AUG I 1983
EPA
LIME MANUFACTURING PLANTS —
BACKGROUND INFORMATION
FOR PROMULGATED STANDARDS
OF PERFORMANCE
DRAFT
EMISSION STANDARDS AND ENGINEERING DIVISION
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF AIR, NOISE, AND RADIATION
OFFICE OF AIR QUALITY PLANNING AND STANDARDS
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
JULY 1983
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TABLE OF CONTENTS
Section Page
1 SUMMARY ........................... 1-1
1.1 Summary of Changes Since Proposal ... ... 1-2
1.2 Summary of Impacts of Promulgated Amendments ..... 1-2
1.2.1 Alternatives to the Promulgated Action ..... 1-2
1.2.2 Environmental Impacts of the Promulgated
Action 1-3
1.2.3 Energy and Economic Impacts of the Promulgated
Action ......... 1-3
1.2.4 Other Considerations
1.2.4.1 Irreversible and Irretrievable
Commitment of Resources 1-3
1.2.4.2 Environmental and Energy Impacts of
Delayed Standards 1-4
1.2.4.3 Urban and Community Impacts ...... 1-4
2 SUMMARY OF PUBLIC COMMENTS ............ 2-1
2.1 Costs and Benefits of the New Source Performance
Standards ....................... 2-1
2.1.1 Costs ..................... 2-1-
2.1.2 Costs and Benefits . 2-3
2.1.3 Mobility and Competition 2-3
2.1.4 Emissions .............. 2-4
2.1.5 Executive Order 12291 ............. 2-5
2.1.6 Health Impacts ............ 2-6
2.2 Applicability Date ........ .... 2-7
2.3 Best Demonstrated Technology ....... 2-10
2.3.1 Use of Wet Scrubbers .............. 2-10
2.4 Mass Emission Standard ................ 2-12
2.4.1 Mass Emission Level ........ 2-12
2.4.2 Stone Feed ................... 2-14
2.5 Visible Emission Standard ... ..... 2-15
2.5.1 Achievability of the Opacity Standard ..... 2-15
2.5.2 Correlation of Opacity Data with Mass Emission
Rates ..................... 2-18
2.5.3 Effect of Particle Size on Visible Emissions . . 2-19
2.5.4 Plant D Tests 2-20
2.5.5 Specific Affected Facility Visible Emission
Standards 2-21
2.5.6 Reference Method 9 Accuracy and Reliability . . 2-23
2.5.7 Failure To Use All Data Reviewed 2-24
2.5.8 Miscellaneous 2-25
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TABLE OF CONTENTS (continued)
Section Page
2.6 Test Methodology ................... 2-25
2.6.1 Isokinetic Conditions ............. 2-25
2.6.2 Production Capacity .............. 2-26
2.6.3 Pitot Tube Specifications and Velocity
Traverses ................... 2-28
2.6.4 Climatic Conditions .............. 2-29
2.7 Continuous Monitoring ......... 2-30
2.7.1 Continuous Monitor Reliability ......... 2-30
2.7.2 Use of Continuous Emissions Monitoring
Results ............. . . 2-32
2.8 Miscellaneous ............... 2-32
2.8.1 Temperature of Lime Production ......... 2-32
2.8.2 Continuous Monitoring of Positive-Pressure
Fabric Filters ................. 2-33
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LIST OF TABLES
Table Page
2-1 List of Commenters ..................... 2-2
2-2 Adjusted Plant B and Plant E Test Results 2-27
IV
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1. SUMMARY
New source performance standards for lime manufacturing plants were
proposed on May 3, 1977 (Docket No. A-80-53/74-5-I-G-2; hereinafter
"Docket No. A-80-53/74-5" will be omitted from the docket references in
this document). Final rules were promulgated on March 7, 1978 (I-K-3).
As promulgated, standards of performance for lime manufacturing plants
limited particulate emissions from rotary lime kilns to no greater than
0.15 kilogram per megagram (kg/Mg) [0.30 pound per ton (lb/ton)] of
limestone feed. The opacity of the exhaust gases from rotary lime kilns
was limited to less than 10 percent. The particulate emission limit for
any lime hydrator was 0.075 kg/Mg (0.15 lb/ton) of limestone feed.
The National Lime Association (NLA) filed a petition for review of
the lime manufacturing standards with the United States Court of Appeals
for the District of Columbia Circuit. On May 19, 1980, the Court of
Appeals remanded the standards.
The lime manufacturing plant standards were reviewed and on September 2,
1982, a response to the Court remand and several amendments to the
standards were proposed in the Federal Register (47 FR 38832) (III-A-1).
The standards of performance for lime manufacturing plants are based on
the use of fabric filters or electrostatic precipitators (ESP's).
Because of the costs involved in the operation of wet scrubbers as
compared to fabric filters and ESP's, scrubbers were not considered best
demonstrated control technology. However, the proposed remand response
made it clear that the standards do not preclude the use of wet scrubbers.
The proposed amendments to the standards of performance raised the
particulate matter emission limit from rotary lime kilns to 0.30 kg/Mg
(0.60 lb/ton) of limestone feed. The visible emission limit for exhaust
1-1
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gases from rotary lime kilns remained at 10 percent opacity. The standard
for hydrators was deleted. Public comment was invited.
A public hearing was held on November 18, 1982, and the public
comment period was extended until December 20, 1982. Eleven speakers
presented comments on the proposed remand response at the public hearing,
and 13 written comments were received. These comments are summarized
and responses are presented in this document, which serves as the basis
for the revisions that have been made to the proposed amendments to the
standards.
1.1 SUMMARY OF CHANGES SINCE PROPOSAL
In response to the public comments, certain changes have been made
in the proposed amendments to the standards.
The most significant change to the proposed standards is to permit
visible emission observations in lieu of continuous monitoring of visible
emissions for positive-pressure baghouses. There are technical problems
in obtaining accurate readings from a single continuous monitor on
positive-pressure baghouses, and the cost of multiple continuous monitors
is considered to be unreasonable. Thus, certified visible emission
observers may be used to monitor the visible emissions of the exhaust
gases from rotary lime kilns equipped with positive-pressure baghouses.
Continuous monitors, however, will continue to be required for negative-
pressure baghouses and ESP's.
There is also a change to the proposed standards that expands the
definition of stone feed to include iron-oxide additives used in the
production of iron-bearing lime because these additives become part of
the final product.
1.2 SUMMARY OF IMPACTS OF PROMULGATED AMENDMENTS
1.2.1 Alternatives to the Promulgated Action
The regulatory alternatives are discussed in Chapter 6 of Volume I
of the standards support and environmental impact statement (Volume I
SSEIS) for the existing standards (EPA-450/2-77-007a). These regulatory
alternatives reflect the different levels of emission control that were
analyzed in determining best demonstrated technology, considering costs,
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nonair quality health, environmental, and economic impacts for lime
manufacturing plants. These alternatives remain the same.
1.2.2 Environmental Impacts of the Promulgated Action
The environmental impacts resulting from the existing standards are
described in Chapter 6 of the Volume I SSEIS. In remanding the lime
standards, the Court did not question the original analysis of economic,
energy, or environmental impacts. The impacts of the amended standards,
based on the original analyses, are summarized below:
The amended standards would reduce particulate matter emissions
from a rotary lime kiln by about 40 percent below those allowed under a
typical State implementation plan (SIP). This would result in a particulate
matter emission reduction of about 1,300 tons industry wide in the fifth
year following proposal. This estimate is based on a projected growth
of 20 new, modified, or reconstructed rotary lime kilns in 5 years.
For rotary lime kilns, the solid waste generation industry wide in
the fifth year would increase by about 0.2 percent relative to that
under a typical SIP. There would be no adverse water, noise, or radiation
impacts associated with these standards.
Because the amended standards would not regulate hydrators, particulate
matter emissions from these sources would increase by about 140 tons
annually, based on our estimate that three new hydrators will be built
in the next 5 years.
1.2.3 Energy and Economic Impacts of the Promulgated Action
Energy and economic impacts resulting from the standard are discussed
in Chapters 6 and 7 of Volume I SSEIS, respectively. No changes in
these impacts have occurred since the standard was proposed.
1.2.4 Other Considerations
1.2.4.1 Irreversible and Irretrivable Commitment of Resources.
The regulatory alternatives defined in Chapter 6 of the Volume I SSEIS
would not preclude the development of future control options nor would
they curtail any beneficial use of resources. The alternatives do not
involve short-term environmental gains at the expensive of long-term
environmental losses. The alternatives yield successively greater
short- and long-term environmental benefits, with the alternative upon
which the final standards are based providing the greatest benefits.
