Collapse to view only § 7476. Other pollutants
- § 7470. Congressional declaration of purpose
- § 7471. Plan requirements
- § 7472. Initial classifications
- § 7473. Increments and ceilings
- § 7474. Area redesignation
- § 7475. Preconstruction requirements
- § 7476. Other pollutants
- § 7477. Enforcement
- § 7478. Period before plan approval
- § 7479. Definitions
§ 7470. Congressional declaration of purpose
The purposes of this part are as follows:
(1) to protect public health and welfare from any actual or potential adverse effect which in the Administrator’s judgment may reasonably be anticipate 1
1 So in original. Probably should be “anticipated”.
to occur from air pollution or from exposures to pollutants in other media, which pollutants originate as emissions to the ambient air) 22 So in original. Section was enacted without an opening parenthesis.
, notwithstanding attainment and maintenance of all national ambient air quality standards;(2) to preserve, protect, and enhance the air quality in national parks, national wilderness areas, national monuments, national seashores, and other areas of special national or regional natural, recreational, scenic, or historic value;
(3) to insure that economic growth will occur in a manner consistent with the preservation of existing clean air resources;
(4) to assure that emissions from any source in any State will not interfere with any portion of the applicable implementation plan to prevent significant deterioration of air quality for any other State; and
(5) to assure that any decision to permit increased air pollution in any area to which this section applies is made only after careful evaluation of all the consequences of such a decision and after adequate procedural opportunities for informed public participation in the decisionmaking process.
(July 14, 1955, ch. 360, title I, § 160, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 731.)
§ 7471. Plan requirements
In accordance with the policy of section 7401(b)(1) of this title, each applicable implementation plan shall contain emission limitations and such other measures as may be necessary, as determined under regulations promulgated under this part, to prevent significant deterioration of air quality in each region (or portion thereof) designated pursuant to section 7407 of this title as attainment or unclassifiable.
(July 14, 1955, ch. 360, title I, § 161, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 731; amended Pub. L. 101–549, title I, § 110(1), Nov. 15, 1990, 104 Stat. 2470.)
§ 7472. Initial classifications
(a) Areas designated as class I
Upon the enactment of this part, all—
(1) international parks,
(2) national wilderness areas which exceed 5,000 acres in size,
(3) national memorial parks which exceed 5,000 acres in size, and
(4) national parks which exceed six thousand acres in size,
and which are in existence on August 7, 1977, shall be class I areas and may not be redesignated. All areas which were redesignated as class I under regulations promulgated before August 7, 1977, shall be class I areas which may be redesignated as provided in this part. The extent of the areas designated as Class I under this section shall conform to any changes in the boundaries of such areas which have occurred subsequent to August 7, 1977, or which may occur subsequent to November 15, 1990.
(b) Areas designated as class II
(July 14, 1955, ch. 360, title I, § 162, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 731; amended Pub. L. 95–190, § 14(a)(40), Nov. 16, 1977, 91 Stat. 1401; Pub. L. 101–549, title I, §§ 108(m), 110(2), Nov. 15, 1990, 104 Stat. 2469, 2470.)
§ 7473. Increments and ceilings
(a) Sulfur oxide and particulate matter; requirement that maximum allowable increases and maximum allowable concentrations not be exceeded
(b) Maximum allowable increases in concentrations over baseline concentrations
(1) For any class I area, the maximum allowable increase in concentrations of sulfur dioxide and particulate matter over the baseline concentration of such pollutants shall not exceed the following amounts:
Pollutant | Maximum allowable increase (in micrograms per cubic meter) |
|---|---|
Particulate matter: | |
Annual geometric mean | 5 |
Twenty-four-hour maximum | 10 |
Sulfur dioxide: | |
Annual arithmetic mean | 2 |
Twenty-four-hour maximum | 5 |
Three-hour maximum | 25 |
(2) For any class II area, the maximum allowable increase in concentrations of sulfur dioxide and particulate matter over the baseline concentration of such pollutants shall not exceed the following amounts:
Pollutant | Maximum allowable increase (in micrograms per cubic meter) |
|---|---|
Particulate matter: | |
Annual geometric mean | 19 |
Twenty-four-hour maximum | 37 |
Sulfur dioxide: | |
Annual arithmetic mean | 20 |
Twenty-four-hour maximum | 91 |
Three-hour maximum | 512 |
(3) For any class III area, the maximum allowable increase in concentrations of sulfur dioxide and particulate matter over the baseline concentration of such pollutants shall not exceed the following amounts:
Pollutant | Maximum allowable increase (in micrograms per cubic meter) |
|---|---|
Particulate matter: | |
Annual geometric mean | 37 |
Twenty-four-hour maximum | 75 |
Sulfur dioxide: | |
Annual arithmetic mean | 40 |
Twenty-four-hour maximum | 182 |
Three-hour maximum | 700 |
(4) The maximum allowable concentration of any air pollutant in any area to which this part applies shall not exceed a concentration for such pollutant for each period of exposure equal to—
(A) the concentration permitted under the national secondary ambient air quality standard, or
(B) the concentration permitted under the national primary ambient air quality standard,
whichever concentration is lowest for such pollutant for such period of exposure.
