United States Office of Air Quality EPA-450/3-83-001b
Environmental Protection Planning and Standards October 1984
Agency Research Triangle Park NC 27711
_
4MEPA Nonmetallic Final
Mineral Processing EIS
Plants-
Background
Information for
Promulgated
Standards
Preliminary
Draft
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NOTICE
This document has not been formally released by EPA and should not now be construed to represent
Agency policy. It is being circulated for comment on its technical accuracy and policy implications.
EPA-450/3-83-001b
IMonmetallic Mineral Processing Plants
Background Information for
Promulgated Standards
Emission Standards and Engineering Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, NC 27711
October 1984
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Th.s report has been reviewed by the Emission Standards and Engineering Division of the Office of Air
Quality Planning and Standards, EPA, and approved for publication. Mention of trade names or commercial
products is not intended to constitute endorsement or recommendation for use. Copies of this report are
available through the Library Services Office (MD-35), U.S. Environmental Protection Agency. Research
Triangle Park, N.C. 27711, or from National Technical Information Services, 5285 Port Royal Road
Springfield, Virginia 22161.
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TABLE OF CONTENTS
Section
Page
1.0 SUMMARY ........................ i_!
1.1 SUMMARY OF CHANGES SINCE PROPOSAL ......... 1-1
1.2 SUMMARY OF THE IMPACTS OF PROMULGATED ACTION ... 1-5
2.0 SUMMARY OF PUBLIC COMMENTS ............... 2-1
2.1 NEED FOR STANDARDS AND SELECTION OF SOURCE
CATEGORY .................... 2-9
2.2 SELECTION OF EMISSION SOURCES FOR CONTROL ..... 2-20
2.3 SELECTION OF AFFECTED FACILITY AND RECONSTRUCTION
PROVISIONS ................... 2-22
2.4 EMISSION CONTROL TECHNOLOGY ............ 2-36
2.5 ECONOMIC IMPACT .................. 2-41
2.6 ENVIRONMENTAL IMPACT ............... 2-62
2.7 ENERGY IMPACT ................... 2-67
2.8 SELECTION OF BEST DEMONSTRATED TECHNOLOGY ..... 2-68
2.9 SELECTION OF FORMAT OF STANDARDS ......... 2-70
2.10 SELECTION OF EMISSION LIMITS ........... 2-71
2.11 LEGAL CONSIDERATIONS ............... 2-83
2.12 TEST METHODS AND MONITORING ............ 2-84
2.13 REPORTING AND RECORDKEEPING ............ 2-91
2.14 WORDING OF REGULATION ............... 2-94
2.15 MISCELLANEOUS ................... 2-100
m
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LIST OF TABLES
Table
2-1 LIST OF COMMENTERS ON THE PROPOSED STANDARDS OF
PERFORMANCE FOR NONMETALLIC MINERAL PROCESSING
PLANTS 2-2
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1.0 SUMMARY
On August 31, 1983, the Environmental Protection Agency (EPA) proposed
standards of performance for nonmetallic mineral processing plants
(48 FR 39566) under authority of Section 111 of the Clean Air Act. Public
comments were requested on the proposal in the Federal Register. There were
52 commenters composed mainly of industries, trade associations, and State
and local regulatory agencies. Also commenting were Senators and Members of
Congress. The comments that were submitted, along with responses to these
comments, are summarized in this document. The summary of comments and
responses serves as the basis for the revisions made to the standards
between proposal and promulgation.
1.1 SUMMARY OF CHANGES SINCE PROPOSAL
In response to the public comments and as a result of EPA revaluation,
certain changes have been made in the standards since proposal. The changes
are in the following areas:
- Replacement of existing facilities with similar new facilities of
equal or smaller size,
- Enclosure of affected facilities in buildings as a control technique,
- Stipulations for use of Method 9 in measuring fugitive opacity,
- Reporting and recordkeeping provisions for wet scrubbers, and
- Rewording of definitions.
i-1-! Replacement of Existing Facilities with Similar New Facilities of
Equal or Smaller Size
Under §60.670, the following provision has been added: An existing
facility which is replaced by a piece of equipment of equal or smaller size
as defined in §60.671, and having the same function as the existing facility
is exempt from the provisions of §§60.672, 60.674, and 60.675. However, an
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owner or operator making such a replacement must comply with reporting
requirements added under §60.676. The purpose of this change is to exempt
such replacements from compliance with the emission limits of the standards
and to gather information on the frequency of their occurrence. EPA does
not believe replacement of individual affected facilities with new facili-
ties of equal or smaller size occurs often. Because such replacements did
not seem likely, EPA did not fully analyze the impacts of requiring control
of such replacements. Rather, EPA analyzed the impacts of the proposed
standards on new plants and capacity expansions at existing plants. Several
commenters, however, claimed that replacement of existing facilities with
new facilities of the same size is common. If such replacements are
frequent, costs and economic impacts, because of the additional costs
associated with retrofitting, could be significant. EPA has requested
specific data on the frequency of such replacements from industry represen-
tatives, but has not received any. Due to the large and dispersed nature of
the industry, representative data are difficult for trade associations or
industry representatives to obtain. To resolve this issue, EPA is exempting
replacement of existing facilities with new facilities of equal or smaller
size from compliance with the particulate emission limits of the standards.
EPA continues to believe such replacements are unlikely, and therefore
expects no significant impact on emissions reductions which could be
achieved by the standards. Recordkeeping provisions have been added to the
standards under § 60.676 to allow the Agency to obtain statistics on the
frequency and type of such replacements which occur. EPA will reassess the
need for this exemption in four years during the review of the standards.
In connection with the provisions for replacement of existing facilities
with new facilities of equal or smaller size, discussed above, a definition
of "size" has been added under. §60.671. Reporting provisions have also been
added. Under §60.676 an owner or operator replacing an existing facility
with a new facility of equal or smaller size must report to the State or EPA
regional office and to the EPA Office of Air Quality Planning and Standards
(1) the type and size of the existing facility and the new facility, (2) a
description of the control device used to reduce particulate emissions from
the existing facility, and (3) the age of the existing facility.
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1.1.2 Enclosure of Affected Facilities in Buildings
Sections 60.672 and 60.675 have been expanded to specify the emissions
standards and methods of determining compliance that apply if affected
facilities are enclosed by a building. Commenters interpreted the proposed
standards to mean that the enclosure of affected facilities in buildings
would not be allowed as a control technique. They also requested that
emissions be measured outside such buildings to determine compliance.
Buildings enclosing affected facilities may be vented or unvented. A vent
is defined as an opening through which there is mechanically induced airflow
for the purpose of exhausting from a building air carrying particulate
matter emissions from one or more affected facilities. Under the final
standards, affected facilities inside an unvented building will be determined
to be in compliance if there are no visible fugitive emissions from the
building as determined by EPA Method 22. If the building is vented and
there are no visible fugitive emissions, and the emissions from the vent
meet the stack particulate standards of 0.05 g/dscm and 7 percent opacity,
then the affected facilities inside the building will be determined to be in
compliance. If emissions from the building exceed the "no visible emissions"
fugitive standard or the stack standards, then opacity must be measured at
each affected facility inside the building, and fugitive opacity standards
(15 percent for crushers without capture systems and 10 percent for all
other facilities) must be met by each affected facility. These provisions
allow buildings to be used as control devices and compliance measurements to
be taken outside the building if the building can meet a "no visible
emissions" fugitive standard and the specified stack emissions standard.
1.1.3 Stipulations for the Use of Method 9 in Measuring Fugitive Opacity
Section 60.675(c) has been expanded to clarify the use of Method 9 to
determine compliance with the fugitive emissions standards in cases where
emissions from two or more facilities interfere. Commenters were concerned
that where wet dust suppression is used, there may be situations where
opacity of fugitive emissions from a single affected facility cannot be
measured due to the continuous interference of emissions from other
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facilities. EPA has found that in most cases changing observer positioning
or waiting for a change in wind conditions will allow the opacity of
emissions from individual facilities to be read. In such cases, opacity of
emissions from each affected facility must be measured using Method 9.
However, sometimes facilities may be located above and below one another so
that emissions from one facility pass through another facility and exit as a
combined emissions stream. EPA has found such situations to be rare, but
the regulation has been clarified to address them. Under 60.675(c)(4), when
emissions from two or more facilities continuously interfere an owner or
operator may show compliance with the fugitive emission limits in §60.672 by
(1) causing the opacity of the combined emissions stream from the facilities
to meet the highest fugitive opacity standard applicable to any of the
individual affected facilities contributing to the emissions stream, or
(2) separating emissions so that opacity of emissions from each affected
facility can be read to determine compliance with the applicable limits
specified for each facility in §60.672. Emissions could be separated by
moving the equipment or by installing a physical barrier or ductwork to
separate emissions. If these courses of action are not feasible, emissions
would have to be captured and ducted to a control device. These options
give plants flexibility in complying with the regulations and may allow them
to continue using wet dust suppression to comply with the regulation even
when fugitive emissions from two or more facilities continuously interfere.
1.1.4 Reporting and Recordkeeping Provisions for Wet Scrubbers
New provisions for the reporting of scrubber operating parameters have
been added in §60.676. Commenters expressed concern that measurements had
to be made weekly, but there were no reporting requirements specified in the
proposed standards. Under the final standards, the owner or operator is
required to record the scrubber liquid flow rate to the scrubber and the
change in pressure of the gas stream across the scrubber during the initial
performance test and at least weekly thereafter. Reporting of the results
of the initial performance test are required by the General Provisions.
Semiannual reporting of subsequent readings is required by the standards
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only when one or more weekly readings of the pressure difference or liquid
flow rate differs by more than ±30 percent from the readings of the most
recent performance test.
1.1.5 Rewording of Definitions
Some wording changes were made in the definitions section of the
regulation to clarify the intent of the definitions of crusher, fixed plant,
and portable plant. A definition of "truck dumping" was added to clarify
EPA's intent that dumping of minerals into any screening operation, feed
hopper, or crusher from trucks or other types of movable vehicles including
front end loaders and skip hoists are exempt from the requirements of
§60.672.
1.2 SUMMARY OF IMPACTS OF PROMULGATED ACTION
1.2.1 Alternatives to Promulgated Action
The regulatory alternatives are discussed in Chapter 6 of the
Background Information Document for the proposed standards. These
regulatory alternatives reflect the different levels of emission control
from which one is selected that represents the best demonstrated technology,
considering costs, nonair quality, health, and environmental and economic
impacts for nonmetallic mineral processing plants. These alternatives
remain the same.
1.2.2 Environmental Impacts of Promulgated Action
The environmental impacts of the standards are presented in Chapter 7
of the Background Information Document for the proposed standards. A review
of these impacts indicated no changes were necessary and therefore, the
impacts remain unchanged since proposal.
The analysis of environmental impacts presented in the Background
Information Document for the proposed standards constitutes the final
Environmental Impact Statement.
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1.2.3 Economic and Energy Impacts of Promulgated Action
The economic impacts of the standards are discussed in Chapter 8 and
Supplement A of the Background Information Document for the proposed
standards. These economic impacts have been reviewed and remain unchanged
for the promulgated standards.
The energy impacts of the standards are discussed in Chapter 7 of the
Background Information Document for the proposed standards and remain
unchanged for the promulgated standards.
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2. SUMMARY OF PUBLIC COMMENTS
A total of 52 letters commenting on the proposed standards and the
Background Information Document for the proposed standards were received. A
public hearing on the proposed standards was not requested. A list of
commenters, their affiliations, and the EPA docket numbers assigned to their
correspondence is given in Table 2-1.
For the purpose of orderly presentation, the comments have been
categorized under the following topics:
(1) Need for Standards and Selection of Source Category
(2) Selection of Emission Sources for Control
(3) Selection of Affected Facility and Reconstruction Provisions
(4) Emission Control Technology
(5) Economic Impact
(6) Environmental Impact
(7) Energy Impact
(8) Selection of Best Demonstrated Technology
(9) Selection of Format for Standards
(10) Selection of Emission Limits
(11) Legal Considerations
(12) Test Methods and Monitoring
(13) Reporting and Recordkeeping
(14) Wording of Regulation
(15) Miscellaneous
The comments, the issues they address and EPA's responses are discussed in
the following sections of this chapter. Changes to the regulations are
summarized in Subsection 1.2 of Chapter 1.
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TABLE 2-1. LIST OF COMMENTERS ON THE PROPOSED STANDARDS OF
PERFORMANCE FOR NONMETALLIC MINERAL PROCESSING PLANTS
Docket Entry Number3 Commenter/Affiliation
IV-D-1 Gary R. Gawreluk
Research-Cottrell, Inc.
P.O. Box 1500
Somerville, NJ 08876
IV-D-2 Robert L. Reynolds
Lake County Air Pollution Control
District
Courthouse - 255 N. Forbes St.
Lakeport, CA 95453
IV-D-3 V. R. Snyder
The General Crushed Stone Company
P.O. Box 231
Easton, PA 18042
IV-D-4 j. N. Siegfriend
Manville Service Corporation
Ken-Caryl Ranch
Denver, CO 80217
IV-D-5 S. J. Major
Lone Star Cement
P.O. Box 420
Norfolk, VA 23501
IV-D-6 Barbara 0. Patala
National Science Foundation
Washington, D.C. 20550
IV-D-7 Joseph L. Harrison
Indiana Mineral Aggregates
Association
4475 Allisonville Road
Vantage Point - Suite 525
Indianapolis, IN 46205
IV-D-8 Charley L. Shelton
Peter Kiewit Sons' Co.
P.O. Box 1055
Glendale, AZ 85311
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TABLE 2-1. (Continued)
Docket Entry Number Commenter/Affiliation
IV-°-9 Mohamed T. El-Ashry, Ph.D.
Tennessee Valley Authority
Knoxville, TN 37902
IV-D-10 Dick Serdoz
State of Nevada
Department of Conservation and
Natural Resources
Capital Complex
Carson City, NV 89710
IV-D-n Robert A. Wilkinson, P.E.
The Ohio Aggregates Association
20 South Front St., Suite 200
Columbus, OH 43215
IV-D-12 John 6. Wheeler
Capitol Aggregates Incorporated
P.O. Drawer 33240
San Antonio, TX 78233
IV-D-13 Charles Ellis
Texas Industries, Inc.
8100 Carpenter Freeway
Dallas, TX 75247
IV-D-14 Keith M. Bentley
Georgia-Pacific Corporation
133 Peachtree St., N.E.
P.O. Box 105605
Atlanta, GA 30348
IV-D-15 Richard A. Morris
National Industrial Sand
Association
900 Spring St.
Silver Spring, MD 20910
IV-D-16 Richard A. Morris
National Sand and Gravel
Association
900 Spring St.
Silver Spring, MD 20910
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TABLE 2-1. (Continued)
Docket Entry Number3 Commenter/Affiliation
IV-D-17 Michael J. Hart
NSPS Task Group
c/o Flatiron Sand and Gravel
Company
P.O. Box 229
Boulder, CO 80306
IV-D-18 ' Edward L. Hynes
Rocky Mountain Energy
10 Long Peak Drive
Box 2000
Broomfield, CO 80020
IV-D-19 Stanley F. Olenn
The Refractories Institute
3760 One Oliver Plaza
Pittsburgh, PA 15222
IV-D-20 Charles A. Collins
The State of Wyoming
Department of Environmental
Quality
Equality State Bank Bldg.
401 W. 19 St.
Cheyenne, WY 82002
IV-D-21 Dow E. Prouty
B. L. Anderon Incorporated
123 Third Ave., S.W.
P.O. Box 2007
Cedar Rapids, IA 52406
IV-D-22 Mike Huddleston, P.E.
Asphalt Pavement Association of
Oregon
3747 Market St., N.E.
Salem, OR 97301
IV-D-23 William Gibbons
Tulsa City-County Health
Department
4616 East 15th
Tulsa, OK 74112
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TABLE 2-1. (Continued)
Docket Entry Number9 Commenter/Affilnation
IV-D-24 Lloyd Kostow
Oregon Department of Environmental
Quality
522 S.W. Fifth Ave.
Box 1760
Portland, OR 97207
IV-D-25 Mallory S. May III
Gifford-Hi 11 & Company, Inc.
P.O. Box 47127
Dallas, TX 75247
IV-D-26 F. A. Renninger, P.E.
National Crushed Stone Association
1415 Elliot Place, N.W.
Washington, D.C. 20007
IV-D-27 Kenneth W. McNichols
Iowa Limestone Producers
Association Inc.
P.O. Box 6006
Des Moines, IA 50309
IV-D-28 John W. Sullivan
Kentucky Crushed Stone
Association Inc.
Depot Place
P.O. Box 326
Frankfort, KY 40602
IV-D-29 C. B. Rash
Ozark-Mahoning Company
Rosiclare, IL 62982
IV-D-30 Stanley Isaacson
Gendler Stone Products Company
1075 Polk Blvd.
Des Moines, IA 50311
IV-D-31 Jack M. Pryor, P.E.
Pennsylvania Glass Sand
Corporation
Berkeley Springs, WV 25411
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TABLE 2-1. (Continued)
Docket Entry Number3 Comnenter/Affiliation
IV-D-32 Jack M. Pryor, P.E.
Floridin Company
Berkeley Springs, WV 25411
IV-D-33 E. H. Shuler
Getty Oil Company
3810 Wilshire Blvd.
Los Angeles, CA 90010
IV-D-34 John P. Gleason, Jr. and
Robert A. Emmett
Brick Institute of America
1750 Old Meadow Road
McLean, VA 22101
IV-D-35 James H. Williams
National Limestone Institute
1840 Wilson Blvd., Suite 203
Arlington, VA 22201
IV-D-36 J. Allen Overton, Jr.
American Mining Congress
Suite 300
1920 N. Street, N.W.
Washington, D.C. 20036
IV-D-37 John M. Clouse for
James Lents, Ph.D.
Colorado Department of Health
4210 East llth Ave.
Denver, CO 80220
IV-D-38 Roger N. Miller
Windsor Minerals Inc.
P.O. Box 680
Windsor, VT 05089
IV-D-39 Jackie Swigart
Commonwealth of Kentucky
National Resources and Environ-
mental Protection Cabinet
Office of the Secretary
Frankfort, KY 40601
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TABLE 2-1. (Continued)
Docket Entry Number0 Commenter/Affiliation
IV-D-40 Bill R. Starr
Weaver Construction Co.
P.O. Box 550
Iowa Falls, IA 50126
IV-D-41 John W. Harris
International Minerals and
Chemical Corporation
Mundelein, IL 60060
IV-D-42 Judith M. Lake
Air Pollution Control District
County of San Diego
9150 Chesapeake Dr.
San Diego, CA 92123
IV-D-43 Greg Sorlie
State of Washington
Department of Ecology
Mail Stop PV-11
Olympia, WA 98504
IV-D-44 George J. Moritz
International Salt Company
Abington Executive Park
Clarks Summit, PA 18411
IV-D-45 Senator Roger Jepsen
U.S. Senate
Washington, D.C. 20510
IV-D-46 Copper Evans, Member of Congress
127 Cannon House Office Bldg.
Washington, D.C. 20515
IV-D-47 Neal Smith, Member of Congress
2373 Rayburn House Office Building
Washington, D.C. 20515
IV-D-48 Senator Lawton Chiles
U.S. Senate
Washington, D.C. 20510
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TABLE 2-1. (Continued)
Docket Entry Number Commenter/Affillation
IV"D"49 Jim Leach, Member of Congress
1514 Longworth House Office
Building
Washington, D.C. 20515
IV-D~50 Sherwood Boehlert, Member of
Congress
1641 Longworth House Office
Building
Washington, D.C. 20515
IV-D-51 Tom Tauke, Member of Congress
435 Cannon House Office Building
Washington, D.C. 20515
IV-D-52 William M. Wilson, Jr.
Sutherland, Asbill & Brennan
First Atlanta Tower
Atlanta, GA 30383
The docket number for this project is OAQPS-78-11. Dockets are on file at
EPA Headquarters in Washington, D.C., and at the Office of Air Quality
Planning and Standards in Durham, N.C.
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2.1 NEED FOR STANDARDS AND SELECTION OF SOURCE CATEGORY
2.1.1 Comment: (IV-D-3, IV-D-12, IV-D-15, IV-D-16, IV-D-17, IV-D-21,
IV-D-26, IV-D-27, IV-D-30, IV-D-35, IV-D-36, IV-D-40)
Eleven commenters questioned EPA's determination that nonmetallic
mineral processing plants are sources of emissions that cause or contribute
significantly to air pollution that may reasonably be anticipated to endanger
public health or welfare. Six of these commenters stated that nonmetallic
mineral processing plants are insignificant sources of fugitive particulate
emissions when compared to other open sources of these emissions. Four
commenters also stated that there are no documented cases, that they are
aware of, of anyone being harmed by the dust from the crushing and processing
of limestone. One commenter questioned whether the determination was made
on the basis of scientific fact. Several commenters felt this industry is
not a significant source of emissions into the ambient air because the
emissions do not leave the plant boundaries.
Response:
Under Section lll(b)(l) of the Clean Air Act, the EPA Administrator is
required to publish and periodically revise a list of categories of
stationary sources. A source category is to be included on the list
"... if in his judgement it causes, or contributes significantly to, air
pollution which may reasonably be anticipated to endanger public health or
welfare." The Act then requires that NSPS be proposed for all listed source
categories. The language of the Act does not require absolute proof that
health or welfare has been harmed by emissions from a source category before
the category is listed. In fact, the legislative history stresses two
points:
(1) The Act is preventive, and regulatory action should be taken to
prevent harm before it occurs; and
(2) The Administrator should consider the contribution of each single
class of sources to the cumulative impact of all particulate
matter emitters.
