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National Emission Standards for Hazardous Air Pollutants

(NESHAP) FOR Lime Manufacturing Background Information

Document - Vol II

PUBLIC COMMENTS AND RESPONSES

( August 2003

Emission Standards Division

u.s. Environmental Protection Agency

Office ofAir Quality Planning and Standards

Research Triangle Park, North Carolina 27711
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Section

TABLE OF CONTENTS

Page

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1.0 Summary 1-1

1.1 Table 1-1 List ofCommenters 1-2

2.0 Rule Changes Since Proposal 2-1

2.1 Emission Limits 2-1

2.2 Monitoring Requirements 2-1

2.3 Emission Testing and Reports 2-2

2.4 Applicability 2-2

2.5 Averaging Periods for Monitoring 2-2

2.6 Averaging Kiln Emissions 2-3

3.0 Comment Summaries and EPA Responses 3-1

3.1 Subcategory for Scrubber-Equipment Kilns 3-1

3.2 PM Emission Limit for Scrubber-Equipment Kilns 3-17

3.3 PM Emission Limit for New Kilns 3-18

3.4 PM Emission Limit - General 3-19

3.5 Monitoring Requirements for Scrubber-Equipped Kilns 3-22

3.6 Monitoring Requirements for Kilns wi Dry Pollution Control Devices 3-23

3.7 Operating Parameters 3-27

3.8 Opacity Limit 3-29

3.9 Stone Handling Operations 3-31

3.10 Test Methods 3-32

3.11 Economic Impact Analysis 3-36

3.12 Risk Analysis 3-42

3.13 Applicability 3-43

3.14 General Comments 3-44
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1.0 SUMMARY

On December 20,2002, the U.S. Environmental Protection Agency (EPA) proposed

national emission standards for hazardous air pollutant (HAP) emissions from lime

manufacturing plants located at major source facilities (67 FR 78046). These proposed

standards implemented section 112(d) of the Clean Air Act as amended in 1990 (CM).

There were 24 comment letters on the proposal (see Table 1-1), and the commenters

consisted of trade associations, manufacturers, and engineering firms, and the general

public. Summaries of the comments, and the EPA's responses, are presented in this

background information document (BID Volume II). This summary of comments and

responses served as the basis for the revisions made to the rule between proposal and

promulgation. Besides summarizing the comments and responses, this document also

presents a summary of the rule revisions. This document supplements the information

used to develop the proposed rule, which is the docket for this rulemaking.

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Table 1-1 List of Commenters

(See Docket No. OAR-2002-0052 and Docket A-95-41-National Emission Standards for

Hazardous Air Pollutants for Lime Manufacturing Plants for the comments)

Document Date Rcvd Cementer, Addressee, Title or Date of

Number in Docket Description, etc. Document

IV-D-01 02-13-03 John S. Morawetz, Center Director, 02-14-03

ICWUC Center for Worker Health and

Safety Education, Cincinnati, OH.

IV-D-02 02-18-03 A. J. Paris, President, Huron Lime Inc. 02-14-03

IV-D-03 02-18-03 William M. Brant, Director, Miami-Dade 02-18-03

Water and Sewer Department, Miami, FL.

IV-D-04 02-18-03 Arline M. Seeger, Executive Director, 02-18-03

National Lime Association, Arlington, VA.

IV-D-05 02-18-03 Tony C. Panchyshyn, Senior 02-14-03

Environmental Engineer, Graymont

Western US Inc., Salt Lake City, UT.

IV-D-06 02-18-03 J. Oscar Robinson, General Partner, 02-16-03

Austin White Lime Co., Austin, TX.

IV-D-07 02-18-03 Dana Stone, Vice President, Operations, 02-13-03

Cutler-Magner Company, Duluth, MN.

IV-D-08 02-18-03 Harold W. Robbins, President, Bison 02-14-03

Engineering Inc., Helena, MT.

IV-D-09 02-18-03 James R. Carson, Senior Staff Engineer, 02-17-03

Environmental Affairs, Ispat Inland Inc.,

East Chicago, IN.

IV-D-10 02-18-03 Jeffrey P. LaCosse, President and 02-17-03

Principal Scientist, Spectral Insights LLC,

Durham, NC.

IV-D-11 02-18-03 Steve Raffensperger, Vice President- 02-17-03

General Manager, MidAmerica Division,

Martin Marietta Aggregates, Mason, OH.

IV-D-12 02-18-03 Lucie Macalister, Environmental Engineer, 02-14-03

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Table 1-1 List of Commenters

(See Docket No. OAR-2002-0052 and Docket A-95-41-National Emission Standards for

Hazardous Air Pollutants for Lime Manufacturing Plants for the comments)

Document Date Rcvd Cementer, Addressee, Title or Date of

Number in Docket Description, etc. Document

Linwood Mining and Minerals Corp.,

Davenport, IA.

IV-D-13 02-18-03 Robert J. Bartosh, Senior Vice President & 02-13-03

COO, Dakota Coal Company, Bismarck,

ND.

IV-D-14 02-18-03 Louis Wolfe, Private Citizen, Newark, DE. 02-15-03

IV-D-15 02-18-03 Stephen A. Loeschner, Private Citizen, 02-18-03

Fort Wayne, IN.

IV-D-16 02-18-03 Ron Downey, Director, Environmental 02-18-03

Compliance, LWB Refractories, York, PA.

IV-D-17 02-18-03 Darin Klewsaat, Assistant Operations 02-21-03

Director, Southern Lime Company, Calera,

AL.

IV-D-18 02-11-03 Lecia Craft, Vice President of Environment, 02-11-03

Pete Lien &Sons Inc., Rapid City, SD.

IV-D-19 02-10-03 Craig Clapsaddle, Mechanical Systems 02-10-03

Inc. (MSI), Raleigh, NC.

IV-D-20 02-17-03 Fred Nast, Chief Executive Officer, 02-17-03

Western Lime, West Bend, WI.

IV-D-21 02-18-03 Spencer C. Stinson, General Manager, 02-18-03

Global Stone Chemstone Corp., Strasburg,

VA.

IV-D-22 02-17-03 Johnney G. Bowers, Vice President, 02-12-03

Manufacturing, United States Lime &

Minerals Inc., Dallas, TX.

IV-D-23 02-15-03 Comment entitled II ~~N AIR IS 02-15-03

ESSENTIAL." subml e By

JeanPublic@yahoo.com.

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Table 1-1 List ofCommenters

(See Docket No. OAR-2002-0052 and Docket A-95-41 -National Emission Standards for

Hazardous Air Pollutants for Lime Manufacturing Plants for the comments)

Document Date Rcvd Cementer, Addressee, Title or Date of

Number in Docket Description, etc. Document

IV-G-01 02-24-03 J. Steven Castleberry, Environmental 02-18-03

Affairs Manager, Mississippi Lime, Alton,

IL. (This document contains

Confidential Business Information.

Please contact the project officer if you

need to review.)

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2.0 Rule Changes Since Proposal

2.1 Emission Limits

We proposed a particulate matter (PM) standard (as a surrogate for non-mercury

hazardous air pollutant [HAP] metals) of 0.12 pounds PM per ton stone feed (lb/tsf) reflecting

the performance of dry pollution control systems (baghouses). We also solicited comment on

having a separate PM standard of 0.60 lb/tsffor kilns controlled with wet scrubbers. In the final

rule, we have decided to adopt these two different standards for PM emissions from existing lime

kilns. We are also indicating that existing kilns subject to the 0.60 IbltsfPM emission limit are

not to be included in any averaging scheme for demonstrating compliance with a PM standard.

2.2 Monitoring Requirements

In the proposed NESHAP, we required facilities using wet scrubbers to monitor

scrubber pressure drop and liquid flow rate. We have written the final NESHAP to

explicitly state that alternative monitoring procedures are allowed under the procedures

described in 40 CFR 63.8(f). However, we do not delegate that authority.

The proposed NESHAP stated that you must install, operate, and maintain a

continuous opacity monitoring system (COMS) as required by 40 CFR part 63, subpart

A, General Provisions, and according to PS-1 in Appendix B to 40 CFR part 60. We

have stated in the rule that COMS installed, relocated, or substantially refurbished after

February 6, 2001, must meet the requirements of PS-1 as revised on August 10, 2000.

Any COMS installed on or before February 6,2001, should continue to meet the

requirements in effect at the time of installation unless specifically required by the local

regulatory agency to re-certify the COMS in question.

In the proposed NESHAP, we required you to monitor the performance of fabric

filters (FF) with either a COMS or a PM detector. In the final NESHAP, we are allowing

existing facilities to monitor FF performance using daily EPA Method 9, in Appendix A

to 40 CFR part 60, visible emission readings if the facility has a positive pressure FF

with multiple stacks, or if it is infeasible to install a COMS in accordance with PS-1 in

Appendix B to 40 CFR part 60.

In the proposed NESHAP, we allowed three alternatives for monitoring

electrostatic precipitator (ESP) performance. These were a COMS, a PM detector, or

monitoring ESP voltage and current. In the final NESHAP, we are allowing only two

alternatives, a COMS or a PM detector. There are no requirements to establish ESP

voltage and current operating limits.

In the proposed NESHAP, we specified that EPA Method 9 in Appendix A to 40

CFR part 60 should be used to determine opacity from fugitive emissions. We have

retained this requirement in the final NESHAP, but we have added additional

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implemented to determine fugitive visible emissions. This language was taken directly

from 40 CFR 60.675(c)(1).

In the proposed NESHAP, §63.7120(b) could be interpreted to imply that

processed stone handling (PSH) operations must be continuously monitored. In the

final NESHAP, PSH operations are subject to monthly (not continuous) visible emission

testing.

2.3 Emission Testing and Reports

In the proposed NESHAP, we required that lime kiln emission testing be

conducted at the highest production level reasonably expected to occur. In the final

NESHAP, we require that lime kilns be tested under representative operating

conditions.

In the proposed NESHAP, we required reporting of deviations from operating,

visible emissions, and opacity limits, including those deviations that occur during

periods of startup, shutdown, or malfunction. In the final NESHAP, we require that

( reports are to be made in accordance with 40 CFR 63.1 O(d).

In the proposed NESHAP, we required testing of all kilns in order to claim area

source status. In the final NESHAP, we have included a provision that allows the

permitting authority to determine if idled kilns must be tested, and also to determine

whether all kilns that use identical feed materials, fuels, and emission controls must still

all be tested.

2.4 Applicability

In the proposed NESHAP, the raw material storage bin was the first emission

unit in the sequence of lime manufacturing that was part of the affected source.

Materials rocessin <> erations between the stora e bin and the kiln were also

covered.

storage bins are

defined as manmade enclosures, and use the term processed stone handling

operations instead of materials processing operations.

In the proposed NESHAP, we included as an affected source lime kilns that

produced lime product from any calcareous substance. In the final NESHAP, we have

excluded lime kilns that produce lime from water softening sludge that contain calcium

carbonate.

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In the proposed NESHAP, we excluded materials handling operations associated

with lime product. In the final NESHAP, we have specifically stated that nuisance dust

collectors are part of lime product handling systems and, therefore, are not part of the

affected source.

In the proposed NESHAP, we defined the affected source as the collection of all

of the lime kilns, lime coolers and materials processing operations. We noted that this

language could be misinterpreted to imply that a new lime kiln erected at an existing

lime manufacturing plant would be considered existing, not new. In the final NESHAP,

we have written the language in 40 CFR

63.7082 to make our intent clear. New lime kilns, whether or not they are built at an

existing lime manufacturing plant, must meet the PM emission limits for new sources.

2.5 Averaging Periods for Monitoring

In the proposed NESHAP, we required that facilities use rolling 3-hour averages

to show compliance with wet scrubber operating limits. We noted that in the proposed

rule, we did not clearly state how to calculate the rolling average. Based on compliance

requirements of other NESHAP, we determined that a rolling average was not

necessary to ensure compliance, but did increase the complexity of the average

( calculation and record keeping process. Therefore, in the final NESHAP, we require

block 3-hour averages instead of rolling 3-hour averages, which is consistent with the

requirement to use block averaging required for ESP that choose to monitor using

COMS.

2.6 Averaging Kiln Emissions

In the proposed NESHAP, we allowed averaging among all lime kilns and

coolers at existing sources, and all new lime kilns and coolers at new sources, but did

not allow averaging of existing and new lime kilns and coolers together. In addition, the

averaging provisions and equations applied whether or not the facility desired to

average. We have written the final NESHAP to state that each individual new lime kiln

and its associated cooler must meet a 0.10 Ib/tsf PM emission limit, and each individual

existing lime kilns and its associated cooler must meet a 0.12 Ib/tsf PM emission limit.

Averaging is optional, so that if each individual kiln meets its emission limit, averaging is

not required. The exception to this is for existing kilns which are subject to the 0.60

Ib/tsf PM emission limit. These kilns are not eligible for averaging.

If the lime manufacturing plant has multiple kilns and wants to average kilns

together to meet the PM emission limit, this is allowed (with one limitation discussed

below, and the exception for kilns subject to the 0.60 Ib/tsf PM emission limit noted

above) and the averaging equations in the final rule must be used. However, in no

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case maya new kiln exceed a 0.10 Ib/tsf emission limit. Where there are both new and

existing lime kilns at a facility, then the PM emission limit will be an average of the

existing and new kiln PM emissions limits, weighted by the annual actual production

rates of the individual kilns. We believe that allowing averaging is appropriate here

because of the identity of the units (kilns and coolers in all cases), and the emissions

(same HAP in same type of emissions, since all emissions result from kilns and

coolers). Averaged emissions under these circumstances would, thus, still reflect

MACT for the affected source. The averaging provisions are included in the final

NESHAP as a result of the recommendations of the Small Business Advocacy Panel

convened as required by section 609(b) of the Regulatory Flexibility Act (RFA) and

improves the compliance flexibility options for small businesses, which is the intent of

the RFA.