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Further, none of the alternatives result in the irreversible and
irretrievable commitment of resources. No change in these considerations
has resulted since proposal of the standard.
1.2.4.2 Environmental and Energy Impacts of Delayed Standards. As
discussed in Chapter 6 of Volume I SSEIS, delay in the amended standards
would cause a similar delay in realizing the beneficial impacts associated
with the standard because enforcement of the standards was suspended
upon remand of the standards. No changes in the potential effects of
delaying the standards have occurred since proposal of the existing
standards.
1.2.4.3 Urban and Community Impacts. Urban and community impacts
of the standards are considered under economic impacts in Chapter 7 of
Volume I SSEIS. No changes in these impacts have occurred since the
standards were proposed.
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2. SUMMARY OF PUBLIC COMMENTS
A list of commenters and their affiliations is presented in Table 2-1.
Eleven individuals representing seven lime companies, two consulting
firms, and one trade association (NLA) presented oral testimony at the
public hearing. In addition, 14 written comments were received, 11 of
which were from organizations commenting at the public hearing. The
remaining three were from two lime companies and one attorney.
The comment letters often contained several comments. Each comment
is addressed separately, and the commenter is identified by the appropriate
docket number.
2.1 COSTS AND BENEFITS OF THE NEW SOURCE PERFORMANCE STANDARDS
2.1.1 Costs
Comment: One commenter (IV-D-6) stated that the incremental cost
effectiveness of emission reduction increases from $25 per ton of
particulate matter removed for baseline SIP control to $364 per ton for
the new source performance standards. The commenter contended that this
increase is enormous and raises a question of whether the standard can
be justified on a cost basis.
Response: The cost effectiveness of the standards is at the lower
end of the range of cost effectiveness ($1,000-$3,000 per ton in 1983
dollars) associated with particulate matter control for other industries
regulated by a new source performance standard. It is, therefore,
considered to be reasonable.
Comment: One commenter (IV-D-2) states that the cost of preliminary
collection devices (i.e., cyclones) was not included in the economic
analysis of the lime plant new source performance standard. He further
states that the sizes of existing ESP's and whether the ESP's are single
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TABLE 2-1. LIST OF COMMENTERSC
No.
ORAL
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Commenter
TESTIMONY:
NLA (L. J. Minnick)
Dravo Lime Co. (J. Thompson)
Martin Marietta (G. Judd)
Mississippi Lime Co. (H. Shell,
Consultant)
Continental Lime Co. (M. D. Roach,
Consultant)
Genstar (B. McCandlish)
Edward Levy Co. /Detroit Lime Co.
(M. 0. Johnson)
Marblehead Lime Co. (D. Garman)
Chemical Lime, Inc. (L. Rice)
(comments based on experience of
Dow Chemical Co. )
Marblehead Lime Co. (J. Kerwin)
Allied Products Co. (C. Dennard)
Date of
comment
11/18/82
11/18/82
11/18/82
11/18/82
11/18/82
11/18/82
11/18/82
11/18/82
11/18/82
11/18/82
11/18/82
Docket
No.
IV-F-1
IV-F-1
IV-F-1
IV-F-1
IV-F-1
IV-F-1
IV-F-1
IV-F-1
IV-F-1
IV-F-1
IV-F-1
Page
No.
7-11
105-113
11-31
32-39
39-46
46-65
66-70
71-77
77-81
81-87
87-96
97-105
WRITTEN COMMENTS:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Continental Lime Co. (J. B. Jordan)
Martin Marietta Chemicals
(L. C. Hanson)
G. R. Repper, Attorney
Tenn-Luttrel 1 Lime Co. (J. Cardosa,
Jr.)
Continental Lime Co. (J. B. Jordan)
Marblehead Lime Co. (J. M. Kerwin)
National Lime Association (A. March,
Attorney)
Genstar Cement and Lime Co.
(W. W. McCandlish)
Mississippi Lime Co. (R. V. Zener,
Pepper, Hamilton, and Scheetz)
Chemical Lime Co. (L. Rice)
Continental Lime Co. (J. B. Jordan)
Dravo Lime Co. (J. Thompson)
Marblehead Lime Co. (J. M. Kerwin)
Marblehead Lime Co. (J. M. Kerwin)
10/01/82
10/20/82
10/20/82
10/29/82
11/10/83
11/18/82
11/18/82
12/06/82
12/17/82
01/17/83
01/31/83
01/31/83
02/02/83
02/04/83
IV-D-1
IV-D-2
IV-D-3
IV-D-4
IV-D-9
IV-G-2
IV-G-3
IV-D-5
IV-D-6
IV-G-4
IV-G-5
IV-G-6
IV-G-7
IV-G-8
A transcript of the oral testimony presented at the public hearing and
copies of all correspondence received from commenters appear in
Docket A-80-53.
''Page numbers locate testimony within the public hearing transcript.
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or multi-field units were not examined. He believes that the cost of
99.7-percent-efficient ESP's cannot be justified.
Response: In the background information document supporting the
original NSPS (I-G-1), the size, design, costs, and use of preliminary
collection devices (i.e., cyclones) and ESP's were analyzed. As discussed
in the response to the preceding comment, the control costs are considered
to be reasonable.
2.1.2 Cost and Benefits
Comment: One commenter (IV-F-1; pp. 102-103) asserted that the
regulation may not result in significant environmental improvement. The
commenter concluded that the regulation will consume the time, effort,
and money of the Government and the industry with little tangible and
measurable improvement.
Response: As recorded in the docket and discussed in Volume I
SSEIS, emission reductions of 7,200 to 10,000 tons a year are expected
in 1987- Thus, there will be significant environmental improvement
associated with the standards.
2.1.3 Mobility and Competition
Comment: One commenter (IV-D-6) noted that in the development of
national standards, the mobility and competitive nature of the industry
are evaluated to preclude the establishment of "havens" for industries
in areas of less-strict pollution regulations. The lime industry is
limited in mobility to sites where customers are close by because of the
cost of shipping lime. This makes it impossible for an outside plant to
compete with plants located close to customers. Therefore, the commenter
believes that mobility and competition are not factors in the lime
industry, "havens" are not an issue, and there is no justification for a
national lime standard.
Response: An assessment of the mobility and competitive nature of
an industry is only one of three considerations taken into account in
establishing the priority of regulation for source categories. As noted
in Section 2.1.4 below, lime manufacturing plants are a significant
contributor and, thus, new source performance standards are appropriate.
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In addition, the availability of raw material or markets does not
necessarily dictate the location of a production facility. If a market
is located in or near several States with an adequate source of raw
materials, a producer has the option of locating a plant in the State
that most suits his needs. This gives a producer the option of locating
a plant at a site that is most favorable to him with regard to environmental
regulations. Therefore, there is a potential for mobility and competition
in the lime industry.
2.1.4 Emissions
Comment: One commenter (IV-D-6) contends that growth in the lime
industry between 1977 and 1982 was overestimated by 200 percent and,
therefore, the emission impacts of the lime industry were overestimated.
The commenter noted that when the lime new source performance standards
were first proposed, the Administrator was directed by the Clean Air Act
to include sources that may contribute significantly to air pollution.
The commenter stated that under the present statute the Administrator
can include a source that does cause or contribute significantly to air
pollution endangering public health and welfare. Therefore, the question
of whether lime does contribute significantly to air pollution should be
reexamined.
Response: The precise rate of growth in an industry is not a prime
consideration in developing a new source performance standard. Growth
projections are used to provide estimates of the nationwide impact of
new source performance standards on the industry. Growth in the lime
industry is lower than originally predicted; however, significant growth
has occurred. At least 16 new lime kilns have been installed in the
past 5 years, and growth is expected to continue, both in additional
production capacity and in replacement capacity for outmoded production
facilities.
Section lll(b)(l)(A) requires the Administrator to list source
categories that ". . . cause[], or contribute^ significantly to, air
pollution which may reasonably be anticipated to endanger public health
or welfare." Lime manufacturing plants meet this "significant contributor"
test. The amendment of this test by the 1977 Clean Air Act Amendments
was intended to ". . . emphasize the preventive or precautionary nature
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of the act" and ". . . to assure consideration of the cumulative impact
of all sources of a pollutant in setting . . . emission standards, not
just the extent of the risk from the emissions from a single source or
class of sources of the pollutant." [H. R. Rep. No. 95-294, 95th Cong.
1st Sess. at 49-50 (1977)].
Comment: One commenter (IV-D-6) believes that the assumed baseline
control level of 1.0 Ib/ton was in error because lime plants may be
subject to more stringent State or local emission limits. For example,
the State of Missouri imposed a 0.7852 Ib/ton emission limit on the
commenter's facility.
