Us Code § 7423 - Stack heights
Full text of Us Code United States Code § 7423 — Stack heights, with citation guidance and answers to common questions.
§ 7423. Stack heights
(a) Heights in excess of good engineering practice; other dispersion techniques
The degree of emission limitation required for control of any air pollutant under an applicable implementation plan under this subchapter shall not be affected in any manner by—
(1) so much of the stack height of any source as exceeds good engineering practice (as determined under regulations promulgated by the Administrator), or
(2) any other dispersion technique.
The preceding sentence shall not apply with respect to stack heights in existence before December 31, 1970, or dispersion techniques implemented before such date. In establishing an emission limitation for coal-fired steam electric generating units which are subject to the provisions of section 7418 of this title and which commenced operation before July 1, 1957, the effect of the entire stack height of stacks for which a construction contract was awarded before February 8, 1974, may be taken into account.
(b) Dispersion technique
For the purpose of this section, the term "dispersion technique" includes any intermittent or supplemental control of air pollutants varying with atmospheric conditions.
(c) Regulations; good engineering practice
Not later than six months after August 7, 1977, the Administrator, shall after notice and opportunity for public hearing, promulgate regulations to carry out this section. For purposes of this section, good engineering practice means, with respect to stack heights, the height necessary to insure that emissions from the stack do not result in excessive concentrations of any air pollutant in the immediate vicinity of the source as a result of atmospheric downwash, eddies and wakes which may be created by the source itself, nearby structures or nearby terrain obstacles (as determined by the Administrator). For purposes of this section such height shall not exceed two and a half times the height of such source unless the owner or operator of the source demonstrates, after notice and opportunity for public hearing, to the satisfaction of the Administrator, that a greater height is necessary as provided under the preceding sentence. In no event may the Administrator prohibit any increase in any stack height or restrict in any manner the stack height of any source.
(July 14, 1955, ch. 360, title I, §123, as added Pub. L. 95–95, title I, §121, Aug. 7, 1977, 91 Stat. 721.)
Statutory Notes and Related Subsidiaries
Effective Date
Section effective Aug. 7, 1977, except as otherwise expressly provided, see section 406(d) of Pub. L. 95–95, set out as an Effective Date of 1977 Amendment note under section 7401 of this title.
About This Section
42 U.S.C. § 7423 is part of Title 42 of the United States Code. The United States Code is the official codification of federal statutes maintained by the Office of the Law Revision Counsel of the U.S. House of Representatives. Congress amends the Code through new public laws, which are eventually incorporated into the relevant title.
This section may be cited in legal writing as 42 U.S.C. § 7423. For the most current official text, including any recent amendments, use the official source links below. Do not rely on this page as the sole authority for legal citation or litigation.
How to Read This Statute
Statutes are organized by title, chapter, section, and subsection. Pay attention to words like "shall," "may," "and," and "or," because they determine whether a requirement is mandatory or permissive and whether multiple conditions must all be met. Historical notes and amendments often appear at the end of a section.
Using This Page
This page is intended for research and educational use. Lawyers, students, journalists, and compliance professionals can use it as a starting point, but should always verify the current text through an official government source before relying on it for legal advice, filings, or compliance decisions.