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On August 21, 1979, the Administrator promulgated a priority list of
source categories for which NSPS are to be promulgated (44 FR 49225). This
action was required under the 1977 Clean Air Act Amendments [Section lll(f)]
Development of the priority list was initiated by compiling data on a large
number of source categories from the literature. Major stationary source
categories were subjected to a priority ranking procedure using the three
criteria specified in Section lll(f) of the Clean Air Act. In this ranking,
first priority was given to quantity of emissions, second to potential
impact on health and welfare, and third priority was given to the mobility
and competitive nature of the source category. Using these criteria, the
nonmetallic minerals industry was ranked 13th out of 59 major source catego-
ries on the priority list (44 FR 49225). Support for this decision can be
found in the background documents for the priority list (EPA-450/3-79-023
and EPA-450/3-78-019).
Nonmetallic minerals industries were included on the NSPS priority list
due to potentially significant emissions of particulate matter. Particulate
matter is a criteria pollutant which has been determined to be an air
pollutant which may endanger public health and welfare and for which a
national ambient air quality standard (NAAQS) has been promulgated. (Lime-
stone dust and other dusts emitted by the nonmetallic minerals industry are
types of particulate matter.) The Administrator's determination that
particulate emissions may endanger public health and welfare is documented
in the document, "Air Quality Criteria for Particulate Matter and Sulfur
Oxides" (EPA-600/8-82-029a-c).
Standards of performance required by Section 111 play a unique role
under the Clean Air Act. Their main purpose is to require new sources,
wherever located, to reduce emissions to the level achievable by the best
technological system of continuous emission reduction considering the cost
of achieving such emission reduction, any nonair quality health and environ-
mental impact, and energy requirements [Section lll(a)(l)]. Congress
recognized that establishing such standards would minimize increases in air
pollution from new sources, thereby improving air quality as the nation's
industrial base is replaced over time. In the past, proof has not been
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required that emissions from specific individual plants cause health and
welfare impacts. Rather, sources are regulated by category, and the goal is
the reduction of emissions of pollutants, such as particulate matter, which
have been shown to impact health and welfare.
The series of determinations outlined above adequately supports EPA's
decision that the nonmetallic minerals industry is a significant source of
air pollution which may endanger public health and welfare, and that an NSPS
must be promulgated for this source category.
2.1.2 Comment: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-27, IV-D-35,
IV-D-36, IV-D-40, IV-D-45, IV-D-46, IV-D-47, IV-D-49, IV-D-51)
Several commenters expressed concern over the following statement in
the preamble to the proposed standards: "The 18 minerals covered by the
proposed standards were selected on the basis of production tonnage rather
than on the basis of any health or welfare considerations as compared to the
other minerals." They believed this selection methodology violates the
intent and scope of the Clean Air Act. Some believed the goal of the Clean
Air Act to be improved air quality through reduction of total suspended
particulates but felt that EPA's approach leads to control of relatively
small point sources of particulate emissions while missing major area
sources. Others said EPA must base regulation of specific industries on
health and welfare considerations rather than on size.
Response:
The statement the commenters quoted was an explanation of how EPA
selected the particular 18 minerals to be covered by the NSPS from all the
nonmetallic minerals that exist. The statement was not intended to provide
any rationale for developing the NSPS for nonmetallic mineral processing
plants.
The opening paragraph of the rationale section of the preamble to the
proposed standards clearly states that nonmetallic mineral processing plants
have been identified by EPA as sources of particulate matter emissions that
cause or contribute significantly to air pollution that may reasonably be
anticipated to endanger public health or welfare (48 FR 39567).
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NSPS source categories have been prioritized by the quantity of
emissions, potential impact on health and welfare, and mobility and competi-
tiveness of the industry as mandated in Section lll(f) of the Clean Air Act.
Nonmetallic minerals industries emit significant quantities of particulate
matter, a criteria pollutant for which an NAAQS was promulgated due to
health and welfare concerns. The nonmetallic mineral industries source
category was listed 13th on EPA's list of 59 source categories (44 FR 49225)
for which standards of performance must be promulgated.
For the purposes of standards development, EPA had to define which
industries would be considered part of the nonmetallic mineral industry
source category. Since similar grinding and crushing processes occur at
most nonmetallic minerals industries, it is assumed that potential particu-
late emissions will be roughly proportional to production tonnage.. There-
fore, the largest sources of emissions will be controlled by regulating the
industries which produce the largest volumes of nonmetallic minerals. Since
the largest emissions reductions can be achieved by regulating the largest
nonmetallic minerals industries, the 18 largest have been selected for
inclusion in the NSPS. These 18 categories are based upon Bureau of Mines
classifications and are the highest mined production segments of the
nonmetallic minerals industry which have crushing and grinding operations,
excluding coal, phosphate rock, and asbestos.
It has been estimated that by the fifth year after proposal of these
standards, nonmetallic mineral processing plants in the 18 industries would
cause annual particulate matter emissions to increase by 45,000 Mg
(50,000 tons) per year if no standards were set. The standards are expected
to reduce these emissions by 41,000 Mg (45,000 tons) per year. Since this
magnitude of emissions reduction of a criteria pollutant can be achieved at
a reasonable cost, EPA believes regulation of the 18 largest nonmetallic
minerals industries is clearly authorized under Section 111 of the Clean Air
Act.
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2.1.3 Comment: (IV-D-19)
One commenter requested that processors of refractory materials be
exempted on the basis of the limited size of the industry, unique require-
ments of particle size, chemistry and introduction of temperature gradients
throughout the process of manufacturing refractory materials.
Response:
The NSPS will affect only the processing of nonmetallic minerals, which
are used as raw materials, at refractory producing plants. It will not
affect the process by which finished refractory products are made since
these products generally do not fall under the definition of nonmetallic
minerals in §60.671 of the regulation. The grinding and crushing of
nonmetallic minerals in refractory manufacture are similar to these same
processes in other affected industries. Control technology is the same for
refractory producers as for other types of nonmetallic mineral industries,
and economic analyses have shown that the impacts of applying this technology
are reasonable. Therefore, refractory producers will not be exempt from the
NSPS. Further details are given in Sections 2.5.10 and 2.10.6.
2.1.4 Comment: (IV-D-29)
One commenter requested that fluorspar processing plants be exempted
because fluorspar is considered a strategic and critical commodity due to
imports of the mineral being greater than 85 percent. In addition, he said,
the domestic fluorspar industry is currently fighting for survival against
imports and any increase in production costs may create a hardship on the
domestic industry.
Response:
Fluorspar is a strategic and critical material as defined by the
Strategic and Critical Materials Stock Piling Act. The purpose of this act
is to "provide for the acquisition and retention of stocks of certain
strategic and critical materials and to encourage the conservation and
development of sources of such materials within the United States and
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thereby to decrease and to preclude, when possible, a dangerous and costly
dependence of the United States upon foreign sources for supplies of such
materials in times of national emergency," [Strategic and Critical Materials
Stock Piling Act, 50 U.S.C. 98 et. seq.]. The Act, however, places no
direct restrictions upon either the domestic industries that produce stra-
tegic materials, or the government bodies that regulate those industries.
In fact many of the materials that are on the Federal Emergency Management
Act's list of strategic minerals are also currently covered by NSPS or
NESHAPs. These materials include: aluminum, lead, copper, zinc, beryllium,
asbestos, and mercury.
The NSPS for nonmetallic minerals is not expected to have any signifi-
cant effect upon either the level of imports of fluorspar or the cost to
produce this mineral. The Background Document for the proposed standards
shows that, in the worst case, NSPS costs will amount to no more than
0.3 percent of fluorspar industry revenues. Of the 23 minerals considered
in the background document only three are estimated to have a lower
percentage of cost to revenues.
Consequently, the Agency does not believe including fluorspar processing
plants in the NSPS will create a hardship for the fluorspar industry.
2.1.5 Comment: (IV-D-34)
One commenter requested that the brick manufacturing industry be
exempted because no plants in the industry were examined or considered by
EPA. In addition, no source or emission tests were conducted at any brick
plant. He felt that EPA should separately assess the brick industry to
determine whether brick plants pose environmental problems, whether any
significant benefits can be gained from an NSPS, and the economic costs of
installing and operating such controls.
Response:
The NSPS for nonmetallic mineral processing plants will apply to only a
portion of the total brick making process. In general, this process can be
distinguished by several stages including: clay preparation (mining,
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transportation, and storage), mixing, deaerating, extruding, cutting,
glazing, stacking, drying, firing, packaging, and storage and shipment. The
NSPS will apply only to the clay preparation stage, which is virtually
identical to the mining and processing of the other minerals covered by the
standard. EPA has tested similar processes at other nonmetallic mineral
processing plants which cover the range of processes and operating conditions
found in the clay preparation segment of brick manufacturing. Based on
these tests, best demonstrated technology has been established for nonmetal-
lic minerals industries (including the brick industry), and analyses have
shown that significant reductions in emissions can be achieved for reasonable
costs by promulgating an NSPS. In response to the comment, EPA visited
brick plants, and found no significant differences between the clay prepara-
tion stage at brick plants and operations at other nonmetallic minerals
processing plants with regard to equipment, control technology, or emissions.
However, since most affected facilities at brick plants are enclosed in
buildings, provisions have been added to the final standards clarifying the
application of stack and visible emissions standards to buildings enclosing
affected facilities. EPA does not believe that the brick industry should be
regulated separately.
2.1.6 Comment: (IV-D-8)
One commenter felt that there already are too many organizations
regulating crushing plants and there is no need for any more regulations.
Response:
The commenter did not specify which regulations he was referring to.
Crushing plants are subject to State, local, and PSD regulations, however,
such regulations do not take the place of an NSPS. Under Section 111 of the
Clean Air Act, the main purpose of standards of performance is to require
new sources, wherever located, to reduce emissions to the level achievable
by the best technological system of continuous emission reduction considering
the cost and any nonair quality health, environmental, or energy impacts.
The nonmetallic minerals industries were included on the 1979 priority list
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of source categories based on the determination that they cause or contribute
significantly to air pollution which may reasonably be expected to endanger
public health or welfare (44 FR 49225). Under Section lll(f) of the Clean
Air Act, EPA is required to promulgate NSPS for all source categories
included on this list. EPA's analyses have shown that typical State regulat-
ions for crushing plants do not require best demonstrated technology, and
that significant emissions reductions (41,000 Mg/yr or 45,000 tons/yr beyond
what is required by State regulations) may be achieved at a reasonable cost
under the proposed NSPS (48 FR 39566, August 31, 1983; EPA-450/3-83-001a).
Therefore, an NSPS is being promulgated which will regulate crushing plants
in nonmetallic minerals industries.
Standards of performance required by Section 111 play a unique role
under the Clean Air Act. The main purpose of standards of performance is to
require new sources, wherever located, to reduce emissions to the level
achievable by the best technological system of continuous emission reduction
considering the cost of achieving such emission reduction, any nonair quality
health and environmental impacts, and energy requirements [Section lll(a)(l)].
Congress recognized that establishing such standards would minimize increases
in air pollution from new sources, thereby improving air quality as the
nation's industrial base is replaced over the long-term. Standards of
performance thereby serve as a distinct means of achieving the Act's goals,
supplementing the role played by RACT-based requirements for existing and
new sources within state implementation plans developed for the purpose of
attaining the NAAQS.
Congress also intended NSPS to play an integral role in the new source
review programs of the Act. Standards of performance required by Section 111
also serve as the minimum level of emission control for BACT and LAER, which
are determined case-by-case. Promulgation of these standards therefore
assures that BACT and LAER for individual sources are not less stringent
than the "best demonstrated technology" (BDT) for the class of sources into
which those individual sources fall. Absent identification of "best demon-
strated technology" through promulgation of NSPS, BACT and LAER might be
less stringent than BDT-level control.
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Standards of performance have other benefits in addition to achieving
emissions reductions. Standards of performance establish a degree of
national uniformity to air pollution standards and, therefore, preclude
situations in which some States may attract new industries as a result of
having relaxed standards relative to other States. Further, standards of
performance provide documentation that reduces uncertainty in evaluations of
available control technology. This documentation includes identification
and comprehensive analyses of alternative emission control technologies,
development of associated costs, evaluation and verification of applicable
emission test methods, and identification of specific emission limits
achievable with alternate technologies. This documentation also provides an
economic analysis that reveals the affordability of controls in a study of
the economic impact of controls on an industry.
2.1.7 Comment: (IV-D-12, IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-31,
IV-D-35, IV-D-36)
Eight commenters felt that the uncontrolled emission rates presented in
the BID were too high for the sand and gravel industry. They felt that
revising the current AP-42 emission factors for nonmetallic minerals indus-
tries is necessary to accurately judge their contribution to air pollution.
They stated that only in rare instances are secondary and tertiary crushing
part of sand and gravel processing. In addition to the limited amount of
crushing, sand and gravel is often processed wet and, in those instances,
negligible emissions are generated. Therefore, they felt if accurate
emission rates were used, sand and gravel plants would not be on the NSPS
priority list. One commenter also stated that without accurate emission
factors it is impossible to make sound and defensible projections regarding
cost and benefit, or the cost efficiency of control strategies.
Response:
Uncontrolled emission rates presented in the Background Document for
the proposed standards are uncertain and may be imprecise, as was noted in
the document (EPA-450/3-83-001a); however, the uncontrolled emission factors
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were not used in the decision to regulate the nonmetallic minerals industry.
Rather, emission levels in the absence of an NSPS and the potential impacts
of a standard were calculated assuming emissions are currently controlled to
the level required by typical State Implementation Plan (SIP) regulations.
EPA recognizes that a wide variety in emission rates exists both
between industries and within any one industry. Emissions are related to
the amount of processing done and are also affected by whether the processing
is wet. The sand and gravel industry was put on the list of industries to
be regulated because of its potential to emit particulate matter. Where wet
processing is used, plants could probably meet the standards without
additional control equipment.
Accurate uncontrolled emission factors are not necessary to project
costs and benefits of the standards, since uncontrolled emission factors
were not used in these projections. Baseline emissions (or the emissions
which would occur if standards were not proposed) were calculated by assuming
plants would control to the level required by SIPs. Typical State process
weight regulations (pounds emitted per ton processed) for typical size
plants in each industry were multiplied by the additional processing capacity
expected to be built in each industry over the 5-year period of analysis.
This resulted in an estimate of emissions for all 18 industries in the
absence of an NSPS. The same procedure was used to calculate emissions
under the proposed NSPS, except that a gas volume was assigned for the
specified plant size and the value 0.05 g/dscm (0.02 gr/dscf) was used to
calculate the emission level in terms of process weight rate. The tons of
emissions reduction is the difference between allowable emissions due to
State regulations (baseline) and the proposed NSPS for new capacity additions.
Costs of the NSPS are based on installing baghouses to control all
additional processing capacity added during the 5-year period of analysis.
Baghouses are the more expensive technology which could be used to meet the
standards. Since it is likely that some new plants will use wet suppression
instead of baghouses to meet the standards and that some new plants may
install baghouses anyway due to State regulations, the costs of the proposed
NSPS have been overestimated. Therefore, EPA's current estimates of the
costs and cost effectiveness of the proposed standards are probably high.
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2.1.8 Comment: (IV-D-18)
One commenter requested that the sodium carbonate industry be excluded
from the proposed standards. They felt this action would be consistent with
the fact that EPA withdrew previously proposed standards for this industry
because they were deemed unnecessary.
Response:
The sodium carbonate industry will be regulated under the standards for
nonmetallic mineral processing plants. Crushing operations at sodium carbo-
nate plants are similar to those at other nonmetallic minerals plants; and
the sodium carbonate industry is capable of meeting the standards. In fact,
new sodium carbonate plants or capacity expansions are already required by
the SIP in Wyoming, where most facilities are located, to meet emission
limits as stringent as those promulgated for nonmetallic mineral processing
plants; so these standards will not be burdensome to the industry.
The promulgation of the nonmetallic minerals NSPS is hot inconsistent
with EPA's decision to withdraw earlier standards of performance for the
sodium carbonate industry. The previous standards pertained specifically to
the sodium carbonate industry and covered different types of equipment from
the equipment covered under the nonmetallic minerals standards. The
previously proposed standards were withdrawn after proposal because the
industry lacks mobility and Wyoming's SIP was sufficiently stringent that
the standards would not have resulted in any emissions reduction.
The generic standards for the nonmetallic minerals source category has
been promulgated for reasons explained in Section 2.1.1. The purpose of
NSPS is to require new sources to reduce emissions to the levels achievable
by the best technological system of emission reduction considering costs and
any nonair quality health, environmental, and energy impacts. It has been
determined that significant emissions reductions will result from the
application of BDT to affected facilities at nonmetallic mineral processing
plants, and that the costs and economic impacts are reasonable. The
economic analyses for the standards included an analysis of the costs of
control and economic impacts on the sodium carbonate industry. Even under
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the assumption that all control costs were attributable to the NSPS rather
than SIPs, the costs of control were determined to be reasonable. The
processing of sodium compounds, including sodium carbonate, has been
included under the generic standards because it is one of the 18 highest
mined production segments in the industry (see Section 2.1.2). No reason
has been found to exclude sodium carbonate processing from the standards.
2.2 SELECTION OF EMISSION SOURCES FOR CONTROL
2.2.1 Comment: (IV-D-13, IV-D-30, IV-D-37, IV-D-39, IV-D-42)
Five commenters were concerned that the most significant sources of
particulate matter at nonmetallic mineral processing plants were not
considered for regulation. They felt that haul roads, stockpiles, truck
dumping, drilling, blasting, open loadouts, overburden and product removal,
loading at the mine and open conveying are more significant sources than the
processing plant equipment. Several commenters pointed out that there are
effective control techniques for these sources. One commenter felt the
regulation addresses approximately 10 percent of the fugitive emissions at a
processing plant. Another commenter stated that his company had never had a
complaint about the emissions from the sources covered by the regulation but
had received complaints about emissions from their haul roads and drilling
and blasting.
Response:
EPA has determined that the sources included in the proposed regulation
are significant sources of particulate matter emissions. Emissions reduc-
tions of 41,000 Mg (45,000 tons) per year could be achieved at a reasonable
cost under the proposed regulation. Sources covered by the standards
include crushers, grinding mills, screening operations, bucket elevators,
belt conveyers, bagging operations, storage bins, and enclosed truck and
railcar loading. Best demonstrated technology (BDT) has been determined for
these sources and will be required under the proposed NSPS.
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Other fugitive sources will be considered in the future for potential
standards development. The timing will depend on budget constraints and EPA
priorities. EPA's Office of Research and Development is researching control
techniques for several of the sources mentioned by the commenters including
haul roads, stockpiles, drilling, blasting, loading at the mine, and
conveying (other than transfer points). Preliminary information on control
techniques for these operations is included in the document "Air Pollution
Control Techniques for Nonmetallic Minerals Industry" (EPA-450/3-82-014).
2.2.2 Comment: (IV-D-13)
One commenter felt it was inconsistent that the standards exempted the
dumping of materials from a truck into a screening hopper or crusher but
included dumping the same materials into the same hopper with loaders, skip
hoists or conveyor belts.
Response:
EPA agrees that the reasons truck dumping was excluded would also apply
to dumping from other types of vehicles. Therefore, to remedy this
inconsistency, a broad definition of truck dumping has been added to
Section 60.671 of the regulation. Under the new definition, truck dumping
includes dumping from other types of movable vehicles including front end
loaders and skip hoists. Thus, dumping of materials from these vehicles
into screens, feed hoppers, or crushers is exempt from compliance with the
emission limits. Dumping of materials from conveyor belts will, however, be
subject to the emission limits. BDT has been established for conveyor
transfer points, and conveyor transfer points must comply with the emission
limits as stated in the regulation.
2.2.3 Comment: (IV-D-52)
One commenter requested clarification as to whether the proposed
standards apply to crushers and grinders which are used in combination with
dryers which are operated by combustion or other means.
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Response:
The standards of performance for nonmetallic minerals processing plants
will cover combined crushing or grinding and drying systems. Dryers which
are not combined with crushers or grinders will be covered under the
calciner/dryer standards currently being developed by the EPA.
The type of systems the commenter is referring to are crushers or
grinders through which additional hot air is passed to accomplish drying of
the minerals as they are being crushed. These systems will be covered under
the promulgated standards whether direct or indirect heat is used to heat
the air. Some facilities of this type were tested by the EPA during
standards development. The facilities referred to as L-l and M-2 in the
Background Document for the proposed standards are grinding mills operated
at higher than ambient temperatures, and these met the standards .using
baghouse control. Grinding mills generally have higher emissions than
crushers and emit a larger fraction of small particulates. If these grinding
mill-dryer combinations can meet the standards, crusher-dryer combinations
would also be able to meet the standards. Thus, the data base for the
nonmetallic minerals standards adequately represents the characteristics of
emissions from crushers and grinders used in combination with dryers, and
the EPA's data show that the promulgated standards can be achieved by such
facilities.
2.3 SELECTION OF AFFECTED FACILITY AND RECONSTRUCTION PROVISIONS
2.3.1 Comment: (IV-D-4, IV-D-5, IV-D-7, IV-D-11, IV-D-12, IV-D-15,
IV-D-16, IV-D-17, IV-D-24, IV-D-26, IV-D-28, IV-D-34, IV-D-35, IV-D-44)
Fourteen commenters objected to the designation of each piece of
equipment at a processing plant as an affected facility. They believed that
the entire plant should be designated as the affected facility. The commen-
ters stated that control systems are designed for the entire processing
plant, not for each piece of equipment. Therefore, retrofitting individual
pieces of equipment at existing plants could entail either replacing
existing multiple facility control technology completely or installing a
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separate control device for each piece of equipment as it is replaced. The
former would mean the entire plant including existing facilities, would be
meeting the standards and the latter would lead to an inefficient control
technology design with each piece having its own control device. The
commenters believe that it was not the EPA's intent to have either situation
occur. The commenters also stated that nonmetallic processing plants are
not similar to other manufacturing operations regulated under Section 111
because they are designed as an integrated unit. They pointed out that a
broken crusher, screen, or conveyer belt can render an entire production
plant inoperative. They recommended that the entire plant be designated as
the affected facility. One commenter felt that since crushers, grinding
mills, screening operations, bucket elevators, belt conveyors, and storage
bins are part of an integral unit, they should be considered an affected
facility. He felt that since bagging operations and truck and railcar
loading stations can operate independently of the rest of the plant, they
could be considered separate affected facilities. Five commenters believed
that Congress intended to protect and enhance air quality by controlling new
plants as they are built and old plants when they are substantially rebuilt.