Response: The baseline control level assumed in analyzing the
impacts of any new source performance standard represents the average
State or local control level imposed on lime plants throughout the
United States. Research of State and local regulations indicated that
1.0 Ib/ton of limestone feed generally represented the baseline control
level imposed on new lime plants. Some plants may be subject to stricter
State or local limits while other plants are subject to more lenient
limits.
2.1.5 Executive Order 12291
Comment: One commenter (IV-D-6) asserted that the analysis called
for by Executive Order 12291 should be done since the health benefits of
new source performance standards for lime plants would not be significant.
The commenter believes that the regulation of lime plant emissions,
based on the absence of significant health benefits, would amount to
"regulating for regulation's sake."
Response: Executive Order 12291 directs that the costs and benefits
of major rules be analyzed. A rule is considered to be a major rule, if
(1) the national, annualized compliance costs total more than $100 million
in the fifth year following adoption of the rule; (2) the standards
cause a major increase in prices or production costs; and (3) the standards
cause significant adverse effects on domestic competition, employment,
investment, productivity, innovation, or competition in foreign markets.
The amended standards would reduce particulate matter emissions from a
rotary lime kiln by about 40 percent below those allowed under a typical
SIP. This would result in a particulate matter emission- reduction of about
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1,300 tons industry wide in the fifth year following proposal. This
estimate is based on a projected growth of 20 new, modified, or recon-
structed rotary lime kilns in 5 years. The solid waste generation
industry wide in the fifth year would increase by about 0.2 percent
relative to that under a typical SIP. There would be no adverse water,
noise, or radiation impacts associated with these standards. The fifth
year annualized.cost of the incremental emissions reduction from a
typical SIP baseline to the level of the standards, including depreciation
and interest, would be about $0.5 million (1981 dollars) assuming all
rotary lime kilns use fabric filter controls. Thus, the new source
performance standards for lime plants are not a major rule as defined by
the Executive Order and, therefore, no regulatory impact analysis is
required.
2.1.6 Health Impacts
Comment: One commenter (IV-D-6) stated that new source performance
standards are based on an analysis of economic, environmental, energy,
and health impacts. The commenter believes that this analysis should
focus on health effects in determining the value of a standard. Because
there is little evidence of adverse health effects, a legislative policy
decision should conclude that national ambient air quality standards are
sufficient to regulate emissions from lime plants.
The commenter stated that particulate emissions from the lime
industry do not harm man and may be beneficial since they tend to neutralize
acid aerosols and react quickly with water vapor and carbon dioxide to
form carbonates. The commenter cited evidence to show that lime emissions
do not pose adverse health impacts. The commenter also stated that the
analysis supporting the new source performance standards did not point
to any harmful effects from lime plant emissions but instead pointed to
the alleged harmful effects of particulate matter in general.
The commenter contended that the risk assessment of particulate
emissions is based on the toxicity of certain particulate species. The
commenter noted that toxicity is correlated to chemical composition.
The commenter contended that the chemical components of lime plant
emissions are nontoxic and nonacidic.
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The commenter concluded that the lime standard should be removed
based on the lack of evidence that lime emissions cause significant
health effects.
Response: The Clean Air Act directs that new source performance
standards are to be developed for an industry if ". . . it causes, or
contributes significantly to, air pollution which may reasonably be
anticipated to endanger public health or welfare." Particulate matter
is a criteria pollutant, and its impact on public health and welfare is
well documented. This issue was addressed fully in the background
materials associated with the original promulgation and was addressed by
the Court. The Court stated:
We think the danger of particulate emissions' effect on
health has been sufficiently supported in the Agency's . . .
previous determinations to provide a rational basis for the
Administrator's finding in this case. Moreover, whatever its
impact on public health, we cannot say that a dust "nuisance"
has no impact on public welfare. (627 F.2d at 431, n. 48.)
Based on Congressional intent with respect to the Clean Air Act, the
Court stated that it ". . . could not say that the Administrator's
determination is arbitrary, even if the dust were shown innocuous to
public health." For these reasons, new source performance standards for
lime manufacturing-piants are considered reasonable.
2.2 APPLICABILITY DATE
Comment: Several commenters (IV-D-2, IV-D-5, IV-D-6) believe that,
because several of the Court-defined issues were amended by the September 2,
1982, proposal, the appropriate effective date for the new source
performance standards should be either the date of proposal or of promulga-
tion of the amendments.
One commenter (IV-D-6) stated that Congress intended to limit the
period between proposal and promulgation to 90 days to reduce the
uncertainty of companies waiting to commence construction. The applica-
bility date of May 1977 would prolong this period to 5 years. Such a
prolonged period of uncertainty goes far beyond Congressional intent.
The commenter also requested that the proposed amendment, which
relaxes the rotary lime kiln particulate matter emission limit from
0.15 kg/Mg (0.30 Ib/ton) to 0.30 kg/Mg (0.60 Ib/ton), be treated in the
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same manner as other amendments to new source performance standards for
electric utility steam generators and petroleum storage tanks (i.e., the
amendments should apply from the date of proposal of the amendments;
they should not apply retroactively to the date of proposal of the
original standards).
Response: Section lll(b)(2) of the Clean Air Act, as amended
[42 U.S.C. 7411(b)(2)], specifies that any stationary source that commences
construction or modification after the publication of the proposed new
source performance standards for that source becomes subject to the new
source performance standards. In interpreting Section lll(b)(2), the
courts have held that the remand of new source performance standards by
judicial order and subsequent revisions do not retroactively void the
obligation of the operator of a source to comply with the new source
performance standards. This holding supports the proposition that new
source performance standards apply to "new sources" as of the date of
the original proposal, notwithstanding subsequent changes or the passage
of time.
Revisions or amendments.to the standards of performance are retroactive
to the date of proposal unless an unreasonable penalty would be imposed
on some facilities by applying the revisions retroactively. No penalties
have been imposed by the proposed changes to the lime plant new source
performance standards because the standards have been relaxed. Thus,
any source that complied with the earlier standards would meet the
revised standards.
Comment: One commenter (IV-D-1) stated that applying the amended
new source performance standards to all sources that commenced construction
after the original Federal Register proposal of May 3, 1977, would be
consistent with the intent of Section 111 of the Clean Air Act, Congress,
and judicial decisions. The commenter contended that if the applica-
bility date were changed to September 2, 1982, those lime plants that
commenced construction or modification between May 3, 1977, and September 2,
1982, would operate under the original new source performance standards
emission limitation (0.30 Ib/ton of feed), while plants that commenced
construction after September 2, 1982, would operate under the amended
new source performance standards (0.60 Ib/ton of feed). This would
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place an unfair burden on older plants and could place the older plants
at a competitive disadvantage compared to plants constructed after
September 2, 1982.
[This commenter later requested that the above comment letter be
removed from the docket because the comment was submitted in error
(IV-D-9). The commenter stated that the lime new source performance
standards should apply only to sources that commence construction after
September 2, 1982. However, items entered into the docket cannot be
removed. Section 307(d)(4)(B)(i) provides in part that "[p]romptly upon
the receipt by the agency, all written comments and documentary information
on the proposed rule received from any person for inclusion in the
docket during the comment period shall be placed in the docket." A
memorandum to the docket can be submitted to explain an error or to
amend a document.]
One commenter (IV-G-8) asked what the effects of changing the
applicability date would be.
Response: The effect of a September 2, 1982, applicability date is
not quite as the commenter describes. Rather, if the applicability date
were changed to September 2, 1982, lime plants that commenced construction
or modification between May 3, 1977, and September 2, 1982, would operate
without any applicable new source performance standards. This action,
although different from that contemplated by the commenter, would place
lime plants that installed control equipment to meet the original new
source performance standards at a competitive disadvantage compared to
lime plants that did not make such an effort to comply with the standards.
More specifically, the principal effect of a September 2, 1982, applic-
ability date would be to relieve those plants which chose not to install
control technology that would meet the new source performance standards
from the requirement to do so. In the preamble to the proposal, comments
were solicited on the applicability date in response to preproposal industry
comments alleging that unreasonable impacts would occur at some lime plants
if the original proposal date remained applicable. Each comment received
during the public comment period was considered, and no unreasonable impacts
associated with the original applicability data were identified. Therefore,
the applicability date of the standards remains May 3, 1977.
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2.3 BEST DEMONSTRATED TECHNOLOGY
2.3.1 Use of Wet Scrubbers
Comment: Two commenters (IV-F-1/IV-D-7, IV-D-6) stated that the
choice of wet scrubbers to control particulate emissions from new rotary
lime kilns is reasonable. The first commenter (IV-F-1/IV-D-7) states
that a wet fan scrubber on a rotary lime kiln at a new plant subject to
the new source performance standards should be considered best demonstrated
technology because it is achieving the 0.60 Ib/ton mass emission standard.