(c) Orders or rules for determining compliance with maximum allowable increases in ambient concentrations of air pollutants
(1) In the case of any State which has a plan approved by the Administrator for purposes of carrying out this part, the Governor of such State may, after notice and opportunity for public hearing, issue orders or promulgate rules providing that for purposes of determining compliance with the maximum allowable increases in ambient concentrations of an air pollutant, the following concentrations of such pollutant shall not be taken into account:
(A) concentrations of such pollutant attributable to the increase in emissions from stationary sources which have converted from the use of petroleum products, or natural gas, or both, by reason of an order which is in effect under the provisions of sections 792(a) and (b) of title 15 (or any subsequent legislation which supersedes such provisions) over the emissions from such sources before the effective date of such order.1
1 So in original. The period probably should be a comma.
(B) the concentrations of such pollutant attributable to the increase in emissions from stationary sources which have converted from using natural gas by reason of a natural gas curtailment pursuant to a natural gas curtailment plan in effect pursuant to the Federal Power Act [16 U.S.C. 791a et seq.] over the emissions from such sources before the effective date of such plan,
(C) concentrations of particulate matter attributable to the increase in emissions from construction or other temporary emission-related activities, and
(D) the increase in concentrations attributable to new sources outside the United States over the concentrations attributable to existing sources which are included in the baseline concentration determined in accordance with section 7479(4) of this title.
(2) No action taken with respect to a source under paragraph (1)(A) or (1)(B) shall apply more than five years after the effective date of the order referred to in paragraph (1)(A) or the plan referred to in paragraph (1)(B), whichever is applicable. If both such order and plan are applicable, no such action shall apply more than five years after the later of such effective dates.
(3) No action under this subsection shall take effect unless the Governor submits the order or rule providing for such exclusion to the Administrator and the Administrator determines that such order or rule is in compliance with the provisions of this subsection.
(July 14, 1955, ch. 360, title I, § 163, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 732; amended Pub. L. 95–190, § 14(a)(41), Nov. 16, 1977, 91 Stat. 1401.)
§ 7474. Area redesignation
(a) Authority of States to redesignate areas
Except as otherwise provided under subsection (c), a State may redesignate such areas as it deems appropriate as class I areas. The following areas may be redesignated only as class I or II:
(1) an area which exceeds ten thousand acres in size and is a national monument, a national primitive area, a national preserve, a national recreation area, a national wild and scenic river, a national wildlife refuge, a national lakeshore or seashore, and
(2) a national park or national wilderness area established after August 7, 1977, which exceeds ten thousand acres in size.
The extent of the areas referred to in paragraph 1
1 So in original. Probably should be “paragraphs”.
(1) and (2) shall conform to any changes in the boundaries of such areas which have occurred subsequent to August 7, 1977, or which may occur subsequent to November 15, 1990. Any area (other than an area referred to in paragraph (1) or (2) or an area established as class I under the first sentence of section 7472(a) of this title) may be redesignated by the State as class III if—(A) such redesignation has been specifically approved by the Governor of the State, after consultation with the appropriate Committees of the legislature if it is in session or with the leadership of the legislature if it is not in session (unless State law provides that such redesignation must be specifically approved by State legislation) and if general purpose units of local government representing a majority of the residents of the area so redesignated enact legislation (including for such units of local government resolutions where appropriate) concurring in the State’s redesignation;
(B) such redesignation will not cause, or contribute to, concentrations of any air pollutant which exceed any maximum allowable increase or maximum allowable concentration permitted under the classification of any other area; and
(C) such redesignation otherwise meets the requirements of this part.