The only limitations we are requiring on averaging are: 1) any new kiln, when

considered alone, must meet the 0.10 Ib/tsf emission limit; 2) kilns equipped with wet

scrubbers for PM emissions control are not eligible for averaging; 3) we are not allowing

averaging for other emission sources, or for opacity.

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3.1 Subcategory for Scrubber-Equipped Kilns

Comment

In the preamble to the proposed rule, EPA requested comment on establishing a

subcategory for existing kilns equipped with wet scrubbers, ifit could be demonstrated factually

that there would be significant environmentally counterproductive effects due to increased

emissions of acid gases, increased energy use, or increased water use. (See 67 FR at 78058.)

Several commenters (IV-D-04, IV-D-06, IV-D-02, IV-D-16, and IV-D-22) asked that a

subcategory for scrubber-equipped kilns be established. One commenter (IV-D-04) also asked

that kilns vented through a mine chamber be defined as scrubber-equipped kilns. The basis for

this request, in the commenters' view, is that wet scrubbers cannot meet the proposed particulate

matter (PM) standard of 0.12 pounds ofPM per ton solid feed (lb/tsf), and therefore kilns with

scrubbers would have to replace them with baghouses. (They also assert that in most cases, wet

scrubbers have higher annualized costs compared to baghouses. Therefore, even if a wet

scrubber could meet a 0.12 lbltsf emission level, facilities will opt to use baghouses due to cost

considerations. See comments on costs which follow.) This will result in an increase in

emissions ofHCI [a hazardous air pollutant (HAP)] and S02 (a non-HAP criteria pollutant), for a

nominal decrease in HAP metal emissions.

( In support ofthis request one commenter provided estimates that not establishing the

requested wet scrubber subcategory would result in a metal HAP emissions decrease of 3 tons

per year (tpy), but would result in an increased emissions of 1823 tpy for HCI and 2894 tpy for

S02.

One commenter (IV-D-12) stated that it had previously provided information on the effect

ofreplacing wet scrubbers with baghouses. They claimed that replacing one plant's wet PM

control system with a baghouse will increase HCI by over 20 tpy, but only decrease metal HAP

by 481 pounds per year (Docket Item No. I-B-116, Appendix C).

Another commenter (lV-D-02) estimated that HAP currently being discharged from its

three existing kilns are 29 tpy ofHCI and 0.38 tpy ofHAP metals. The emissions from the same

kilns ifdry air pollution control equipment were used would be 652 tpy ofHCI and 0.075 tpyof

HAP metals. They also claim that the higher operating temperatures of dry systems cause metals

to vaporize and pass through a particulate collector, resulting in a lower metal concentration in

the captured particulate. As a result, they claim that even though dry control equipment may

reduce HAP metals emissions, the reduction will be minimal, while the release ofHCI will

increase significantly. In addition, the commenter notes that approximately 39 percent ofthe

HAP metal emissions attributed to the lime industry is manganese, which is not classified as a

known or suspected carcinogen. The commenter provides data which it claims show the only

conventional pollutant that will be reduced with the installation of a dry control system will be

particulate emissions, and, "fugitive dust emissions from a dry system could more than offset the

improved particulate collection on the kiln exhausts."

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Response

Standards implementing section 112 (d) of the Act must, of course, be of a

minimum level of stringency, usually referred to as the MACT floor. For existing

sources, this floor level of control cannot be less stringent than "the average emission

limitation achieved by the best performing 12 percent of the existing sources (for which

the Administrator has emissions information)." In this rule, EPA is establishing section

112 (d) standards to control emissions of HAP metals, for which PM is a surrogate.

None of the commenters challenge that the level of PM emissions reflecting the

average of the 12 per cent of the best performing sources is 0.12 Ib/tsf.

Notwithstanding, the commenters contend that EPA should subcategorize on the basis

of the type of air pollution control device used, and then separately determine the floor

for each subcategory.

Although the Act contemplates that EPA may establish subcategories when

promulgating MACT standards, subcategorization typically reflects "differences in

manufacturing process, emission characteristics, or technical feasibility". See 67 FR at

78058; see also 63 FR at 18768 (April 15, 1998) determining whether or not to

subcategorize based on "the type of equipment used in the process, the emission

potential of each emission point, and any variations in the process due to pulp type". A

classic example, provided in the legislative history to section 112 (d), is of a different

process leading to different emissions and different types of control strategies - the

specific example being Soderberg and prebaked anode primary aluminum processes.

lSection 112 (d) (1) provides that "[t]he Administrator may distinguish among classes,

types, and sizes of sources within a category or subcategory in establishing such

standards.....". In addition, section 112 (c) (1) encourages EPA to adhere to the

subcategorization scheme already used in establishing NSPS: "To the extent

practicable, the categories and subcategories listed under this subsection shall be

consistent with the list of source categories established pursuant to section 111

[requiring EPA to establish technology-based New Source Performance Standards] and

Part e" (although the NSPS for the lime industry does not contain subcategories, nor

was it ever suggested when establishing NSPS that subcategories would be

appropriate).

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( [See A Legislative History of the Clean Air Act Amendments of 1990 at 1138-39 (floor

debates on Conference Report)].

Normally, it would be legally impermissible to subcategorize based on the type of

air pollution control device. The problem with subcategorizing on the basis of pollution

control device, quite simply, is that it leads to situations where floors are established

based on something other than the "best performing" sources. For example, suppose a

source category consists of 100 sources using the same process and having the same

emission characteristics, but that 50 sources use control device A to control HAP

emissions, and 50 use control device B which is two orders of magnitude less efficient.

If one subcategorized based on the type of pollution control device, the MACT floor for

the 50 sources with control device B would reflect worst, rather than "best"

performance. Although the disparity in levels of emission control between the best

performing sources here, and the best performing sources using wet scrubbers is not

this dramatic - roughly a factor of 5, not orders of magnitude - the difference is

nonetheless ample and evident.

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The question of whether it is permissible to subcategorize on the basis of

pollution control device has been litigated in the context of the effluent guideline

provisions of the Clean Water Act. These provisions, which were the prototype of the

MACT provisions in the Clean Air Act [see 5 Legislative History at 8473-74 (Senate

Report)], require control of toxics reflecting performance of best technology, although

the Clean Water Act gives EPA more flexibility to subcategorize than the Clean Air Act,

since there is no floor provision, and EPA is required to consider manufacturing

process, age, engineering aspects, costs, and types of control equipment (among other

factors) in setting the standards. Clean Water Act section 304 (b). Nonetheless, the

Fifth Circuit rejected the argument that EPA erred in not subcategorizing based on

different types of pollution control equipment:

[P]etitioners' plants do not differ materially from other [chemical] plants with

respect to manufacturing operations or wastewater characteristics.... Their plants

differ only with respect to the type of treatment petitioners voluntarily chose to

employ. Petitioners did not choose to employ the type of ... treatment system

that is most commonly used by good performers in the [chemical] industry ....

Instead, petitioners chose to employ ... treatment systems which generate

additional pollutants .... The EPA asserts that it therefore reasonably required

petitioners' plants to meet the limitation demonstrated to be achievable by the

'best' plants in the industry, rather than providing less stringent limitations for

these plants simply because they chose to employ less effective treatment

technology....

Petitioners cannot now be excused from meeting the BPT [Best Practicable

Technology] limits on the grounds that their present method of treatment is less

effective than the average of the best.... Such a construction of section 304 (b)

(1) (B) would defeat the very purpose of establishing BPT limits. The EPA is not

required to base BPT upon a technology that is less effective than the best

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practicable technology demonstrated in the industrv....We therefore hold that the

EPA was entirely reasonable in declining to create a subcategory for plants

employing [the less effective] treatment systems.

Chemical Manufacturers Association v. EPA, 870 F. 2d 177,218-19 (5th Cir. 1989)

(emphasis supplied), modfd on different grounds on rehearing, 885 F. 2d 253 (5th Cir.

1989).

This remains EPA's concern in the final rule. Subcategorizing purely on the

basis of pollution control device type "would defeat the very purpose of establishing

[MACT]" because such a construction would mean the MACT floor would no longer

reflect the performance of best performing sources, as required.

It has been suggested here, however, that the best performing sources with

respect to HAP metal emissions should not be considered "best performing" because

that performance comes at an environmental cost, namely increased emissions of HCI

and S02 compared to what lime kilns equipped with wet scrubbers would emit. There is

some support for the idea that if an ostensibly best performing pollution control device

creates potentially counterproductive environmental effects, such performance need no

longer be considered "best" due to the counterproductive effects, and could justify

differentiation in the form of subcategorization (See 66 FR at 3187 [January 12, 2001]).

Commenters suggest that is the case here due to increased emissions of HCI and S02

which would result (they maintain) if lime kilns replace wet scrubbers with baghouses.

First, it is not clear the commenters' starting premise, that baghouses are either

needed or will be used to achieve the PM standard, is correct. We continue to believe

that a properly designed and operated wet scrubber can meet the proposed PM

emission limit of 0.12 Ib/tsf. The reasons for this are specifically addressed in our

following response to comments on achievable wet scrubber performance.

The commenters provided no data to refute that application of a 0.12 Ib/tsf PM

emission limit represents best control of HAP emissions if we do not create any kiln

subcategories. We note that as part of their comments, they claim that the higher

temperatures of dry PM controls result in metals vaporizing and passing through the PM

control. However, the data provided in their comment does not substantiate their claim,

and analyses performed for the Hazardous Waste Combustor NESHAP indicate that all

but a few percent of the metals in question exit the kiln as solid particulate (see pages

1-1 through 1-4 in the Draft Technical Support Document for HWC MACT Standards,

February 1996, which are in the docket for this rulemaking). The same comments

stated that the increased PM emissions control that results from baghouses could be

more than offset by increased fugitive dust emissions from dry systems. We know of

no data that supports that statement. Dry dust systems can be designed and operated

to minimize fugitive emissions. Moreover, we do know that fabric filters are commonly

used when high levels of PM control are desired in many industries. In none of these

cases do we know of any instance where less efficient wet scrubbers were applied in

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( lieu of more efficient fabric filters due to concerns of fugitive dust emission from the

collected particulate.

We also evaluated the concerns that switching to dry controls may result in

increases of S02 and HCI emissions. However, our analysis indicates that the extent to

which S02 and HCI emissions actually increase may have been overstated by the

commenter. EPA estimates that if all facilities currently using wet scrubbers switched to

dry controls, HCI emissions would increase by approximately 1,310 tpy (vs 1,800 tpy

estimated by the commenter) and S02 emissions would increase by about 1,830 tpy (vs

2,900 tpy estimated by the commenter). (See the memorandum "Environmental

Impacts of Decision on Best Control for Wet-Scrubber controlled Kilns" in the docket for

this final rule).

We do not regard either level of increased HCI emissions as significant. We

modeled this emissions increase as part of our determination (pursuant to section 112

(d) (4» that emissions of HCI from lime kilns are below an HCI risk threshold, with an

ample margin of safety. See FR 78054 - 78057 and the risk analysis in the docket for

the final rule. Given this determination, we cannot view these HCI increases as being

so significant as to call into question whether the best-performing sources with respect

to HAP metal reductions are in fact "best performing".

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The commenters also cite projected increases in the criteria pollutant S02 that

may result from our decision not to subcategorize by existing control device. They did

not initially address the reductions in PM emissions resulting for the decision that 0.12

Ib/tsf represents best-control for scrubber equipped kilns. We estimate that nearly

1,080 tpy of additional PM would be removed if all existing kilns were to meet a

standard of 0.12 Ib/tsf, of which approXimately 1.6 tpy are metal HAP. Although EPA

may not promulgate standards for non-HAP under section 112 (d), Congress expected

reductions in emissions of criteria pollutants such as PM to be a benefit of the MACT

program. 5 Legislative History at 8512 (Senate Report) ("When establishing

technology-based standards under this subsection, the Administrator may consider the

benefits which result from control of air pollutants that are not listed but the emissions of

which are, nevertheless, reduced by control technologies or practices necessary to

meet the prescribed limitation [going on to give VOC reductions as an example].") In

comparison to estimates of increased emissions of S02 by either the commenter or

EPA, the decrease in captured PM emissions (and attendant decrease in capture of

non-mercury metal HAP) if all existing kilns are not required to meet a standard of 0.12

Ib/tsf is significant.

There is a further consideration, however. Based on the available size distribution data

from Compilation ofAir Pollutant Emission Factors, AP-42, Fifth Edition, Volume I: Stationary

Point and Area Sources, 73 percent ofthe PM emitted directly by lime kilns is coarse PM (PM in

the size range of 2.5 to 10 micrometers). Some ofthe S02 emitted to the atmosphere undergoes

chemical reactions to fonn fine PM. [See generally the respective Criteria Documents for PM

(EPA/600/P-95/001aF-cf. 3v, 1996) and S02 (EPA/600/8-82-029aF-cF. 3v., 1982 and addenda)].

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systems are not best performing, some comparison of coarse verses fine PM emissions is needed.

If we retain a single PM emission limit of 0.12 lb/tsffor all existing kilns, total PM

emissions would be reduced (compared to separate standards for kilns with wet scrubbers and dry

controls) by an additional 1,080 tpy. Ofthat number, 630 tpy is fine PM and 450 is coarse PM.