The second commenter (IV-D-6) stated that two kilns currently under
construction should be exempt from the NSPS because: (1) scrubbers are
not considered to be best demonstrated technology and this company had
no choice other than to install scrubbers, and (2) the scrubbers used
for their two new kilns are designed to meet the State emission limit
rather than the new source performance standards because the commenter
believed that no new source performance standards were in effect. The
commenter maintains that there was not enough space to install an ESP or
baghouse at this location; there was only sufficient room to install a
scrubber. Rearranging the production area to accommodate a baghouse or
ESP would be unreasonably expensive. Further, baghouses were not considered
suitable ^for these kilns because the necessary precooling of the kiln
exhaust gas stream would preclude recovery of carbon dioxide (C02).
Electrostatic precipitators were not considered suitable because it was
believed that there would be explosion hazards associated with their
application to rotary lime kilns. The commenter further maintains that
in the circumstances prevailing at this company, wet scrubbers must be
declared the best demonstrated technology. Finally, the commenter
states that operating the wet scrubbers to achieve emissions of 0.60 Ib/ton
would require an energy expenditure equivalent to about $1,400 per ton
of additional particulate matter removed beyond the State requirement of
approximately 0.78 Ib/ton. This commenter believes that this additional
cost is unreasonable. Therefore, the commenter believes rotary lime
kilns controlled by wet scrubbers should be exempt from the new source
performance standards.
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Response: The new source performance standards do not require
installation of any specific emission control technology. Plant operators
may install any control device which meets the numerical emission limits
included in the new source performance standards. Under Section 111 of
the Clean Air Act, however, standards of performance must be based on
the degree of emission reduction achievable through application of the
best technological system of continuous emission reduction (taking into
consideration the cost of achieving such emission reduction, and any
nonair quality health and environmental impact and energy requirements)
which has been adequately demonstrated. Analysis of the performance,
costs, and other impacts associated with the use of a wide variety of
emission control technologies indicates that fabric filters and ESP's
represent best demonstrated technology for the control of particulate
matter emissions from rotary lime kilns. Wet scrubbers are not considered
best demonstrated technology because of the high energy costs associated
with their use. However, venturi scrubbers have demonstrated the ability
to achieve the level of the proposed standards and can be used to meet
the standards. A company may choose to use a scrubber to meet the
standards if it is willing to incur the high operating costs that would
be associated with the pressure drop necessary to meet the standards.
In investigating and considering the situation described by second
commenter, it was found that four kilns have been removed and that two
larger kilns are to be installed in their place. The four kilns were
bounded at each end with feedstock and product handling facilities.
Because the new kilns are longer than the space that the four old kilns
had occupied, the product handling facilities were moved back to accommodate
the additional length of the new kilns. The product handling facilities,
however, could have been moved to accommodate the space requirements of
the new kilns with fabric filters or ESP's instead of just being moved
to accommodate the space requirements of the new kilns with scrubbers.
The inlet gas stream to baghouses can be precooled in a variety of
ways. This commenter noted that an air-to-air heat exchanger would be
suitable for cooling the inlet gas stream for the purpose of C02 recovery
but was not considered because of space limitations. As explained
above, space was not a crucial limitation. Experience with an ESP on a
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lime kiln in a similar industry indicates that the potential for an
explosion is eliminated if automatic controls are installed that permit
the exhaust to bypass the ESP when the kiln malfunctions and combustible
gases are passed through the kiln. In conclusion, this company could
have used a baghouse or ESP to control emissions from the new kilns.
Consequently, the standards do not include an exemption for rotary lime
kilns which use wet scrubbers to control particulate matter emissions.
2.4 MASS EMISSION STANDARD
2.4.1 Mass Emission Level
Comment: One commenter (IV-D-3) stated that the amended standard
of 0.30 kg/Mg (0.60 Ib/ton) is not justified by the data base and concludes
that the appropriate emission standard for lime kilns is 0.25 kg/Mg
(0.50 Ib/ton). The commenter pointed out that in setting the original
standard, the emission limit was about 6 percent greater than the tested
emissions from the worst performer of the four plants included in the
data base. The amended standard is about 30 percent greater than the
worst-case controlled emission level of the five plants now included in
e r
the data base. The commenter concluded that, absent further justification,
the amended particulate matter emission standard is too lenient and
should be reduced from the proposed level of 0.30 kg/Mg (0.60 Ib/ton) to_
0.25 kg/Mg (0.50 Ib/ton).
Response: The precise level at which a standard should be set to
reflect use of best demonstrated technology is a matter of judgment. A
level of 0.25 kg/Mg (0.50 Ib/ton) could have been selected for the final
standard, but the margin of safety would have been very small [about
5 percent based on a 0.25 kg/Mg (0.50 Ib/ton) standard at Plant A]. It
is reasonable to provide a higher margin to ensure that all new sources
that install the emission control technology upon which the final standards
are based will be able to meet the standard. Establishing the standard
at 0.30 kg/Mg (0.60 Ib/ton) provides a margin that is somewhat larger
and still ensures that best demonstrated technology will be installed.
Comment: Two commenters (IV-D-5, IV-G-7) stated that the standard
of 0.30 kg/Mg (0.60 Ib/ton) does not consider the addition of coal
emissions to total emission rates. The demand for burning coal to
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manufacture lime is growing rapidly and should be considered when setting
the standard. Therefore, the commenters support a 0.5 kg/Mg (1.0 Ib/ton)
emission limit.
Reponse: Three of the kilns tested during development of the new
source performance standards were coal-fired units. Thus, the measured
emissions included emissions generated by the combustion of coal in the
kilns. Plants A, B, and E have coal-fired kilns, and their average
emission rates were 0.23, 0.11, and 0.14 kg/Mg (0.46, 0.22 and 0.28 Ib/ton),
respectively. Therefore, the achievability of the standards is adequately
demonstrated for coal-fired rotary lime kilns.
Comment: One commenter (IV-D-2) believes that the emission limit
for rotary lime kilns may be unachievable and that the appropriate limit
is 0.50 kg/Mg (1.0 Ib/ton) of feed. The commenter has applied typical
baghouse and ESP collection efficiencies (99.7 and 97 percent, respectively)
to emission factors from "Compilation of Air Pollutant Emission Factors"
(AP-42) and determined that controlled rotary lime kiln emissions from a
baghouse would be 0.29 kg/Mg (0.57 Ib/ton) and from an ESP would be
2.85 kg/Mg (5.7 Ib/ton). The commenter notes that the AP-42 controlled
lime kiln emission factor is 0.50 kg/Mg (1.0 Ib/ton) of product and
states that the new source performance standards require a lower value.
The commenter presented information about the allowable emission
rates in the States of Ohio and Michigan. The commenter claims that the
new source performance standards would require a substantial decrease in
these allowable rates and would require a large investment. The commenter
notes that the costs to reduce emissions increase as the emissions are
reduced to zero. Therefore, the commenter believes that a standard of
0.50 kg/Mg (1.0 Ib/ton) of feed would provide cleaner air and would be a
compromise between existing and proposed allowable emissions.
Response: Section lll(a) of the Clean Air Act requires that standards
of performance reflect "... the degree of emission reduction achievable
through the application of the best system of continuous emission reduction
which (taking into consideration the cost of achieving such emission
reduction, and any nonair quality health and environmental impact and
energy requirements) the Administrator determines has been adequately
demonstrated for that category of sources." The lime plant new source
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performance standards are based on performance tests of plants that
incorporate the best technological systems of control. The costs of the
proposed standard were estimated for typical facilities and are considered
to be reasonable. In remanding the lime new source performance standards,
the Court did not question the technological basis for the standard nor
the economic, energy, or environmental analyses.
AP-42 emission factors are used to project or estimate typical
emissions. AP-42 values are often based on estimates or incomplete
data. In contrast, the new source performance standards are based on
actual tests of well-designed and well-operated modern control equipment,
and the data from the tested lime plants support the achievability of
the amended new source performance standards. Consequently, the standard
has not been increased to 0.50 kg/Mg (1.0 Ib/ton).
Comment: One commenter (IV-D-2) agrees that baghouses and ESP's
can be designed to accommodate a great range of particle sizes and high
gas velocities. However, the commenter notes that particle resistivity
changes as the moisture content and temperature of the exhaust gas
change and that any operating variable that will alter temperature or
moisture content has a great effect on the collection efficiency of the
ESP. He further notes that an ESP designed to handle high temperature
gases cannot be operated efficiently at low temperatures.