They felt that designating the entire plant as the affected facility is more
consistent with this intent. The commenters felt that specific pieces of
equipment within a plant that are replaced without causing any increase in
emissions should not be subject to the NSPS if such replacements fall under
the 50 percent fixed capital cost threshold as outlined in the modification
and reconstruction provisions.
One commenter suggested another alternative would be that the EPA
provide a waiver for plants that can show technical and cost reasons for
designating the entire plant as the affected facility. He also believed
that even under current court decisions, a broad definition of affected
facility is allowable in attainment areas.
One commenter (IV-D-39) asked that replacement of worn-out equipment
with a new piece of equipment of the same type and with the same capacity be
exempt from coverage. The commenter called this type of replacement common.
Another commenter (IV-D-5) requested clarification on whether total
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replacement of an individual piece of equipment is exempt from the NSPS.
Another commenter (IV-D-26) stated that these replacements were made on a
regular and relatively routine basis.
Response:
It is EPA's interpretation that these comments fall essentially into
three subject areas: (1) Should the standards differentiate between sources
located in attainment versus nonattainment areas? (2) Should the affected
facility be defined more broadly than proposed (i.e., the whole plant
instead of each piece of equipment)? (3) Is it reasonable to subject owners
or operators to the standards if they are replacing an existing piece of
equipment with another piece of equipment of equal or smaller size? In
summary, the EPA has concluded that the standards should not differentiate
between sources located in attainment versus nonattainment areas and that
the narrow definition should be retained. However, the Agency agrees that
the replacement of an existing piece of equipment with another piece of
equipment of equal or smaller size should be excluded from coverage in this
case due to special characteristics of this source category. The rationale
for these conclusions is discussed in the remaining paragraphs of this
response.
Attainment versus nonattainment areas — Section lll(b)(4) of the Clean
Air Act states "the provisions of this section shall apply to any new source
owned or operated in the United States." There is no distinction made in
Section 111 between new sources which locate in attainment areas and new
sources which locate in nonattainment areas. Therefore, the EPA has
concluded that the standards should not differentiate between attainment and
nonattainment areas.
Broad versus narrow definition of affected facility — In accordance
with its congressional mandate to set performance standards based on best
systems of continuous emission reduction considering cost, the EPA reviewed
all operations associated with the mining and processing of nonmetallic
minerals for possible coverage by the NSPS. Those facilities now listed as
affected and covered by the NSPS represent those for which the EPA has
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adequately demonstrated control techniques, which can be applied at
reasonable cost.
As discussed in the proposal preamble, the choice of the affected
facility is based on the Agency's interpretation of Section 111 of the Act
and judicial construction of its meaning. [The most important case is
ASARCO. Inc. v. EPA. 578 F.2d 319 (D.C. Cir. 1978)]. Under Section 111, the
NSPS must apply to "new sources;" "source" is defined as any building,
structure, facility, or installation which emits or may emit any air pollu-
tant" [Section lll(a)(3)]. Most industrial plants, however, consist of
numerous pieces or groups of equipment that emit air pollutants and that
might be viewed as "sources." The EPA, therefore, uses the term "affected
facility" to designate the equipment, within a particular kind of plant,
which is chosen as the "source" covered by a given standard.
Since the purpose of Section 111 is to minimize emissions by application
of the best demonstrated control technology (considering cost, health and
environmental effects, and energy requirements) at all new, modified, and
reconstructed sources, there is a presumption that a narrower designation of
the affected facility is proper. In order to promulgate the broader
designation, EPA would have to find that it would achieve greater total
emission reductions or equivalent total reductions with significant other
benefits such as reduced costs, energy consumption or other environmental
impacts. In determining the appropriate designation of affected facilities
for this NSPS, the EPA considered the cost, environmental, energy, and
economic impacts associated with the narrow designation as it was proposed
(i.e., each crusher, grinding mill, screening operation, bucket elevator,
belt conveyor, bagging operation, storage bin, enclosed truck or railcar
loading station) and determined them to be reasonable. For all new
processing plants expected to be constructed in the first 5 years after
proposal of the NSPS, cost and economic impact analyses were prepared which
analyzed the NSPS impacts on the economic feasibility of new plants. Where
the analysis showed that the cost of control equipment had unreasonable
impacts on the economic feasibility of a particular size of new plant, an
exemption from compliance with this NSPS was given (e.g., 25 ton per hour
stationary crushed stone plants, See §60.670).
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For existing facilities within the nonmetallic mineral industry, the
EPA's information about the industry indicated that there would be few
modifications and reconstructions. Modifications were not expected to occur
because of the industry's operating characteristics. For example, changes
to the equipment are not typically made for processing different types of
raw materials because the equipment is designed to process different
materials and changing raw materials would, therefore, not constitute a
modification. In fact, the only plausible case the Agency found in which
emissions would be increased from an existing facility was the case of
increasing operating hours, a case which is specifically exempt from
coverage through modification provisions if it is accomplished without a
capital expenditure.
Similarly, reconstruction in its usual sense was not expected to occur
frequently. While parts of affected facilities (narrow definition) are
replaced, these replacements are regular, routine maintenance activities,
such as replacement of ore contact surfaces and other nondepreciable items.
These routine replacements are performed to keep existing equipment
operational. Because of these maintenance activities, the equipment has a
long operational life and neither reconstructions nor replacements are
expected to be frequent. Based on information available to the Agency, the
EPA's judgment is that total replacements, if they occurred, would most
likely consist of replacing existing equipment with larger capacity
equipment for purposes of increasing production capacity or changing product
specifications.
After considering processes using existing equipment and additions and
changes which might be made to them, the EPA concluded that the most likely
change to occur would be the addition of completely new production lines of
equipment with equipment designed for increased production or changes in
product specifications. Based on the cost and economic impact analyses
prepared, the EPA concluded that it was economically reasonable to control
new production lines.
Expansions of plant capacity typically occur with the addition of a new
crushing or grinding line, which may include one or more of each of the
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facilities listed above. With the entire plant designated as the affected
facility (broader designation), the addition of a new crushing or grinding
line would cause the entire plant to be covered by the standards. This
could cause significant cost, economic and energy impacts because of
retrofitting control equipment on the existing pieces of equipment. Under
the narrow designation of affected facility, the standards would cover only
the new equipment used to expand the plant. Because the economic impact
analysis showed it was reasonable to control the new equipment and because
of the potential for significant impacts associated with the broader
designation, it was concluded that the narrow designation of affected
facility was appropriate and reasonable.
Replacement of equipment with similar equipment of equal or smaller
size — Contrary to the information developed by the EPA, representatives of
several major trade groups representing the Associated General Contractors
of America, The Colorado Rock Products Association, The National Crushed
Stone Association, The National Industrial Sand Association, The National
Lime Association, The National Limestone Institute, The North Carolina
Aggregates Association, The Ohio Aggregate Association, The Southern
California Rock Products Association and the Brick Institute of America have
commented that replacements of equipment with new equipment of the same size
do occur. In fact, The National Crushed Stone Association said that
replacements, including replacements of existing pieces of equipment with
similar pieces of equipment of equal size occur on a regular and relatively
routine basis.
These comments are inconsistent with the other information the EPA
gathered in support of the standards. Because the Agency's information
indicated that such replacements are not likely, the impacts of replacement
of equipment with new equipment of the same or smaller size were not fully
analyzed. However, it is true that control technology will normally be
designed for an entire plant. And, if such replacements are frequent, costs
and economic impacts, because of the additional costs associated with
retrofitting, could be significant.
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The EPA requested specific data on the frequency of replacement of
equipment with equipment of the same or smaller size from these industry
representatives but received nothing more definitive. However, the nature
of this industry may make this type of information difficult to obtain.
There are over 10,000 existing sand and gravel and crushed stone plants in
the U.S. Because there are so many producers, so widely dispersed, it is
difficult for either the industry or EPA to gather comprehensive information
needed to fully quantify the equipment replacement practices at all of these
plants. However, EPA agrees that the replacement practices cited by the
industry are certainly possible and to the extent that such replacement does
occur where controls are in place, separate control of each individual piece
of equipment is not warranted.
Therefore, to resolve this issue, the EPA has included an exemption
from compliance with the particulate emission limits of the standards for
replacement of existing equipment with similar equipment of equal or smaller
size. Although industry commenters have said that such replacement is
common, the EPA has no data that would indicate that it is a widespread
practice. Moreover, EPA's growth and environmental impact projections were
not based on such replacements. Therefore, the EPA expects no significant
impact on emission reductions which could be achieved under the standards.
The EPA will, however, reassess this exemption in 4 years during the review
of the standards. Recordkeeping provisions have been added to the final
standards to allow the Agency to obtain statistics on the number and type of
such replacements which occur. Then, during the review, the EPA will
reconsider the need for this exemption and, if appropriate, analyze the
cost, economic, energy, and environmental impacts associated with regulation
of emissions in cases where equipment is replaced with similar equipment of
equal or smaller size.
2.3.2 Comment: (IV-D-5)
One commenter questioned whether the proposed designation of affected
facility is consistent with the definition of source that is found in the
Clean Air Act. He felt that an individual piece of equipment is not a
building, a structure, a facility, or an installation.
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Response:
As summarized in Section 2.3.1, EPA believes the definition of each
piece of equipment as the affected facility is consistent with Section 111
of the Clean Air Act and its interpretation in court cases such as ASARCO,
Inc. v. EPA (578 f.2d 319).
2.3.3 Comment: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-31, IV-D-32,
IV-D-35)
Six commenters believe that the current designation of affected facility
is appropriate for two industries, industrial sand processing and fuller's
earth processing.
Response:
EPA concurs with these commenters that the proposed definition of
affected facility is appropriate for these industries. As detailed in
Section 2.3.1, EPA believes the proposed narrow definition is also
appropriate for other nonmetallic minerals industries.
2.3.4 Comment: (IV-D-5, IV-D-11, IV-D-24, IV-D-28)
Several commenters complained that the proposed affected facility
designation would cause permitting costs to be dramatically increased
because a permit would be required for each piece of equipment instead of
one permit for the entire plant. In addition, they said, the paperwork
requirements would be substantially higher than if the entire plant were
designated the affected facility. One commenter (IV-D-24) stated the
current designation would require Federal, State and local agencies to
track, or keep a record of, all elements of each processing plant
manufactured after August 31, 1983. He said such tracking would require
diverting field enforcement resources to essentially administrative duties,
thus substantially reducing inspection activities.
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Response:
EPA has checked with State agencies in every State the commenters were
concerned about and found that, in all cases, only one permit would be
required for air emissions from a new plant. This one permit could cover as
many affected facilities as there are at the plant. Other NSPS with narrow
definitions of affected facility have been promulgated, and no problems have
been reported concerning multiple permits being required because of this
definition. Therefore, EPA finds that permitting costs will not increase
and paperwork will be reasonable.
The EPA or State agencies administering the standards would have to
track, or keep records of, new equipment at both new plants and capacity
expansions at existing plants under either a narrow or broad definition of
affected facility. Because of reconstruction provisions, they would also
have to track the installation of new equipment at existing plants under the
broad or narrow definition of affected facility. When plants replace
existing facilities with new facilities of equal or smaller size, as
provided for in §§60.670 and 60.676, the owner or operator will be required
to notify the States and EPA's Office of Air Quality Planning and Standards,
but they will not have to comply with the NSPS emission limits. Administra-
tive reporting and recordkeeping requirements for these standards are
similar to those for other NSPS. The EPA has estimated the administrative
recordkeeping burden, and it has been determined to be reasonable.
2.3.5 Comment: (IV-D-34)
One commenter stated that at brick plants the processing equipment is
normally enclosed in a building. Under the current designation of affected
facility, emissions would be limited from each piece of equipment without
any consideration as to whether the emissions were leaving the building.
Therefore, he said, EPA would be regulating the air in the workplace as
opposed to the ambient air.
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Response:
It was not EPA's intent to regulate workplace air. The intent of
Section 111 of the Clean Air Act is to limit emissions to ambient air. EPA
has added provisions to the promulgated standards addressing the enclosure
of affected facilities in buildings. As described in Section 2.4.1,
emissions tests may be conducted outside such a building. If there are no
visible fugitive emissions and the exhaust vent from the building (if there
is one) meets the stack standard of 0.05 g/dscm (0.02 gr/dscf) and 7 percent
opacity, then the affected facilities inside are in compliance. Only if
these limits are exceeded, must one take opacity measurements inside the
building to determine which individual facilities are in compliance.
2.3.6 Comment: (IV-D-13, IV-D-25, IV-D-41)
Several commenters requested that additional items be included in the
list of components that are replaced regularly as part of routine repair and
maintenance. One commenter suggested that conveyor idlers, shafts, pulleys,
gears and bucket elevator chains be added to the list. Another commenter
suggested that electrical drive components such as motors, bearings, and
speed reducers be added and considered as routine repair and maintenance.
Response;
Most of the items the commenters list are "nondepreciable" components.
Replacement of all nondepreciable components is already excluded from
calculation of fixed capital costs of new components and will not trigger
reconstruction provisions as explained in the preamble to the proposed
regulation (48 FR 39574). EPA cannot provide an exhaustive, all-inclusive
list of frequently replaced components in the standards. Therefore, plants
should be aware that replacement of any nondepreciable component will be
excluded from reconstruction provisions. Depreciable items, other than ore
contact surfaces (which are frequently replaced), will not be exempt from
reconstruction provisions.
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2.3.7 Comment: (IV-D-19, IV-D-25)
Two commenters suggested that changes be made to what is allowable or
exempt from reconstruction provisions. One commenter requested that preven-
tive maintenance and emergency repairs to existing facilities be exempted.
Another commenter requested that all expendable materials be exempted from
the two year accumulation requirement.
Response:
Routine maintenance as defined in the preamble for the proposed
regulation will be exempted. This exemption includes nondepreciable
components and routinely repaired ore-contact surfaces including crushing
surfaces, screen meshes, bars, and plates, conveyer belts, and elevator
buckets. All other depreciable repair and maintenance activities will be
subject to the reconstruction and modification provisions.
Repairs to a facility that occur as a result of an unplanned emergency
or catastrophic occurrence are not exempted from reconstruction considera-
tions unless they are covered under the nondepreciable or ore contact surface
exemptions. The reconstruction provisions apply in a straight-forward
manner to any existing facility undergoing substantial component replacement.
As noted in the preamble to the regulation regarding reconstruction of
existing facilities (40 FR 58417, December 16, 1975), the purpose of the
reconstruction provisions is to "recognize that replacement of many of the
components of a facility can be substantially equivalent to totally replacing
it at the end of its useful life with a newly constructed affected facility."
By requiring this type of essentially new facility to comply with NSPS, the
Agency furthers Congress1 intent of ensuring that best demonstrated
technology is applied during the turnover of the nation's industrial base.
Neither the language nor the purpose of either Section 60.15 nor the
definition of "new source" in Section 111 supports an exemption based on the
owner's reasons for replacing the facility component.
The second commenter gave the items listed in comment number 2.3.6
as examples of "expendable" materials he thought should be exempt from
reconstruction provisions. EPA assumes he meant that these items are
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"expensible", or could be expensed, and are not depreciable. As stated in
the preamble, nondepreciable components are excluded from consideration in
calculating component replacement costs (48 FR 39574). Therefore, replacing
such items would not cause an affected facility to be subject to reconstruc-
tion provisions.
2.3.8 Comment: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35)
Five commenters requested clarification on what is considered as the
beginning of the two year period related to the reconstruction provisions.
As they interpret it, a continuous program of component replacement is one
that is proposed or initiated within a two year period. Another commenter
requested clarification on whether the replacement of an affected facility
is exempted if it does not increase emissions or does not cost over
50 percent of the cost of a new plant.
Response:
The two year period begins when the owner or operator commences a
reconstruction as by signing a formal contract for the construction or by
beginning the actual reconstruction if the work is done in-house. Any
activities that commence during that two year period, whether or not the
construction is actually completed, are counted towards the 50 percent
reconstruction threshold.
An affected facility (e.g., crusher, grinding mill, etc.) is subject to
reconstruction provisions if the fixed capital costs of reconstruction in a
two year period exceed 50 percent of the fixed capital cost which would be
required to construct a comparable entirely new affected facility. The
affected facility for the purpose of determining these costs is the indivi-
dual piece of equipment as defined in 40 CFR §60.670 and §60.671, not the
entire plant. However, replacement of an existing affected facility with a
new facility of equal or smaller size as described in §60.670(d) is exempt
from compliance with emission limits, but is subject to the reporting and
recordkeeping requirements in §60.676.
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2.3.9 Comment: (IV-D-23)
One commenter objected to the special definition of reconstruction in
the proposed standards. He was concerned that the exclusion of the
replacement of ore-contact surfaces will lessen the likelihood that plants
or facilities will become subject to the standards due to reconstruction.
He suggested that the definition of reconstruction in Subpart A be retained
as the basis for reconstruction determinations.
Response:
Under the reconstruction provisions, applicable to all standards of
performance, an existing facility might become subject to the standards if
the components were replaced to such an extent that the fixed capital cost
of new components exceeded 50 percent of the fixed capital cost required to
construct a comparable new facility.
As noted in the preamble to the proposed regulation regarding
reconstruction of existing facilities, (40 FR 58417, December 16, 1975), the
purpose of the reconstruction provisions is to "recognize that replacement
of many of the components of a facility can be substantially equivalent to
totally replacing it at the end of its useful life with a newly constructed
affected facility." By requiring this type of essentially new facility to
comply with NSPS, the Agency furthers Congress1 intent of ensuring that best
demonstrated control technology is applied during the turnover in the
nation's industrial base. The reasoning underlying the reconstruction
provisions may apply even when replacement of the components of a facility
occurs over a relatively long period of time.
Section 60.15 defines the "fixed capital cost" of replacement components
as the capital needed to provide all the "depreciable" components. By
excluding nondepreciable components from consideration in calculating
component replacement costs, this definition excludes many components that
are replaced frequently to keep the plant in proper working order. There
may, however, be some relatively minor depreciable components that are
replaced frequently for similar purposes. For example, crusher jaws,
spindle surfaces, and screen meshing are typically replaced on regular
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intervals ranging from 1 to 6 months, and may represent from 5 to 10 percent
of the cost of new equipment. In the Agency's judgment, maintaining records
of the repair or replacement of these items may constitute an unnecessary
burden. Moreover, the Agency does not consider the replacement of these
items an element of the turnover in the life of the facility which concerned
Congress when it enacted Section 111. Therefore, in accordance with
40 CFR 60.15(g), the standards exempt certain frequently replaced compo-
nents, whether depreciable or nondepreciable from consideration in applying
the reconstruction provisions to non-metallic processing plant facilities.
The cost of these components will not be considered in calculating either
the "fixed capital cost of the new components" or the "fixed capital costs
that would be required to construct a comparable new facility" under §60.15.
In the Agency's judgment, these items are ore-contact surfaces on processing
equipment, including crushing surfaces; screen meshes, bars, and plates;
conveyer belts; and elevator buckets.
2.3.10 Comment: (IV-D-25)
One commenter requested that the proposed standards be revised to use
the definition of capital expenditures in the accelerated cost recovery
system program in IRC Section 263.
Response:
The commenter did not provide any additional details or clarification
of his comment. EPA assumes that he is referring to the fact that the
General Provisions use the "annual asset guideline repair allowance
percentage" in defining capital expenditure. The standards state that
increases in production rate will not be considered modifications if they
can be accomplished without a capital expenditure exceeding the product of
the existing Internal Revenue Service annual asset guideline repair
allowance of 6.5 percent per year and the facility's basis (48 FR 39573).
This annual repair allowance is part of the Asset Depreciation Range System
(ADR) under the Internal Revenue Code. In 1981, the Accelerated Cost
Recovery System (ACRS) was introduced as the method of calculating
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depreciation for assets placed in service after 1980. The ACRS does not
include an allowable repair percentage.
EPA believes it is reasonable to base the modification exemption on the
6.5 percent repair allowance. The annual asset guideline repair allowance
percentage is still in effect for facilities existing prior to 1981, and it
is included in IRS Publication 534 for 1983 tax returns.
The portion of the standards where the annual asset guideline repair
allowance is used are the modification provisions, which state that
facilities can make capital expenditures of up to the 6.5 percent repair
allowance without becoming subject to the modification provisions. However,
EPA believes few plant owners will need to calculate the repair percentage
or will spend in excess of 6.5 percent, because EPA has excluded the most
likely types of repairs from the calculation of capital expenditures. As
explained in the preamble to the proposed standards (48 FR 39573) facilities
may spend unlimited amounts on routine maintenance, repair, and replacement
such as replacement of ore contact surfaces subject to high abrasion without
becoming subject to the modification provisions. Replacements of existing
affected facilities with new facilities of equal or smaller size are also
exempt from compliance with the emissions limits. Because of these
provisions, it is unlikely existing facilities will be impacted by the EPA's
use of the annual asset guideline repair allowance. The 6.5 percent repair
allowance for this standard is therefore deemed reasonable.
2.4 EMISSION CONTROL TECHNOLOGY
2.4.1 Comment: (IV-D-13, IV-D-34, IV-D-41)
One commenter was concerned that no provision was made for enclosure of
facilities that emit fugitive dust. The commenter said they had found that
enclosure and shrouding are among the most cost-effective control measures
available. Two commenters objected to the fact that the proposed standards
do not allow for enclosing the affected facilities as a control option.