Subparagraph (A) of this paragraph shall not apply to area redesignations by Indian tribes.
(b) Notice and hearing; notice to Federal land manager; written comments and recommendations; regulations; disapproval of redesignation
(1)
(A) Prior to redesignation of any area under this part, notice shall be afforded and public hearings shall be conducted in areas proposed to be redesignated and in areas which may be affected by the proposed redesignation. Prior to any such public hearing a satisfactory description and analysis of the health, environmental, economic, social, and energy effects of the proposed redesignation shall be prepared and made available for public inspection and prior to any such redesignation, the description and analysis of such effects shall be reviewed and examined by the redesignating authorities.
(B) Prior to the issuance of notice under subparagraph (A) respecting the redesignation of any area under this subsection, if such area includes any Federal lands, the State shall provide written notice to the appropriate Federal land manager and afford adequate opportunity (but not in excess of 60 days) to confer with the State respecting the intended notice of redesignation and to submit written comments and recommendations with respect to such intended notice of redesignation. In redesignating any area under this section with respect to which any Federal land manager has submitted written comments and recommendations, the State shall publish a list of any inconsistency between such redesignation and such recommendations and an explanation of such inconsistency (together with the reasons for making such redesignation against the recommendation of the Federal land manager).
(C) The Administrator shall promulgate regulations not later than six months after August 7, 1977, to assure, insofar as practicable, that prior to any public hearing on redesignation of any area, there shall be available for public inspection any specific plans for any new or modified major emitting facility which may be permitted to be constructed and operated only if the area in question is designated or redesignated as class III.
(2) The Administrator may disapprove the redesignation of any area only if he finds, after notice and opportunity for public hearing, that such redesignation does not meet the procedural requirements of this section or is inconsistent with the requirements of section 7472(a) of this title or of subsection (a) of this section. If any such disapproval occurs, the classification of the area shall be that which was in effect prior to the redesignation which was disapproved.
(c) Indian reservations
(d) Review of national monuments, primitive areas, and national preserves
(e) Resolution of disputes between State and Indian tribes
(July 14, 1955, ch. 360, title I, § 164, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 733; amended Pub. L. 95–190, § 14(a)(42), (43), Nov. 16, 1977, 91 Stat. 1402; Pub. L. 101–549, title I, § 108(n), Nov. 15, 1990, 104 Stat. 2469.)
§ 7475. Preconstruction requirements
(a) Major emitting facilities on which construction is commencedNo major emitting facility on which construction is commenced after August 7, 1977, may be constructed in any area to which this part applies unless—
(1) a permit has been issued for such proposed facility in accordance with this part setting forth emission limitations for such facility which conform to the requirements of this part;
(2) the proposed permit has been subject to a review in accordance with this section, the required analysis has been conducted in accordance with regulations promulgated by the Administrator, and a public hearing has been held with opportunity for interested persons including representatives of the Administrator to appear and submit written or oral presentations on the air quality impact of such source, alternatives thereto, control technology requirements, and other appropriate considerations;
(3) the owner or operator of such facility demonstrates, as required pursuant to section 7410(j) of this title, that emissions from construction or operation of such facility will not cause, or contribute to, air pollution in excess of any (A) maximum allowable increase or maximum allowable concentration for any pollutant in any area to which this part applies more than one time per year, (B) national ambient air quality standard in any air quality control region, or (C) any other applicable emission standard or standard of performance under this chapter;
(4) the proposed facility is subject to the best available control technology for each pollutant subject to regulation under this chapter emitted from, or which results from, such facility;
(5) the provisions of subsection (d) with respect to protection of class I areas have been complied with for such facility;
(6) there has been an analysis of any air quality impacts projected for the area as a result of growth associated with such facility;
(7) the person who owns or operates, or proposes to own or operate, a major emitting facility for which a permit is required under this part agrees to conduct such monitoring as may be necessary to determine the effect which emissions from any such facility may have, or is having, on air quality in any area which may be affected by emissions from such source; and
(8) in the case of a source which proposes to construct in a class III area, emissions from which would cause or contribute to exceeding the maximum allowable increments applicable in a class II area and where no standard under section 7411 of this title has been promulgated subsequent to August 7, 1977, for such source category, the Administrator has approved the determination of best available technology as set forth in the permit.