Response: The writer's comments about sizing, moisture content,
and temperature of the gas stream relative to ESP's are correct. However,
they were considered and accounted for in the development of the new
source performance standards as discussed in the background information
document. The test data used in setting the level of the standard show
that properly designed and operated control devices can achieve the
standard.
2.4.2 Stone Feed
Comment: One commenter (IV-F-1, IV-G-2) stated that a few plants
produce a few thousand tons each year of a product called "dead-burned
dolomite." Dead-burned dolomite is a sintered or double-burned form of
dolomitic quicklime, which is further stabilized by the addition of iron,
that is chemically inactive and is employed primarily as a refractory for
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lining open-hearth steel vessels. The feed material for this product is
usually about 80 percent dolomitic limestone and 20 percent iron oxide
(mill scale). The commenter noted that while dead-burned dolomite is a
lime product, its components are not included within the stone feed
definition in the regulation. The commenter, therefore, questioned the
reasonableness of the definition of stone feed and requested that the
definition be changed to include iron-oxide additives used in the production
of dead-burned dolomite.
Response: It is appropriate to include the iron-oxide additive in
the definition of stone feed because the iron becomes part of the final
product. Therefore, the definition of stone feed has been changed to
include mill scale.
2.5 THE VISIBLE EMISSION STANDARD
2.5.1 Achievability of the Opacity Standard
Comment: One commenter (IV-F-1, IV-G-6) stated that a 10 percent
visible emission standard is not achievable on a continuous monitoring
basis. The commenter reviewed a study of rotary lime kiln dynamics,
particle composition, and particle size distribution at the control
device inlet and concluded that long-term variation in visible emissions
would be expected during normal kiln operation and that visible emissions
data gathered to develop the standard do not reflect this variation.
The study presented the theory that this variation was caused by unique
properties of the hydrate particles generated prior to the baghouse that
are smaller than the other dust particles generated in the kiln. The
commenter stated that the visible emission standard should be attainable
by a majority of lime plants, that it should consider the vagaries of
normal kiln practice, and that it should be commensurate with the mass
emission standard (IV-G-6, p. 38). In the absence of visible emission
data taken from a number of kilns over a period of a year, the commenter
believes that a reasonable standard would be 20 percent opacity.
A second commenter (IV-D-5) stated that, given the variable conditions
inherent with lime and fly ash stack plumes, a visible emission limit of
20 percent opacity would be more realistic than the visible emission
limit of 10 percent opacity. The commenter contended that a visible
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emission limit of 10 percent opacity would result in constant conflict
between EPA inspectors and plant operators, costing the operators $5,000
to $7,000 per stack test to prove compliance with the mass emission
standard.
A third commenter (IV-F-1, p. 40) stated that even though the
0.30 kg/Mg (0.60 Ib/ton) mass emission standard was based on EPA stack
tests, none of the opacity data given in Table 9 of the preamble to the
proposed revision (47 FR 38852) were obtained when mass emissions were
actually at the 0.30 kg/Mg (0.60 Ib/ton) level. The commenter stated
that the highest mass emission level recorded during testing was 0.12 kg/Mg
(0.23 Ib/ton).
Response: Two points mentioned by these commenters require
clarification. First, compliance with the visible emission standard is
not determined by continuous monitors but rather with Reference Method 9.
As explained in Section 2.6 of this document, continuous monitoring data
are used to determine if the rotary kiln control device has been properly
operated and maintained. Second, the highest mass emission level recorded
during testing was 0.23 kg/Mg (0.46 Ib/ton), not 0.12 kg/Mg (0.23 Ib/ton).
The first commenter's study of rotary lime kiln dynamics does provide
some support for his theory that hydrate particles are formed prior to the
baghouse inlet. The study does not, however, include any data about
particle characteristics, concentration, or opacity at the baghouse
outlet. The absence of these data does not, in itself, invalidate the
commenter1s theory or conclusion. However, existing fabric filter theory
and studies have demonstrated that particle characteristics and concen-
trations at fabric filter outlets are invariant over a broad range of
fabric filter inlet particle characteristics and concentrations. In
addition, the extensive data base supporting the visible emission standard
(discussed below) covers the range of particle characteristics, concen-
trations, and kiln operations expected in the industry and demonstrates the
achievability of a standard more stringent than that suggested by the
commenter. Thus, the study's conclusions cannot be corroborated. Moreover,
while data were being gathered, the fabric filter controlling emissions
from the kiln under study was operated at air flows ranging from 27 to
62 percent greater than design values. Thus, the particle behavior
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observed during the study may not represent behavior that would occur if
the control device air flows were at design specifications.
In contrast to this study, the lime plant visible emission standard
is supported by over 1,200 Reference Method 9 visible emission tests
from six rotary lime kiln control device exhaust stacks for which Reference
Method 5 mass emission data were gathered. Each of these Reference
Method 9 visible emission tests consists of 24 individual visible emission
observations made during a 6-minuce period. The Reference Method 5 test
data include individual tests where the mass emission levels were as
high as 0.29 kg/Mg (0.58 Ib/ton). The highest raw visible emission test
is 6.7 percent. After normalizing the visible emission data to a 3.0-meter
(9.8-foot) stack diameter, more than 71 percent of the Reference Method 9
visible emission data exhibit opacities of 0 percent and 99.7 percent
exhibit opacities of less than 10 percent. Only 4 of the over 1,200 test
data points exceed 10 percent opacity, and the maximum value is 10.6 percent
opacity.
The relevant variables upon which opacity depends are stack diameter,
particle size, particle shape, particle, refractive index, particle
density, and concentration. Lime manufacturing plant stack diameter was
accounted for by normalizing the raw opacity data to the largest stack
diameter likely to be installed in this industry. The particle
characteristics at the tested plants are representative of the industry.
Although there may be some variation in the particle characteristics of
the emissions from rotary lime kilns, the tested plants cover the variation
likely to be found in the industry.
Comment: One commenter (IV-G-7) stated that there are some plants
that can meet the mass emission standard but cannot comply with the
visible emission standard of 10 percent opacity. The commenter stated
that the mass emission limit is the real standard and that visible
emissions are only a rough indicator and should include a margin of
safety to account for lime plants that will have proble'ms complying with
the visible emission standard. The commenter concluded that a 20 percent
opacity standard would include this margin of safety.
The commenter also submitted two stack test reports dated July 1975
and December 1978 and included photographs of visible emissions for two
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baghouses -during the December test. The co.mmenter stated that the
emission rates for the 1975 and 1978 stack tests were 0.34 and 0.31 Ib/ton,
respectively, but visible emissions were near 20 percent opacity. The
commenter concluded that the plant could comply with the mass emission
standard but could not meet the visible emission standard of 10 percent
opacity.
Response: Although the kilns and baghouses were not designed to
comply with the mass emission and visible emission standards of the new
source performance standards, the 1978 Reference Method 5 test report
indicates that mass emissions from the baghouses were less than 0.6 Ib/ton.
However, no Reference Method 9 visible emission data were taken during
the mass emission tests to substantiate any problems. The photographs of
visible emissions from the baghouses appear to indicate visible emissions
during the mass emission tests. However, accurate visible emission readings
cannot be determined from these photographs, and the plume evident in the
photograph appears to be a combination of two plumes from the two adjacent
baghouses. Therefore, the information presented by the commenter does not
provide a basis for revising the visible emission standard. As discussed
previously, the visible emission standard of 10 percent opacity is based on
over 1,200 Reference Method 9 visible emission tests, 99.7 percent of which
exhibited less than 10 percent opacity.
Finally, as described in Section 2.5.5 of this document, if this
facility were subject to the new source performance standards and met
the mass emission limit but not the visible emission limit, Section 60.11(e)
of the General Provisions of 40 CFR Part 60 ensures that it would be
treated equitably. This provision, upon demonstration of certain criteria
(see Section 2.5.5), permits a facility that meets the mass emission
standard to obtain an individual visible emission standard tailored to
its unique circumstance. This individual standard is automatically
approved once the facility demonstrates that it meets the requirements of
Section 60.11(e).
2.5.2 Correlation of Visible Emission Data With Mass Emission Data
Comment: Two commenters (IV-F-1) assert that no correlation between
mass emissions and visible emissions is obvious either from data supporting
the visible emission standard or from data obtained at one commenter1s
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company. The commenters conclude that the visible emission standard
should be relaxed to a value more representative of similar processes
(i.e., the 20 percent visible emission standard used by most States for
chemical and mineral kilns).
Response: The comment about the correlation between mass and
visible emissions requires clarification. In general, a correlation
does exist between particulate matter and visible emissions. However,
this correlation is demonstrated not with mass emission data (i.e.,
pounds of particulate matter per ton of feedstock) but rather with data
on the particulate matter concentration in the exhaust gas stream from
the control device.