They stated that the use of a building to house these sources is precluded
by the affected facility designation. The commenters said the 1979
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Background Information Document stated that observations could be made
outside of a building to determine if facilities inside were in compliance,
but that this language was excluded from the 1983 Background Information
Document. The commenters therefore believed the proposed standard would
require observations to be taken at each piece of equipment inside a
building, and that facilities might be held in violation even if emissions
did not escape the building. They felt the building should be considered a
control system and measurements taken outside of it.
Response:
Provisions have been added to the promulgated standards which apply to
affected facilities enclosed in buildings. Buildings may be vented or
unvented. A vent is defined as an opening through which there is induced
air flow for the purpose of exhausting from a building air carrying
particulate matter emissions from one or more affected facilities. If a
building is unvented and no visible fugitive emissions escape from the
building, as determined by EPA Method 22, then all affected facilities
inside the building will be determined to be in compliance with the fugitive
emissions standard. If there are visible fugitive emissions from the
building, opacities of individual affected facilities must be measured
inside the building to determine whether they are in compliance with the
fugitive standard.
If such a building is vented, there are no visible fugitive emissions,
and emissions from the vent meet the stack standard of 0.05 g/dscm
(0.02 gr/dscf) and 7 percent opacity, then the affected facilities inside
the building will be determined to be in compliance. If emissions exceed
these standards, measurements must be taken inside the building at the
individual affected facilities, and the standards applicable to each
affected facility must be met inside the building. These provisions allow
buildings to be used as control devices and compliance measurements to be
taken outside the building if the building can meet a "no visible emissions"
fugitive standard and the specified stack emissions standards if emissions
are vented.
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2.4.2 Comment: (IV-D-1)
One commenter was concerned because electrostatic precipitators (ESPs)
were not mentioned as viable and demonstrated control devices for the non-
metallic minerals processing industry.
Response:
ESPs were not mentioned as a demonstrated control technology because
they are rarely used in the nonmetallic minerals processing industry and may
not be applicable to the range of conditions found in the industry. However,
the standard does not preclude the use of ESPs. If a plant met the stack
emissions standard of 0.05 g/dscm (0.02 gr/dscf) and 7 percent opacity using
an ESP, it would be in compliance with the standards.
2.4.3 Comment: (IV-D-18, IV-D-21, IV-D-22)
Three commenters stated that a baghouse is not a feasible control
option for portable plants. They said that the standard portable equipment
for a crushing plant is made up of several units, each of which in itself is
portable. According to the commenters, to put a hood or some other unit on
these is not a practical solution. They thought it unreasonable to
dismantle and remove some type of hood every time the plant is moved.
Response:
EPA conducted an economic analysis of the application of baghouses to
portable plants. This is presented in Supplement A of the Background
Information Document for the proposed standards (EPA-450/3-83-001a).
Several sizes of model plants in the crushed stone and sand and gravel
industries were evaluated. The average number of moves per year was
estimated to be four if an entire plant moved from one quarry to another.
If a plant moved within one quarry, it moved up to 24 times per year. Two
control options were considered: one using a single baghouse to control
several pieces of equipment at the plant, and the other assuming individual
baghouses on each crusher and its associated screen as well as on the final
screen. Costs of control were estimated using information from a variety of
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sources. Movement parameters and associated costs were also estimated and
included in the economic analyses. Both installed capital cost and total
annualized cost were developed for each model plant using each of the 2
control options.
A Discounted Cash Flow analysis (DCF) was used to further analyze
economic impacts of NSPS on portable plants. The model was used to estimate
the financial status or profitability of portable plant operations, both
before and after the addition of NSPS controls. The costs of moving the
plant and control devices were included in the analysis. The model was run
under several different scenarios varying portable plant capacity, average
hours of operation per year, and the level of mobility among and within
quarries. The analysis is thought to be conservative. Assumptions as well
as results are detailed in Section 2.5.4 of this chapter and in Supplement A
of the Background Document for the proposed standards (EPA-450/3-83-001a).
It was found that baghouse control might be unreasonably costly for portable
crushed stone plants and portable sand and gravel plants with capacities of
136 Mg/hr (150 tons/hr) or less. Therefore, they were exempted from the
proposed NSPS. EPA's analysis shows that larger portable plants can use
baghouses and retain profitability.
2.4.4 Comment: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35)
Five commenters objected to wording in the preamble to the proposed
standards related to baghouses. The two statements they objected to are:
(1) "In other instances, wet dust suppression may not provide the necessary
control and baghouse controls would be needed", and (2) "The most efficient
collection device used in the nonmetallic mineral industry is the fabric
filter or baghouse." They felt that these statements contradict other
statements in the preamble and the performance-oriented standards. One
commenter was also concerned that wet scrubbers were not mentioned as best
demonstrated technology.
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Response:
The preamble statements are correct. Wet dust suppression cannot be
used in all cases since moisture may interfere with certain processing
steps. It also may not be possible in freezing weather or in arid regions.
Wet suppression may be inadequate if the material processed contains a high
percentage of fines (EPA-450/3-83-001a). For these reasons, some plants
must use combination systems or dry collection followed by baghouses.
The collection efficiencies given in the preamble for the proposed
standards (48 FR 39569) support the statement that fabric filters are the
most efficient collection device used in the industry. Collection efficien-
cies of over 99 percent can be attained even for particles under 1 micron in
diameter. The typical 6 inch pressure drop scrubbers used in the industry
are less efficient, and even 15 inch pressure drop scrubbers achieve only
80 to 95 percent collection of submicron particles. Only high energy wet
scrubbers, rarely used in the industry, with pressure drops of about
30 inches can achieve over 99 percent collection efficiency for particles
0.2 to 1.0 microns in diameter, and would be less efficient for smaller
particles. Thus, fabric filters are the most efficient collection devices
for small particulates.
Standards were set based on emissions achievable using fabric filters,
however, if plants can meet the stack emissions standards of 0.05 g/dscm
(0.02 gr/dscf) and 7 percent opacity, other technologies can be used. The
best technology for every specific plant may not be a fabric filter. When
operating conditions, plant configuration, and costs are considered, another
technology may give comparable emissions reduction at a lower cost. In the
case of scrubbers, the opacity standard does not have to be met. This
provision was specifically included in both the proposed and final versions
of the standards (44 FR 39573) because scrubbers are a demonstrated
technology which can be used to achieve the specified outlet concentrations.
But opacity has been shown not to be a reliable indicator of particulate
emissions concentrations from wet scrubbers. The standards therefore allow
a variety of technologies including scrubbers to be used, and as long as the
standards are met, all are considered acceptable.
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2.5 ECONOMIC IMPACT
2.5.1 Comment: (IV-D-3, IV-D-18, IV-D-24)
Several commenters questioned EPA's conclusion that requiring baghouse
control on portable plants is reasonable. They stated that each time a
facility was relocated the operator would have to modify the control system.
They did not believe the costs associated with this activity were included
in the cost estimates.
Response:
EPA modeled portable plants with 2 different plant configurations and
2 control options to account for variability in portable plants. The two
types of configurations are straight-line and L-shaped. Control option 1
assumes one baghouse is used to control the entire portable plant if the
plant's capacity is 270 Mg/hr (300 tons/hr) or less. For larger plants, it
was assumed that the primary crusher would be ducted to one baghouse and all
other pieces of equipment would be ducted to a second baghouse. Option 2
assumes the following sources are controlled by individual baghouses:
- primary crusher,
- secondary crusher and associated screen,
- tertiary crusher and associated screen, and
- final screen.
For both options, emissions from conveyer transfer points are hooded and
ducted to the baghouse system.
Plants are assumed to move an average of 4 moves per year between
quarries or 24 moves per year within a quarry. It is believed the plant
would usually be set up in a similar configuration in order to minimize
moving and set-up costs and to avoid modification of process equipment. The
costs of dismantling, moving, and reassembling the control system were
estimated to be between $8,500 and $16,000 per move (EPA-450/3-83-001a).
These costs were included in the discounted cash flow (DCF) analysis used to
predict the profitability of portable plants with and without an NSPS.
These estimated costs of moving include costs of minor modifications in the
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duct work. Economic analysis was not performed for the specific case where
a portable plant added new pieces of equipment. However, if an analysis of
this situation were done, both processing capacity and control costs would
be similar to those calculated for larger size model portable plants. The
costs for moving portable plants have been included in EPA's economic
analyses; and it has been determined that the costs of controls required by
the proposed standard are reasonable. (See Section 2.5.2 for details on the
determination that costs are reasonable.)
2.5.2 Comment: (IV-D-3, IV-D-18)
One commenter stated that most operators in the industry would hardly
consider costs such as $936,000 and $219,000 for baghouse control systems
reasonable. Another commenter stated the costs as presented in the preamble
do not make sense because a portable plant with 50 percent more capacity
than a fixed plant could not have the same dust control for 25 percent of
the cost.
Response:
The estimated cost of baghouse control for fixed plants with crushing
operations ranges from $70,000 for a 9 Mg/h (10 tons/h) plant to $396,000
for a 544 Mg/h (600 ton/h) plant or from 12 to 9 percent, respectively, of
the plants' total capital costs. There was a typographical error in the
preamble to the proposed rule in the Federal Register (48 FR 39566), where
the $396,000 cost for baghouse control was written as $936,000. The correct
cost estimate is $396,000. For fixed plants with crushing and grinding
operations estimated costs range from $109,000 for a 9 Mg/h (10 ton/h) plant
to $219,000 for a 136 Mg/h (150 ton/h) plant, or from 16 to 6 percent,
respectively, of the plants' total capital cost. EPA's economic analyses
concluded that for each mineral industry, the annualized control cost in the
fifth year divided by annual output is less than 2 percent of the price of a
ton of product. The discounted cash flow analyses showed that most new
plants would be able to operate profitably if they were required to install
baghouses. Conservative assumptions were used in these analyses, and if
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plants chose to use wet suppression or scrubbers to meet the standards,
costs would be lower. However, DCF analyses showed the cost of baghouses
might prevent the construction of small plants in certain industries, so
these types of plants were exempted from the regulation. Thus, the plants
covered under the standards will not face unreasonable economic impacts if
the standards are promulgated, and substantial emissions reductions can be
achieved.
The commenters1 concern about control costs for portable versus fixed
plants was partly caused by the misprint on costs for fixed plants in the
Federal Register (explained above). However, estimated control costs for
portable plants are less than for fixed plants. One reason for the
difference in control costs is that portable plants are typically more
compact, so ducting is less expensive. Another factor is that portable
plants generally have fewer steps and less equipment than typical fixed
plants with the same processing capacity. Since there are fewer affected
facilities at typical portable plants, control costs for the entire plant
would be lower.
2.5.3 Comment: (IV-D-18)
The commenter suggested that all of the cost data be presented in
current dollars because the higher costs may affect the economic analysis
results.
Response:
When dollar amounts or cash flows for multiple years are compared, such
dollars must be defined as either constant (real) or current (nominal)
dollars. The difference is that constant dollars are adjusted to eliminate
the effects of inflation, while no such adjustment is made for current
dollars. For this reason current dollars are not directly comparable
because they may embody various degrees of purchasing power. On the other
hand, constant dollars are comparable because they are adjusted by an index
that reflects the rate of inflation. Constant dollars are always expressed
in terms of a single year's dollars. In the case of the economic analysis
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constant (1976) dollars were used in Chapter 8 of the Background Document
for the proposed standards while constant (1979) dollars were used in the
portable plant analysis contained in Supplement A.
The economic analysis has used a Discounted Cash Flow (DCF) methodology
to estimate how the decision to construct new plants will be affected by the
NSPS costs. Because the DCF analysis considers costs and revenues over the
useful life of the new plant, the use of constant dollars provides a standard
of reference for evaluating the real resource costs of the standard, as
those costs are incurred at various points in the future. However, consis-
tency is ensured because the analysis discounts future income streams by a
real (i.e., inflation adjusted) interest rate. If current dollars had been
used in the DCF analysis, a nominal interest rate, which includes inflation,
would be more appropriate for discounting. However, in this case the
evaluation of real resource costs over time would become more complicated
because future control costs would be inflated by some assumptions regarding
future rates of inflation. Such complications are typically avoided through
the use of constant dollars in the economic analysis.
Finally, if the 1976 and 1979 constant dollars used in the analysis are
updated to 1983 dollars, the conclusions presented in the economic analysis
would still hold. This is true because between those years, prices for
nonmetallic minerals and the costs to operate the NSPS control equipment
have increased at a similar rate. Consequently, inflation has not altered
the basic ratio of NSPS control costs to industry revenues over recent years
(Docket No. ).
2.5.4 Comment: (IV-D-18, IV-D-24)
The commenters questioned why EPA chose a cutoff size of 150 tons per
hour for portable plants when the data presented in the BID indicates that
plants with capacities of 150 tons per hour and 300 tons per hour could not
operate in an economically feasible manner given baghouse control costs.
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Response:
EPA's Discounted Cash Flow (DCF) analysis indicates that for crushed
stone and sand and gravel plants, controls required by the standards would
make investment in portable plants of 150 tons per hour economically
infeasible, but for portable plants with 300 ton per hour capacities the
analysis does not indicate clear economic feasibility or infeasibility.
However, in order to avoid the understatement of the adverse economic
consequences that would affect the industry members, several "worst case"
(i.e., from the industry point-of-view) assumptions have been made by the
DCF analysis. Among the assumptions are: NSPS costs are calculated from an
uncontrolled baseline (i.e., there are no SIP costs); the plant is operated
as a separate business entity; cost pass-through is limited by competition
from existing plants in the same area; the plant will operate at most
1,600 hours per year (vs. 2,000 hours per year for a stationary plant); a
small crane and flatbed truck will be needed to move the portable plant
baghouse; and baghouses will be used as opposed to wet dust suppression
systems which cost significantly less.
The cutoff point was set at 150 tons per hour because the economic
analysis shows that even if the worst case assumptions noted are relaxed,
the economic viability of portable plants of this and smaller sizes remains
in doubt. On the other hand, for plants larger than 150 tons per hour, the
benefits of "economies of scale" increase the profitability of these plants
so that NSPS costs are significantly less burdensome. Finally, it should be
noted that although the economic analysis questions the economic feasibility
of the 300 ton per hour portable plant (Supplement A) with NSPS controls, it
is highly unlikely that all worst case assumptions would hold true for such
a plant. In reality, if only one or two of the worst case assumptions are
relaxed the plant is shown to be economically feasible.
2.5.5 Comment: (IV-D-24)
One commenter suggested that portable plants in remote areas be
exempted because they are generally smaller operations where water is
unavailable and trucking of water or adding baghouses for control could be
cost prohibitive.
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Response:
EPA's economic analyses show that baghouses are affordable for all
portable plants except those specifically exempted. (Portable sand and
gravel plants and crushed stone plants with capacities under 136 Mg/h
(150 tons/h) are exempt from the standards.) Since baghouses are affordable,
the affordability of other less costly technologies does not need to be
analyzed; although, plants may use other technologies to meet the standards.
The purpose of NSPS is to require new sources, wherever they are located, to
reduce emissions to the level achievable by the best technological system of
emissions reductions, considering cost, energy, and environmental impacts.
Individual plants within a source category cannot be excluded on the basis
of remoteness when economic analyses show their costs of control to be
reasonable.
2.5.6 Comment: (IV-D-14, IV-D-16, IV-D-31, IV-D-32)
Several commenters felt that it was neither reasonable nor economical
to require a performance test on a small baghouse. Three of them said it
would cost more to test small baghouses than to buy them. They were
concerned with the costs of manifolds, stacks, and test platforms which
would be required for a test. Three commenters defined a small baghouse as
one which has a maximum cloth area of 500 square feet. Another person
suggested that the cutoff be 10,000 cfm. One commenter questioned why no
mention was made of stack testing preparation costs and stack testing cost.
They felt that these costs should be included in the cost and economic
impact analyses.
Response:
Small baghouses will not be exempt from performance tests under the
standards. Performance tests are necessary to ensure compliance with the
standards and gain information for the 4-year NSPS review. EPA has found
that similar facilities with similar control devices may not have the same
emissions characteristics due to variables in types of processes, process
operating conditions, and control system operation. Because of this
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variability, performance tests are necessary to ensure compliance. Opacity
is used as an indicator of performance, but does not allow the necessary
precision of a stack test. Furthermore, testing assures the manufacture of
quality baghouses. Without testing, price competition could promote the
sale of inferior quality equipment.
EPA has found the cost of performance testing to be reasonable. The
agency has calculated that the costs of performance testing would amount to
at most one third of the installed capital costs of a small baghouse. These
costs are based on the smallest baghouse expected for the model plants
described in the Background Document for the proposed standards. The cost
of manifolds, stacks, and test platforms are relatively low if they are
designed and incorporated into the baghouse control system when the system
is purchased. There is a factor covering these items in the installed
capital costs presented in the Background Document for the proposed
standards. Furthermore, baghouses would have to be designed to allow
testing even if they were exempt from the performance test requirement,
because if a facility could not meet the opacity standard, a performance
test would be required to determine compliance. Designing baghouses to
allow testing would avoid the costs of retrofitting in this situation.
Other NSPS, such as the lead-acid battery manufacturing plants
standards, require performance tests on baghouses at least as small as those
considered under the nonmetallic minerals NSPS. The costs of testing have
been determined to be reasonable in these cases.
2.5.7 Comment: (IV-D-7, IV-D-41)
One commenter stated that eventually all existing plants will fall
under these standards and this will entail retrofitting all facilities with
control systems. He was skeptical of the reasonableness of this situation
and doubted that the $105,000 annualized cost for a 600 ton per hour plant
would include the maintenance and increased labor associated with many of
these systems. Another commenter did not believe that additional retro-
fitting costs such as additional structural steel for supporting bag
collectors at roof top elevations or extensive duct lengths and configura-
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tions to reach control equipment which cannot be adjacent to the affected
facility have been adequately addressed in the economic impact assessment.
Response:
Since replacement of existing affected facilities with new facilities
of equal to smaller size and replacement of routinely replaced ore contact
surfaces and nondepreciable components of affected facilities have been
exempted from compliance with the emission limits in the regulation, EPA
believes few, if any, existing plants will be affected by the modification
and reconstruction provisions of the standards. Where retrofitting may be
necessary, EPA does not believe it will entail costs high enough to affect
the economic analysis results. Existing plants will be required to comply
with the standards if new equipment is added. Capacity expansions at
existing plants were modeled prior to proposal of the standards (EPA-450/3-
83-OOla). Discounted cash flow analysis showed that control would be
economically feasible in these situations.
2.5.8 Comment: (IV-D-12, IV-D-15, IV-D-16)
Three commenters questioned the industry growth rates discussed in the
preamble. Specifically, they felt the growth estimates of up to six percent
for the crushed stone and sand and gravel industry were too high. They
claimed growth rate predictions made by the Bureau of Mines are approximately
one percent for both industries through 1990. One commenter suggested that
EPA withdraw the proposed standards and make new calculations based on
realistic growth rates.
Response:
Table 8-42 of the Background Information Document (BID) identifies a
four percent annual rate of growth for crushed stone and a one percent
annual rate of growth for sand and gravel. More recent estimates made by
the Bureau of Mines suggest that annual growth rates for both industries
should be about one percent up to 1990.
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However, an assumed rate of growth for total output of an industry,
cannot be translated directly into an estimate of the number of new plants
that will be constructed. For example, the replacement of existing plants
that have reached the end of their useful lives would require the construc-
tion of new plants even if total production is assumed to be constant, or
even decline, over future years. Also, because of the local nature of the
markets in question, growth in demand at the local level may prompt new
plant construction regardless of future output at the national level.
Finally, the conclusions presented in the BID regarding the economic
feasibility of this NSPS would still hold, regardless of the assumed rate of
industry growth. This is so because NSPS control costs and economic
feasibility have been evaluated on an individual plant basis.
2.5.9 Comment: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35)
Five commenters believed that the economic impact analysis should be
updated at some future time to reflect more accurate cost effectiveness
figures. However, they did not believe an updated analysis would change the
determination of wet dust suppression as best demonstrated technology.
Response:
The cost effectiveness calculated prior to the standards proposal is
conservative. Emissions reductions were calculated assuming that in the
absence of an NSPS, plants would have to control particulate emissions to
meet typical State process weight regulations. Only reductions in emissions
beyond the level required by SIPs were credited to the NSPS. However, costs
were calculated assuming baghouses, an expensive technology, would be the
control technique chosen by all affected facilities. Furthermore, it was
assumed all costs of control were due to the NSPS (i.e., that plants
incurred no costs in complying with SIPs). Therefore, costs are overesti-
mated. Even with these conservative assumptions cost effectiveness was
determined to be reasonable. Updating the analysis could change the cost-
effectiveness somewhat due to variation in current SIP control levels, but
as the commenters noted, this would not change the determination that BDT is
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baghouses or wet suppression, the selection of emission limits based on BDT,
or the economic analyses. (See Sections 2.5.3 and 2.5.16 for comments and
responses on updating the DCF economic analyses to current dollars.)
2.5.10 Comment: (IV-D-19)
One commenter suggested that the economic impact analysis is incomplete
and fails to address the typical refractory producer. In particular, he
believed the following items were not considered in the analysis:
(1) additional energy costs due to the nature of the required processing in
a refractory plant, i.e. additional baghouse heating costs, additional
collector operation costs, etc.; (2) the impact of imports which have
significantly increased in recent years; and (3) disposal costs of waste
materials.