The potential amount ofincreased S02 emissions is 1,830 try. A portion ofthis 1,830 tpy of S02

will be converted in the atmosphere to produce 1,270 tpy offine PM. Therefore, the incremental

impact of a single PM standard ofO.12Ib/tsffor both wet scrubbers and dry controls would be an

increase of 640 (l,270-630) tpy in fine PM emissions, and a decrease of450 tpy in coarse PM

emissions. This assumes that all facilities that currently have wet scrubbers switch to dry

controls, and that 46 percent ofthe S02 converts to fine PM. The 46 percent conversion estimate

used by the commenter is consistent with information in the respective Criteria Documents for

PM and S02 referenced above.

As recently summarized by EPA (68 FR 28339, May 23,2003), scientific studies show

ambient PM (both fine and coarse) is associated with a series of adverse health effects. Fine PM

is associated with increases in daily mortality. Coarse PM is more strongly linked to morbidity

(e.g. hospital admissions). See generally the respective Criteria Documents for PM (EPA/6001P95/001aF-cF. 3v, 1996) and S02 (EPA/600/8-82-029aF-cF. 3v., 1982 and addenda). Therefore,

it is difficult to make comparisons between the relative benefits ofreducing emissions offine and

( coarse PM.

We view this situation as equivocal: it is unclear which ofthese types of performance is

best since on the one hand there is reduced emissions ofHAP metals and coarse PM but foregone

control ofS02 and sulfate (fme) PM, and, for kilns controlled with wet systems, the converse. In

this situation, and based on these facts, which, with current analytic tools seem to us to be largely

in equipoise, we are not prepared to view either wet or dry systems as best performing and

instead are promulgating a separate PM standard for each.

We emphasize that considerations ofrisk and relative environmental benefits are

normally irrelevant to MACT floor determinations [unless expressly authorized by statute, as in

Clean Air Act (CAA) section 112(d)(4) as applied in the final rule], since floor standards must

reflect the performance ofthe specified number of best performing sources. See National Lime

Ass'n v. EPA, 233 F. 3d at 640 (considerations of cost and de minimis risk cannot be considered

in making MACT floor determinations). We considered these factors in the final rule solely for

the purpose of evaluating the commenters' claim that sources using wet and dry control systems

should be evaluated separately for MACT floor purposes due to environmental benefits and

disbenefits associated with wet and dry control systems. Given the equivocal facts here, we are

not prepared to state that either the wet or dry systems are "best performing" for existing kilns,

and are instead promulgating separate PM standards (as a surrogate for non-mercury HAP

metals) for each.

(

\

Comment

3-6
(

Commenter IV-D-04 stated that wet scrubbers cannot meet the proposed PM emission

limit of 0.12 lb/tsf. They claimed that a wet scrubber manufacturer will only guarantee this limit

ifless than 1 percent ofthe particles to be removed are less than 1 micrometer in diameter. The

commenter stated that EPA assumes that the average mass diameter of particles in lime kiln gas

effluent is 2 micrometers, and that this assumption is based on a single reference, and that

reference was actually fugitive lime dust, not lime kiln particulate. They further claimed that

volatilization and homogenous nucleation of potassium chloride particles in the gas stream

generates particles in the 0.1 to 0.5 micrometers size range. "As particle size decreases below 1

micrometer, inertial compaction becomes decreasingly effective. Above 0.1 micrometers,

Brownian displacement is ineffective. In the range between 0.1 and 0.5 micrometers, neither of

these two main particle capture mechanisms relied upon in wet scrubber design is very

effective." The commenter presents a recent example of a scrubber installation and an

analysis of Docket item No. II-B-126 (an EPA memo titled "Technical Feasibility of

Venturi Scrubbers in Meeting 0.12 Ib/ton Outlet PM Level") to demonstrate this point.

Commenter IV-D-02 claimed that a scrubber performance efficiency of99.9 percent

will be required to meet the 0.0072 grain/dry standard cubic foot (gr/dscf) particulate

concentration which they claimed corresponds to the proposed PM emission limit ofO.12Ib/tsf.

The commenter's environmental consultant advised that it is unlikely a wet scrubber with a 35-

inch water gauge (w.g.) pressure drop could achieve this level of performance with the facility's

current inlet exhaust particulate loading.

Response

We continue to believe that a properly designed and operated venturi wet scrubber with a

35 inch w.g. pressure drop can achieve the proposed PM emission limit ofO.12Ib/tsf. The

commenter argues that EPA's basis for a 35 inch w.g. scrubber pressure drop to obtain 99.94

percent efficiency is not realistic. They base their arguments on perceived improper use of

estimation procedures, incorrect choice oftypical particle size, faulty vendor estimates, and lack

ofknowledge regarding measurements of an existing scrubber in Virginia.

This commenter misunderstands the manner in which EPA evaluated venturi scrubber

performance. The particle size data used in the preliminary estimate came from several sources;

not one as suggested by the commenter. Second, ofthe various data available, we chose the data

on fugitive lime dust PM because they had the smallest mean particle size diameter, which was 2

micrometers. This was a very conservative assumption, because, for a normal particle size

distribution, the wet scrubber pressure drop required to meet a specific removal efficiency

increases as the mean particle size decreases. All the other data presented in our analysis

indicates that the mean particle size for lime kiln particulate is much larger than the 2

micrometers we chose. For example, the particle size data reported in EPA's AP-42, Section

11.15, Lime Manufacturing, indicate that the mean particle size for uncontrolled kilns is over 15

micrometers.

We used this atypically small particle size as a median diameter to input into simplified

methods to estimate the pressure drop required to meet a scrubber PM removal efficiency of

99.94 percent (the removal efficiency required to meet a 0.12Ib/tsfPM emission limit).

3-7
(

The fIrst commenter also asserted that the pressure drop estimation procedure we used is

inappropriate. The commenter stated that in determining the required wet scrubber pressure drop

in a particular application, the particulate must be assigned to a set of discrete size ranges and the

scrubber effIciency evaluated at a specifIc pressure drop size range by size range. These results

must then be used to calculate the overall PM removal effIciency.

We agree that, if data are available, the procedure described above is more accurate.

However, we note that the commenter did not provide any particle size data that would either

substantiate the contentions, or allow us to use the procedure claimed to be more accurate. In the

absence ofthe type of data described by the commenter, the conservative and simplified

approach to estimating wet scrubber pressure drop used here, that is, using a conservative

estimate ofmedian particle size, is reasonable. Therefore, based on the data available, the

procedure we have used to estimate what scrubber pressure drop, on average, will be necessary to

meet a 0.12 Ib/tsfPM emission limit, is suffIciently accurate. As explained, this procedure

results in an estimate that a 35-inch w.g. pressure drop is needed.

However, as a check, we also contacted wet scrubber vendors to provide more

rigorous estimates to confirm whether the 35-inch w.g. pressure drop value was valid.

One vendor, using proprietary data, estimated a 35-inch w.g. pressure drop was

sufficient provided there is sufficient moisture in the gas stream ahead of the venturi

throat to increase particle size so that the venturi scrubber can remove the PM. We

believe that the fact that two independent estimates produced the same result verifies

our estimation procedure.

If necessary, cooling water can be added prior to the venturi in order to

sufficiently increase particle size. In some cases, more water can be added through a

packed bed. Note that the cooled gas stream would have lower gas volume resulting in

smaller fan, motor, and duct requirements.2

This same commenter presented data from a wet scrubber controlled calcimatic

lime kiln indicating that potassium chloride in limestone leads to generation of a

significant quantity of particles in the 0.1 to 0.3 micrometer range, which are difficult to

collect in a wet scrubber. This wet scrubber was designed for an outlet concentration of

0.01 gr/dscf at a pressure drop of 22 inches w.g., but, after modifications, could only

reach about 0.04 gr/dscf. The commenter asserted that it is "often the case" that 10

percent of the inlet loading to a lime kiln scrubber is in the 0.1 to 0.3 micrometer range.

2 Packed beds were not specifically costed out in our model kilns, but the additional cost

for the packed bed (if ever needed) would be offset by the reduced cost of the fan,

motor, and ductwork as well as reduced annual cost for power that result from the effect

of gas cooling which reduces gas volume. However, some plants could possibly

upgrade their existing scrubber for about 40 percent of the cost of a new wet scrubber.

In these cases, our model plant costs overstate capital cost by about 150 percent. On

a nationwide basis, our scrubber costs probably overstate what actual costs are likely to

be.

3-8
( The commenter later provided data they claim supports this statement. The

commenter cited this example to call into question EPA's conclusion that a wet

scrubber with a pressure drop of 35 inches of water can meet a 0.12 Ib/tsf PM emission

limit.

First, and most important, the example cited by the commenter can in no way be

used to make generalized industry-wide conclusions about the ability of wet scrubbers

to meet a 0.12 Ib/tsf PM emission limit. The commenter did not include in their

comments information from a BACT analysis for the Global facility (Global Chemstone

Corporation, March 15,2002) written by the same person who wrote the commenter's statement

regarding pressure drop and particle size. This BACT analysis states that the calcimatic kiln

being controlled has different characteristics than the more conventionally found rotary kiln.

Statements about the scrubber and kiln indicate that they present a unique case, not likely to be

found at other lime kiln sites. Examples are,

" ... the existing total filterable particulate matter emission limit of 0.022 grains/dry

standard cubic foot is too low given the unique issues associated with operating a

calcimatic kiln with a moderate-to-high potassium content limestone feed [363 parts per

million (ppm)]." (p.l ofthe analysis)

(

"Global has a Calcimatic lime kiln, which is fundamentally different from a traditional

rotary lime kiln." (p. 2 ofthe analysis)

"However, there are significant differences between a rotary lime kiln and calcimatic

lime kiln." (p. 5 ofthe analysis)

"The dominant characteristic ofrotary lime kilns is the high concentration ofparticulate

matter entrained in the gas stream due to the direct contact ofthe hot flue gas with the

tumbling feed materials within the kiln. This particulate matter provides the surface area

necessary for the condensation (heterogeneous nucleation) ofvapor phase materials.

Potassium and other vapor phase materials in the kiln gas stream will concentrate

primarily in moderate-to-Iarge particulate matter that can be controlled with high

efficiency wet scrubber systems." (p. 5 ofthe analysis)

"... the particulate matter loadings from a calcimatic kiln are lower than those of a rotary

kiln. Due to the low particulate matter concentrations in the calcimatic kiln effluent gas

streams, a significant fraction ofthe vapor phase potassium and other vapor phase

material can condense (homogeneously nucleate) to form submicrometer sized particles

after the gas stream exits the kiln. Therefore, emission figures based on rotary kiln

control equipment are not relevant to calcimatic lime kilns." (p. 6 ofthe analysis)

" ... a reverse air fabric filter with membrane bags is technically infeasible at Global. The

problems inherently involved with submicrometer sized potassium chloride also preclude

the use of(l) reverse air fabric filters with conventional woven filter media and (2) pulse

jet fabric filters with membrane-coated felted bags." (p, 8 ofthe analysis, note that fabric

filters have been used to control lime kilns for decades)

3-9
(

"The Calcimatic kiln is more vulnerable to homogeneous nucleation than rotary lime

kilns due to the low particulate matter concentrations in the Calcimatic kiln effluent gas

stream." (p. 11 ofthe analysis).

Based on these comments, it is clear that the situation at the Global Stone Chemstone

facility is unique, and not applicable to the industry as a whole.

However, the information presented here could be used to imply that wet scrubbers are

not as effective on calcimatic kilns as on to rotary kilns. (Note that calcimatic kilns make up only

about 6 percent ofthe currently operating lime kilns). However, as we have never claimed

that a wet scrubber with a 22 inch w.g. pressure drop can meet the proposed PM

emission limit of 0.12lb/tsf (as explained above, we estimated that a 35 inch W.g.

pressure drop will be necessary), we do not see how the example cited by the

commenter is relevant. Also, given the fact that the particle size data appear to have been

collected after the scrubber was installed, we conclude that that there are certain site specific

factors that were not accounted for in the scrubber design.

However, this commenter goes on to claim that the wet scrubber in question

could not meet a PM emission limit of 0.12 Ib/tsf even if the pressure drop were

increased to 35 inches. They claimed this is because of the presence of a large

amount of particles in the 0.1 to 0.5 micrometer size range at this particular facility, and

that particles in this size range are the most difficult to collect with a wet scrubber.

However, it should still be possible to meet 0.12 Ib/tsf even in this case, though

additional costs for water injection or for steam injection (to provide additional moisture

in the exhaust gas) may be required. In that case, if a facility was required to meet a

0.12 Ib/tsf PM emission limit, it might opt for a fabric filter. Our model plant costing

does not purport to predict how any individual kiln might'react. Finally, based on our

determination that facilities that currently have wet scrubbers meeting 0.6 Ib/tsf are

environmentally equivalent to dry controls meeting 0.12 Ib/tsf, the fact that this facility

claimed it cannot meet 0.12 Ib/tsf is moot.

Another point made by this commenter concerned the choice of gas flow rate

used for scrubber-equipped kiln modeling. From Information Collection Request (lCR)

data available to EPA, exhaust gas flow rates for scrubber-equipped kilns were found to

vary from about 100,000 actual cubic feet per minute (acfm)/ton of lime to about

310,000 acfm/ton of lime. The EPA chose an intermediate value of 165,000 acfm/ton

of lime for modeling purposes (see docket item 11-8-14). There was no intent to

choose either the lowest or the highest flow rate in the database because on average,

an intermediate value would be more representative. This commenter also stated that

the value of the PM concentration in the flue gas was incorrect because we did not

account for the water vapor from evaporation in the scrubber, and used a 800°F flue

gas temperature. The concentration calculation was used to define inlet conditions to

the model scrubber so that scrubber sizing and water requirements could be estimated

by a vendor. The estimated PM concentration was not used in determining scrubber

pressure drops, or in estimating costs.