There are situations in which it is difficult to establish a correla-
tion between particulate matter and visible emissions. Such would be
the case when much of the visible emission data consist of visible
emission observations of zero percent opacity. The rotary lime kiln
visible emission data present such a situation because 71 percent of the
over 1,200 Reference Method 9 test results are zero percent opacity.
This situation, however, does not impugn the visible emission standard
because 99.7 percent of the Reference Method 9 test data are below
10 percent opacity.
As discussed in the response to the remand of the standards of
performance for portland cement plants, a direct correlation between
mass and visible emissions is unnecessary in determining the appropriate
level of the visible emission standard. The visible emission standard
is established at a level supported by an extensive data base of over
1,200 Reference Method 9 tests performed concurrently with Reference
Method 5 mass emission tests. Consequently, the visible emission
standard has not been relaxed to 20 percent opacity as had been requested
by the commenter.
2.5.3 Effect of Particle Size on Visible Emissions
Comment: One commenter (IV-F-1) presented four general comments
about the effect of particle size on visible emissions. He stated that
actual information on particle size distribution after the control
device (i.e., particle size distribution in the outlet gas stream) was
not examined. He also stated that particle size distribution before the
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control device is not a good indicator of the particle size distribution
after the control device. The commenter stated that the analysis supporting
the new source performance standards was based on the assumption that
the particle size distribution after the control device does not include
a significant number of particles whose size affects light scattering
and, hence, visible emissions, and that this assumption is false. In
addition, the commenter believes that visible emission levels are not a
consistent predictor of a source's failure to comply with the mass
emission level.
Response: It is correct that inlet (to the control device) particle
size distribution is not indicative of outlet particle size distribution
and that it is outlet particle size distribution that affects visible
emissions and the analysis supporting the new source performance standards
does not assume otherwise. To account for possible variation in outlet
particle size, the visible emission limit is based over 1,200 Method 9
6-minute average visible emission observations during mass emission
tests at plants that are representative of the industry, normalized to a
common path length of 3.0 m (9.8 ft). (See Section 2.5.1.) As discussed
in the port!and cement remand response, compliance with the opacity
limit is a good indication of compliance with the mass emission standard.
2.5.4 Plant D Tests
Comment. One commenter (IV-F-1) quoted from the proposed preamble
(47 FR 38854) as it pertained to test data from a kiln at Plant D:
"Thirty-two percent of the particles emitted from this kiln were in the
size range that is expected to produce the greatest light scattering,
i.e., less than 2 microns. And yet Plant D easily achieved the promulgated
opacity limit and the mass emission limit." The commenter stated that
the above condition was achieved because the plant operator was requested
to increase the operating temperature above normal and decrease the
production rate of the kiln to 70 percent of design capcity during the
emission test at this facility.
Response: The plant operator at Plant D was not requested to
increase the operating temperature above normal or to decrease the
production rate of the kiln. The three test runs were conducted at 100,
106, and 86 percent of design capacity.
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For the test in question, the inlet control device temperature
ranged from 372° to 378°C (702° to 712°F) for the three test runs performed
on three successive days. Near the end of the first test, the ESP inlet
temperature had increased to 377°C (710°F), at which time it was noticed
that visible emissions from the stack were improving. The plant chemist
was asked if he could maintain the inlet temperature between 371° and
377°C (700° and 710°F) for the second test, which would start the next
day. The next day the visible emissions were 0 percent opacity, and the
process operator stated that the ESP inlet temperature had not dropped
below 371°C (700°F) for the last 16 hours. In an earlier test program
at this facility, during which no requests were made to maintain any
particular temperature, the inlet control device temperature ranged from
362° to 385°C (683° to 725°F). Consequently, the inlet temperature
between 371° and 377°C (700° and 710°F) for the test in question did not
cause kiln operation outside of normal operating conditions.
2.5.5 Specific Affected Facility Visible Emission Standards
Comment: Two commenters (IV-F-1) stated that variance procedures
afforded lime plants that meet the mass emission standard but do not
meet the visible emission standard would be burdensome, time consuming,
and expensive. The commenters supported their statements by asserting
that, as a purely economic issue, the $10,000 cost of proving compliance
and the possibility of incurring this cost every quarter would place an
undue burden on the industry.
Another commenter (IV-F-1) stated that variances for affected
facilities that meet the mass emission limit but do not meet the visible
emission limit imply a lack of faith in the visible emission standards.
Another commenter (IV-D-4) does not endorse the proposed procedure
of requiring a lime plant to obtain a variance for the visible emission
standard when the mass emission standard is being met and proposes that
a visible emission standard of 20 percent opacity would be more appropriate.
The commenter disagrees that new lime plants will have stack diameters
less than 3.0 m (9.8 ft). This company states that it has a new plant
with a stack larger than 3.0 m (9.8 ft) in diameter.
Response: The procedure referred to by the commenters does not
involve a variance. Rather, Section 60.11(e) 40 CFR 60 provides that
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owners or operators of any affected facility from any source category
that meets the mass emission standard but does not meet the visible
emission standard may apply for an individual visible emission standard
tailored to the unique circumstances of their facility. This standard
is good for the life of the affected facility and is automatically
approved upon demonstration that: (1) the facility is in compliance
with the mass emission standard; (2) the facility and associated air
pollution control equipment were operated and maintained in a manner to
minimize the opacity of emissions during the performance tests; (3) the
performance tests were performed under the conditions established by the
Administrator; and (4) the facility and associated air pollution control
equipment were incapable of being adjusted or operated to meet the
applicable opacity standard.
There are no costs associated with this procedure beyond those of
the initial performance test and report. This cost is typically $10,000
and constitutes a small fraction of a plants annual operating budget.
In view of the environmental benefits associated with the performance
test procedure, the $10,000 cost is considered reasonable.
The provisions of 40 CFR 60.11(e) do not reflect a lack of confidence
in the rotary lime kiln visible emission standard. Quite the contrary,
the extensive data base supporting the visible emission standard indicates
that recourse to these provisions will be needed rarely.
The commenter's belief that a standard of 20 percent opacity would
be more appropriate is not supported by any data. As discussed previously,
analysis of over 1,200 Reference Method 9 visible emission test results
collected during development of the visible emission standard support a
standard of 10 percent opacity.
Available stack diameter data indicate that lime plants are unlikely
to be constructed with stacks greater than 3.0 m in diameter. Although
one stack with a diameter greater than 3.0 m (9.8 ft) was found in a
survey of 16 new plants, the trend in the industry is toward smaller
stacks or roof monitors. The opacity of visible emissions will be much
lower from these stacks than from larger stacks.
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2.5.6 Reference Method 9 Accuracy and Reliability
Comment: Several commenters (IV-F-1) stated that the visible
emission standard of 10 percent opacity, would be difficult to enforce.
The commenters asserted that the ±7.5 percent observational error associated
with visible emission reading is almost as high as the allowable opacity
limit. The commenters were concerned that, because the visible emission
standard is so low, it would be possible for a transmissometer to show
compliance while a visible emission reader observes noncompliance. The
commenters concluded that since enforcement is dependent upon visible
emission readings, the standard must make allowances for the inherent
inaccuracies of the visible emission reading process. The commenters
further concluded that a 20 percent opacity limit would be more reasonable
with respect to enforcement.
Response: The response to the port!and cement plant remand discusses
in great detail the reliability and accuracy of Reference Method 9 and
accompanying certification techniques for determining compliance with
visible emission standards. On the basis of this response, the visible
emission standard included in the new source performance standards for
Portland cement plants was affirmed by the Court on appeal (Portland Cement
Association v. Train, 513 F.2d 506).
The data gathered in responding to the remand for port!and cement
plants convincingly demonstrate that visible emission observers can,
with a high confidence level, read the opacity of visible emissions to
within the certified error tolerance of 7.5 percent. The ±7.5 percent
error tolerance is taken into account in the enforcement process, as
provided explicitly by the Reference Method 9 regulations.
There are four categories of factors that can affect opacity:
(1) factors related to the source category and its operations, (2) factors
related to opacity observations, (3) factors considered in the determination
of compliance, and (4) factors with an insignificant or non-prejudicial
effect on apparent plume opacities. As discussed in detail in the "EPA
Response to Remand Ordered by U.S. Court of Appeals for the District of
Columbia in Portland Cement Association v. Ruckelshaus (486 F.2d 375,
June 29, 1973)", factors in categories two, three, and four are taken
into account in the Reference Method 9 procedures or in compliance
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procedures. The first category includes factors such as effluent
concentration, stack diameter, mean particle size, polydispersity of
emissions, refractive index, particle density, and stack gas temperature.
