James A. Jahnke - Continuous Emission Monitoring

Code of Federal Regulation citations are given in the format: (Title) CFR (Part). For example, 40 CFR 60 refers to the part of the code where the New Source Performance Standards (NSPS) are found. Performance specification test procedures for CEM systems are found in 40 CFR 60 Appendix B(U.S. EPA 2020c). Federal Register citations are given in the format: (Volume No.) FR (Page No.) (Date). As another example, the final performance specification test procedures 1–4 were published in the Federal Register in 1975 at 40 FR 46240 10/ 6/75. CFR publications can be found on http://www.ecfr.gov. Federal Register publications can be found on http://www.govinfo.gov/app/collection/fr. Federal Register publications can be useful by providing a background behind decisions that went into a final rule. Preambles to final rules include EPA’s responses to comments submitted on the proposed rule on which the final rule is based. Most of the rules do not stand alone and refer to other rules, test methods, monitoring specifications, and quality assurance requirements in other subparts and/or appendices of the Code of Federal Regulations.

Once promulgated, implementing rules may be amended or superseded by subsequent rules. This can create some confusion, particularly when rules overlap, as has been the case with the acid rain rules of 40 CFR 75 and the New Source Performance Standards of 40 CFR 60. Because the source‐specific standards are written at different times by different people, the formats, terminology, and specifications are sometimes inconsistent between the different standards. Although there are periodic attempts to harmonize the rules, inconsistencies often remain.

U.S. EPA regulations concerning stationary sources are found under Title 40 Subchapter C of the Code. Newly constructed sources are required to meet New Source Performance Standards (NSPS), which are given in Part 60 of Title 40 (expressed as 40 CFR 60). Each source category, such as the electric utilities, municipal incinerators, or cement plants, is assigned a Subpart letter (Subpart Da, Eb, and F, respectively) by which it is referred to in the CFR (U.S. EPA 2020a).

The rules prepared by this office affect newly constructed sources. A “new source” is defined as one constructed after the date the rules are first proposed in the Federal Register. An “existing source” is a source constructed before that date. Rules for existing sources are given by the individual states, usually in facility operating permits, with federal guidance and approval. The Part 60 Subparts address primarily new sources, but also include subparts that provide guidance to the states to develop rules for existing sources. When meeting the federal guidance requirements, the rules for specific source categories can be incorporated into the State Implementation Plan (SIP) (U.S. EPA 2020b). Source categories required to install CEM systems under NSPS are given in Table 2‐1.

Figure 2‐3 U.S. Rulemaking requiring CEM systems.

Table 2‐1shows the depth of CEM applications in U.S. industry and power production, but it should also be viewed as a guide to the Part 60 Subparts. The table gives applicability dates that distinguish “existing” sources from “new” and modified or reconstructed sources. The table lists those source categories required to monitor the concentration of gaseous pollutants, flue gas opacity, and/or particulate matter (PM). The table also lists the types of operational units on which a CEM system is to be installed. For example, Subpart BB for Kraft pulp mills may require monitoring on a number of devices, such as the recovery furnace, lime kiln, and digester contained within the plant. Sources such as the electric utilities or municipal waste combustors may have multiple boilers or combustors, all of which may require monitoring.

Note that most of the “effective dates” are old, and one might consider that “new” sources first affected by this program are now “old.” When Part 60 source requirements prove to be inadequate, new subparts are added to address newer “new” sources. This is the case for Subparts D and Da for electric utilities, Subparts Ea and Eb for municipal waste combustors, and Subparts J and Ja for petroleum refineries. The newer rules become more proscriptive and often require the installation of CEM systems not required in earlier subparts. Both new and existing stationary sources can be further regulated through programs such as the acid rain program of 40 CFR 75 and the air toxics program of 40 CFR 63, in addition to state permit requirements. Each of these programs can impose additional monitoring requirements.

TABLE 2‐1 Summary of New Source Performance Standards (NSPS) 40 CFR 60 CEM Requirements for Sources with Effective Dates 1971–1990

Source : Data from U.S. EPA (2020b).

aNSPS applies if construction commenced after this date.