3-10
(

The second commenter supplied no data to support the assertion by their

consultant that a 35-inch w.g. pressure drop scrubber could not achieve the required

efficiency. Our responses above also address their comment.

Comment

Commenter IV-D-04 provided an analysis of wet scrubber feasibility prepared by

a consultant to supplement their summarized comment above. This analysis raised

several additional points not included in our previous comment response. These are as

follows:

It took issue with the statement in Docket item No. 11-8-126 "Scrubbers have

been reported to collect submicron particles as low as 0.006 grains per dry

standard cubic foot in EPA's Handbook of Control Technologies for Hazardous

Air Pollutants. The commenter pointed out that this statement concerned

hydrosonic scrubbers.

It claimed the calculated PM concentration at the scrubber outlet equivalent to

0.12 Ib/tsf was incorrect.

The inlet mass loading data are limited.

The static pressure drop estimate is not applicable to bimodal distributions

common to lime kilns.

Response

The commenter correctly points out that the statement above related to

hydrosonic scrubbers. However, this statement was only intended as an introductory

statement in the memo. We based our analysis on our estimation of the performance

of venturi scrubbers. Therefore, the comment, though correct, is irrelevant.

The calculated PM concentration was not useo to estimate the required scrubber

efficiency. The required scrubber efficiency was estimated based on mass emission

rates. Therefore, the concentration value has no relevance to our estimate of the

scrubber pressure drop required to meet a PM emission limit of 0.12 Ib/tsf.

We agree that the inlet loading PM data are limited. However, we believe that

we have chosen a conservative value. We note that this commenter provided data

elsewhere in their comments that indicated our estimate of 160 to 175 Ib/tsf may be

very conservative.

The commenter did not provide any data to support the statement that the

particle size distribution from lime kilns is bimodal in the size range of 0.1 to 0.5

microns. The aerodynamic particle sizing information from the scrubber at the Virginia site

does not cover the range below 0.5 microns. Apparently the commenter is basing the statement

that the particle size distribution is bimodal on data from wet-scrubber controlled lime kilns with

3-11
(

high sodium feed rates in the pulp and paper industry. However, there are no data that

substantiate the commenter's statements for either calcimatic lime kilns, such as the kiln in

Virginia, or for rotary lime kilns not in the pulp and paper industry, which make up the bulk of

the kiln population.

Comment

Commenter IV-D-04 contends that EPA asserts incorrectly that lime plants will

choose high efficiency venturi scrubbers to replace their current wet scrubbers because

high efficiency venturi scrubbers have lower capital costs and sometimes lower annual

costs than baghouses. They further stated that, according to Docket Item No. II-F-7,

five of the six model kilns the Agency examined had much higher annualized costs for

high efficiency venturi scrubbers than for baghouses. This commenter submitted a

manufacturer's cost proposal that shows a scrubber with a 35-inch w.g. pressure drop

costs substantially more than EPA estimates. They conclude from this that lime kilns

will be forced to use baghouses, with attendant increases in HCI and 802 emissions.

Another commenter (IV-D-22) stated that the cost for the installation of a baghouse will

be greater than EPA estimated due to the location of existing equipment in the area

where the collector should be located, construction of the duct collector in a congested

area with plant operations, and accessibility to existing lime kiln dust handling systems.

Commenter IV-D-22 commented that the cost for the installation of a baghouse

will be more costly than EPA estimated due to the location of existing equipment in the

area where the collector should be located, construction of the duct collector in a

congested area with plant operations, and accessibility to existing lime kiln dust

handling systems.

Response

Regarding modeled high costs for scrubbers compared to baghouses, individual

models may show this characteristic. However, the distribution of kiln sizes in the lime

industry and the allocation of model plants to those kilns show that estimated

nationwide costs for installing venturi scrubbers is about the same as for installing

baghouses. Tables 1 and 2 illustrate this condition.

In all cases, the estimated capital cost for each model scrubber is less than its

corresponding model baghouse. Five ofthe nine models have estimated annual scrubber costs

that exceed the annual baghouse costs by amounts ranging from 4 percent to 75 percent.

However, when model costs are converted to national costs based on kiln type and size, the

tables show a lower estimated total annual cost for upgrades with venturi scrubbers than for

upgrades with baghouses. For both types of control system, costs for any specific plant may be

more or less than the value shown by the model used to estimate nationwide cost. The plant is

expected to buy whatever system its management believes is in the best business interests ofthe

( owners, but in the aggregate, the tables indicate that estimated annual cost for control systems is

lower if all plants replace existing equipment with venturi scrubbers rather than baghouses.

However, based on the specific model kiln costs, we still find that at least some kilns would

replace wet systems with dry ifrequired to meet a uniform PM emissions limit ofO.12Ib/tsf.

3-12
(

(

(

We developed these model plants based on actual facility data from the industry

responses to questionnaires. Our model plants cover the various types ofkilns currently in

service, and a range ofsizes offacilities. Other than the comment on gas flow rates previously

addressed, we received no comments that the model kilns are not representative ofthe industry.

The model plant parameters are generally based on the mid-range ofthe characteristics ofthe

segment ofthe existing kiln population that they are designed to represent. Because they are

based on mid-range values, comparing them to actual costs at anyone specific kilns may result in

a higher or lower cost estimate. However, there is no reasonable way to model every individual

kiln or account for every site-specific factor. Using model kilns based on mid-range values

provides an accurate estimate ofthe nationwide costs, even if costs for some sites may deviate

from the modeled estimates.

Regarding a cost proposal substantially higher than EPA's estimate for a scrubber with

35-inch w.g. pressure drop, it is expected that some proposals will have higher costs, and some

lower, than costs estimated by EPA's methodology. The methodology is based on estimates of

basic equipment costs, and factors to calculate direct and indirect capital costs that constitute

total capital investment. Unit costs are applied to labor, utilities, waste disposal, and other

operating and maintenance costs to obtain direct annual costs. Indirect annualized costs based on

capital recovery and other service charges are also estimated and added to direct annual costs to

obtain total annual cost. The methodology is explained in the EPA Air Pollution Control Cost

Manual. For establishing projected control costs in the lime industry, the methodology was

applied to model plants having characteristics based on industry responses to questionnaires.

These model estimates account for all ofthe components needed to build and operate a wet

scrubber. However, the specific cost of anyone component in our models, which are based on

industry averages, may be different from those for a specific plant. Overall, our model plant

approach still provides a reasonable estimate on which to base regulatory decisions.

The previous response also applies to the comment regarding installation of a fabric filter

that is projected to cost more than the model cost obtained by EPA. The cost estimation

methodology for lime plants contains factors that account for demolition and salvage of existing

equipment that will have to be replaced by the new control system. A retrofit factor is also

included to account for difficulties in replacing existing equipment with new equipment in an

existing plant. As stated in the previous paragraph, estimates made with model plants will not

address each specific case found in industry. However, nationwide costs are reasonably

estimated, and small business concerns, where they may appear, are addressed within the

regulation.

3-13
,,""'-'" ,~, ~,

Table 1. Cost to Upgrade Existing Kilns Equipped with Wet Scrubbers to Venturi Scrubbers

Model No. of kilns wI ws* Model Kiln Capital Cost Model Kiln Annual Cost

kiln ($1000/kiln)* ($1000/kiln)*

A 4 252 113

8 5 288 131

C 14 520 293

o 11 663 403

G 1 301 146

H 1 499 278

I 0 682 420

L 1 351 180

M 4 177 64

Preliminary 41

Total

TOTAL (assuming 70% are major sources and 90% of scrubbers will upgrade)

*Source: Economic Impact Analysis for the Lime Manufacturing MACT Standard, II-A-44.

Total Capital Cost

($1000)

1,008

1,440

7,280

7,293

301

499

o

351

708

18,880

11,894

Total Annual Cost ($1000)

452

655

4,102

4,433

146

278

o

180

256

10,502

6,616

Table 2. Cost to Upgrade Existing Kilns E~ped-"vithWetScrubbers to Baghouses (wI water sprays)

Model No. of kilns wI ws* Model Kiln Capital Cost Model Kiln Annual Cost Total Capital Cost

kiln ($1000/kiln)* ($1000/kiln)* ($1000)

A* 4 790 204 3,160

8 5 859 225 4,295

C 14 1488 274 20,832

o 11 2824 386 31,064

G 1 558 90 558

H 1 984 . 71 984

I 0 2395 131 0

L* 1 665 237 665

M* 4 569 197 2,276

Preliminary 41 63,834

Total

TOTAL (assuming 70% are major sources and 90% of scrubbers will upgrade) 40,215

* Model plant costs for models A, L, and M are the cost of baghouses plus cost of water injection (see 11-8-111).

3-14

Total Annual Cost ($1000)

816

1,125

3,836

4,246

90

71

o

210

788

11,182

7,045
( Comment

Several commenters (IV-D-04, IV-D-06, and IV-D-12) stated that not establishing a

subcategory for scrubber-equipped kilns will adversely affect small businesses. Commenter IVD-04 states the annualized cost of upgrading all scrubbers is $9.45 million, based on the

distribution ofkilns and EPA's estimate oftotal annualized costs in Docket Item No. I1-B-127.

According to the commenter, EPA predicts that upgrading these kilns will reduce HAP metals by

3.1 tpy, resulting in a cost effectiveness of$3.0 million/ton ofmetal HAP. The commenter stated

that EPA's assumption that 30 percent oflime plants are area sources and won't be affected by

the rule reduces the removal ofmetal HAP's attributed to upgrading scrubber-equipped kilns to

2.2 tpy (although the commenter stated that EPA has provided no support for the assumption that

30 percent oflime plants are area sources).

Commenter IV-D-12 notes that EPA's estimated annualized cost for the commenter to

install baghouses is $2,236,000, which equates to $9.3 million per ton ofparticulate HAP

control.

Response

(

The comments state that requiring kilns currently controlled by wet scrubbers to meet the

proposed 0.12 lb. tsfPM emission limit is too costly considering the environmental benefits.

However, section 112 ofthe Clean Air Act precludes us from considering cost when calculating

MACT floors. Therefore, none ofthe cost issues discussed above are sufficient to support a

separate subcategory for existing kilns with wet scrubbers. The commenters point to no process

or other difference which would prevent them from achieving the level ofperformance attainable

by the average ofthe best performing existing sources, nor suggest that those best performing

sources are unrepresentative of other kilns in terms of process, baseline emissions, or other

factors which traditionally would justify a separate subcategory.

Though costs cannot not be a consideration here, our estimate shows a cost of$7.15

million to upgrade all scrubbers, versus the $9.45 million figure provided by the commenter.

Our estimate assumes 70 percent of kilns are located at major sources and 90 percent of

scrubbers will require an upgrade.

We also note that, in addition to decreasing the emissions ofHAP metals, significant PM

emission reductions will result from upgrading existing scrubbers. Upgrading the existing

scrubber equipped kilns will reduce PM emissions by approximately 1,300 tons/year for an

approximate cost effectiveness of $5,500/ton ofPM. The cost per ton ofreduction is reasonable

compared to other PM control regulations recently promulgated or proposed (such as the nonroad diesel engine rule). We acknowledge that, in individual cases, costs and cost effectiveness

will vary and in some cases be higher or lower depending on individual circumstances.

In addition, in our cost analysis, we assumed that 90 percent of existing scrubbers would

( be replaced, and included all the capital cost ofreplacement in the cost ofthe final rule. This is

probably an overly conservative way of estimating costs. In reality, it is reasonable to assume

3-15
(

that, on average, the existing scrubbers have only 50 percent oftheir useful life remaining.

Because we allocated all ofthe capital cost of a new scrubber to the cost ofthe rule, our costs are

conservative.

Comment

One commenter (IV-D-21) objects to EPA's rationale of using PM as a surrogate for

controlling toxic emissions. The commenter states that ifEPA has sufficient data to indicate that

toxic emissions from lime kilns are an ambient air problem, then the regulation should focus on

reducing gaseous emissions such as HCI.

Response

By limiting emissions of PM, the rule will reduce emissions of non-volatile and semivolatile metal HAP, which are a subset ofPM. As stated in the preamble to the proposed rule, air

pollution controls for HAP metals are the same as the PM controls used by the lime

manufacturing industry, i.e., FF, ESP, and wet scrubbers. These controls capture non-volatile

and semi-volatile metal HAP non-preferentially along with other PM, thus making PM an

acceptable indicator ofthese HAP metals. Quite simply, "PM control technology

indiscriminately captures HAP metals along with other particulates....". National Lime Ass'n v.

EPA, 233 F. 3d at 639. Consequently, it is an appropriate indicator when the technical basis of

the standard is performance of back-end particulate control technology. Id. Another reason for

using a surrogate is the lower cost of emissions testing and monitoring for PM as compared to

the cost of emissions testing and monitoring for multiple metal HAP that would be required to

demonstrate compliance. Because PM control devices control metal HAP to roughly the same

efficiency, and because ofthe associated cost savings associated with emissions testing and

monitoring, the Agency has promulgated several other NESHAP where PM is a surrogate for

non-volatile and semi-volatile metal HAP.

Regarding the commenter's second point concerning regulating emissions ofHCI, the

preamble to the proposed rule explained in detail the Agency's decision not to regulate HCI

emissions from lime kilns. To summarize that discussion, the EPA determined that, under the

authority ofsection 112(d)(4) ofthe CAA, no further control was necessary because HCI is a

threshold pollutant and HCllevels emitted from lime kilns are below the threshold value with an

ample margin ofsafety, after considering potential threats to both humans and the environment.

3-16
( Comment

One commenter (IV-D-12) requests a subcategory for their unique mine chamber exhaust control.