Response:
In response to the commenter1s first concern, these standards are not
expected to cover high temperature emission streams at refractory manufac-
turing plants. The standards will cover only affected facilities (crushers,
screens, grinding mills, etc.) processing nonmetallic minerals as defined in
§60.671 of the regulation. The crushing and grinding operations at refrac-
tory plants which process nonmetallic mineral raw materials are similar to
crushing and grinding operations at other types of nonmetallic minerals
processing plants, and emissions are near ambient temperature. Air swept
grinding mills, also referred to as combined drying and crushing systems or
drying and grinding systems, where hot air is introduced to crushers or
grinders in order to dry the material as it is crushed, will be covered
under the NSPS for nonmetallic minerals processing plants. However, these
systems generally operate at temperatures of below 180°F and can be
controlled by the type of baghouses costed in the Background Document for
the proposed standards. EPA tested combined grinding and drying systems at
clay processing plants during standards development, and found that these
facilities could meet the standards (see Section 2.2.3).
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Calciners and dryers which are not operated in combination with crushers
or grinders will be covered under separate calciner/dryer standards being
developed by EPA. If there are dryers processing nonmetallic minerals at
refractory manufacturing plants, they would not be subject to the nonmetallic
minerals standards, unless emissions streams from the dryers were ducted
together with emission streams from affected facilities. EPA's information
is that high temperature emission sources are typically ducted separately
from facilities affected by this NSPS. In the one case reported to EPA
where a dryer and crusher were ducted together, the temperature of the
emission stream was below 180°F (Docket No. II-D-75). A baghouse to control
these facilities would not require special high temperature materials or
design.
EPA therefore believes the costs of controlling affected facilities at
refractory manufacturing plants will be reasonable. First, as explained,
most high temperature emission streams at refractory manufacturing plants
will not be covered. And, the cost and economic analyses in the Background
Document for the proposed standards, adequately consider the costs of
control for emission streams with the temperatures and characteristics'of
those streams at refractory manufacturing plants which will be affected by
the standards. Second, the standards are expected to impact mainly new
plants and new production lines added to existing plants. Since replacement
of existing equipment with new equipment of the same or smaller size is
exempt from compliance with the emission limits, few existing plants will be
affected by the standard unless they expand their capacity. Therefore,
retrofitting should be rare. The provisions of the standards could be
considered when designing process operations and control systems at new
plants or capacity expansions. Thus, high temperature sources could be
ducted separately from affected facilities, and the least expensive
techniques for meeting the standards could be chosen.
With regard to imports, the economic analysis shows that the costs of
producing nonmetallic minerals used to manufacture refractory products
(i.e., fire clay, kyanite, etc.) will not be significantly affected by the
cost of NSPS controls. Furthermore, because these minerals are only one of
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several inputs in the refractory manufacturing process, the significance of
very slight NSPS-related price increases is further reduced at the finished
refractory product level. Consequently, there is no reason to expect that
the prices of refractory products will increase to the extent that increased
imports could result.
EPA has concluded that the impacts of solid waste disposal would not be
significant. Disposition of quarry, plant and dust collector waste materials
depends somewhat upon State and local government and corporate policies.
When fabric filter systems are used, about 1.4 megagrams (1.6 tons) of solid
waste are collected for every 250 megagrams (278 tons) processed. In many
cases this material can be recycled back into the process, sold, or used for
a variety of purposes.
Where no market exists for the collected fines, they are typically
disposed of in the mine or in an isolated location in the quarry. A
544 Mg/hr (600 TPH) crushing plant using dry collection for control would
generate about 27.6 megagrams (30 tons) of waste over an eight hour period.
This is about 0.5 percent of the plant throughput. Generally, the collected
fines are discharged to a single haul truck at the end of the day and
transported to the quarry for disposal. This dumping and transporting can
be a source of fugitive dust if these operations are not protected from the
wind or controlled by wet suppression. No subsequent air pollution problems
should develop, provided the waste pile is protected from wind erosion.
Consequently, it is EPA's judgment that the application of dry controls
in the nonmetallic minerals industry will not have a significant solid waste
disposal impact. Where wet dust suppression can be used, no solid waste
disposal problem exists over that resulting from normal operation.
2.5.11 Comment: (IV-D-27, IV-D-30, IV-D-40)
One commenter pointed out that while the proposed standards are not
expected to exceed two percent of the product price this could easily be 20
to 25 percent of the company's profits. In addition, several commenters
stated that the proposed standards will cause limestone and other producers
to delay purchasing new equipment in order to be more competitive. They
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said this action will decrease the number of jobs in the equipment
manufacturing and sales industries that have been depressed in recent years.
Response:
It may be true that for some plants during certain years, NSPS control
costs could exceed 20 to 25 percent of a plant's profit. However, the
Discounted Cash Flow (DCF) analysis considers cash flows over the entire
useful life of the facility, to judge how the incentive to invest is affected
by the additional costs. Thus, although control costs relative to profit
for particular years may be high, over the entire life of the plant such
costs may be offset by several factors including: the increased ability to
pass NSPS costs through to consumers, in the form of higher prices; and
reduced taxes due to investment tax credits and higher depreciation charges.
The DCF analysis has demonstrated that with the exception of certain
size plants in some of the nonmetallic minerals industries, the feasibility
of purchasing and operating new nonmetallic minerals processing facilities
will not be changed by the costs related to the installation and operation
of NSPS control equipment. While there may be isolated situations in which
a producer might delay making an investment in new equipment, the DCF
analysis indicates that such delays would not be warranted in most cases.
Consequently, there is no reason to suspect that the outlook for the
manufacturers of nonmetallic minerals processing equipment will be adversely
affected.
2.5.12 Comment: (IV-D-44)
One commenter proposed that salt plants with a total production of less
than 100,000 tons per year be exempted. According to the commenter, salt
operations have a complex distribution system, with mining and initial
processing being done at one central location and the product transported to
several small satellite operations, often hundreds of miles away for further
crushing, screening and bagging. These satellite operations have to comply
with State and local emission regulations. The commenter suggested that
small salt processing plants be exempt as are fixed crushed stone and sand
gravel plants with capacities under 23 Mg/h (25 ton/h).
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Response:
The economic analysis has concluded that the smallest new plant in the
salt industry would need to raise prices about 1.2 percent in order to pass
through all NSPS costs to consumers. This increase has been judged to be
low in light of increases exceeding 13 and 15 percent for small crushed
stone and sand and gravel plants, respectively. It should be noted that the
1.2 percent price increase mentioned above is based upon the assumption that
SIP or local regulations do not exist, and therefore all control costs are
attributed to the NSPS. If it is true that the satellite salt operations
are covered by SIP and local regulations, the incremental control costs
required to reduce emissions from SIP to NSPS levels would be lower than
those used in the economic analysis. Consequently, the product price
increase needed to pass-through NSPS costs would be less than the estimated
1.2 percent.
2.5.13 Comment: (IV-D-38)
One commenter stated that if a continuous mining machine used in the
talc industry is covered by the proposed standards the cost increase for the
talc industry would exceed two percent.
Response:
Mining operations are not covered under the proposed or final
nonmetallic minerals NSPS. Only those facilities listed in the proposed
regulation (crushers, grinding mills, screening operations, bucket elevators,
belt conveyors, bagging operations, storage bins, and enclosed truck and
railcar loading stations) are covered by the standard.
2.5.14 Comment: (IV-D-34)
A trade association stated that EPA should separately assess the brick
industry to determine whether brick plants pose environmental problems,
whether any significant environmental benefits can be gained from imposing
NSPS emission controls on the brick industry, and the economic costs of
installing and operating such controls. They pointed out that during the
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standards setting process, no visits were made to brick plants, no meetings
were held with representatives of the brick industry, and no tests were
conducted at brick plants. Therefore, they claimed the data base is
inadequate for requiring control on the brick industry. In addition, EPA
listed brick and related clay products as a separate source category on the
NSPS priority list and listed them as a lower priority than nonmetallic
minerals. The commenters stated that the brick industry should not be
grouped with mining operations that it has little in common with but should
be analyzed separately for its emission reduction potential.
Response:
In response to this comment, EPA met with representatives of the Brick
Institute of America and visited brick plants. The clay preparation stage
of the brick manufacturing process will be covered under the standards of
performance for nonmetallic minerals processing plants. This stage includes
crushing, grinding, screening, and conveying operations similar to those at
other nonmetallic minerals industries. While these operations are currently
enclosed and controlled at many brick plants, they have the potential to
emit significant quantities of particulate matter which may endanger health
and welfare. The purpose of standards of performance is to ensure that best
demonstrated technology is applied to new facilities as the nation's
industrial base is replaced. A second purpose is to establish uniform
regulations from State to State. Covering brick plants under these
standards of performance will ensure that stringent emissions control is
applied whenever new plants are built.
BDT is the same for affected facilities at brick plants as it is for
affected facilities at other nonmetallic mineral plants. Baghouses and wet
suppression have been designated BDT in the standards and are in use at many
brick plants. However, since buildings enclose affected facilities at many
brick plants, provisions have been added to the final standards to clarify
emissions limits and techniques for measuring emissions from buildings (see
Section 2.4.1 for details). In conclusion, the brick industry is not
substantially different from other nonmetallic mineral processing industries,
and these standards of performance are applicable to the brick industry.
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The fact that the brick industry was listed separately on the priority
list does not preclude the industry's inclusion in the nonmetallic minerals
source category. It was determined that a separate standard for the brick
industry is not necessary since they can be adequately covered under the
nonmetallic minerals standards. Order of placement of the priority list
does not influence the stringency of the standards promulgated for a source
category.
2.5.15 Comment: (IV-D-12, IV-D-15)
Some commenters felt that EPA's assumption for crushed stone and sand
and gravel plants that 25 percent of the cost of control technology could be
passed through to their customers every four years was unrealistic. Because
of the low unit value of some of the minerals, the cost of transporting the
product to the market must be kept low. They stated that for sand and gravel
the cost of the material doubles every 20 miles. In many geographically
competitive markets, they felt that a new plant would have to completely
absorb the NSPS costs. One commenter felt that EPA has not considered the
unfair competitive consequences which will occur when a fully portable'
construction aggregate processing plant, exempt from the regulations, is
moved into an area to compete for construction jobs with a fixed plant
subject to the regulations. He suggested that consideration be given to
exempting both portable and fixed facilities below some level of production.
Response:
The economic analysis recognizes that the ability of individual
producers to pass NSPS costs to consumers depends upon local market condi-
tions, and in particular, the location of new plants relative to existing
plants. Unfortunately, it would be impossible to conduct separate analyses
for each local market, due to the large number of local markets that exist
in the United States. Thus there is a need to make simplifying assumptions
in the DCF analysis, but it should be understood that when such assumptions
are made, care has been taken to avoid the understatement of impacts.
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The assumption that new plants will be capable of passing through
25 percent of the total NSPS control costs each four years is a simplifying
assumption made necessary by the wide variation in local market conditions.
However, it is believed that in reality most new plants will be able to pass
through NSPS control costs sooner. Among the factors that would promote
faster pass through are: the relative cost-efficiency of new plants; the
rate of turnover of existing plants; and the need for existing plants to
comply with SIP emission limits and related costs. All of these factors
have the effect of decreasing the disparity in operating costs between new
and existing plants, thus promoting the more rapid pass-through of NSPS
control costs to the consumers of the affected nonmetallic minerals.
With regard to the competitive consequences of exempt portable plants
operating in the same areas as fixed plants subject to the NSPS, it seems
that two situations might be possible. Specifically, the competition could
be related to either new, exempt portable plants (i.e., those less than
150 tons per hour), or older portable plants that were put into operation
prior to the proposal of this NSPS.
In the former case it is highly unlikely that portable plants that are
exempt from this standard will pose a threat to new fixed plants, because if
the advantage of such portable plants is real, those who would build new
fixed plants would use new portable plants instead. Because facilities at
new fixed plants are expected to be the most common type of facilities which
will be covered by the standards, potential investors in fixed plants will
have adequate opportunity to use exempted (i.e., less than 150 t.p.h.)
portable plants instead. However, because most new fixed plants would be of
about 300 tons per hour capacity, it is highly unlikely that two 150 ton per
hour plants could prove to be competitive replacements. This is true
because the portable plants will need to comply with regulations other than
the NSPS (e.g., SIP, PSD, and local regulations) and will have to overcome
the considerable economies of scale associated with operating multiple small
plants. It is apparent that economies of scale alone are capable of limiting
the ability of two 150 tons per hour plants to compete effectively with one
300 tons per hour plant.
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In the latter case, it is not true that older portable plants built
prior to the proposal of this NSPS would have a significant cost advantage
over new fixed plants. In this case the older portable plants would need to
comply with SIP regulations, thus restricting any control costs differential
as noted in the former case. In addition, it seems that the older portable
plant would be less efficient relative to the new plant, due to higher
maintenance expenditures, and the possible reliance upon an older
technology.
2.5.16 Comment: (IV-D-12)
One commenter stated that because the minerals vary so much in price
per ton, a more detailed economic analysis on a mineral commodity basis
using current statistics would better anticipate the economic impact.
Response:
The economic analysis contained in the BID has explicitly recognized
the wide variation in prices for the nonmetallic minerals covered by the
NSPS. Price per ton data were used to rank order minerals according to the
percent price increases required to completely pass through NSPS control
costs to the consumers of those minerals. Those minerals for which price
increases were, in the worst case, expected to exceed two percent, were
assessed more vigorously through the Discounted Cash Flow (DCF) analysis.
Updating the economic analysis through the use of more current
statistics for prices and costs would not affect the conclusions of the
economic analysis. This is because constant dollars, as opposed to current
dollars, were used in the analysis (see Response 2.5.3). Constant dollars
are adjusted to eliminate the effects of inflation. Constant dollars are
expressed in terms of a base year. They provide a standard of reference for
evaluating the real resource costs of a standard when such costs are incurred
at different points in time. Furthermore, between the years of 1976 and
1979 when the economic analysis was performed, prices for nonmetallic
minerals and costs of operating the NSPS control equipment have increased at
a similar rate. Inflation has not altered the basic ratio of NSPS control
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costs to industry revenues over recent years, so the conclusions presented
in the economic analysis are still applicable.
2.5.17 Comment: (IV-D-18)
One commenter suggested that because the cutoff points were determined
based on production rates, the exemptions should also be based on actual
production rates and not capacity. They also suggested that EPA base the
cutoff point for portable plants on the percentage of time per year a
facility actually operates using realistic production rates rather than
maximum design process rates.
Response:
Regulations are typically based on a source's potential to emit. EPA
realizes that plants typically may not operate at full capacity, but they
have the potential to do so. It would be extremely difficult and imprac-
tical to enforce a regulation based on actual production rates or hours of
operation. If this were done, a single plant could be below the regulatory
cut-off in some years and above it in others.
Furthermore, having a cut-off based on production rates should not
seriously impact the industry. Unless they expand production, few, if any,
existing plants will become subject to the regulations, because under the
final standards replacement of existing affected facilities with new
facilities of equal or smaller size is exempt from compliance with the
emissions regulations. When plans for capacity expansions or new plants are
made, the planners can take the NSPS size cut-offs into account in deciding
how much over-capacity to design for.
2.5.18 Comment: (IV-D-30, IV-D-50)
Two commenters stated that the equipment required under the proposed
standards for portable plants would be expensive to purchase and would
entail considerable expense every time they move. They represented small
companies and do not feel that the economic impact analysis adequately
addresses the impact on producers of their size.
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Response:
The portable plant analysis contained in Supplement A of the Background
Document for the proposed standards has recognized control costs specific to
portable plant operations. That analysis has explicitly considered both the
cost to purchase and operate NSPS control equipment, as well as the cost to
move this equipment as the portable plant moves from one site to another.
Among the costs specific to portable plant operations considered in
Supplement A are: control system investment, operating and maintenance
costs; control system setup costs; control system dismantling costs; the
cost to lease and operate a crane to move the control system; and the cost
to transport the control system to a different site. These costs have been
evaluated under two methods of portable plant operation, that is, movement
to four different quarries per year, and 24 moves within the same quarry per
year.
The portable plant analysis has been structured to allow consideration
of impacts upon firms of all sizes. This has been accomplished by
considering a wide range of plant sizes, under the assumption that the plant
operates as a separate business entity. Consequently, because the analysis
has examined small plants operating as separate businesses, it is felt that
small companies have been appropriately addressed in the portable plant
analysis.
2.5.19 Comment: (IV-D-34)
One commenter stated that the change in the affected facility definition
from the entire processing plant to each piece of equipment at a plant was
made only recently. They were concerned that no adjustment was made to the
economic impact analysis to take into account the additional economic
burdens of applying the NSPS to each piece of equipment.
Response:
The economic analyses presented in the Background Document for the
proposed standards (EPA-450/3-83-001a) included the cost of controlling each
piece of equipment at new and expanded plants. Therefore, the economic
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analyses would give the same results regardless of whether the entire plant
or individual pieces of equipment are designated the affected facility.
Economic impact had to be analyzed on plant and industry levels of aggrega-
tion, since one piece of equipment is not a business unit. Cost and
economic impacts for the two most likely patterns of growth, opening of new
plants and expansions at existing plants, were analyzed. Replacement of
individual affected facilities was not analyzed because it was believed to
be unlikely. However, replacement of affected facilities with equipment of
the same or smaller size has been exempted from compliance with emission
limits in the final standards. Since this exemption has been provided,
there will be no economic impacts on plants replacing worn-out equipment.
Thus EPA's economic impact analysis adequately represents the economic
impacts of the standard where the affected facility has been designated as
the individual piece of processing equipment.
2.5.20 Comment: (IV-D-41)
One commenter suggested that since the costs refer to the fifth year
after proposal they be presented in 1989 dollars rather than 1979 dollars.
Response:
The expression of control costs in any base year other than 1979
dollars, would not affect the conclusions presented in Chapter 8 of the BID.
The broadest measures of economic impact used in the BID are based upon a
comparison of NSPS control costs to the revenues generated through the sale
of nonmetallic minerals by the affected plants. The economic impact
analysis was conducted using constant as opposed to current dollars (see
Response 2.5.3). Constant dollars are adjusted to eliminate the effects of
inflation. They are expressed in terms of a base year. The economic
analysis of stationary plants in the BID used constant 1976 dollars while
the portable plant analysis used constant 1979 dollars. For comparitive
purposes, the costs were escalated from 1976 to 1979 dollars in the preamble
to the proposed standards (48 FR 39566). Because both NSPS control costs
and revenues must be expressed in the same dollars, the magnitude of costs
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relative to revenues will be similar regardless of the year dollars used as
the base. Furthermore, it is impossible to predict accurately the value of
the dollar in 1989.
2.5.21 Comment: (IV-D-26)
One commenter suggested that productivity losses may occur with the
application of wet dust suppression and that any loss of capacity due to
control technology must be included in the cost of the regulations.
Response:
The economic impact analyses were based on baghouse control of all
affected facilities because this is a universally applicable technology in
the industry. It was found that plants covered by the proposed and final
regulations would be able to afford the costs of baghouse control. Wet
suppression is generally cheaper than baghouse control and is allowed under
the proposed and final regulations. Droplets are usually small and evapora-
tion occurs rapidly after contact with the dust. In some newer types of wet
suppression systems, evaporation occurs immediately. Therefore, production
losses are not likely to occur. However, if in a particular case wet
suppression is more expensive than a baghouse, it is assumed the plant would
use baghouse control technology. The costs of baghouses have been analyzed
and found to be reasonable.
2.6 ENVIRONMENTAL IMPACT
2.6.1 Comment: (IV-D-3, IV-D-18, IV-D-31, IV-D-32, IV-D-37)
Five commenters questioned whether the proposed standards would reduce
the total amount of particulate matter emissions into the atmosphere by
41,000 megagrams per year (45,000 tons per year). Two of these commenters
stated that this is a paper estimate that overstates the benefits to air
quality. One commenter also stated that EPA's assumption that the process
weight regulation, which represents the maximum allowable emission rates
authorized by State implementation plans (SIP's), would represent actual
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emission rates, and that the proposed NSPS could reduce those potential
emissions by 90 percent, causes the reduction estimates to be overstated.
They felt that because the States rely on some form of effective dust
control which is usually a wet dust suppression system, a 90 percent
reduction is not realistic. Another commenter suggested that when you
consider what would actually be required in the absence of the proposed
standards, the reduction that would be achieved by the standards is probably
closer to 50 percent. One commenter questioned how anyone can reasonably
estimate a reduction in emissions over a 5-year period because no one knows
how many new facilities will be constructed or how many old ones will be
modified or reconstructed. In addition, he pointed out that no one knows
what percentage of the facilities will be controlled with baghouses and what
percentage will use wet dust suppression systems.
Response:
The 41,000 Mg (45,000 tons) per year emission reduction is an estimate
made by EPA using the best available data and reasonable assumptions. Base-
line emissions (those which would occur in the absence of an NSPS) were
estimated by assuming new and expanded plants would comply with typical
State process weight regulations. These were compared with emissions
estimated to occur if new and expanded plants were controlled to the level
required by the proposed NSPS. For details on the procedure, see
Section 2.1.7. By this method of estimation, the emissions reduction
achievable under the proposed NSPS was found to be 41,000 Mg/yr
(45,000 tons/yr). This is a reduction of 90 percent over baseline
emissions. (The 90 percent reduction was calculated from the results of the
analysis; the commenter is apparently confused in thinking it was an
assumption used in the analysis.)
The analyses assumed baghouses would be used by all new plants to meet
the proposed standards. However, wet suppression could be used as long as
the standards are met. The effectiveness of wet dust suppression systems
cannot be quantified in terms of emissions. However, where their use is
feasible technologically, they are almost as effective as baghouse systems
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in reducing visible emissions. They cost about one-third as much as
baghouses and use less energy. Therefore, the Administrator has determined
that the small difference in visible emissions is justified by the large
difference in cost and energy usage and has selected wet dust suppression as
well as baghouses as BDT for cases where it can be used.
EPA recognizes that there are uncertainties in the 41,000 Mg/yr
(45,000 tons/yr) emissions reduction estimate. Variability in current
control levels and variability in processes and emissions occurring at
individual plants within each industry and among the 18 nonmetallic minerals
industries lead to uncertainty in emissions estimates. Furthermore,
economic predictions of the growth of the industries are always uncertain.