(b) Exception
(c) Permit applications
(d) Action taken on permit applications; notice; adverse impact on air quality related values; variance; emission limitations
(1) Each State shall transmit to the Administrator a copy of each permit application relating to a major emitting facility received by such State and provide notice to the Administrator of every action related to the consideration of such permit.
(2)
(A) The Administrator shall provide notice of the permit application to the Federal Land Manager and the Federal official charged with direct responsibility for management of any lands within a class I area which may be affected by emissions from the proposed facility.
(B) The Federal Land Manager and the Federal official charged with direct responsibility for management of such lands shall have an affirmative responsibility to protect the air quality related values (including visibility) of any such lands within a class I area and to consider, in consultation with the Administrator, whether a proposed major emitting facility will have an adverse impact on such values.
(C)
(i) In any case where the Federal official charged with direct responsibility for management of any lands within a class I area or the Federal Land Manager of such lands, or the Administrator, or the Governor of an adjacent State containing such a class I area files a notice alleging that emissions from a proposed major emitting facility may cause or contribute to a change in the air quality in such area and identifying the potential adverse impact of such change, a permit shall not be issued unless the owner or operator of such facility demonstrates that emissions of particulate matter and sulfur dioxide will not cause or contribute to concentrations which exceed the maximum allowable increases for a class I area.
(ii) In any case where the Federal Land Manager demonstrates to the satisfaction of the State that the emissions from such facility will have an adverse impact on the air quality-related values (including visibility) of such lands, notwithstanding the fact that the change in air quality resulting from emissions from such facility will not cause or contribute to concentrations which exceed the maximum allowable increases for a class I area, a permit shall not be issued.
(iii) In any case where the owner or operator of such facility demonstrates to the satisfaction of the Federal Land Manager, and the Federal Land Manager so certifies, that the emissions from such facility will have no adverse impact on the air quality-related values of such lands (including visibility), notwithstanding the fact that the change in air quality resulting from emissions from such facility will cause or contribute to concentrations which exceed the maximum allowable increases for class I areas, the State may issue a permit.
(iv) In the case of a permit issued pursuant to clause (iii), such facility shall comply with such emission limitations under such permit as may be necessary to assure that emissions of sulfur oxides and particulates from such facility will not cause or contribute to concentrations of such pollutant which exceed the following maximum allowable increases over the baseline concentration for such pollutants:
Maximum allowable increase (in micrograms per cubic meter) | |
|---|---|
Particulate matter: | |
(D)
(i) In any case where the owner or operator of a proposed major emitting facility who has been denied a certification under subparagraph (C)(iii) demonstrates to the satisfaction of the Governor, after notice and public hearing, and the Governor finds, that the facility cannot be constructed by reason of any maximum allowable increase for sulfur dioxide for periods of twenty-four hours or less applicable to any class I area and, in the case of Federal mandatory class I areas, that a variance under this clause will not adversely affect the air quality related values of the area (including visibility), the Governor, after consideration of the Federal Land Manager’s recommendation (if any) and subject to his concurrence, may grant a variance from such maximum allowable increase. If such variance is granted, a permit may be issued to such source pursuant to the requirements of this subparagraph.
(ii) In any case in which the Governor recommends a variance under this subparagraph in which the Federal Land Manager does not concur, the recommendations of the Governor and the Federal Land Manager shall be transmitted to the President. The President may approve the Governor’s recommendation if he finds that such variance is in the national interest. No Presidential finding shall be reviewable in any court. The variance shall take effect if the President approves the Governor’s recommendations. The President shall approve or disapprove such recommendation within ninety days after his receipt of the recommendations of the Governor and the Federal Land Manager.