Exhaust gas from the kilns is vented to an underground mine chamber which is unlike a

baghouse or conventional scrubber, but functions like a scrubber due to moisture in the mine.

The typical exhaust temperatures at the exhaust stack range from 107 to 112 degrees F - well

below 400 degrees F (a work practice temperature standard that had been considered by EPA for

HCI control, but was rejected). In addition, the condensation moisture assures saturation ofthe

exhaust stream and the contact time exceeds those possible under any conventional pollution

control device. The commenter also points out that the mine is not subject to mechanical failures

or operator induced malfunctions as are conventional control devices. According to the

commenter, stack testing done in 1995 demonstrated removal efficiencies of 98.9 percent for

PM, 99.1 percent for S02, 52.3 percent for NOx, and 71.9 percent for CO.

According to the commenter, the cooling of exhaust gases and subsequent condensation

ofwater and the presence of entrained water droplets makes continuous opacity monitoring

infeasible, which is why visible emission readings are currently performed. The visible emission

readings taken in the last several years show little variation and no exceedances ofthe applicable

new source performance standards (NSPS) subpart HH kiln opacity standard of 15 percent.

Response

(

(

'.

The commenter is requesting that their use of a mine as a PM control device for their kiln

exhausts be placed in a subcategory for wet scrubbers. But, as discussed above in a response to a

previous comment, EPA has decided that it will not develop a separate subcategory for wet

scrubbers. Subcategorization is normally based on differences in manufacturing process,

emission characteristics, or technical feasibility and is not justified solely on the basis of a

different type of control device being used. Under this principal, the use of a mine as an

emission control device does not warrant a separate subcategory.

3.2 PM Emission Limit for Scrubber-Equipped Kilns

Comment

In response to EPA's request for comments on what the MACT floor limit should be if

there was a subcategory for scrubber-equipped kilns, three commenters (IV-D-04, IV-D-06, and

IV-D-16) state that the PM emission limit for scrubber-equipped kilns should be 0.6Ib/tsf. This

is based on actual operational data and permit limits for the top 12 percent ofthe existing kilns

that use wet scrubbers for PM emissions control. These data were compiled by the National

Lime Association (NLA) and provided to EPA.

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Response

As discussed above, EPA has determined that subcategorizing by existing controls is not

appropriate. However, we have also determined that from an overall environmental standpoint, a

wet scrubber meeting an emission limit of 0.60 lb/tsf could be considered best control ifthe

environmental disbenefits ofswitching to a dry control are considered. Therefore, we have set an

emission limit of 0.60 lb/tsffor kilns that currently have wet scrubbers for PM control.

3.3 PM Emission Limit for New Kilns

Comment

One commenter (IV-D-04) states that the PM emission limit for new lime kilns should be

0.12Ib/tsf, the same as the emission limit for existing kilns. The commenter notes that the

proposed limit is based on two three-hour test runs at one plant. According to the commenter,

EPA recognized in the proposal preamble that 3-hour test results are just a snapshot in time, and

should not be used as the basis for establishing an enforceable standard, and that EPA expressly

rejected such an approach when establishing the MACT floor for existing kilns.

The commenter believes that data in the docket shows that 0.10 lb/tsf is not continuously

achievable by lime kilns, and EPA should not establish a separate PM limit for new lime kilns.

Another commenter (IV-D-16) believes 0.10 lbs PM/tsffor a new kiln is too restrictive,

and EPA does not have adequate data to determine that a baghouse or scrubber equipped kiln

could achieve this low level of emissions on a sustained basis.

Response

The approach to which the commenter refers whereby EPA rejected the use ofthe

"average or mean" in establishing the MACT floor for existing sources, did not refer to the

average ofindividual test runs as implied by the comment. Rather, it refers to EPA's decision to

use the median (instead of a simple mean) ofthe top performing 12 percent to set the MACT

floor. Furthermore, as an indication ofthe achievability ofthe technology over the long-term,

EPA chose to rely on State-imposed permit limits (in conjunction with emissions test data

showing that those permit limits are representative of actual performance) in arriving at the

MACT floor emission limit.

In test data cited by the commenter, the three-run averages for two sets of emissions tests

for the kiln used to set the new source MACT PM limit, are below (0.079 and 0.091Ib/tsf) the

proposed PM limit ofO.1lb/tsffor new lime kilns. The commenter noted that one ofthe test

runs was at the proposed O.llb/tsfPM limit and that the proposed O.llb/tsflimit was, therefore,

inappropriate. (It is, of course, reasonable for EPA to establish a standard based on the same

methodology that will be used for complying with that standard. Cf. Chemical Waste

Management v. EPA, 976 F. 2d 2, 34 (D.C. Cir. 1992) (facially reasonable to require compliance

based on methodology used to establish the standard). EPA notes that compliance with emission

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limits is normally based on a three-run average which can accommodate occasional elevated

results as long as the average is at or below the established limit. Furthermore, the emission test

results for five ofthe six top performing kilns were 0.0091,0.013,0.026,0.027, and 0.091Ib/tsf

and are below the 0.10 Ib/tsfPM emissions limit. These results adequately account for operating

variability and indicate that any new kiln using well designed and operated control devices can

meet the O.1lb/tsflimit. Based on this, we see no basis to conclude that a 0.10 Ib/tsfPM

emission limit is not achievable or appropriate.

Comment

One commenter (IV-D-06) claimed that the proposed NESHAP will require the

replacement of their two wet scrubbers with baghouses. They claim there is no space

for FF retrofit, and that converting to baghouses will trigger prevention of significant

deterioration (PSD) non-attainment review due to increasedS02 emissions.

Response

While we recognize that a facility may (or may not) have site-specific space

restrictions, we have, on average, adequately accounted for these factors by

incorporating cost analysis factors to account for retrofit and equipment demolition. We

have also allowed existing facilities 3 years to comply with the final NESHAP. This will

provide sufficient time for facilities to replace or upgrade existing equipment during

scheduled outages. The averaging provisions in the final NESHAP also provide

facilities with additional flexibility concerning replacement or upgrade of existing

equipment.

Requiring an existing kiln equipped with a wet scrubber to upgrade their PM

controls will not necessarily trigger new source review (NSR). First, we have written the

final rule to allow existing kilns equipped with wet scrubbers to meet a 0.60 Ib/tsf

emission limit, rather then the 0.12 Ib/tsf PM emission limit. No commenters have

raised any cost or technical issues to indicate that a PM emission limit of 0.60 Ib/tsf will

force any facilities to choose to convert existing kilns from wet scrubbers to dry controls.

Therefore, the facility can choose to replace or upgrade their existing scrubbers, which

means there will be no S02 (or other collateral pollutant) emissions increase to trigger

NSR requirements. Second, if they choose to use a baghouse, they may be able to

avoid NSR by qualifying for a pollution control project exclusion (67 FR 80186).

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3.4 PM Emission Limit - General

Comment

One commenter (IV-D-14) believes the particulate matter emission limits proposed for

lime manufacturing kilns and coolers do not represent the maximum achievable control

technology and are much less stringent than the limits actually required by the Clean Air Act.

The commenter notes that the proposed rule discredits performance test data which demonstrate

that particulate emissions ofless than halfthe proposed standard for existing plants are routinely

achieved by claiming they may not be consistently achievable, but EPA has provided no

statistics. The commenter claims that EPA has chosen instead to base the standards on permit

limits, but has selectively eliminated from consideration those permits calling for stringent

controls which are currently in place. The commenter gives the examples ofContinental Lime

which is in compliance with a BACT limit for PM emissions of 0.05 Ib/ton limestone, and

Western Lime which is in compliance with a permit limit for PM emissions ofO.06Ib/ton

limestone. The commenter states, "Considering just these plants, a recalculation ofthe existing

plant limit leads to a standard of0.09 to O.llib/ton. The new source MACT floor should be no

less stringent than 0.05 lb/ton. However, ifEPA chooses to establish a MACT floor on the basis

ofpermit limits, it should consider all ofthe permit data in its possession (and available to it

through delegated State agencies). It is likely that a lower emission limit would represent the

MACT floor and that still lower beyond-the floor alternatives would result."

The commenter notes that ifperformance data do not represent achievable emission

limits, EPA should consider design standards based on air-to-cloth ratios. The commenter also

believes the proposed particulate emission limits for grinders, conveyors, and bins are also based

on data which overstate emissions (in nearly all cases) and do not represent MACT. The

commenter believes EPA should examine actual performance test data test or actual permit

limitations.

Response

The kilns to which the commenter refers are Graymont Western Lime (formerly

Continental Lime in Broadwater County, Montana and Western Lime in Green Bay, Wisconsin.

The permit limits cited by the commenter were apparently reported on EPA Technology Transfer

Network (TTN) website. We contacted the Montana Department ofEnvironment and found that

the limit for the kiln in question is actually 0.5 lb/tsf and not 0.05 lb/tsf as reported on the TTN

website. Also, the complete permit for Western Lime was located on the Wisconsin Department

ofNatural Resources website, which showed the permit limit for the kiln in question as being

0.12Ib/tsfrather than the 0.058 lb/tsf as reported on the TTN website. Based on the correct PM

permit limits for these two lime sources, our conclusions regarding MACT PM limits for

existing and new sources are still appropriate. (As the response to a previous comment shows,

these permit limits are also representative of actual performance.)

The floor for grinders, conveyors, and bins are based on the existing new source

performance standards. We have no data to support a different floor.

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Comment

Several commenters (IV-D-04, IV-D-06, and IV-D-22) comment that the rule should

allow the use ofscrubber pump amperage and other indirect measures ofliquid flow rate.

Commenter IV-D-04 takes issue with EPA's claim that pressure drop and liquid flow rate are

most often monitored scrubber parameters. The cornmenter states that liquid flow rate is not the

most cornmon scrubber parameter measured; in part, because the NSPS for lime manufacturing

requires the measurement ofthe liquid supply pressure to the control device. The commenter

also states that most permits for lime plants do not require that flow rate be measured directly,

and provided permit requirements at existing plants to demonstrate this. They note that ofthe 8

lime plants that do have flow-related permit limits, 5 ofthem are provided the option of

monitoring scrubber pump amperage instead offlow rate. The cornmenter also notes that ofthe

four example CAM plans for scrubber-equipped kilns in EPA's CAM guidance, none includes

liquid flow rate among the parameters to be monitored. The cornmenter recommends that the

rule allow liquid flow rate to be measured directly (e.g., with a flow meter) or indirectly (e.g., by

monitoring scrubber exhaust temperature).

(

One cornmenter (IV-D-04) believes the rule should allow the use of parameters other than

gas pressure drop ifpre-approval from the permitting authority is obtained. The commenter

states that monitoring gas stream pressure drop is not appropriate for all kiln types. They use the

example of double shaft kilns, for which scrubber pressure drop is measurable only during the

fuel firing cycle, returning to zero during the reversing cycle. In addition, the cornmenter notes

that, "like the MACT standard for lime kilns at pulp and paper mills, the lime MACT should be

revised to allow the use ofparameters other than gas pressure drop ifpre-approval from the state

permitting agency is obtained."

Response

The first commenter is correct in stating that the NSPS requires that the liquid

supply pressure to the control device be monitored and not liquid flow rate. However,

we note that scrubber-equipped lime kilns in other industries have requirements to

monitor liquid flow rates to the scrubber. For example, the NESHAP for chemical

recovery combustion sources at kraft, soda, sulfite, and stand-alone semi-chemical pulp

mills requires that lime kilns (used in reprocessing black liquor at pulp and paper

facilities) which are equipped with a wet scrubber must continuously monitor the

pressure drop as well as the scrubbing liquid flow rate. (See 66 FR 3196)

The rule as proposed does allow the owner or operator to monitor alternative

control device operating parameters subject to approval by the Administrator. Under

the proposed rule, if you wish to request the use of an alternative monitoring method,

you must submit a request following the procedures in General Provisions section

63.8(f). In order to make this more obvious, we explicitly cross-reference this provision

( in the monitoring requirements of the rule. However, major modifications to monitoring

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case-by-case basis by the Administrator as set out in 63.8(f).

3.6 Monitoring Requirements for Kilns With Dry Air Pollution Control Devices

Comment

Several commenters (IV-D-04, IV-D-17, and IV-D-16) request that the proposed

requirements in § 63.7113(d)(1) and (e)(1) that BLD and particulate monitoring devices

(PMDl be certified by the manufacturer to be capable of detecting PM at or below 10

mg/m should be deleted because no specifications exist on which to base the

certification. Commenter IV-D-04 notes that unlike COMS, there are no technical

specifications, regulations, or checks and balances to verify claims made by the BLD or

PMD vendor or manufacturer.

Response

We disagree. The EPA is currently aware of instruments certified to meet levels

of 0.2 mg/m3

. Specifications on which to base certifications are available in EPA

guidance documents.

( Comment "

One commenter (IV-D-04) states that the requirements in §63.7113(d)(6) and

(e)(6) that BLD and PMD be "installed, operated, adjusted, and maintained so that they

follow the manufacturer's written specifications and recommendations" should be

revised to require adherence to the manufacturer's written specifications and operating

procedures (rather than "recommendations") except where other procedures are

determined to be more appropriate and are described and justified in the plant's

operations, maintenance and monitoring (OM&M) plan. The commenter noted that

there is no industry-based consensus or EPA specifications, and "there certainly will be

applications where the manufacturer's procedures or recommendations may not be

appropriate or where a better approach can be used."

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Response

We agree that there may be cases where other procedures are more appropriate

then the manufacturers recommendations. For this reason, we allow alternative

monitoring under the procedures in 63.8 (t). However, in general, we believe

adherence to written specifications and recommendations is more appropriate.

Therefore we have retained the requirements in §63.7113(d)(6) and (e)(6) in the final

rule.