However, the estimates are based on reasonable assumptions and are adequate
for decision-making purposes.
The sources of particulate matter regulated under the nonmetallic
minerals NSPS have been found to be significant contributors to particulate
emissions which may reasonably be anticipated to endanger public health and
welfare. For this reason, they were included on EPA's priority list of
source categories for which NSPS must be promulgated (44 FR 49225). EPA's
emissions reduction estimate of 41,000 Mg/yr (45,000 tons/yr) supports the
conclusion that potential emissions reductions are significant, but the
actual magnitude of emissions reductions are not important for standards
promulgation. Since the source category has been listed, and EPA has
identified a BDT for certain facilities at nonmetallic minerals plants which
can be applied for a reasonable cost, Section 111 of the Clean Air Act
requires that an NSPS must be promulgated.
2.6.2 Comment: (IV-D-13, IV-D-28)
Two commenters were concerned that the proposed standards did not
address particle size, particle drift, re-entrainment, particle deposition,
or property line standards. They stated that it is unclear how a significant
reduction in ambient particulate concentrations will result from setting the
proposed standards, since neither particle size nor property line concentra-
tions are considered. One commenter also felt consideration should be given
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to the amount of material emitted that falls within the respirable range and
this regulation coordinated with the proposed regulation in that area.
Another commenter (IV-D-22) said once the new NAAQS revisions are promul-
gated, EPA should establish emission limits for the finer size particles.
Response:
Under Section 111 of the Clean Air Act, it is not necessary to estimate
or prove impacts on particulate concentrations in ambient air to promulgate
an NSPS. Particulate matter has been identified as a criteria pollutant
which may reasonably be anticipated to endanger health and welfare
(EPA-600/8-82-029a-c). Nonmetallic minerals processing plants have been
included on EPA's priority list of source categories for which an NSPS must
be promulgated under Section lll(f) because of their potential to emit
particulate matter which may reasonably be anticipated to endanger public
health and welfare (44 FR 49225).
EPA is therefore required by law to promulgate standards. In order to
set standards under Section 111, EPA must show that emissions can be reduced
by the application of best demonstrated technology. BDT is the best system
of continuous emissions reduction which has been adequately demonstrated for
the category of sources considering cost and any nonair quality health,
environmental, and energy impacts. EPA is not required to estimate effects
on ambient air quality.
One commenter questions whether EPA should consider particle size and
evaluate the nonmetallic minerals NSPS in terms of the proposed revision to
the NAAQS for particulate matter based on particle size. The EPA is
currently evaluating the proposed change in the NAAQS for particulate matter
based on particle size considerations. The new NAAQS has not been promul-
gated in final form. If the proposed changes in the NAAQS are promulgated,
the secondary NAAQS standard will still be based on total particulates of
all sizes, so total particulates will still be a consideration in standards
development. Furthermore, nonmetallic mineral processing plants do emit
respirable particulates. Controls which have been specified as BDT in these
standards achieve substantial reduction of particulate matter, including
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respirable particulates. Baghouses have been shown to attain greater than
99 percent collection efficiency even for material of submicron sizes
(48 FR 39569). For these reasons, the proposed revision of the particulate
matter NAAQS would not significantly effect the need for the nonmetallic
minerals standards or the control technology and emission limits specified
in the standards.
2.6.3 Comment: (IV-D-13, IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35,
IV-D-36)
Six commenters stated that the total reduction of 41,000 Mg/yr
(45,000 tons/yr) in the fifth year after proposal is only about 0.02 of
1 percent of the total particulate emissions annually generated from unpaved
roads. They questioned the significance of the nonmetallic mineral
processing industry's contribution to the nation's total suspended
particulate problem.
Response:
The sources of particulate matter emissions regulated under the '
nonmetallic minerals NSPS have been found to be significant contributors to
particulate emissions which may reasonably be anticipated to endanger public
health and welfare. For this reason, they were included on EPA's priority
list of source categories for which NSPS must be promulgated (44 FR 49225).
EPA estimates emissions can be reduced by 41,000 Mg/yr (45,000 tons/yr).
This is a large and significant number, despite the fact that percentages
may be small when compared to even larger numbers. Particulate matter
sources are dispersed, each contributing a small percent of a large total
emission. EPA has identified a BDT for certain facilities at nonmetallic
minerals plants which can be applied for a reasonable cost, so an NSPS is
being promulgated. Analysis of the relative potential emissions from
nonmetallic minerals industries versus other source categories is not
required before promulgation of this NSPS.
Other sources of emissions at nonmetallic minerals processing plants,
as well as emissions from other source categories, will be considered for
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standards development in the future. If a BDT which will reduce emissions
from considered sources can be established, and economic analyses show it
can be applied at a reasonable cost, then standards will be developed. The
timing of standards development for various emission sources will depend on
EPA's time and budget constraints.
2.7 ENERGY IMPACT
2.7.1 Comment: (IV-D-27, IV-D-30, IV-D-40)
Three commenters pointed out that the preamble states that the use of
wet dust suppression would increase the amount of energy used by 15 percent
over the amount of energy used if additional controls were not required.
Because energy is one of the biggest cost factors in limestone production,
they felt a 15 percent increase is a very substantial cost increase that
should be given careful consideration.
Response:
EPA's economic analyses were based on the use of baghouses, a
universally applicable control technology for the industry. Energy costs
were included. Energy requirements were calculated for model plants of
different sizes with either crushing operations only or both crushing and
grinding operations. Fabric filter control was found to increase a plant's
energy consumption by 5 to 20 percent. The cost of this energy was included
in all economic analyses. Price screening found that for 17 of 23 indus-
tries considered, the costs of control would cause a maximum price increase
of less than 2 percent assuming all control costs were passed through to
consumers. Further economic analysis determined that for all industries,
the annualized control cost is less than 2 percent of the annual revenue for
that industry. DCF analysis of various size model plants in the six indus-
tries with price increases over 2 percent showed that the plants covered by
the standard would be economically feasible despite control costs. The
total costs and economic impacts of control were, therefore, found to be
reasonable for the size plants covered by the proposed and final regulations.
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Wet suppression systems are generally less expensive than baghouses, and
plants may use this technology if they consider it more practical than
baghouses and can meet the standards.
2.8 SELECTION OF BEST DEMONSTRATED TECHNOLOGY
2.8.1 Comment: (IV-D-7, IV-D-12, IV-D-15, IV-D-16, IV-D-17, IV-D-26,
IV-D-35, IV-D-37)
Several commenters stated that the proposed standards are truly
performance-oriented by allowing for wet dust suppression as well as capture
and control devices. One commenter stated that at most wet pit sand
operations, no add-on control equipment would be necessary to meet the
proposed limits. One commenter requested that the discussion on wet dust
suppression systems should note that water freezes in the northern tier of
States during the winter; and in dry and arid areas, water may be unavail-
able or too scarce and precious to use on dust control. One commenter noted
that wet suppression can cause extra wear on metal parts and blinding of
screens. Others believed use of wet suppression would interfere with
product specifications.
Response:
EPA has determined that both baghouses and wet suppression are efficient
control devices and are BDT. It is stated in the Background Document for
the proposed standards (EPA-450/3-83-001a) that wet suppression cannot be
used in all cases. Freezing conditions, lack of available water, and
interference with certain processing steps or product specifications may
limit the use of wet suppression at certain plants. In such cases, baghouses
(also specified as BDT) or other control techniques could be used to meet
the standards. Where it can be applied, wet suppression is an effective
control technique which costs about one third as much as a baghouse and uses
less energy, so it has also been designated as BDT.
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2.8.2 Comment: (IV-D-39)
One commenter was concerned that the allowance of wet dust suppression
systems would result in a trend away from the use of control devices such as
baghouses which have been proven effective in controlling emissions from
these sources.
Response:
EPA has determined that wet dust suppression is effective at controlling
particulate emissions from the sources covered by the standards. The exact
effectiveness of wet dust suppression systems cannot be quantified in terms
of mass emissions. However, where their use is technologically feasible,
they are almost as effective as baghouse systems in reducing visible
emissions. Furthermore, wet suppression systems cost about one-third as
much as baghouses and use less energy, so are very cost effective control
measures. EPA does not want to preclude the use of wet suppression simply
because of the inability to quantify exact mass emissions reduction.
Therefore, both baghouses and wet suppression are BDT.
2.8.3 Comment: (IV-D-18)
One commenter requested that only wet dust suppression systems be
identified as best demonstrated technology for portable plants because
baghouses are not proven control devices for these plants.
Response:
Both wet dust suppression and baghouses have been determined to be BDT
for portable plants. However, an owner or operator may use any control
technology as long as the standards are met. Baghouses have been demon-
strated to be an effective and feasible control technique for the 18 nonme-
tallic minerals industries regulated under the standard. One factor which
might make the economic feasibility of baghouses different for portable and
fixed plants, is the cost of moving control devices when portable plants
move. EPA performed an economic analysis to investigate this question. It
is presented in Supplement A of the Background Document for the proposed
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standards (EPA-450/3-83-001a). DCF analyses were performed to determine the
profitability of various size portable plants using baghouse control.
Five plant sizes with two different configurations and two baghouse control
options were modeled. Costs of disassembling, moving, and reassembling
control equipment were included. Plants were assumed to move four times per
year between quarries or 24 times per year within one quarry. It was
determined that baghouse control would be feasible for portable plants
larger than the sizes exempted from the regulations.
2.9 SELECTION OF FORMAT FOR STANDARDS
2.9.1 Comment: (IV-D-34)
One commenter recommended that EPA specify a mass emissions limitation
to be used at the election of those plant owners or operators which have the
capability to measure short-term production rates. He stated that EPA based
its decision not to specify a mass emissions standard upon its finding that
most nonmetallic mineral processing plants do not measure the production or
feed rate of a process operation over the short term. However, EPA
acknowledged that a mass emissions standard would be more meaningful because
it relates directly to the quantity of emissions discharged into the
atmosphere.
Response:
The final emission limit will be in a concentration format rather than
in a mass emissions format. EPA's test data does not allow the establish-
ment of a mass emissions standard because the process throughput was not
measured during the testing. Thus, mass emissions per unit of production
cannot be calculated. Furthermore, nonmetallic mineral processing plants
typically do not measure production or feed rate over the short term, so
they would find it difficult to determine compliance with a mass emissions
standard.
EPA's test data does support the development of a concentration
standard of 0.05 g/dscm (0.02 gr/dscf). While the preamble to the proposed
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standards states "a mass standard may_ ^ear more meaningful in the sense
that it relates directly to the quantity of emissions discharged into the
atmosphere;" it concludes that a concentration standard is also meaningful
(48 FR 39572). EPA reaffirms this conclusion and has finalized the standard
in a concentration format.
2.10 SELECTION OF EMISSION LIMITS
2.10.1 Comment: (IV-D-5, IV-D-10. IV-D-18, IV-D-19, IV-D-25, IV-D-26,
IV-D-28, IV-D-33, IV-D-36, IV-D-42)
Nine commenters stated that the 7 percent opacity limit for emissions
discharged from a stack unless a wet scrubbing device was used is too low.
Six of these commenters suggested the limit be raised to 10 percent. Two
commenters suggested the limit be raised to 15 percent. Most of the
commenters stated that the eye is not calibrated well enough to distinguish
between 5, 7, and 10 percent opacity. Because the observers are trained to
read in 5 percent increments, they felt the limit set should be divisible
by five Several commenters pointed out that EPA Reference Method 9 is only
an estimation technique accurate to plus or minus 7.5 percent opacity. They
questioned whether a 7 percent limit can be consistently and reliably
enforced using this method. One commenter felt that the limit was not
entirely unreasonable because a properly maintained baghouse for nonmetallic
mineral processing will almost always show less than 5 percent opacity.
Another commenter stated the appropriateness of the standards is confirmed
through statements from persons proposing new nonmetallic mineral processing
plants in San Diego County. He said that from these statements, indications
are that baghouse manufacturers have guaranteed particulate emission
performance not exceeding 10 percent opacity for a period or periods
aggregating 3 minutes in any 60-minute period.
Response:
Test data from 25 baghouses demonstrates the achievability of the
7 percent stack opacity standard. At 21 baghouses, the maximum 6-minute
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average opacity was 0 percent; at three baghouses, the 6-minute average was
1 percent; and at one baghouse, it was 6 percent. The commenters submitted
no data to support their suggested changes to the opacity standard. No
reason has been found to raise the standard.
Opacity results from Method 9 tests represent the average of
24 readings over a 6-minute period. While each reading is recorded as an
increment of 5 percent opacity, the average of all the readings can be any
value. The new source performance standard is based on 6-minute averages
and, therefore, is not limited to an increment of 5 percent opacity.
Contrary to the commenters' suggestions, Method 9 does not require that
the maximum 7.5 percent positive error discussed in the section entitled
Certification Requirements be taken into account for enforcement purposes.
The only portion of Method 9 addressing the enforcement issue is the
introductory section. That section requires that the accuracy of the method
be considered for enforcement purposes and describes that accuracy in terms
of the following ranges of positive error derived from extensive data
obtained in the field.
(1) For black plumes . . .,100 percent of the sets were read with a
positive error of less than 7.5 percent opacity; 99 percent were
read with a positive error of less than 5 percent opacity.
(2) For white plumes . . .,99 percent of the sets were read with a
positive error of less than 7.5 percent opacity; 95 percent were
read with a positive error of less than 5 percent opacity.
This language does not suggest an average positive error of 7.5 percent.
Nor is it appropriate to consider for enforcement purposes the maximum
average 7.5 percent error that observers are permitted for qualification
purposes under the certification section. During the certification test,
the observer is challenged with plume opacities that are randomly varied
from 0 to 100 percent opacity for each group of 25 readings. This contrasts
sharply with the range of opacities with which qualified readers are
typically challenged on field inspections. In the field, an observer can
expect that opacities from a given stack will usually vary within only a
narrow range during the 6-minute time span encompassing a set of 24 readings,
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In the Administrator's judgment, an observer's error, when reading plumes
with relatively constant opacity levels, will be significantly less than the
observer's error when reading a full range of randomly varied opacity
levels. Since readers enforce opacity limits in the field, the EPA properly
required that the range of error demonstrated under field conditions, rather
than the maximum allowable average error associated with certification
testing in an artificial environment, be considered for enforcement purposes.
2.10.2 Comment: (IV-D-13, IV-D-33, IV-D-39)
Three commenters questioned the need to set a uniform stack opacity
standard or the basis upon which the standard was set. One commenter
suggested that the stack opacity standard be eliminated and reliance be put
on the mass per volume concentration standard because the actual quantity of
dust emitted is the factor which has the potential to affect human health
and welfare. One commenter felt that because the observation of visible
emissions is an important enforcement tool for the States, a case-by-case
adjusted opacity standard should be set for any control device including wet
scrubbers. Another commenter stated that the opacity standards are based on
observations of 25 baghouses at four crushed stone plants and one sand and
gravel plant. Some commenters felt the limited sample size does not
consider naturally occurring variations in sand, gravel, and stone deposits
that could significantly affect emissions. They claimed this is a very
unscientific and statistically inaccurate method of setting performance
standards.
Response:
An opacity standard was set to ensure that air pollution control
systems controlling stack emissions are properly installed, operated, and
maintained. Properly operated baghouses can meet the 7 percent opacity
limit, and readings above this would indicate a problem in system operation.
Opacity can be quickly and easily measured at very low cost, so it is a more
practical method of routine monitoring than instrument methods used to test
compliance with the concentration standard. For these reasons, an opacity
standard is believed to be a necessary part of the stack emissions standard.
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A uniform opacity standard is necessary for efficient enforcement of
the regulation. The opacity standard for stack emissions would be applicable
in all cases unless EPA were to approve establishment of a special opacity
standard under the provisions of 40 CFR 60.11(e). The provisions allow an
owner or operator to apply to EPA for establishment of a special opacity
standard for any source that meets the applicable concentration standard
(demonstrated through performance tests under conditions established by EPA)
but is unable to meet the opacity standard despite operating and maintaining
the control equipment so as to minimize opacity. A special opacity standard
might be established, for example, where an unusually large diameter stack
precludes compliance with the proposed opacity standard.
No opacity standard was proposed for scrubbers, because opacity does
not correlate with particle concentrations for this type of control. Some
high opacity readings (25 percent) were observed at very low outlet concen-
trations (0.006 gr/dscf) at scrubbers on metallic minerals processing
plants, while readings of 0 percent opacity were observed for outlet
concentrations near 0.02 gr/dscf. Opacity standards were not set for wet
scrubbers, but monitoring pressure drop and scrubber liquid flow rate is
required by the standard. This monitoring will ensure that control devices
are properly operated and will allow the detection of operating problems on
a routine basis.
The stack opacity standard is based on 25 baghouses from various types
of equipment at five crushed stone plants (three limestone and two traprock
plants), a fullers earth plant, a kaolin plant, a feldspar plant, and
five metallic minerals processing plants. The metallic minerals data were
included because this industry uses the same type of equipment as nonmetallic
minerals plants, and key parameters of emissions such as particle size
distribution and mass loading are similar for both industries. Furthermore,
ores from which metallic elements are extracted are primarily nonmetallic,
and emissions from metallic mineral processing operations are primarily
nonmetallic mineral constituents.
A range of particle sizes and inlet loadings were covered by these
tests. At kaolin plants, 70 percent of emissions from grinding mills are
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under 5 ym in diameter, while average particle sizes at some crushed stone
operations were 20 ym. It is felt that the tests are representative of the
range of conditions found in the 18 nonmetallic minerals industries. At
21 of the 25 baghouses, the maximum 6-minute average was 0 percent opacity,
at three baghouses the 6-minute average was 1 percent, and at one, it was
6 percent. All could meet the 7 percent stack opacity standard (EPA-450/3-
83-OOla, EPA-450/3-82-014).
2.10.3 Comment: (IV-D-10, IV-D-15, IV-D-16, IV-D-17, IV-D-18, IV-D-19,
IV-D-20, IV-D-21, IV-D-25, IV-D-26, IV-D-28, IV-D-35, IV-D-36, IV-D-37,
IV-D-40, IV-D-42, IV-D-48)
Sixteen commenters objected to the opacity limits for fugitive sources
of 10 and 15 percent. Several commenters felt that these limits could not
be consistently met. One commenter stated that impact crushers will easily
exceed the 15 percent limit during startup periods or periods when there is
a break of material feeding in. One commenter felt that the current opacity
limits were unreasonable. He stated that at 15 feet a very small fugitive
emission could easily put a source in violation when there really would not
be much of an impact on the ambient health standard. Two other commenters
stated that the emissions from a processing plant tend to be diffuse and
inconsistent with time, and to emanate from ground level. In addition,
because the sources are close to each other, commenters said it is not
possible to enforce a 10 percent and a 15 percent limit. They felt one
limit should be set for all fugitive sources at a plant. Four commenters
suggested an opacity limit of 20 percent be set for the entire plant.
Five other commenters suggested the limit be 15 percent. One additional
commenter requested the limits be 30 percent for crushers and 20 percent for
all other sources. One commenter stated that the results of emission tests
supplied by the National Lime Association show that a 10 percent limit for
fugitive sources is not technologically feasible. On the other hand,
one commenter stated that the proposed standards would help the State of
Colorado control these sources by decreasing the allowable opacity from
20 percent. No commenters provided opacity data to support their comments.
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Response:
EPA's test data shows that affected facilities can meet a 10 percent
fugitive emissions standard (15 percent for crushers at which capture
systems were not used). EPA measured opacity of fugitives escaping from
hoods and enclosures of capture systems at 53 affected facilities at
13 different types of plants. Seven plants processed nonmetallic minerals
and six processed metallic minerals. Types of plants included crushed
limestone, traprock, feldspar, gypsum, mica, and talc. Crushers, grinding
mills, screens, transfer points, bucket elevators, product bins, and bagging
operations were tested. The 6-minute average opacity at 35 of the
53 facilities was 0 percent. Only two facilities exceeded 5 percent opacity
at any time, and all could meet the 10 percent opacity limit.
Fugitive emissions were also tested at four crushed stone (limestone,
granite) and one sand and gravel plant using wet suppression, and at a
traprock and a feldspar plant using wet suppression to control some
operations. Two plants were portable. The plants were selected with the
aid of industry representatives. At all process equipment (except crushers)
being operated under normal conditions for which the wet dust suppression
system was properly designed and operated, emissions were below 5 percent
opacity. At crushers operated under the same conditions, emissions were
below 15 percent opacity. Based on this data, plants using wet suppression
should be able to meet the fugitive opacity standards of 10 percent for all
affected facilities, except crushers where capture systems are not used.
The standard for such crushers is 15 percent. If a plant cannot meet these
standards using wet suppression, baghouses can be used.
In response to the commenter's concern about effects of emissions on
ambient air quality, Section 2.6.2 explains that consideration of effects on
ambient air is not required in the development of NSPS.
The standards contain stipulations for the use of Method 9 which
address the commenters1 concerns that if affected facilities are close to
each other, it may be difficult to measure opacity of emissions from each
source. EPA followed the stipulations for observer positioning in
Section 60.675(c) during its testing program, and found that cases where
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opacity of emissions from an affected facility cannot be measured due to
interfering emissions are very rare. In most cases, repositioning of the
observer or waiting for a change in wind conditions will allow the emissions
to be read separately. In such cases, opacity of emissions from each
affected facility must be read separately to determine compliance with the
standards. Furthermore, the majority of affected facilities covered by the
standards will be located at new plants or expansions of existing plants,
and owners or operators of these can plan the location of new facilities so
that emissions do not interfere.