The factors are specific to the source category and its operations and
are considered in the development of visible emission standards. Although
these factors can significantly affect the apparent opacity of visible
emissions, the maximum expected effects of normal variations in these
factors on visible emissions are used to ensure that the visible emission
standard for a source category is established at a level no more restrictive
than the corresponding concentration or mass standard. In addition to
the above consideration of these factors, should a source have a stack
of larger than expected diameter or have other anomalous operating
conditions which preclude achieving the visible emission standard, the
provisions of 40 CFR Section 60.11(e) allow the owner or operator to
petition for establishment of an individual visible emission limit.
Thus, ample consideration of the effects of these factors is provided.
The use of visible emission standards is technically sound and
provides the most practical and inexpensive means to ensure that control
equipment necessary for a source to meet mass standards is properly
maintained and operated. Moreover, as discussed in Section 2.5.1, the
visible emission standard of 10 percent opacity is based on over
1,200 Reference Method 9 visible emission tests performed concurrently
with the Reference Method 5 tests that support the mass emission standard.
2.5.7 Failure To Use All Data Reviewed
Comment: One commenter (IV-F-1/IV-G-3) believes that visible
emission data submitted by the Arizona Department of Health Services
were ignored. These data demonstrate that a visible emission standard
of 10 percent opacity cannot be achieved.
Response: The data referred to by the commenter are for a gravel
bed filter control device. Gravel bed filters were evaluated during the
development of the new source performance standards; however, they were
not selected as best demonstrated technology because of their high mass
emission levels and costs. Also, the gravel bed filter is not represen-
tative of the control techniques used in the industry. Therefore, the
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test referred to by the commenter cannot be used to evaluate the achiev-
ability of the visible emission standard.
2.5.8 Miscellaneous
Comment: One commenter (IV-G-3) stated that National Lime Association
(NLA) representatives were assured that a visible emission standard
would be proposed commensurate with the increase in the mass emission
standard.
Response: The NLA was assured that the visible emission standard
would correspond to the mass emission limit, as is true for all new
source performance standards. After review of over 1,200 Reference
Method 9 visible emission tests that constitute the data base for the
visible emission standard, the standard is considered to be commensurate
with the mass emission standard.
2.6 TEST METHODOLOGY
2.6.1 Isokinetic Conditions
Comment: One commenter (IV-F-1/ IV-G-3) stated that the mass
emission tests at Plants B and E were not within the isokinetic limits
specified by Reference Method 5. Therefore, the commenter concluded
that the tests at Plants B and E do not adequately demonstrate the
achievability of the proposed standards.
Response: Sampling at probe tip velocities equal to the gas stream
velocity is a condition known as isokinetic sampling. Errors in measured
concentrations may occur under conditions of nonisokinetic sampling
because of the inertia of some particles and may result in biased concen-
tration measurements.
Section 6.12 of Reference Method 5 (40 CFR Part 60 Appendix A—
Reference Method 5) specifies that test results are acceptable if they
are within ±10 percent of isokinetic. A procedure is available to
calculate the maximum error which can occur because of anisokinetic
sampling. The approach accounts for the inertia! effects of particulate
matter and the maximum effect they might have on the measured particulate
matter concentration.
The probe tip velocity during the emission testing at Plant B
ranged from 93.7 to 107.0 percent of the isokinetic velocity, and the
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mass emission rate ranged from 0.033 to 0.11 Ib/ton (Table 2-2). The
velocities are within ±10 percent of isokinetic values. Therefore, the
Plant B tests are considered acceptable and adequately demonstrate the
achievability of the standards.
The tests at Plant E show that for four test runs, the probe tip to
gas stream velocity ratios ranged from 111.2 to 117.9 percent (Table 2-2)
of isokinetic. The corresponding emission rates ranged from 0.018 to
0.034 Ib/ton. These emission rates were adjusted using the procedure
referred to above. The adjusted emission rates ranged from 0.018 to
0.036 Ib/ton (Table 2-2). Because the adjusted mass emission rates do
not exceed the proposed mass emission limit of 0.60 Ib/ton, data from
the Plant E tests are considered to be acceptable and demonstrate the
achievability of the standards.
2.6.2 Production Capacity
Comment: One commenter (IV-F-1/IV-G-3) stated that the tests at
Plants C, D, and E were conducted below the design production capacity
of the kilns. The commenter stated that the tests at Plant C were
conducted with only two of the three available kilns in operation and
that this was stated to be ". . . the normal operating mode of the
plant." However, the control equipment at Plant C was designed to
accommodate three kilns instead of two and, therefore, the data from the
tests are invalid. The commenter further stated that Plant D was operating
at 81 percent of capacity during tests. The commenter concluded that,
because the tests were not conducted under conditions representative of
design production conditions, the results of the tests do not adequately
demonstrate the achievability of the standards. The commenter supported
his conclusion by citing Essex Chemical Corporation v. Ruckelshaus,
486 F. 2d and 27, and 36 (D.C. Cir. 1973) for the proposition that,
where tests are conducted with plants operating at less than capacity,
". . . the relevancy of the test results is at best minimal."
Response: Plant C has three operating rotary lime kilns, each
rated at 250 tons/day and emissions from all three kilns are ducted to
the same ESP. Plant C seldom operates all three kilns at the same time,
and usually only two are on-line. In a letter dated September 4, 1974,
information was requested from Plant C on operating conditions during the
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TABLE 2-2. ADJUSTED PLANT B AND PLANT E TEST RESULTS
Plant Run No.
B 1A
IB
2A
2B
3A
3B
E 1-1
2-2
1-2
3-1
3-2
2-3
Percent
isokinetic3
103.6
104.1
99.7
93.7
103.7
107.0
96.3
112.2
111.2
117.9
115.6
108.5
Emission
rate3
Ib/ton
0.039
0.077
0.033
0.115
0.046
0.110
0.041
0.018
0.027
0.024
0.034
0.018
Adjusted
emission rate
Ib/ton
N.N.C
N.N.
N.N.
N.N
N.N
N.N.
N.N.
0.018
0.028
0.025
0.036
N.N.
Decision
A
A
A
A
A
A
A
A
A
A
A
A
.Data from test reports.
A = Accept stack test.
CN.N. = Not necessary.
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May 1974 tests and on any nontypical conditions. Plant C responded on
October 8, 1974, stating that two kilns were in operation during the
test and that operation on these dates was normal. There is no indication
that operation of two rather than three kilns at Plant C is abnormal.
Therefore, the operation of two kilns is considered to be the normal
operating mode of Plant C.
Emission testing is usually conducted at the maximum production
rate for a given plant, which, in most cases, is within approximately 10
to 15 percent of design capacity. During the emission testing at Plant D,
the production rates ranged from 86 to 106 percent of design capacity
(I-G-1, p. C-5). [The 81 percent stated by the commenter is an error.]
Although the tests at Plant D were conducted at -14 percent to +6 percent
of design capacity, the test results show that the emission levels
between test runs in both Plant D tests were consistent, averaging
0.275 Ib/ton. Emission testing at Plant E was performed at 91 percent
of capacity. Consequently, the test results at Plants D and E are
considered valid.
The Essex Chemical Corporation case cited by the commenter refers.
to a situation where testing was performed at 52 percent of capacity
and, as the Court stated in the remand of the lime manufacturing plant
new source performance standards, the regulations there in question,
unlike those for lime plants, expressly required performance tests while
the affected facility operated at the maximum pollutant production rate.
Thus, the case is not relevant to this situation.
2.6.3 Pi tot Tube Specifications and Velocity Traverses
Comment: One commenter (IV-F-1/IV-G-3) stated that there were
errors in the Plant E emissions tests:
1. The pi tot tubes were not within the specified pi tot coefficient
(C ) range of 0.85 ± 0.02, but instead were 0.807 and 0.819.
2. Reference Method 1 specified 24 points per traverse (48 total
sample points) for stacks of this configuration, while 22 points per
traverse (44 total sample points) were sampled.
The commenter further stated that the errors would have a profound
effect on the test data. Therefore, the Plant E tests do not adequately
demonstrate the achievability of the standard.
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Response: Reference Method 2 states that the type-S pitot tube
shall have a known coefficient, determined by one of the procedures
outlined in the method. The 0.85 coefficient noted by the commenter is
a nominal coefficient used to set up the nomograph used for establishing
isokinetic sampling rates during an actual test. Where the exact pitot
coefficient is known, the method specifies it must be used in the equations
provided, in place of the nominal 0.85 coefficient, to determine the
actual test run isokinetic rate. The contractor who tested Plant E
supplied calibrated pitots for this work, and the procedure outlined in
the method was followed. The minor variations between the nominal
coefficient used in the nomograph and the actual coefficients used in
the calculations accounted for the nonisokinetic sampling rates for the
tests.