Comment

Several commenters (IV-D-04, IV-D-18, IV-D-17, IV-D-05, IV-D-16, IV-D-13, and

IV-D-20) believe COMS should be retained as a monitoring option. Commenters IV-D04, IV-D-17, and IV-D-16 state that COMS are sensitive enough to detect changes in

fabric filter performance at concentrations corresponding to the proposed PM limit and,

unlike BLD, are subject to specifications that enable third party evaluation of their

performance. Commenter IV-D-04 notes that COMS have been used to detect relative

changes in particle mass loading for many years at lime plants. This commenter also

states that, "actual COM data acquired at lime kilns with high efficiency filters

demonstrate that COM data are appropriate and effective for detecting gradual changes

in fabric filter performance over time." According to this commenter, EPA has

suggested that BLD are preferable to COMS because they are more sensitive, but that

all lime kilns currently equipped with CaMS are capable of meeting the sensitivity

requirement proposed for BLD.

Commenter IV-D-04 also noted that although the presence of bias makes any

determination of absolute opacity below 10 percent inaccurate, "it has no affect on the

ability of a COMS to detect changes in opacity at a particular facility -- and hence

changes in control equipment performance over time. Detecting relative changes in

mass loading is all that BLD are capable of doing (preamble at 78062). COMS are

more than adequate to detect changes in the opacity level necessary to detect minor

variations in fabric filter or ESP performance well before catastrophic failures occur."

In addition, several commenters (IV-D-04, IV-D-18, IV-D-17, IV-D-05, and IV-D16) state that requiring only BLD would create unnecessary and duplicative monitoring

since other CAA rules and permits require CaMS. Since the CAM rule requires that if a

COM is required under the CAA or state or local law, it must be used to satisfy the

requirements of the CAM rule, requiring BLD or PMD would result in duplicative

monitoring.

Response

EPA proposed that COMS be allowed as an alternative to BLD, PM detectors,

and electrical current and voltage readings for ESP for monitoring continuous

( compliance with the proposed PM emission limits for lime kilns and coolers. EPA also \

solicited comments on requiring the use of PM detectors and BLD in lieu of COMS. In

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response, several commenters stated their support for retaining COMS as a monitoring

option. The commenters argued that COMS have a long history of use by the lime

manufacturing industry and that they are effective for detecting changes in control

device performance over time. As a result, EPA sees no reason to not allow the use of

COMS.

The commenters also claimed that requiring BLD or PM CEM would be

redundant because the CAM rule requires COMS. The CAM rule only applies where a

control device is used to comply with an emission limit proposed prior to November 15,

1990. Therefore, the CAM rule will not apply to monitoring requirements related to

compliance with the Lime Manufacturing NESHAP.

Comment

One commenter (IV-D-04) commented that EPA should clarify that only COMS

installed, relocated, or substantially refurbished after February 6, 2001 must comply

with the version of PS-1 revised on August 10,2000. Because many COMS at lime

plants were certified to meet the PS-1 requirements in effect at the time of installation,

the commenter states that it is "impractical and cost prohibitive to remove these units

from service for several months and return them for testing to the COM manufacturer.

The cost to re-certify a single monitor would exceed the cost of a new monitor due to

the test regime specified in the ASTM standard."

Response

The proposed rule states that you must install, operate, and maintain COMS as

required by 40 CFR part 63, subpart A, General Provisions and according to PS-1 of

Appendix B to part 60. The current version of PS-1 itself specifies that it only applies to

COMS installed, relocated, or substantially refurbished after February 6,2001.

However, this could result in the rule being unclear on the requirements for COMS

installed on or before February 6, 2001. Therefore, we have clarified the rule to state

that COMS installed, relocated, or substantially refurbished after February 6, 2001,

must meet the requirements of PS-1 as revised on August 10, 2000. Any COMS

installed on or before February 6, 2001, should continue to meet the requirements in

effect at the time of installation unless the local regulatory agency specifically required

recertification of the COMS in question.

Comment

One commenter (IV-D-19) states that opacity does not correlate to PM mass

emissions. The commenter notes the EPA has stated on several occasions that STET

systems (COMS) can determine opacity, but COMS cannot determine PM emissions.

And if particle density changes but the particle size remains the same, opacity will not

change while the mass emission rate will change in proportion to the density change.

The commenter agrees that PM is a technically sound surrogate for HAP metals, but

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preamble.

The commenter does not believe that a COMS can be used to evaluate the

continuous compliance status of kilns, coolers, or materials processing operations

(MPO) that have a mass emission limit. The commenter is not aware of any data that

shows a definitive link between opacity and mass emissions except in very limited and

controlled situations. In addition, the commenter does not understand how a 15

percent 6-minute average opacity limit can be correlated to a 3-hour rolling average PM

emission limit of Ib/ton of stone feed.

The commenter states, "the error in using a COMS to determine compliance with

the PM mass emission limit can be demonstrated from the data presented to you by the

National Lime Association. If one of the top performing lime kilns has a measured

emission rate well below the 0.12 Ib/ton of feed emission limit, but has a reportable

opacity between 10 and 15 percent, there can be no correlation."

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The commenter believed a better alternative is to use a monitor that measures

PM mass emissions in units that are directly related to the mass emission limit. The

EPA should consider using a PM continuous emissions monitor (CEM) for continuous

compliance determination of kiln, cooler, and MPO emissions with or without a PM CEM

performance specification. The commenter notes that EPA's stated reluctance to use a

PM CEM in the absence of performance specifications is inconsistent with the

remainder of the standard, since the use of bag leak detector systems (BLDS) and a

PM detector are proposed without performance specifications. The commenter also

notes that an extractive type PM CEM designed to operate in wet exhaust streams

would provide a direct indication of compliance for wet scrubbers.

Response

We agree that a COMS cannot directly measure PM emissions. However, we believe that

a properly calibrated and maintained COMS is sufficient to demonstrate long term PM control

device performance. The purpose ofthe monitor is to demonstrate, with reasonable certainty,

that the PM control device is operating as well as it did during the PM emission test used to

demonstrate compliance. Though we agree that a continuous monitor that directly measures PM

emissions would provide direct evidence ifthe PM emission limit is exceeded, we have no data

to demonstrate that this would result in additional PM emissions reductions compared to

monitoring the control device with a COMS. Therefore, requiring facilities to remove their

currently installed COMS and replace them with a PM CEM only adds additional costs with no

quantitative environmental benefit. We also note that we know ofno lime kiln that currently has

an operating PM CEM.

Comment

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One commenter (IV-D-19) provided comments on the cost ofPM CEM. The commenter

provides cost data for several monitor technologies, and notes that the list price is only part ofthe

cost ofinstalling and using a PM CEM.

Response

We thank the commenter for this additional data. However, because we are not

requiring PM CEM as a monitoring option, we are assuming that facilities will opt to use

a CaMS due to the lower costs. Because most existing facilities already have a CaMS

installed, we have not revised our rule costs to incorporate this data.

Comment

On commenter (IV-D-19) provided comments on the relation of a PM CEM requirement

to the proposed PM emission limits. The commenter sees no reason to change the proposed level

or averaging time ofthe PM emission limit if a CEM is used. The commenter suggests having a

lime manufacturing plant purchase, install, and operate a PM CEM to monitor emissions over a

period oftime (e.g., 6 months) to confrrm the proposed limit and averaging intervaL

Response

( Since we believe that the monitoring options of the proposed rule are adequate

to show good operation of emissions control devices, it is not necessary to perform

testing using a PM GEM.

Comment

One commenter (IV-D-04) states that PM GEM should not be required in the lime

MACT because EPA has no data on which to establish an achievable CEM-based PM

limit.

Response

We disagree. Because PM CEM directly measure the PM emission rate, the

appropriate limit would be 0.12lb/tsf (existing sources) or 0.10 Ib/tsf (new sources).

However, we are not requiring PM CEM, they are an option.

Comment

Gommenter IV-D-19 believes that EPA needs to include beta gauge and optical

scintillation along with light scattering technology for the PM detector.

( Response

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meet appropriate performance specifications. Any type ofPM CEM, including those that rely on

beta gauges or optical scintillation, that meets the performance specifications may be used.

Comment

Several commenters (IV-D-04, IV-D-18, IV-D-06, IV-D-11, and IV-D-09) believe

EPA Method 9 should be allowed for positive pressure baghouses. According to

commenter IV-D-04, the BLD Guidance Document recognizes that requiring BLD would

be very costly, and states that the document does not apply to this type of baghouse

(BLD Guidance Document, pg 2). This commenter gives the example of a small

business (Austin White Lime) that would be required to have a BLD for each of the 8

compartments in its baghouse under the proposed rule, and whose Title V permit

allows Method 9 monitoring for the baghouse. According to commenter IV-D-09, the

associated costs of installing a separate BLD or PM CEM sensor on each discharge or

new common stack could easily exceed $1,000,000. The commenter notes that,

"baghouse pressure differential readings, together with fan amperage and daily visible

emission notations (Method 22) will provide the necessary performance assurance with

ample and timely indication of baghouse failures or malfunctions."

Response

( We acknowledge that there are precedents for the use of alternatives to COMS,

BLD, and PM CEM on positive pressure baghouses that have multiple stacks. The

NESHAP for portland cement, an industry that has similarities to the lime manufacturing

industry, allows the use of method 9 opacity monitoring for kilns having control devices

with multiple stacks. For existing lime kilns controlled by positive pressure control

devices having multiple stacks, the final rule provides the option of using method 9 for

daily opacity monitoring. We are also revising the rule to allow Method 9 monitoring if

the control device vents through a monovent, or if installation of a COM in accordance

with PS-1 is infeasible.

Comment

One commenter (IV-D-04) believes that COMS should be used as the monitoring

option for ESP. The commenter claims that using PM detectors on ESP is problematic,

as is parametric monitoring if the ESP is over-designed such that operating at or above

the voltage levels measured during the performance test is not needed to maintain

compliance with the PM limit.

One commenter (IV-D-19) comments that there are no data to support the use of

ESP operating parameters to determining compliance. The commenter notes that until

the lime industry collects this data in three-hour rolling averages for extended periods of

time in a reportable format that can be analyzed by others, no conclusions can be made

( regarding the usefulness of ESP operating parameters in determining compliance or

mass emissions.

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Response

We agree with the commenters that COMS and PM CEM should be sued to

monitor the performance of an ESP. Therefore we have modified the final rule ro

require a COMS or PM CEM to be used to demonstrate continuous compliance.

Because we are now requiring COMS or PM CEM, monitoring ESP voltage and current

is not be required.

Comment

One commenter (IV-0-09) believes that stack testing on positive pressure

baghouses should not be required. The commenter notes that the eight stacks at each

of its positive pressure baghouses are nearly inaccessible and too short to be properly

tested, and "attempting a performance test ...would be dangerous without significant

additional improvements..., "and, "the cost of all of these improvements could exceed

$1,000,000." The commenter believes positive pressure baghouses with multiple

inaccessible stacks should be given the option to perform a 3-hour Method 9

performance test when operated in conjunction with performance monitoring.

Response

EPA regulations generally require, at a minimum, initial performance testing to

demonstrate compliance with emission limits for affected sources. Further, the General

Provisions section 63.7(d) require sources to provide adequate testing. Positive

pressure baghouses are used in many of the industries that are subject to EPA

regulations and are required to conduct performance testing in order to demonstrate

compliance. EPA has developed procedures for testing PM emissions from various

configurations of positive pressure baghouses, which are contained in Method 50 of 40

CFR part 60, appendix A. Therefore, we have decided not to alter the compliance

requirements for sources using positive pressure bagh6uses.

Comment

One commenter (IV-0-19) does not understand how an alarm level will be set for

a PM detector or a BLO system that will have any correlation to a PM emission limit in

units of Ib/ton of stone feed. The commenter states that an extensive amount of

testing over varying conditions at or near the limit would be needed to establish the

response of BLO or PM detectors as a function of actual PM emissions. The

commenter also notes that EPA's bag leak detector guidance does not provide such

procedures.

Response

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We have not stated that BLD limits and PM limits correlate. BLD are calibrated

at the time the PM emission test is run. The BLD then detects changes in performance

verses performance during the PM emission test.

3.7 Operating Parameters

Comment

One commenter (IV-D-04) states that a single excursion from operating parameters

recorded during a 3-hour compliance test should not constitute a violation. The commenter

believes that, "the NSPS kilns are the lime industry's top performers, and their monitoring

regime should be the benchmark against which monitoring under the MACT rule is prescribed."

Since a violation under the NSPS does not occur unless the parameter is greater than 30 percent

below the rates established during the performance test, the commenter recommends a 30 percent

"buffer" between the permit limit and the 3-hour average recorded during the compliance test.

Or, "alternatively, like the Pulp and Paper MACT, the rule should specify that a violation ofthe

standard does not occur unless 6 or more 3-hour average parameter values are recorded outside

the established range within the 6 month reporting period."

The commenter notes that EPA's CAM guidance document states, "Use of only

3 hours of parameter data may not be sufficient to fully characterize parameter values

during normal operation." The commenter also noted that language in the proposal

preamble cautions against developing enforceable emission standards based on 3-hour

compliance tests. The commenter also notes that none of the CAM plans for scrubbers

base a permit limit on the 3-hour average reading that occurred during a compliance

test, and two of the plans allow a 15 percent buffer to account for variability.

The commenter provided gas pressure drop readings and concurrent PM test

data for three kilns, and noted that for each of them, gas pressure drop during one or

more 1-hour runs was below the proposed 3-hour average. The commenter stated that

under the proposed rules, these readings below the 3-hour average would constitute a

violation.