However, sometimes affected facilities may be located above and below
one another, so emissions from one facility pass through the other facility
and the emission streams are continuously combined. Although EPA believes
situations were emissions from two or more facilities continuously interfere
will be rare, provisions have been added to Section 60.675(c) clarifying the
use of Method 9 to determine compliance in such situations. If opacity from
an individual facility cannot be measured the owner or operator may
demonstrate compliance with the emission limits in Section 60.672 by either
(1) demonstrating that the combined emissions from the facilities meet the
highest fugitive opacity limits applicable to any of the individual affected
facilities contributing to the emissions stream or (2) separating the
facilities or emissions so that the opacity of emissions from each facility
can be measured to determine compliance. This issue is discussed in greater
detail in Section 2.12.1.
In conclusion, EPA has shown that the fugitive opacity standard can be
met, and it has not been changed between proposal and promulgation.
2.10.4 Comment: (IV-D-22)
One commenter requested that for the asphalt concrete industry, the
proposed limit be raised to 0.04 gr/dscf, the same as the limit set by the
asphalt concrete NSPS. He also felt that the opacity standard at asphalt
plants should be 20 percent, the same limit as set for the rest of the plant
by the asphalt plant NSPS.
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Response:
The commenter did not mention any distinctive elements of the asphalt
process which would justify a standard different from that applied to other
nonmetallic minerals industries. The portions of the asphalt plants covered
under these standards are the initial crushing and grinding operations,
which are similar to operations in the other nonmetallic minerals industries.
Later steps in the process, after asphalt-concrete has been produced, are
not covered. The test data explained in Sections 2.10.1 through 2.10.3 are
applicable to the range of conditions found at asphalt plants and demonstrate
that the proposed stack and opacity standards can be met. Therefore, the
standards have not been changed for asphalt concrete plants.
2.10.5 Comment: (IV-D-12, IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35)
Six commenters stated that while they agree that there are many
similarities between the metallic and nonmetallic minerals processing
industries, there are limits to the transferability of data. They cited
three limitations. First, the per ton value of the metallic minerals is
higher than that of nonmetallic minerals. Second, collection devices are
often used in the metallic industry primarily to collect valuable products
as opposed to capturing particulate emissions. Third, different percentages
of material go through all processing phases at particular plants and in
particular industries. Therefore, different emission levels and different
size particulate emissions could occur from plant to plant.
Response:
Metallic minerals industry data were included to broaden the data base
and further our understanding of control device performance under worst case
conditions. The metallic minerals processing industry data included were
from plants using process equipment and controls similar to those used in
nonmetallic minerals industries. As noted in the Background Document for
the proposed standards (EPA-450/3-83-001a), key parameters of emissions such
as particle size distribution and mass loading are similar for metallic and
nonmetallic minerals industries. Furthermore, ores from which metallic
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elements are extracted are primarily nonmetallic, and emissions from
metallic mineral processing operations are primarily nonmetallic mineral
constituents.
The cost data used for the price screening and discounted cash flow
(DCF) analyses came solely from nonmetallic mineral industries, so the
commenters1 concern about the higher cost per ton of metallic minerals has
no impact on EPA's analysis of the economic feasibility of the standard.
The metallic minerals plants tested use baghouse control for the same
types of affected facilities as the nonmetallic plants tested. The reason
these plants use baghouses (product recovery versus emissions control) is
not important to the performance of the baghouses.
EPA recognizes the fact that particle size distribution and emission
levels vary from plant to plant both within and between industries, but
EPA's tests represent the range of variability found in nonmetallic minerals
processing operations. Particle size data at nonmetallic minerals facilities
tested by EPA show that particle size ranges from a median particle diameter
of 1.5 urn at the fluid energy mills at a fuller's earth plant and 3.5 ym for
a roller mill at a kaolin plant up to 20-25 ym at ball mills at a feldspar
plant and at the primary crusher, hammermill, and final screen at a limestone
plant (EPA-450/3-82-014). At metallic minerals facilities tested, there was
also a range of particle sizes. The median particle size was 4 urn for truck
dumping stations at a copper ore plant, while 95 percent of the emissions
from a primary crusher complex were over 8 ym (the median was not recorded
but would be larger than 8 ym) (EPA-450/3-83-001a). Particular attention
was given to collection of small particles since these are generally
considered more difficult to collect. Baghouse systems at all facilities
tested at these metallic and nonmetallic minerals processing plants met the
proposed stack and fugitive emissions standards.
2.10.6 Comment: (IV-D-19)
One commenter felt that the stack limit of 0.02 grains per dry standard
cubic foot (0.02 gr/dscf) is too restrictive for the refractories industry.
He said that refractories manufacturing requires substantially smaller,
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dryer particles than those required for other minerals and uses. In
addition, baghouse operations at refractories have higher air flows and
operate at temperatures well above the ambient temperature. Because all of
these factors affect baghouse performance, the commenter requested the limit
for his industry be raised to 0.04 gr/dscf.
Response:
The stack particulate emissions standard is 0.02 gr/dscf for
nonmetallic minerals processing plants including refractories. Only facili-
ties processing nonmetallic minerals at refractory manufacturing plants are
covered by the standards. These facilities are similar to those at other
types of nonmetallic minerals processing plants. Fine particle sizes were
adequately considered during the development of the standards. Tests on
control of emissions from clay processing facilities with median particle
diameters as low as 1.5 ym showed that the standards could be achieved using
baghouse technology.
High temperature sources such as calciners and dryers are not covered
under these standards, unless they are combined with crushers or grinders in
the same piece of equipment or are ducted together with affected facilities.
EPA has estimated the costs of controlling combined drying and grinding
systems, and found these costs to be reasonable. Systems where dryers are
ducted together with affected facilities are not typical, and EPA has found
that the costs of control in known situations where this does occur are
reasonable. The response to comment 2.5.10 details the economic feasibility
of requiring controls at refractory manufacturing plants. EPA has
determined that the 0.02 gr/dscf standard is achievable and reasonable.
2.10.7 Comment: (IV-D-20, IV-D-42)
One commenter stated that the standard of 0.02 gr/dscf is not more
stringent than the State of Wyoming currently requires. He also stated that
most manufacturers of baghouses will guarantee this proposed rate. Another
commenter stated that baghouse manufacturers will guarantee a rate of
0.01 gr/dscf and, therefore, the standard should be lowered to that rate.
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Response
The EPA's data support the achievability of the proposed 0.02 gr/dscf
standard in all cases; however, the same is not true of a 0.01 gr/dscf
level. The EPA tested emissions from properly designed and operated
baghouses at nonmetallic minerals plants under normal operating conditions.
The test data show that the 0.01 gr/dscf level was exceeded in several
cases, and could not be considered an achievable standard using BDT.
2.10.8 Comment: (IV-D-23)
One commenter felt that standards should be set for each mineral
process to reflect best demonstrated control technology rather than setting
a single standard for 18 industries. He felt the current approach leads to
less stringent standards.
Response:
Processes, emissions, and control technology for the 18 nonmetallic
minerals industries regulated under this NSPS are similar. BDT for
particulate control (baghouses and wet suppression) is the same for all'
18 industries. Individual analysis for each industry would not change the
selection of BDT or the emission limits. A range of particle sizes and
types of minerals were considered in the EPA's emissions tests. Tests show
that particle size and type of mineral processed have little influence on
baghouse performance (EPA-450/3-83-001a).
Depending on product specifications for any individual plant, there can
be tremendous variation in size of particulates within one industry as well
as between industries. Best demonstrated technology and emission limits
that were effective and applicable to all sources under this typical variety
of operating conditions were selected, and this same BDT and emission limit
would have been selected for all industries whether they were covered under
one NSPS or individually.
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2.10.9 Comment: (IV-D-22, IV-D-33)
Two commenters felt that because nonmetallic minerals vary considerably
as to fineness of the particles, hardness, and the requirements of crushing
to meet product specifications, the proposed standards are unreasonable.
One commenter felt that the EPA should exempt from the proposed standards
any mineral which was not tested. The other commenter suggested that the
EPA permit each State to set its own standard with the EPA having the
authority to approve the State's requirements. They felt that the emission
test data base does not adequately characterize the full range of minerals
to which the standards would apply. They recommended including provisions
in the standards whereby an operator could petition the EPA to establish a
specific standard for any facility for which compliance is impossible or
impractical.
Response:
The EPA tested emissions from 25 baghouses at 13 different plants, as
well as fugitive emissions from 53 sources at these plants. Fugitive
emissions were also tested at five plants using wet suppression. Plants
tested processed crushed stone (limestone, traprock, granite), feldspar,
gypsum, mica, talc, sand, gravel, and clay (kaolin and fuller's earth), and
metallic minerals. These materials cover the range of hardness found in the
industries, and represent a variety of end uses with different product
specifications. The range of particle sizes found in the industries is
represented in the test data. Baghouses at kaolin and fuller's earth plants
controlling clay emissions with median particle diameters of 1.5 ym to
3.8 ym could meet the proposed stack concentration and opacity standards.
Feldspar and limestone facilities with particulate emissions of 20-25 ym
median diameter also met the standards. Particle size and type of mineral
processed were not found to affect baghouse performance. Tests on the
effectiveness of wet suppression also covered a variety of hardnesses and
particle sizes. All plants with well designed and operated systems met the
fugitive opacity standards.
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Since test data adequately covers the variability between industries
and between individual plants in each industry, the proposed standards will
be applied to all affected facilities in the 18 nonmetallic minerals
industries regulated. The standards include provisions to raise the stack
opacity limit at individual plants on a case-by-case basis if the concentra-
tion limit is met but for some reason opacity cannot be met. This is
allowable because the purpose of the opacity standard is to provide a simple
indicator of emissions concentration.
Section 111 of the Clean Air Act does not allow the EPA to permit each
State to establish standards as a substitute for an NSPS or to grant
exemptions on a case-by-case basis. The main purpose of standards of
performance is to require new sources, wherever located, to reduce emissions
to the level achievable by the best technological system of emissions
reduction considering the cost of achieving such emission reduction, any
nonair quality, health, and environmental impact, and energy requirements.
Standards of performance establish a degree of national uniformity to air
pollution standards and, therefore, preclude situations in which some States
may attract new industries as a result of having relaxed standards relative
to other States.
2.10.10 Comment: (IV-D-2)
One commenter stated that the standards would contribute greatly to
uniform standards in the nation and would preserve air quality. They felt
that the approach and standards appear sound and consistent with their
experience.
Response:
The EPA is in agreement with this commenter.
2.11 LEGAL CONSIDERATIONS
2.11.1 Comment: (IV-D-34)
One commenter stated that the EPA lacks the authority under the Clean
Air Act to regulate air within the workplace. Because the standards define
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the affected facilities as each piece of equipment at a processing plant and
do not allow for a building to be considered a control device, he felt that
the standards are regulating the air in the workplace that is not accessible
to the general public.
Response:
It was not EPA's intent to regulate workplace air. The intent of
Section 111 of the Clean Air Act is to limit emissions to ambient air. The
EPA has revised the proposed regulation to clarify the use of buildings as
control devices. As explained in Section 2.4.1, buildings enclosing affected
facilities must meet the stack standards of 0.05 g/dscm (0.02 g/dscf) and
7 percent opacity if emissions are vented from the building. They must also
meet a fugitive emissions standard of no visible emissions escaping the
building. If these standards are violated, then ambient air quality is
being impacted and the EPA will require opacity tests at individual affected
facilities inside the building to determine whether they are in compliance
with fugitive standards. If individual affected facilities are not in
compliance, controls must be added in order to reduce emissions to the
ambient air.
2.12 TEST METHODS AND MONITORING
2.12.1 Comment: (IV-D-44)
One commenter stated that when pieces of processing equipment are
located next to each other, it would be impossible to ascertain how much
dust is coming from each piece of equipment or to state with certainty that
each piece meets the required level.
Response:
EPA believes situations where opacity of emissions from individual
affected facilities cannot be read will be rare; however, provisions have
been added to §60.675(c) of the regulation clarifying how compliance will be
determined if emissions from two or more facilities continuously interfere.
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sect,on 60.675(0 of the proposed and final standards centals stipula-
tion, to be followed for using Method 9 to read fugitive em^ons These
o
,ns emphasize correct positioning of the observer t, ,
ts
interference from other emission sources. Following these stipulates
during its testing program that situations where fugitive opacity
Id not be measured due to emissions fro* other pieces of equipment
ccurred very rarely. And they occur only when wet dust -PP- ™<
as a control technique, and not when emissions are collected y ca pur
systems, in most cases, repositioning of the observer or waiting or a
in wind conditions will allow the observer to read opacity or e
facility. in such situations, opacity of emissions from individual affected
facilities must be measured to determine compliance. Furthermore he E A
ntici a4 that the majority of facilities affected by the standards «i
be at new plants or capacity expansions at existing p ants these cases,
owners can design and locate facilities so emissions from deferent
Tcilities do not continuously interfere and the opacity of emissions fro.
each facility can be measured.
However, sometimes affected facilities may be locate above , an- * «
one another so emissions from one facility pass through the other faclity,
the emission streams from the facilities are continuously co.bi.e-.
Since it is possible that there may be cases where emissions from two or
more facilities continuously interfere, provisions have -«-««-*»
660 675(c) clarifying the use of Method 9 in such cases. Under these
visions, if opacity of emissions from a single affected facility .cannot
be measured due to the continuous interference of emissions from oh r
facilities, then plants may take one of two courses of ac ion:
opacity of the combined emission stream from the mterfer ng fac, 1, es
mLts L highest opacity standard in §60.672 W"""*" ™«™ ^
affected facilities contributing to the emiss.ons, then the flue
be determined to be in compliance; (2) the equipment may be moved or a
ys 1 barrier or ductwor* may be installed to separate emissions from
each facility. For example, if a screen is located below a crusher
controlled by wet suppression and emissions from the two facilities
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continuously interfere, the owner or operator could meet the standards by
showing that combined emissions from the two facilities meet the 15 percent
fugitive opacity standard applicable to the crusher, or he must somehow
separate emissions from the two facilities and meet the opacity limits for
each (10 percent for the screen and 15 percent for the crusher).
If neither of these courses of action are feasible, he would have to
capture the emissions, duct them to a control device, and meet the
applicable stack and fugitive emissions standards. The economic analysis
for the proposed standards assumed emissions from all affected facilities
would be captured and ducted to baghouses; and under this assumption the
costs of control were found to be reasonable. However, the EPA believes
offering the other options to show compliance may allow some plants to use a
less costly method such as wet dust suppression, to comply with the
regulation.
2.12.2 Comment: (IV-D-10, IV-D-16)
Two commenters disagreed with the monitoring requirements proposed for
wet scrubbers. One commenter stated that while he did not oppose the '
replacement of an opacity standard with monitoring of operating parameters,
he suggested that a range be selected during the initial performance test
rather than one set of numbers. He said this approach would allow for
slight variations in processing conditions such as outside temperature, clay
content, and particle size. The other commenter stated that maintaining a
given pressure drop and flow rate is no guarantee that the scrubber is
achieving the desired efficiency. He felt that the pressure drops and water
flows could vary widely and emission rates could soar, but as long as
measurements were recorded weekly, the scrubber would be in compliance.
Response:
EPA has made additions to Section 60.676 of the standards which address
these comments. The section details requirements for periodically recording
and reporting scrubber operating parameters.
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EPA has provided for slight routine variations in operating parameters,
but by a different method than that suggested by the first commenter. The
owner or operator is required to report the liquid flow rate and change in
pressure of the gas stream at the time of the initial performance test; and
these parameters are recorded weekly thereafter [40 CFR 60.676(c)]. These
weekly readings must be reported semiannually only if one or more readings
vary by more than ±30 percent from the readings of the most recent
performance test. The ±30 percent allows for normal variations in process
conditions, so selecting a range of values at the time of the initial
performance test is not necessary.
In response to the second comment, the recording and reporting of
scrubber liquid flow rate and pressure drop will provide an inexpensive and
easily verifiable check on the operation and maintenance of wet scrubbers.
The principle factors affecting the performance of scrubbers include the
pressure drop and the liquid to gas ratio (Docket No. IV-J-1). Monitoring
liquid flow rate and pressure drop will allow maintenance personnel to
detect and correct decreases in scrubber performance before major breakdowns
occur, reducing overall control cost and enhancing control efficiency.
Routine recording and reporting will also allow EPA to check that the
scrubber is maintained and operated properly indicating that the emission
limits continue to be met over time. As described above, weekly readings
must be recorded and they must be reported to EPA semiannually if one or
more readings varies by more than ±30 percent from the readings of the most
recent performance test.
2.12.3 Comment: (IV-D-3)
One commenter felt that a stack test should not be required unless the
control device fails to meet the stack opacity limit of 7 percent. He felt
that if an opacity test is sufficient to show compliance for a noncapture
system, it should be the same for a capture and collection system.
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Response:
Opacity tests are the only compliance tests required for noncapture
systems, because noncapture systems emit fugitive particulate matter
emissions. There are no practical methods for measuring mass emissions or
particulate concentrations of fugitive emissions. Therefore, opacity or
equipment standards are the only formats available for regulating emissions
from noncapture systems. The same opacity standard applies to fugitive
emissions from both capture and noncapture systems.
Stack emissions from capture systems can be quantified using standard
EPA reference methods. A concentration or mass emission standard can
therefore be developed and enforced. For nonmetallic minerals processing
plants it has been determined that a concentration standard of 0.05 g/dscm
(0.02 gr/dscf) is achievable using BDT and will result in significant
emissions reduction. Performance tests are necessary for enforcement of
this standard. The information obtained from performance tests is used by
EPA to ensure compliance and also to aid in standards development. Emission
test data collected during performance tests will be used in the periodic
4-year review of the NSPS to reevaluate the appropriateness of the emission
limits established in the current NSPS.
While performance tests are necessary to ensure compliance with the
standards, a less rigorous method has been provided for ensuring that
compliance is maintained. The 7 percent stack opacity standard has been
provided as an inexpensive and verifiable check on the operation and
maintenance of air pollution control devices. It is useful as an indicator
of control device performance but does not provide the precision required
for a performance test.
The cost of performance tests is reasonable. Performance test costs
are a small percentage of the cost of control equipment, and the costs and
economic impacts of control have been found to be reasonable in EPA's
economic analyses.
It should be noted that under the General Provisions [40 CFR 60.8(b)],
an owner or operator may petition for a waiver of the requirement for
performance tests or for the use of an alternative testing method. The
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Administrator may approve the use of an alternative method for performance
testing on a case-by-case basis if he has determined the alternative method
is adequate to show compliance. The Administrator may waive the requirement
for a performance test in a specific case if the owner or operator has
demonstrated by other means to the Administrator's satisfaction that the
affected facility is in compliance with the standard.
2.12.4 Comment: (IV-D-39)
One commenter was concerned with the use of EPA Reference Method 9 for
reading fugitive emissions. He stated that EPA has already promulgated
Reference Method 22 for determining fugitive visible emissions from material
processing sources; and he did not understand why the proposed regulation
utilizes a method which has inherent weaknesses when used for fugitive and
typically intermittent releases, when a more appropriate method exists.
Response:
EPA's testing program for fugitive emissions from metallic and nonmetal-
lic minerals processing plants was based on Method 9 and showed that Method 9
can be used and is appropriate. The use of Method 22 was attempted and
found to be inappropriate. Method 22 measures the accumulated emission time
during an observation period, or the frequency of visible fugitive emissions.
It is, therefore, only applicable to sources which are intermittent in
nature. The affected facilities at nonmetallic minerals processing plants
(crushers, grinding mills, screening operations, etc.) are not intermittent;
in fact they emit some visible fugitives almost continuously during the time
they are operating. Therefore, Method 22 is not appropriate for these
sources.
The EPA has determined that an opacity standard is appropriate for this
industry, rather than a frequency of emissions standard. Method 9 is the
method applicable for the determination of the level of opacity of visible
emissions. During the data collection activities in support of these
standards, observers trained in the use of Method 9 followed the guidelines
of that method with some stipulations in recording visible process fugitive
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emissions data. These stipulations are included in subsection 60.675(c) of
the standards. They clarify correct observer positioning, and contain
guidelines for avoiding the confusion of particulate emissions with visible
water mist from wet suppression systems. They also clarify the use of
Method 9 to determine compliance when emissions from two or more facilities
continuously interfere with one another.
2.12.5 Comment: (IV-D-34)
One commenter requested that EPA delete the performance test require-
ments because they are expensive and burdensome. Instead, he suggested that
EPA accept an engineering certification that the air pollution control
equipment meets the necessary specifications.
Response:
Performance tests are necessary to gain information and ensure
compliance with the standards as explained in Section 2.12.3. Costs of
these tests are a small percentage of the capital cost of new plants. EPA's
economic analyses have determined that costs and economic impacts of control
are reasonable. Performance tests will not be an unreasonable burden on
industry, and will be required.
The approach suggested by the commenter was considered and rejected.
EPA has found that similar facilities with similar control devices often do
not have the same emissions characteristics. There are many variables in
types of processes, process operating conditions, and control system opera-
tion at individual plants which may not be accounted for in an engineering
certification and which may greatly influence emissions. Therefore, the use
of engineering certifications rather than performance tests for enforcement
of the standards would be unreasonable.
2.12.6 Comment: (IV-D-52)
One commenter was concerned about how EPA Reference Method 9 will be
used to read emissions from enclosed truck and railcar loading stations.
Because the method is unclear as to where the observer should stand, he
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requested that EPA specifically state that in observing emissions from
enclosed truck and railcar loading stations, the observer should stand such
that his line of vision is perpendicular to the tracks or road upon which
the railcar or truck is being loaded.
Response:
Method 9 and the stipulations for its use contained in Section 60.675(c)
of the regulation give adequate guidance on observer positioning. Para-
graph 2.1 of Method 9 and the stipulations in the regulation emphasize that
the observer should be at least 15 feet from the emission source, and have a
clear view of the source and emissions with the sun at his back. The
stipulations also state that the observer shall position himself to minimize
interference from other fugitive emission sources such as road dust.