(iii) In the case of a permit issued pursuant to this subparagraph, such facility shall comply with such emission limitations under such permit as may be necessary to assure that emissions of sulfur oxides from such facility will not (during any day on which the otherwise applicable maximum allowable increases are exceeded) cause or contribute to concentrations which exceed the following maximum allowable increases for such areas over the baseline concentration for such pollutant and to assure that such emissions will not cause or contribute to concentrations which exceed the otherwise applicable maximum allowable increases for periods of exposure of 24 hours or less on more than 18 days during any annual period:
MAXIMUM ALLOWABLE INCREASE | ||
|---|---|---|
(In micrograms per cubic meter) | ||
Period of exposure | Low terrain areas | High terrain areas |
24-hr maximum | 36 | 62 |
3-hr maximum | 130 | 221 |
(iv) For purposes of clause (iii), the term “high terrain area” means with respect to any facility, any area having an elevation of 900 feet or more above the base of the stack of such facility, and the term “low terrain area” means any area other than a high terrain area.
(e) Analysis; continuous air quality monitoring data; regulations; model adjustments
(1) The review provided for in subsection (a) shall be preceded by an analysis in accordance with regulations of the Administrator, promulgated under this subsection, which may be conducted by the State (or any general purpose unit of local government) or by the major emitting facility applying for such permit, of the ambient air quality at the proposed site and in areas which may be affected by emissions from such facility for each pollutant subject to regulation under this chapter which will be emitted from such facility.
(2) Effective one year after August 7, 1977, the analysis required by this subsection shall include continuous air quality monitoring data gathered for purposes of determining whether emissions from such facility will exceed the maximum allowable increases or the maximum allowable concentration permitted under this part. Such data shall be gathered over a period of one calendar year preceding the date of application for a permit under this part unless the State, in accordance with regulations promulgated by the Administrator, determines that a complete and adequate analysis for such purposes may be accomplished in a shorter period. The results of such analysis shall be available at the time of the public hearing on the application for such permit.
(3) The Administrator shall within six months after August 7, 1977, promulgate regulations respecting the analysis required under this subsection which regulations—
(A) shall not require the use of any automatic or uniform buffer zone or zones,
(B) shall require an analysis of the ambient air quality, climate and meteorology, terrain, soils and vegetation, and visibility at the site of the proposed major emitting facility and in the area potentially affected by the emissions from such facility for each pollutant regulated under this chapter which will be emitted from, or which results from the construction or operation of, such facility, the size and nature of the proposed facility, the degree of continuous emission reduction which could be achieved by such facility, and such other factors as may be relevant in determining the effect of emissions from a proposed facility on any air quality control region,
(C) shall require the results of such analysis shall be available at the time of the public hearing on the application for such permit, and
(D) shall specify with reasonable particularity each air quality model or models to be used under specified sets of conditions for purposes of this part.
Any model or models designated under such regulations may be adjusted upon a determination, after notice and opportunity for public hearing, by the Administrator that such adjustment is necessary to take into account unique terrain or meteorological characteristics of an area potentially affected by emissions from a source applying for a permit required under this part.
(July 14, 1955, ch. 360, title I, § 165, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 735; amended Pub. L. 95–190, § 14(a)(44)–(51), Nov. 16, 1977, 91 Stat. 1402.)
§ 7476. Other pollutants
(a) Hydrocarbons, carbon monoxide, petrochemical oxidants, and nitrogen oxides
(b) Effective date of regulations
(c) Contents of regulations
(d) Specific measures to fulfill goals and purposes
(e) Area classification plan not required
(f) PM–10 increments
(July 14, 1955, ch. 360, title I, § 166, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 739; amended Pub. L. 101–549, title I, § 105(b), Nov. 15, 1990, 104 Stat. 2462.)
§ 7477. Enforcement
The Administrator shall, and a State may, take such measures, including issuance of an order, or seeking injunctive relief, as necessary to prevent the construction or modification of a major emitting facility which does not conform to the requirements of this part, or which is proposed to be constructed in any area designated pursuant to section 7407(d) of this title as attainment or unclassifiable and which is not subject to an implementation plan which meets the requirements of this part.
(July 14, 1955, ch. 360, title I, § 167, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 740; amended Pub. L. 101–549, title I, § 110(3), title VII, § 708, Nov. 15, 1990, 104 Stat. 2470, 2684.)
