature. Continuously monitoring the temperature is a superior approach to observing the temperature only once per shift, and this would be the monitoring requirement included in the permit based on a streamlining analysis.

Innovative/flexible permits can include plant-wide applicability limits (PALs) and emission caps for a pollutant. In this case, the permit incorporates an overall emissions limit for a pollutant on a plant-wide basis (e.g., tons of volatile organic compound emissions per year). The PAL or cap is designed to maintain compliance with all applicable emission limits, but provides the facility with some flexibility in the operation of individual emissions units. When a PAL or emission cap is included in a flexible permit, the monitoring requirements are particularly important because the monitoring must be sufficient to calculate emissions to determine compliance with the PAL or emission cap.

EPA conducted a study to evaluate six of the pilot innovative permits that had been implemented; the results of this study are documented in a series of reports. The report series includes a summary report entitled "Evaluation of Implementation Experiences with Innovative Air Permits," as well as separate implementation review reports for each of the six permits evaluated. These white papers and reports are accessible via the link listed below.

Study Supporting Innovative Air Permits

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State / Local / Tribal Permit Programs

Most title V permits are issued by state / local / tribal permitting authorities. Many of these authorities have web sites that include information on their operating permit programs. Some websites provide general information about the operating permit program; other websites provide links to draft or final permits for specific facilities. The link below takes you to a website that will allow you to choose an EPA Region to check links for specific state / local / tribal permitting programs.

Clean Air Act Permitting Where You Live

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