Sampling too close to the stack wall (i.e., within 1 inch) can bias
the sample because of flow turbulence and, thus, as in the case of
Plant E, sampling is not conducted when the probe is near the wall. A
report entitled "Particulate Sampling Strategies for Large Power Plants
Including Nonuniform Flow" examines the errors incurred by changing the
number of sampling points for stack gas particulate sampling. It
demonstrates that the expected error in measurement of particulate
concentration decreases as the total number of sample points over 24
increases. The largest expected error for 24 or more sample points is
less than 1.0 percent. For Plant E, the decrease in the total number of
sample points from 48 to 44 cannot be expected to change the emission
rate determination by more than about 1 percent. Thus, these errors
would not have a significant effect on the test data because the highest
Plant E emission rate, adjusted for error as noted in Section 2.5.4.1,
was 0.036 Ib/ton.
2.6.4 Climatic Conditions
Comment: One commenter (IV-F-1) stated that the statement in the
proposal preamble that ". . . stack gas exit velocity is not an independent
variable because it depends on the gas flow rate and stack diameter ..."
is erroneous. He indicated that excess moisture is present in the gas
stream during the winter months as a result of the feedstock laden with
snow and ice that is added to the kiln. The commenter states that this
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moisture increases the stack gas velocity and, thus, increases visible
emissions.
Response: The velocity of the gas stream is dependent on the gas
flow rate and the stack diameter. The addition of moisture to the gas
stream will increase the volume (cubic feet) and, thus, the gas flow
rate (cubic feet per minute). The velocity at which the gas stream
moves through the viewer's line of vision has no effect on the opacity
of visible emissions. The commenter appears to be indicating that an
increase in moisture content during some months of the year in certain
geographical areas would increase the visible emissions of the exhaust
gas stream. Although the addition of moisture could increase the apparent
opacity of visible emissions under certain conditions, Reference Method 9
has specific procedures for the reading of plumes with high moisture
contents. These procedures require reading of the plume at the point of
dissipation of the moisture. Thus, compliance with the standards is not
adversely affected by the addition of moisture to the plume.
The capacity of a kiln is a function of its evaporative load.
Addition of large quantities of water to the kiln would decrease the
capacity. Thus, the mass emissions would be expected to decrease.
Consequently, the visible emissions should decrease or remain at about the
same level.
2.7 CONTINUOUS MONITORING
2.7.1 Continuous Monitoring Reliability
Comment: One commenter (IV-F-1) stated that transmissometers
necessary to fulfill the continuous monitoring requirement are subject
to a high frequency of false readings and require excessive maintenance.
The commenter concluded that continuous monitoring is unachievable
because there does not seem to be any instrumentation that can provide
reliable continuous monitoring.
The commenter further stated that imposing three monitoring require-
ments—Reference Method 5, Reference Method 9, and continuous opacity
monitoring—amounts to overkill. Therefore, the commenter recommended
that the continuous monitoring requirement be deleted from the regulation.
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The commenter also felt that wet scrubbers should have the same
visible emission monitoring requirements that fabric filters and ESP's
have.
Response: Studies indicate that continuous monitors are in operation
in many industries, and when they comply with the performance specifications
included in 40 CFR 60, Appendix B, these monitors perform accurately and
reliably.
Reference Methods 5 and 9 are test methods to determine compliance
with standards of performance and are not performed on a continuous
basis (except by choice in the case of using certified visible emission
observers for positive-pressure fabric filters). Thus, the requirement
to monitor visible emissions is the only "monitoring" requirement. This
requirement is considered reasonable because continuous monitoring
provides the information necessary to ensure proper operation and main-
tenance of the control system. Without continuous monitoring, neither
the plant operator nor enforcement personnel can determine whether
control equipment is operating properly or is in need of maintenance
without costly performance testing to determine compliance with the
standard.
Scrubbers are not subject to the lime plant visible emission standard
because the formation of steam plumes from scrubbers makes it difficult
to accurately determine plume opacities. It is difficult to determine
where the steam plume from a scrubber on a rotary lime kiln actually
dissipates and the visible emissions begin. However, the pressure drop
and liquid flow rate monitoring and recording requirements will ensure
that scrubbers are operated and maintained properly.
Comment: One commenter (IV-D-5) contends that the most reliable
system to verify compliance with the standard would be a realistic
visible emission standard rather than a continuous monitoring system.
The commenter also stated that the requirement to record readings from a
continuous mon.itor should be dropped because it is an unfair burden.
Response: The cost of continuous monitoring (or pressure drop and
liquid flow monitoring in the case of wet scrubbers) on other than
positive-pressure fabric filters is small (about $5,000 annually). The
data gathered by continuous monitors are necessary to indicate problems
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in operation and maintenance of the control device. Consequently,
collecting and recording this data does not impose an unreasonable
burden.
2.7.2 Use of Continuous Emissions Monitoring Results
Comment: One commenter (IV-F-1) was concerned about whether transmis-
someter data would be used by enforcement personnel as evidence of
noncompliance with the standards.
Response: The continuous monitoring results are not used to determine
violations of the standards. The purpose of the continuous monitoring
requirement is to provide plant operators and enforcement personnel with
information about whether a control device is properly operated and
maintained. If the data recorded by the transmissometer indicate visible
emissions approaching or exceeding the visible emission standard, then
plant operators are forwarned that the control device needs maintenance.
Data generated by the transmissometers are not used to cite plants for
violations of the new source performance standards. However, to the
extent that continuous monitoring data indicate visible emissions in"
excess of the standard over a period of time, an enforcement agency may
require a plant to perform a performance test to determine compliance
with either the mass emission standard or the visible emission standard.
2.8 MISCELLANEOUS
2.8.1 Temperature of Lime Production
Comment: One commenter (IV-F-1) stated that some important facts
were not addressed in the preamble (47 FR 38851) in the discussion of
particle sizes at various stages in the production of lime. The commenter
stated that calcining lime by going from 1000°C (1832°F) to 1648°C
(2998°F) as the preamble indicated would ruin the quality of the lime.
Response: The discussion on temperature, referred to by the commenter,
is included in the preamble only to show how particle sizes tend to
increase with increasing process temperature. This information was
obtained from "Chemistry and Technology of Lime and Limestone" by
R. S. Boynton (Interscience Publishers, 1967) (II-I-4). Boynton states
that as the temperature in the kiln increases to 1000°C (1832°F), the
0.1-um crystals coalesce into larger particles of approximately 1 pm in
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diameter. At 1100°C (2012°F), these coalesced lime particles are irregular
spheres greater than 1 urn, and at 1648°C (2998°F) (the temperature
required for the sintering of dead-burned lime), the particles are
approximately 100 urn in diameter. This discussion does not imply that
the calcining process is normally run from 1000° to 1648°C (1832° to
2998°F).
Note: Continuous Monitoring of Positive-Pressure Fabric Filters.
Although not specifically mentioned by any commenters, there may be some
difficulties associated with the use of continuous monitors on positive-
pressure fabric filters. Positive-pressure fabric filters have either
multiple exhaust points or a single exhaust point running the length of
the fabric filter. To monitor visible emissions adequately, continuous
monitors must be mounted at each emissions point or a single monitor
must be positioned to monitor the visible emissions across a single
"line of sight." In some instances, the distance to be traversed by the
beam from a single monitor positioned on the "line of sight" exceeds the
capability of the monitor. Thus, in these cases, multiple monitors
would be required to monitor visible emissions adequately on a positive-
pressure fabric filter. Installation of these monitors greatly increases
both the capital and operating costs required to monitor visible emissions,
and these increased costs are considered to be unreasonable.
In lieu of transmissometers, observations of visible emissions
discharged to the atmosphere from positive-pressure fabric filters can
be employed on a routine basis to ensure proper operation and maintenance
of the control device. The final standards, therefore, require that if
a continuous monitor is not installed on a positive-pressure fabric
filter, a certified visible emission observer must monitor and record
the opacity of visible emissions from each compartment or exhaust point
once per day during normal kiln operation, for up to five times per
week, in accordance with Reference Method 9. Production rates within 10
to 15 percent of design capacity are considered to be normal operation
of the rotary lime kiln. The frequency of the visible emission readings
was established at the point where the annualized costs of these readings
are equal to the annualized costs of transmissometers. Because a Reference
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Method 9 test is the method used to determine compliance with the control
device visible emission standard, reports of such tests from positive-
pressure fabric filters may be used to determine compliance with the
control device visible emission standard. The monitoring requirements
for control devices other than positive-pressure fabric filters remain
unchanged.
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