§ 7478. Period before plan approval
(a) Existing regulations to remain in effect
(b) Regulations deemed amended; construction commenced after June 1, 1975
(July 14, 1955, ch. 360, title I, § 168, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 740; amended Pub. L. 95–190, § 14(a)(52), Nov. 16, 1977, 91 Stat. 1402.)
§ 7479. Definitions
For purposes of this part—
(1) The term “major emitting facility” means any of the following stationary sources of air pollutants which emit, or have the potential to emit, one hundred tons per year or more of any air pollutant from the following types of stationary sources: fossil-fuel fired steam electric plants of more than two hundred and fifty million British thermal units per hour heat input, coal cleaning plants (thermal dryers), kraft pulp mills, Portland Cement plants, primary zinc smelters, iron and steel mill plants, primary aluminum ore reduction plants, primary copper smelters, municipal incinerators capable of charging more than fifty tons of refuse per day, hydrofluoric, sulfuric, and nitric acid plants, petroleum refineries, lime plants, phosphate rock processing plants, coke oven batteries, sulfur recovery plants, carbon black plants (furnace process), primary lead smelters, fuel conversion plants, sintering plants, secondary metal production facilities, chemical process plants, fossil-fuel boilers of more than two hundred and fifty million British thermal units per hour heat input, petroleum storage and transfer facilities with a capacity exceeding three hundred thousand barrels, taconite ore processing facilities, glass fiber processing plants, charcoal production facilities. Such term also includes any other source with the potential to emit two hundred and fifty tons per year or more of any air pollutant. This term shall not include new or modified facilities which are nonprofit health or education institutions which have been exempted by the State.
(2)
(A) The term “commenced” as applied to construction of a major emitting facility means that the owner or operator has obtained all necessary preconstruction approvals or permits required by Federal, State, or local air pollution emissions and air quality laws or regulations and either has (i) begun, or caused to begin, a continuous program of physical on-site construction of the facility or (ii) entered into binding agreements or contractual obligations, which cannot be canceled or modified without substantial loss to the owner or operator, to undertake a program of construction of the facility to be completed within a reasonable time.
(B) The term “necessary preconstruction approvals or permits” means those permits or approvals, required by the permitting authority as a precondition to undertaking any activity under clauses (i) or (ii) of subparagraph (A) of this paragraph.
(C) The term “construction” when used in connection with any source or facility, includes the modification (as defined in section 7411(a) of this title) of any source or facility.
(3) The term “best available control technology” means an emission limitation based on the maximum degree of reduction of each pollutant subject to regulation under this chapter emitted from or which results from any major emitting facility, which the permitting authority, on a case-by-case basis, taking into account energy, environmental, and economic impacts and other costs, determines is achievable for such facility through application of production processes and available methods, systems, and techniques, including fuel cleaning, clean fuels, or treatment or innovative fuel combustion techniques for control of each such pollutant. In no event shall application of “best available control technology” result in emissions of any pollutants which will exceed the emissions allowed by any applicable standard established pursuant to section 7411 or 7412 of this title. Emissions from any source utilizing clean fuels, or any other means, to comply with this paragraph shall not be allowed to increase above levels that would have been required under this paragraph as it existed prior to November 15, 1990.
(4) The term “baseline concentration” means, with respect to a pollutant, the ambient concentration levels which exist at the time of the first application for a permit in an area subject to this part, based on air quality data available in the Environmental Protection Agency or a State air pollution control agency and on such monitoring data as the permit applicant is required to submit. Such ambient concentration levels shall take into account all projected emissions in, or which may affect, such area from any major emitting facility on which construction commenced prior to January 6, 1975, but which has not begun operation by the date of the baseline air quality concentration determination. Emissions of sulfur oxides and particulate matter from any major emitting facility on which construction commenced after January 6, 1975, shall not be included in the baseline and shall be counted against the maximum allowable increases in pollutant concentrations established under this part.
(July 14, 1955, ch. 360, title I, § 169, as added Pub. L. 95–95, title I, § 127(a), Aug. 7, 1977, 91 Stat. 740; amended Pub. L. 95–190, § 14(a)(54), Nov. 16, 1977, 91 Stat. 1402; Pub. L. 101–549, title III, § 305(b), title IV, § 403(d), Nov. 15, 1990, 104 Stat. 2583, 2631.)