The commenter also believes the rule should provide an exemption from the PM

emission limit during performance testing. The commenter stated, "plant operators may

need to conduct a series of performance tests to determine the minimum pressure drop

and liquid flow rate levels that will assure compliance for each set of operating

conditions used for a particular kiln. Results for these tests are not available until posttest laboratory analyses are completed."

Response

Each owner/operator is required to define the compliance parameters to be

monitored in their OM&M plan. Then, during the initial performance tests they are

required to monitor and establish the value or range of the parameters. EPA believes

that the initial performance tests will be designed to give the owner or operator flexibility

in adhering to the established range for monitored parameters. These values must be

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reported in the results of the test and in the notification of compliance status to the

permitting authority and must be approved by the permitting authority. During

subsequent operations, if the monitored parameters exceed the values or fall outside

the range determined during the initial performance test, it is a violation of the operating

requirements of the standard (unless it is the result of a malfunction to which the facility

responds to in accordance with the startup, shut down, and malfunction [SSM] plan).

We have has no basis for allowing deviations before considering the facility to be in

violation. The owner/operator has ample opportunity to establish a range for the

operating parameters and must thereafter operate within that range.

Most operating parameters are calculated as 3-hour averages. This is generally

consistent with performance test times. Thus, a one-hour period of insufficient gas

pressure drop would not, by itself, be considered a deviation.

Comment

One cornmenter (IV-D-04) stated that the accuracy criteria in Table 4 (items 8, 9,

13, and 14) for devices used to measure operating parameters should be deleted. The

commenter notes that the lime MACT is unique because it includes both accuracy and

minimum tolerance criteria for measurement devices; other recent MACT rules contain

only tolerance criteria. In addition, the commenter states that EPA has offered no

explanation for the proposed accuracy criteria in Table 4. The commenter believes it is

the precision of a device (Le., the value of a parameter relative to what was recorded

during the performance test) that is important in the context of the lime MACT, not its

accuracy.

Response

We disagree. We commonly include accuracy criteria in MACT standards for

devices used to measure operating parameters. We continue to believe that monitoring

devices of known accuracies should be used.

3.8 Opacity Limit

Comment

In response to EPA's request for comments on the appropriate opacity limit (EPA

is considering an opacity of 10 to 15 percent), several commenters (IV-D-04, IV-D-18,

IV-D-17, and IV-D-16) agree that the opacity standard for lime kilns should be 15

percent as proposed. One commenter (IV-D-04) provided additional data in the form of

opacity data from four kilns. According to this commenter, the opacity data for selected

kilns (Docket Item No. 1-8-125) are not reliable for establishing an opacity standard

because they are from visible emission data collected for brief periods of time under

poor viewing conditions.

Response

3-30
( Based on information considered prior to proposal as well as additional

information supplied by commenters, EPA is retaining the 15 percent opacity limit for

sources controlled using FF and ESP. Information considered by EPA in proposing the

opacity limit suggested that the average opacity permit limit of the top performing lime

kilns was 15 percent. Information provided by the commenters supporting the

proposed opacity limit indicated that opacity levels may vary between 10 and 15

percent even for well operated and maintained control devices. No information

supporting a more stringent opacity limit than the one proposed was submitted by any

commenter. Therefore, EPA finds no justification for a limit more stringent than the

proposed 15 percent.

Comment

Several commenters (IV-D-04, IV-D-18, IV-D-17, IV-D-07, IV-D-05, and IV-D-13)

state that the rule should specify a time period during which opacity readings greater

than 15 percent are not considered a violation. One commenter (IV-D-04) requests at a

minimum that the rule state that opacity readings greater than 15 percent for less than 1

percent of the reporting period are not considered to be a violation.

One commenter (IV-D-07) noted that it operates two of the top six performers in

the industry, and it is impossible not to have occasional readings that would be

violations if there were no allowances for them. The commenter's State permits allow 1

( percent of operating time per quarter to exceed the opacity limit. "

Commenter IV-D-05 requests that the final rule state that a particulate matter

violation has occurred if: (1) opacity readings exceed the15 percent opacity limit for 6

percent or more of the operating time in a quarter or, (2) opacity readings exceed the 15

percent opacity limit for 20 total hours in a quarter, whichever time frame is longer.

Commenters IV-D-04 and IV-D-05 refer to the Pulp and Paper MACT as an

example of an existing rule with such an exemption.

Response

We find no justification to support allowing excursions above the 15 percent

opacity limit. We believe that well operated and maintained control devices will typically

operate at opacity levels much lower than 15 percent. Other NESHAP, including the

portland cement NESHAP, contain opacity limits from which no exceedances are

allowed.

In response to the commenters' concerns about occasional excursions above the

opacity limit, there are times when opacity levels above 15 percent are not considered

to be a violation of the rule. These include periods when a control device malfunctions,

or is in a period of startup or shutdown. If opacity levels exceed 15 percent as a result

of a control device startup, shutdown, or malfunction, it would not be considered a

violation of the opacity limit. The same is true during periods when a monitoring system

3-31
(

(

malfunctions or is being calibrated; provided the startup, shutdown, and malfunction

(SSM) plan is followed. Information supplied by one commenter showed opacity

readings for several kilns over several days. Nearly all of the readings were well below

the 15 percent limit with just a few exceptions for each kiln. The commenter that

supplied the opacity readings was asked to supply additional information regarding the

opacity excursions above 15 percent. In each instance, the high opacity reading was

explained by a startup, shutdown, or malfunction of the control device or by a

malfunctioning monitor or a monitoring system that was undergoing calibration, none of

which would be considered a violation of the opacity limit. As a result, we believe that

well operated and maintained control devices can meet the opacity limit, and that

occasional excursions above the limit due to control device or monitoring system

malfunction will not be a violation of the rule provided the SSM is followed.

3.9 Stone Handling Operations

Comment

Several commenters (IV-D-04, IV-D-17, and IV-D-11) request that the terms "raw

material processing" or "material processing operation (MPO)" be replaced with the

term "processed stone handling" since the only ingredient used to make lime is

processed limestone. Commenter IV-D-11 noted that the use of "raw material" could be

construed to include unprocessed stone and thus potentially include stone handling

operations in the quarry.

Commenter IV-D-09 notes "the exclusion of storage piles from this proposed

NESHAP is consistent with other standards such as the Portland Cement

Manufacturing MACT, Integrated Iron and Steel Manufacturing MACT and the Nonmetallic Minerals Processing Plants (Subpart 000) NSPS." The commenter believes

that storage piles prior to any processing operation are a continuation of raw material

handling and should be exempt from the MACT.

Response

Comment

Several commenters (IV-D-04, IV-D-17, IV-D-16, and IV-D-11) commented that

the definition of "storage bin" in § 63.7143 should be revised to clarify that bins are

manmade enclosures used to store processed stone feed for the kiln. Commenter IV3-32
( 0-04 noted that this is consistent with the definition in the cement MACT, and that it

clarifies that storage piles are not subject to the rule. Commenters IV-0-04 and IV-0-16

recommend the following amended definition: "A manmade enclosure for storage of

processed limestone prior to its use as lime kiln feed."

Response

The rule has been revised to darify that storage bins refer to manmade bins for

storage of processed limestone.

Comment

One commenter (IV-0-04) believes the rule should not require the use of

proposed Methods 203A, 203B, and/or 203C to measure opacity from fugitive sources.

The commenter notes that the preamble does not state why Method 9 is unsuitable,

"nor does it specify how Methods 203A,B, or C would be used and what the

corresponding opacity limit would be.

Response

(

(

,

We requested comment in the proposed rule on the use of proposed Methods

203A, 203B, and/or 203C to measure opacity from fugitive sources. We never stated

that Method 9 was unsuitable. We were concerned that because Method 9 was

developed to measure emissions from stacks, and an alternative method might be more

suitable.

We have decided not to allow the use of proposed Methods 203A, 203B, and/or

203C in the final rule. However, we have added additional language to the final rule to

explain how to use Method 9 to determine opacity from fugitive sources. This language

was taken directly from 40 CFR 60, subpart 000, Standards of Performance for

Nonmetallic Mineral Processing Plants.

Comment

Two commenters (IV-0-04 and IV-0-17) request section 63.7120(b) be revised

to clarify that periodic (not continuous) monitoring is required for stone handling units.

Response

EPA has revised the rule to clarify that stone handling operations are generally

subject to monthly visible emissions testing and not continuous monitoring.

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(

(

3.10 Test Methods

Comment

Several commenters (IV-D-04, IV-D-05, and IV-D-08) asked that EPA delete the

bias and precision criteria for HCI test results using ASTM Method. Commenter IV-D04 states, "the commercial lime industry has invested substantial resources to develop

a method to address EPA's concern that Method 26 understates HCI emissions. An

ASTM committee has concluded that Method D 6735-01 generates data that has no

statistically significant bias. It is arbitrary and unreasonable for the Agency to burden

the commercial lime industry - half of which is comprised of small businesses - with a

requirement to conduct analyte spiking to prove that HCI test results are unbiased.

Likewise, requiring paired runs to comply with a precision criteria is not warranted

because (1) EPA has never raised any concerns about the precision of impinger

generated HCI data, and (2) ASTM Committee D22 on Sampling and Testing of

Atmospheres approved the impinger-based method after evaluating the precision of the

data generated with the method. Accordingly, the bias and precision criteria for HCI test

results obtained using ASTM Method D6735-01 should be deleted from the rule."

Commenter IV-D-05 notes that these criteria are not found in the ASTM method.

Response

The ASTM validation proved that, when ASTM Method D6735-01 is conducted

properly, it is possible that data are not biased. However, because the ASTM method

lacks precision, the power of this conclusion is not very strong. The validation does not

assure that future applications of the method run by another group will also be

unbiased. Sampling for HCI in a lime plant environment is difficult. The purpose.of

analyte spiking is to assure that a representative sample is transported from the stack

through the probe and filter to the impingers regardless of who is performing the test.

Analyte spiking is an option in the ASTM procedure; because of the importance of the

decision made as result of this data, we chose to exercise that quality assurance option.

We agree with the commenters that analyte spiking is a complex procedure. However,

it is a requirement of the Method 320 instrumental FTIR method which we believe is

superior. There is no reason to allow less quality assurance for the inferior method.

However, we agree with the commenter that for the purpose of determining major/area

status, it is not necessary to reject a set of data if the apparent bias does not change

the major/area source determination.

With respect to the commenters' suggestion that the precision criterion be

deleted, EPA disagrees. It is an option in the ASTM procedure which EPA chose to

require. Reasonable agreement between paired samples is considered a strong

indication that the method is being consistently operated, recovered and analyzed.

One commenter (IV-D-04) cited section 6.3.1.2 (of EPA Method 301) as the EPA

precision criteria for an acceptable alternative method. They mistakenly thought the

proposed rule would impose a much more stringent precision criteria (i.e. 50 percent

3-34
( RSO). In fact, when an acceptable method already exists (as in this case), Section 6.2

of EPA Method 301 applies, which requires a candidate alternative method to be at

least as precise as the method for which it is intended to be substituted. However,

because the industry is reluctant to embrace the use of the acceptable method (EPA

Method 320 or 321), we waived the requirement that the alternative method to be at

least as precise (as allowed by section 1.1.1 of EPA Method 301). Therefore, in order

to allow the use of the less precise ASTM method, we instead chose to have the testers

demonstrate their ability to get reasonable agreement at the actual facility. Note 3 in

section 4.1.4 of the ASTM method reinforces this approach in that it states "The

particulate matter of mineral calcining facilities adsorbed HCI and HF to varying

degrees. The amount of adsorption depends on process parameters and the

physical/chemical properties of the dust."

Comment

Commenters IV-0-05 and IV-0-08 note that ASTM Method 06735-01 includes

optional paired train and spiking procedures. The commenter is unclear what basis

EPA has used to make these optional procedures mandatory.

Response

(

We disagree. Exactly because it is an option to use paired trains and analyte

spiking procedures in the ASTM method, EPA clarified that for this application those

options were exercised. Section 5.4 of the ASTM method states "the test specific

precision may be determined by conducting paired runs." Paired runs aid in identifying

possible suspect data and provide backup in the event one train is invalidated.

Performing paired runs depends on the test specific data quality objectives. Section 5.3

has a similar statement regarding analyte spiking. In the bigger picture, if the only

options available to us were to accept or reject an ASTM method with no alterations, we

would have to reject many more ASTM methods for relatively easily corrected reasons.

This would severely limit our good-faith implementation of the National Technology

Transfer and Advancement Act.

Comment

Commenter IV-0-08 notes that there is no discussion in the proposal preamble

explaining where the 20 percent limit for absolute relative standard deviation (RSO)

came from. The commenter requests that the requirement be deleted,since the ASTM

method does not mention criteria for accepting or rejecting a test, and since the ASTM

results are completely consistent with EPA's own RSO criteria of 50 percent. If EPA

insists on including the paired train requirement and an associated RSO criterion, the

commenter believes a ppm difference should be considered, particularly for low

concentration sources. The commenter suggests that if the RSO exceeds 50 percent,

the results continue to be valid provided the absolute difference between the two train

( values is 3 ppm or less.

3-35
(

(

Commenter IV-0-05 requests that the ASTM method be incorporated by

reference as it is written.

Response

We agree with the commentator that it may not be necessary to reject data with

poor precision if it doesn't affect the major/area source decision. However, we disagree

that the way to attain this goal is to provide an absolute value that is acceptable

regardless of how close to the action level the data are.

Comment

Commenter IV-0-08 stated that the regulation would require four valid runs,

which are too many, noting that nearly all methods require three runs and not four. The

commenters states that the ASTM method defines the test to be three or more runs and

that EPA should have the same wording. Commenter IV-0-05 asked that if a spiking

procedure and spike recovery criterion are included in the final rule, that we confirm that

the three test-run requirement of the ASTM method is met with two non-spiked runs

and a third, spiked run.