Paragraph 2.1 of method 9 states that when possible the observer's line of
sight should be perpendicular to the direction of flow of the emissions or,
if emissions from a rectangular outlet are being observed, to the long axis
of the outlet.
2.13 REPORTING AND RECORDKEEPING
2.13.1 Comment: (IV-D-15, IV-D-16)
Two commenters requested that sand and gravel operations, which are wet
processes and maintain a high degree of moisture in the processed material,
be exempt from reporting and recordkeeping requirements. They said that
because EPA recognizes these plants as negligible contributors of
particulate emissions, they felt this approach reasonable. While still
subjecting the operator to the emission limits of the proposed standards
and, therefore, creating no adverse environmental impact, they felt that
such an exemption would greatly reduce the paperwork and concurrent economic
burden on EPA and State regulatory agencies, as well as on these particular
operations. They suggested that one letter from the operator to the State
or EPA certifying the material at a plant is processed wet and generates no
visible emissions from processing equipment should suffice as notice.
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Response:
The only reporting and recordkeeping requirement for plants using wet
dust suppression is an initial performance test during which the opacity of
emissions from each affected facility must be measured. This is necessary
to ensure that the facilities are in compliance with the standards. No
further monitoring, reporting, or recordkeeping is required where wet
suppression is used, with the following exception: under the provisions of
§60.676, the State or the EPA regional office and the EPA Office of Air
Quality Planning and Standards must be notified if an existing facility is
replaced with a new facility of equal or smaller size. Such replacements,
however, are not subject to the emission limits of the standards. The
reporting and recordkeeping requirements for plants using wet dust suppres-
sion, summarized above, are minimal. EPA has determined that they will not
be an unreasonable burden for industry or enforcement agencies. Plants in
the sand and gravel industry are subject to the same requirements as plants
in other nonmetallic minerals industries.
2.13.2 Comment: (IV-D-24)
One commenter stated that because of the affected facility designation,
Federal, State and local agencies will have to track all elements of each
processing plant manufactured after August 31, 1983. He felt that such
tracking would require diverting field enforcement resources to essentially
administrative duties, thus substantially reducing inspection activities.
He considered it essential that the tracking, reporting, and other paperwork
requirements be reduced before promulgation.
Response:
EPA or State agencies enforcing the standards would have to track, or
keep records of, new equipment at both new plants and capacity expansions at
existing plants under either a narrow or broad definition of affected
facility. Because of reconstruction provisions, they would also have to
track the installation of new equipment at existing plants under the broad
or narrow definition of affected facility. Administrative reporting and
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recordkeeping requirements for these standards are similar to those for
other NSPS. The EPA has estimated the agency resource requirements
associated with reporting and recordkeeping, and has determined them to be
reasonable.
2.13.3 Comment: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35)
Five commenters were concerned about the paperwork burden the proposed
standards would put on industry if notification of both State agencies and
the Federal EPA is required. They suggested that in cases where the State
Implementation Plan has been approved, notification to the State agency
alone be allowable.
Response:
In States that have been delegated the authority to enforce NSPS,
reporting is directly to the State agency. The authority to enforce NSPS is
separate from the authority to administer a State Implementation Plan. In
States that have not been granted this authority, the EPA regional office
should be notified. In addition, in cases where an existing affected
facility is replaced by a new piece of equipment of equal or smaller size,
the industry must also notify the Federal EPA Office of Air Quality Planning
and Standards as described in 40 CFR 60.676.
2.13.4 Comment: (IV-D-3)
One commenter stated that portable plants which are designed to be
moved, set up and put in production quickly should not be subject to the
performance test requirements on each move. He felt that the initial
performance test at the first site should be sufficient.
Response:
Performance tests for portable plants will be required only at the
first site and not a subsequent sites to which they move with two excep-
tions. First, if a new affected facility is added, a new performance test
is required. If emissions from the facility are ducted to an existing
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baghouse, a new performance test of that baghouse is required. If wet dust
suppression is used, only the new affected facility must be tested. The
second exception is that if a portable plant moves from one State to
another, the new State may require a performance test.
2.14 WORDING OF REGULATION
2.14.1 Comment: (IV-D-3)
One commenter requested that impactor be added to the types of crushers
listed in the proposed standards.
Response:
Impactors have been added to the types of crushers listed in the
promulgated standards. However, it should be noted that in both the
proposed and final standards (48 FR 39576; 40 CFR 60.671) a crusher is
defined as a machine used to crush any nonmetallic mineral, and includes,
but is not limited to, the listed types of machines. Therefore even if a
particular type of crusher is not explicitly listed in the definition, it
would still be covered by the standards.
2.14.2 Comment: (IV-D-13, IV-D-14, IV-D-15, IV-D-16, IV-D-17, IV-D-26,
IV-D-35)
Seven commenters asked for clarification as to which conveying systems
are subject to the standards and which are exempt. In addition, they
requested clarification on which portions of the conveying systems are
covered.
Response:
Belt conveyors are the designated affected facility, however, only
transfer points must comply with the emissions limits. In the preamble to
the proposed regulation, it is clearly stated that conveying, other than
transfer points, is not covered (48 FR 39568). In the regulation, belt
conveyors are designated as an affected facility for purposes of determining
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if existing facilities are subject to modification or reconstruction
provisions (40 CFR 60.670). The standards for particulate matter state that
no owner or operator "shall cause to be discharged into the atmosphere from
any transfer point on belt conveyors or from any other affected facility any
fugitive emissions which exhibit greater than 10 percent opacity..."
(40 CFR 60.672(b)). A transfer point is defined as "a point in a conveying
operation where the nonmetallic mineral is transferred to or from a belt
conveyor except where the nonmetallic mineral is being transferred to a
stockpile" (40 CFR 60.671). Thus, belt conveyors are the affected facility,
but only transfer points must meet the emission limits.
2.14.3 Comment: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35)
Five commenters requested clarification as to when the two year period
begins for consideration for the reconstruction provisions. In addition,
they were confused about whether a continuous program of component replace-
ment is one which is proposed or initiated within a two year period or one
in which the equipment is actually installed within a two year period.
Response:
"Commenced" is defined in the General Provisions (40 CFR 60.2) as
meaning that an owner or operator has undertaken a continuous program of
construction or modification or that an owner or operator has entered into a
contractual obligation to undertake and complete, within a reasonable time,
a continuous program of construction or modification. The two year period
for reconstruction begins when the owner or operator "commences" the
reconstruction as by signing a formal contract for the construction. If
work is done in-house, various activities such as purchasing equipment for
the construction or assigning personnel to do the work could be considered
as commencing the reconstruction. In these situations, the beginning date
of the 2-year period is made by the appropriate enforcement personnel on a
case by case basis. The 2-year period includes any activities that commence
during the following two years whether or not they are actually completed.
Thus, if one or more construction programs are commenced within 2 years and
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together will result in reconstruction of over 50 percent of an affected
facility, then that facility will become subject to reconstruction
provisions.
2.14.4 Comments: (IV-D-15, IV-D-16, IV-D-17, IV-D-26, IV-D-35)
Five commenters requested clarification on the first notification
requirement. The General Provisions [40 CFR 60.7(a)(l)l require notifica-
tion of the date construction of an affected facility is commenced. However,
§60.7(a)(l) goes on to say that this requirement does not apply in the case
of mass-produced facilities which are purchased in completed form. They
were confused as to when the notification must be submitted. They suggested
that the definition of mass-produced facilities is needed in the standards.
Response:
A mass-produced facility is one which is purchased in completed form.
The first notification required under 40 CFR 60.7 is a notification of the
anticipated date of initial startup postmarked between 30 and 60 days prior
to such date.
2.14.5 Comment: (IV-D-18, IV-D-26, IV-D-27)
Three commenters believed the definitions of fixed and portable plants
in the regulation need clarification. They were concerned that the
connecting of a portable facility to a power source could cause the plant to
be considered a fixed plant. The commenters noted that the definition of
portable plant as presented in the proposed regulation is: "any nonmetallic
mineral processing plant that is mounted on any chassis or skids and may be
moved by the application of a lifting or pulling force. In addition there
shall be no cable, chain, turnbuckle, bolt or other means by which any piece
of equipment is attached or clamped to any anchor, slab, or structure,
including bedrock, that must be removed prior to the application of a
lifting or pulling force for the purpose of transporting the unit." They
suggested the definition be modified to exempt electrical connections
because other regulations in the Federal Mine and Safety Act of 1977 state
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that all plants that are electrically powered shall be properly grounded.
One commenter suggested the following wording as the definition of a portable
plant: "Portable facility means any nonmetallic processing facility mounted
on any chassis or skids and which may be moved from site to site with the
application of a lifting or pulling force." In addition, one commenter
requested that the fixed plant definition be changed to read as follows:
"Fixed plant means any nonmetallic mineral processing plant at which the
processing equipment specified in Subsection 60.670(a) is attached by a
cable, chain, turnbuckle, bolt or other means to any anchor, slab or
structure including bedrock."
Response:
The definition of fixed plant has been modified in the promulgated
regulation as the commenter suggests. The portable plant definition in
40 CFR 60.671 has also been revised. It now reads,
"Portable plant means any nonmetallic mineral
processing plant that is mounted on any chassis or skids
and may be moved by the application of a lifting or
pulling force. In addition, there shall be no cable,
chain, turnbuckle, bolt, or other means (except electri-
cal connections) by which any piece of equipment is
attached or clamped to any anchor, slab, or structure,
including bedrock, that must be removed prior to applica-
tion of a lifting or pulling force for the purpose of
transporting the unit."
2.14.6 Comment: (IV-D-36)
One commenter requested that all operations exempted be stated in the
regulation. He recommended exemptions be stated for the following opera-
tions: haul roads, stockpiles, blasting, loading at the mine, conveying
(other than at transfer points), waste piles, truck and railcar loading and
unloading, and mining operations such as excavation and stripping.
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Response:
In the regulation (40 CFR 60.670 and 60.671), EPA has provided a legal
definition of those nonmetallic mineral processing facilities that are
"affected" by the regulation. The EPA does not provide a list of
"non-affected" facilities in the regulation because it would be impractical
to attempt to devise a complete list of the many facilities which are not
covered. Furthermore, questions would arise as to the legal standing of
nonmetallic mineral facilities or operations that were not specifically
listed as either "affected" or "non-affected".
In the preamble to the proposed regulation (48 FR 39568) the EPA
discussed the rationale for exempting from the proposed standards certain
operations or facilities at nonmetallic minerals plants (including those the
commenter lists). This discussion was intended to provide the public with
background information, and is not appropriate to include in the regulation.
2.14.7 Comment: (IV-D-36)
One commenter suggested that the language of subsection 60.675(c) be
revised as follows:
"When determining compliance with the standard prescribed under
subsections 60.672(b) and (c), the Administrator shall adhere to the
following stipulations in addition to those listed in Method 9."
Additionally, he requested that both subsection 60.675(c) and Method 9 be
amended to clarify that water mist from wet dust suppression and steam
plumes from operations should not be confused with particulate matter
emissions and are not to be considered visible emissions.
Response:
Subsection 60.675(c) has been reworded to include the wording
"stipulations in addition to those listed in Method 9", as requested by the
commenter. Paragraph 2.3 of Method 9 adequately discusses water vapor. It
states,
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When condensed water vapor is present within the plume
as it emerges from the emission outlet, opacity observa-
tions shall be made beyond the point in the plume at
which condensed water is no longer visible .... When
water vapor in the plume condenses and becomes visible
at a distinct distance from the emission outlet, the
opacity of emissions should be evaluated at the emission
outlet prior to the condensation of water vapor and the
formation of the steam plume.
Paragraph 60.675(c)(3) of the regulation includes further clarification
for the use Method 9 when water mist generated by wet dust suppression is
present. The paragraph is as follows:
(3) For affected facilities utilizing wet dust
suppression for particulate matter control, a visible
water mist is sometimes generated by the spray. The
water mist must not be confused with particulate matter
emissions and is not to be considered a visible
emission. When a water mist of this nature is present,
the observation of the emissions is to be made at a
point in the plume where the mist is no longer visible.
2.14.8 Comment: (IV-D-26)
One commenter stated that portable plants in the crushed stone industry
are composed of several affected facilities, all of which do not necessarily
process the full throughput of the primary crusher. He felt the 150 tons/hr
exemption should be applied to each facility instead of the whole plant. He
suggested section 60.670 be reworded to state clearly that any portable
facilities with capacities below those specified are exempt from these
regulations.
Response:
EPA recognizes that affected facilities within a plant often vary in
capacity. In order to analyze economic impacts using discounted cash flow
analysis, however, EPA had to assume a production level for the entire plant
and assess profitability of the portable plant as a whole. This is because
individual pieces of equipment do not make saleable products. Since exemp-
tions are based on economic analysis of plant profitability or feasibility
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and it is necessary to include the whole plant in this analysis, exemptions
are based on plant size rather than size of individual affected facilities.
2.15 MISCELLANEOUS
2.15.1 Comment: (IV-D-23)
One commenter complained that the exemption for portable sand and
gravel and crushed stone plants is too broad and lenient and allows
operation of a new portable plant without controls at a larger capacity than
allowed for a fixed plant. He suggested that any exemption should be
conditioned to require specific control equipment when the portable plant
operates, or plans to operate, at a specific quarry/site for six months or
more without an inter-quarry movement. Further, he suggested that plant
intra-quarry moves should be excluded as a basis for exemption from
controls. Finally, he stated that the standards should not be relaxed as
they provide a minimum control technology base for BACT considerations.
Response:
EPA has conducted separate analyses addressing operating conditions at
portable plants and at fixed plants because they are two distinctly
different types of plants with different modes of operation. The results of
the analyses of economic feasibility showed that the cut-off size for
exemption from the regulation should be different for portable and fixed
plants. Under Section lll(b) of the Clean Air Act, the Administrator is
empowered to distinguish among classes, types, and sizes within categories
of new sources for the purpose of establishing standards.
It is not possible to base exemptions and control requirements on the
length of time a portable plant operates in one location. The commenter
suggests a six-month cut-off time. However, in many cases, an operator does
not know how long he will remain in one location. Therefore, the operator
and EPA would not be able to determine whether a plant should be covered by
the regulations until after the fact.
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Intra-quarry moves are made by portable plants to reduce the need for
haul trucks to transport newly blasted rocks to the primary crusher. This
mode of operation must be considered in the analysis of portable plants. If
it were not considered, portable plants would be forced to operate identi-
cally to stationary plants within a quarry. Portable plants form a
different class or type of plant from fixed plants and are a necessary
segment of the nonmetallic minerals industry. EPA is authorized under the
Clean Air Act to distinguish between types and classes of plants within a
source category and has done so in this case.
2.15.2 Comment: (IV-D-50, IV-D-24, IV-D-36)
One commenter (IV-D-50) favored the exemptions for fixed crushed stone
and sand and gravel plants with capacities of 25 tons/h or less and portable
plants with capacities of 150 tons/h or less. The other two commenters
(IV-D-24 and IV-D-36) requested that the cutoff sizes be raised for portable
and stationary sand and gravel and crushed stone plants to 300 tons per hour
for portable plants and 100 tons per hour for stationary plants. These two
commenters also requested exemptions for plants operating in remote areas
where there are no air quality problems and no impacts on persons or
property. One commenter suggested that a higher minimum capacity be
exempted for plants in the Western United States for this reason. The other
commenter felt that all remotely sited plants should be exempted.
Response:
EPA's discounted cash flow (DCF) analysis showed that it probably would
not be economically feasible to control fixed crushed stone and sand and
gravel plants with capacities of 23 Mg/h (25 tons/h) or less, common clay
plants with capacities of 9 Mg/h (10 tons/h) or less, and portable plants
with capacities of 136 Mg/h (150 tons/h) or less (EPA-450/3-83-001a), so
these plants were exempted from the regulation. However, for all larger
sized plants the analysis did not indicate clear economic infeasibility.
The conservative assumptions upon which the DCF analysis was based are
explained in Sction 2.5.4.
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The cutoff points were set at the sizes listed above because the
economic analysis shows that even if the worst case assumptions noted in
Section 2.5.4 are relaxed, the economic viability of plants of these and
smaller sizes remains in doubt. On the other hand, for plants larger than
these sizes, the benefits of "economies of scale" increase the profitability
of these plants so that NSPS costs are significantly less burdensome.
Finally, it should be noted that although the economic analysis is
inconclusive about the economic feasibility of some larger sized model
plants with NSPS controls, it is highly unlikely that all worst case
assumptions would hold true for any plants. In reality, if only one or two
of the worst case assumptions are relaxed, the plants of sizes larger than
those exempted are shown to be economically feasible.
Plants in remote areas are not exempt from the regulation. Once a
source category has been determined to impact health and welfare and has
been included on the priority list, NSPS must be promulgated. The main
purpose of NSPS is to require new sources, wherever located, to reduce
emissions to the level achievable by the best technological system of
emission reduction considering the cost of achieving such emission reduction,
any nonair quality health and environmental impact, and energy requirements
(Section lll(a)(l)). One intent of the Act is to prevent air quality
degradation due to industrial growth. Another purpose of NSPS is to
establish a degree of national uniformity to air pollution standards and,
therefore, preclude situations in which some States may attract new indus-
tries as a result of having less stringent standards than other States.
Exempting plants on the basis of remoteness would be contrary to these
purposes of the Clean Air Act. EPA's economic analyses have determined that
the costs and economic impacts of control are reasonable for all sizes and
types of plants covered under the standard regardless of location and
remoteness.
2.15.3 Comment: (IV-D-26)
One commenter submitted comments that had previously been presented to
EPA at the National Air Pollution Control Techniques Advisory Committee
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(NAPCTAC) meetings in September 1975 and July 1978, but he felt these
comments had never been adequately addressed. These comments address the
draft standards that were being developed for only the crushed stone
processing industry and the later draft standards for the entire nonmetallic
mineral processing industry. The commenter stated in his earlier comments
that crushed stone and sand and gravel are highly competitive commodities in
those areas where both exist and that EPA was acting in a discriminatory
manner by subjecting only the crushed stone industry to a set of standards.
The commenter also stated that the standards under consideration at that
time (October 1975) would require energy demands as high as 28 percent of
the total energy being consumed by a crushed stone plant, and this would
have a regressive impact upon the industry. He also was concerned that if a
piece of equipment experienced a major malfunction it might take as long as
60 days before a permit would be granted to replace the equipment. The
commenter was concerned that the cost of disposing of fines collected in
baghouse was being underestimated and that the economic impact analysis was
not based on the producer's profit margin. The commenter also stated that
because individual plants would be impacted at different times, plants could
be at a serious economic disadvantage as a result of the standards. The
earlier comments included a request to consider wet dust suppression systems
as BDT.
Response:
In 1973, EPA began developing standards for the crushed stone
processing industry. Draft standards and the associated background informa-
tion were presented at a NAPCTAC meeting in July 1975. In July 1977, the
crushed stone processing industry was combined with other nonmetallic
mineral processing industries for standards setting purposes because of the
similarities between the equipment used at their plants and the potential
for particulate matter emissions from the equipment. Draft standards and
the associated background information were presented by EPA at a NAPCTAC
meeting in July 1978. Standards of performance for the nonmetallic mineral
processing industry were proposed on August 31, 1983. The comments submitted
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by the commenter were previously submitted on a number of occasions (see
docket entries II-D-17, II-D-19, and II-E-4). These comments have been
given consideration by EPA each time. In fact, the standards cover the sand
and gravel processing industry as well as the crushed stone processing
industry. The standards also allow for the use of wet dust suppression
systems. Because of the allowance of wet dust suppression systems, the
energy impact of the standards is much lower than that of the earlier draft
standards that the comments are based on.
The cost of disposal of collected fines has been evaluated by EPA and
found to be minimal (see Comment 2.5.10). The commenters concern about the
impact of the cost of the standards on the producer's profit margin has also
been evaluated and found to be reasonable by EPA (see Comment 2.5.11). In
preparing the economic impact analysis, EPA considered that the ability of
individual producers to pass NSPS costs to consumers could be hindered
because of competition from plants that were not covered by the NSPS (see
Comment 2.5.15).
The commenter1s concern about the potential of a 60 day delay in
obtaining a permit to replace broken equipment has also been addressed in
the final standards. As long as an operator replaces the broken equipment
with a new piece of equipment that is of equal or smaller size, the
standards only require that the operator report the replacement to EPA and
notify the Federal EPA Office of Air Quality Planning and Standards as
described in 40 CFR 60.676.
2.15.4 Comment: (IV-D-40)
One commenter stated that it has been his past experience with the
officials in Rules and Standards that they do not have the hands-on
knowledge needed to understand what the problems could be when the
individuals in the field try to achieve the desired results.
Response:
Industry has been provided with opportunities to communicate such
problems to EPA at many stages during the standards development process.
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During standards development activities, EPA representatives have made
approximately 60 visits to plants in 24 States. EPA conducted stack tests
at 17 baghouses, at 8 nonmetallic minerals plants, and at 8 baghouses at
5 metallic mineral processing plants. Fugitive emissions from 53 operations
at 13 plants using baghouses, and from 36 facilities at 6 plants using wet
suppression were tested. In addition, EPA reviewed test data from other
sources. During standards development, two NAPCTAC meetings were held (in
September 1975 and July 1978), and EPA held 15 other meetings with industry
or trade association representatives. EPA also held numerous telephone
conversations and corresponded with industry representatives. Industry
representatives submitted comments on the proposed standard which were
considered and addressed prior to promulgation. Records of the above plant
visits, tests, meetings, correspondence and all other references used in
standards development are included in the project docket (Docket No.
OAQPS 78-11) which is open to the public. Information which EPA lacked was
supplied by these contacts with industry representatives.
EPA's record shows that comments on problems industry may face are
solicited and given appropriate consideration. Furthermore, standards are
periodically reviewed and revised as necessary every four years, so future
industry comments on the promulgated standards will be considered during
such revisions.
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