Response

As discussed above, EPA disagrees that we are confined to exactly what the

ASTM method states. In this case the ASTM method merely sets a minimum of three.

However, in this case EPA, agrees that three or more runs may constitute a test.

Our intent is that two of the three runs be made with paired trains, and one run

be made with paired trains where one train is spiked.

Comment

One commenter (IV-0-10) believes ASTM D6735-01 to be a "primitive" or inferior

measurement technique, and EPA Method 320 (FTIR) to be a clearly superior method

for HCI measurements. The commenter notes that EPA Method 320 directly measures

HCI, while 06735-01 measures total chloride. There is no need to conduct indirect

measurements, since there is a reliable test method that directly measures HCI.

The commenter states that EPA Method 320 has a typical RSO of

approximately 1 to 2 percent compared to 30 to 50 percent RSO for 06735-01. The

commenter provides cost data for EPA Method 320, and notes that the methods (EPA

Method 320 and ASTM 06735-01) have virtually identical costs. The commenter urges

EPA to require the use of EPA Method 320 for lime HCI measurements.

( Response

3-36
( We agree that FTIR is the best choice of test method to measure emissions of

Hel, and note that the cost estimate provided by the commenter is close to the EPA

estimate of cost to perform the ASTM method. However, we feel that the EPA can use

data from a properly conducted ASTM 06735-01 test to determine if the source

qualifies as an area source. We agree that there is a potential to incorrectly conclude

that the source is major, when in fact, it is not.

3.11 Economic Impact Analysis

Comment

One commenter (IV-0-06) claimed that the econimic impacts analysis (EIA)

neglected to include some significantcosts of implementing the proposed rule,

including the cost of dismantling existing equipment, lost sales during downtime, and

the cost of re-hiring personnel after plant modifications if scrubbers must be replaced.

The commenter also noted that maintenance and supervisory personnel currently do

not work evening and weekend shifts, but would likely be required in the event of failure

of the recommended monitoring equipment.

Another commenter (IV-0-02) believes EPA's estimated $1.17 per ton of lime

cost estimate is low, and the cost to a typical lime producer will be significantly higher.

In particular, the commenter noted that the additional power required for high pressure

( drop scrubbers alone would be approximately $1.30 per ton of produced lime. In

addition, EPA's estimated equipment costs appear to be low.

Response

The commenters believe either that implementation costs (IV-D-06) or power costs (IVD-02) are not properly represented. As discussed in the response to comments regarding a

separate subcategory for scrubbers, estimated implementation costs used for the EPA model

plants include costsfor demolition of existing equipment and credits for salvage value. Because

plants have a three-year period in which to comply with the proposed rule, it is expected that

scheduled downtime will be used for disconnecting an existing scrubber and connecting a new

scrubber. As a general practice, building a new scrubber while the existing scrubber remains in

operation .is preferable to taking the associated kiln out ofservice for an extended period oftime

and losing production from the kiln. The plant is expected to use its labor force in the manner

normally found for planned downtime. Such labor costs (or savings) would not be attributable to

compliance with the proposed rule.

(

Power costs for new scrubbers are costed incrementally, i.e., costs are estimated for the

difference between 35 in. w.g. (new scrubbers) and 14 in. w.g. (existing scrubbers) as used in

Docket Item No. II-B-122. For individual model kilns, summing the power costs and dividing by

the model's production rate gives estimated incremental power costs ranging from $0.82 to

$1.47/ton oflime. On a nationwide basis, aggregating the model kiln costs apportioned among

the affected kiln population provides average costs as estimated by EPA.

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(

(

Comment

Commenter IV-D-04 stated that the EIA is seriously flawed because it assumes lime

producers can pass control costs through to consumers. The commenter maintains that lime

producers cannot raise prices. The reasons include a highly competitive market due to

overcapacity, competition from unregulated sources, competitive substitutes exist for most key

markets, and significant market resistance. The commenter also claimed that recent history

proves that prices cannot be increased. Finally the commenter stated that because the price

increase assumed by EPA is erroneous, EPA's prediction that only two lime plants will close

seriously understates the impact. One other commenter (IV-D-12), also stated that they could not . . Increase pnces.

Response

The fact that many lime plants are currently operating at less than full capacity implies

that their supply curves should be relatively elastic (flat) at current production levels because

lime producers can fairly easily change output without running into capacity constraints. Based

on standard economic theory, under perfect competition the supply curve for each firm is equal to

their marginal cost curve and each producer chooses to produce the quantity where their marginal

costs are equal to the market price in order to maximize their profits. The market supply curve is

the sum ofthe supply curves ofthe individual firms and will reflect the responsiveness ofthe

individual firms to changes in price. Assuming that the lime industry is very competitive (as

argued by IV-D-04) and has substantial overcapacity implies that the industry marginal cost

curve (and the market supply curve) should be relatively flat at current production levels. To the

extent that the costs ofthe lime manufacturing MACT standard increase the marginal costs of

lime production3

, having a very elastic (flat) supply curve is a textbook case where the majority

ofthe costs are passed on to consumers. A highly competitive market implies, by definition, that

individual producers cannot unilaterally increase their prices without losing most, ifnot all, of

their customers. It does not imply that the market price will not increase in ,response to a general

increase in the cost oflime production due to environ1T1ental regulations.

It is certainly true that foreign lime suppliers (including suppliers located in Mexico) gain

because this regulation applies only to domestic lime producers. The EIA assumed that import

supply was quite elastic (elasticity of 7.0) and foreign suppliers are shown to increase their output

and their profits in the EIA. However, imports oflime account for an extremely tiny share ofthe

lime market prior to the regulation (about 1 percent nationally) and even a fairly large percentage

increase in imports shows up as a very small change in absolute terms. The fact that imports

account for such a small share ofthe u.s. lime market implies that transportation costs are too

high for imported lime to be competitive in the majority ofthe u.s. The barrier to imports

3A substantial portion ofthe cost associated with this rule is for kiln retrofits with capital

equipment such that compliance capital expenditures may not vary greatly with output.

However, maintenance costs and compliance capital depreciation are expected to vary directly

with output such that the marginal costs ofproduction are increased.

3-38
( caused by these high transportation costs is expected to prevent significant replacement of

domestic lime with imported lime.

Commenter IV-D-04 states that commercial lime producers would be unable to raise

prices for lime they sell to paper plants during times when the paper plants' captive lime facilities

are off-line because the paper plants would simply manufacture and store more lime at their own

facilities at much lower cost. It is possible that this would happen to some extent, although paper

plants already have the option to produce more lime captively. The fact that they purchase

commercial lime currently suggests that they value the option ofbuying on the spot market and

may not substantially change their inventory practices unless there is a sufficient increase in

price. In addition, it is true that captive lime kilns that are exempt from this MACT standard

(e.g., kilns that are covered by other regulations, such as those in the beet sugar industry) could

possibly begin to operate during their current down times and sell lime into the commercial

market. However, the fact that they do not currently find it worthwhile to do so again implies

that the price increase would have to be large enough for them to significantly change their

current operating procedures.

(

To examine the historical supply responsiveness in the lime market, we estimated the

supply elasticity for lime using data from 1983-2001. These estimates capture the overall change

in the quantity oflime supplied in response to a change in the real (inflation-adjusted) price of

lime, including any entry or exit of captive suppliers from the market. Based on estimates

obtained from the econometric model, the domestic lime supply elasticity was 1.24 at the average

price and quantity for the period and 0.98 using the lime price and quantity for 1997, the baseline

year for the EIA. The value for the baseline year implies that a 1 percent increase in price would

lead lime producers to increase their lime production by 0.98 percent, other things being equal.

For the lime price to remain constant due to entry into the commercial market by captive

suppliers, that entry would need to be sufficient that it led to the market supply curve being

perfectly elastic. There is no evidence for a perfectly elastic market supply curve due to largescale entry based·on historical estimates ofthe responsiveness oflime supply to changes in real

pnce.

There are substitutes for lime in many ofthe markets in which it competes, such as

crushed limestone, caustic soda, soda ash, and other products. However, unless the alternatives

are perfect substitutes, this does not imply that the price oflime will not increase in response to

an increase in production costs. The products have different attributes and different prices and

are clearly not perfect substitutes. In addition to estimating the overall responsiveness ofsupply,

we also estimated the responsiveness ofthe quantity oflime demanded using an econometric

model and data from 1983-2001. In that model, an inflation-adjusted price for alkalies and

chlorine was used to represent the effect ofthe price oflime substitutes on the quantity oflime

demanded.4 The results show that the cross-price elasticity oflime with respect to the alkalies

4Many alternative substitutes were used in alternative model specifications, but the model with

( the alkalies and chlorine price was the preferred model based on model fit and consistency with

economic theory.

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(

(

and chlorine price is 0.30 for the baseline year. This suggests that a 1 percent increase in the

alkalies and chlorine price would result in a 0.30 percent increase in the quantity oflime

demanded, implying that these products are substitutes. However, they are not perfect

substitutes. While it is expected that there would be some substitution of alternative products for

lime in response to a higher lime price, it is highly unlikely that other products would be treated

as perfect substitutes for lime such that the market lime price literally could not increase without

all buyers substituting other products.

Assuming that lime is a highly competitive market, economic theory tells us that

individual lime producers should not be able to unilaterally increase the price oftheir

output without losing most, if not all, their customers. If a firm raises their selling price

above the market price, their customers are expected to shift all oftheir business to firms

selling at the market price. However, this does not imply that the market price for lime

cannot increase in response to changes in production costs that shift the market supply

curve.

To test the responsiveness oflime demand to price, we estimated the demand elasticity

for lime using an econometric model ofthe industry and data from 1983-2001. The results ofthe

model suggest that the demand for lime is elastic, with an elasticity of-1.43 at the average price

and quantity over the 1983-2001 period. Based on the price and quantity in the baseline year,

1997, the elasticity for that year is calculated to be -1.14. The value for the baseline year means

that the quantity oflime demanded would fall by 1.14 percent in response to a 1 percent increase

in price based on historical data. A claim that the lime price literally cannot increase due to high

demand responsiveness implies that the market demand curve is perfectly flatS (elasticity is equal

to negative infinity), which is clearly not supported by empirical evidence. The fact that some

firms are tied into long term contracts at a fixed price may delay increases in price in some

markets until the contracts expire, but prices are still expected to increase following expiration of

existing contracts.

The fact that lime prices have not increased in recent years despite plant closures and

increases in real prices in no way implies that those events do not exert upward pressure on

prices. The relevant comparison is the price with and without those events, not before and after

they occur. It is expected that prices would have been even lower ifthere had not been closures

and increases in input prices.

As outlined in the responses to these comments, there is no evidence to support the claim

that the assumption that lime price will increase is erroneous, and that the estimated economic

impact ofthe rule is understated.

Comment

( sUnlike the market demand curve, the demand curve facing an individual firm in a perfectly

competitive market is expected to be perfectly flat (demand elasticity of negative infinity).

3-40
( Two commenters (IV-D-04, and IV-D-20) claimed that the EPA's sensitivity analysis

does not adequately respond to the small business advocacy review (SBAR) Panel's

recommendations.

Response

In response to industry comments and to verify the reasonableness ofthe EIA results,

market supply and demand elasticities were estimated for lime. The values from the preferred

model for 1997 are very close to the primary elasticities used in the main text ofthe EIA and are

well within the range of elasticities used in the sensitivity analysis in Appendix B. In addition to

the preferred model, numerous alternative models were estimated. As with any modeling

exercise, there were some differences in results across different model specifications. However,

the results were generally similar across specifications and there were no cases in which the

estimated supply or demand elasticity fell outside the ranges currently used in the Appendix B

sensitivity analysis included in the EIA. Thus, the current analysis adequately responds to SBAR

panel recommendations that a reasonable sensitivity analysis be employed and the empirical

evidence is supportive ofthe current scenario presented in the Section 4 ofthe EIA.

Comment

(

One commenter (IV-D-04) stated that the EPA economic model for the lime market

assumes a nationally perfectly competitive market, but lime prices are primarily dictated by large

producers who sell capacity regardless ofprice.

Response

This comment suggests that large lime producers have market power and therefore face a

downward sloping demand curve and have some ability to set prices. Iflarge lime producers do

possess market power, then profit-maximizing behavior would imply that they would restrict

output below the levels expected under perfect competition in order to increase market price to

the point that their marginal revenue is equal to their marginal cost. The large producers may

have lower marginal costs such that the resulting price makes it difficult for the small producers

that take the market price as given to remain in business. However, the presence ofmarket

power in the lime industry would tend to increase prices relative to the perfectly competitive

case, not decrease them.

Comment

One commenter (IV-D-06) stated they sell 40 to 50 percent oftheir lime to the soil

stabilization market, an area that has encountered competition from liquid petroleum byproducts.

These low-cost, marginally effective products have made substantial progress entering this

market with an inexpensive, unproven product and any increase in lime costs will reduce the

competitiveness oflime in this market.

( Response

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(

(

(

An increase in the price oflime relative to substitutes will tend to reduce the quantity of

lime purchased. However, to the extent that liquid petroleum byproducts are marginally effective

and unproven, they are presumably not close substitutes for lime.

Comment

One commenter (IV-D-06) claims that although EPA has indicated its rule will have

larger impacts on small businesses than large ones, the disparity is even greater than EPA

estimates. The reductions in pre-tax earnings presented in the EIA understate losses for small

firms because the costs ofimplementation will be higher than EPA estimates and the price of

lime will not increase. They also state that even if only 2 to 3 ofthe 14 small lime firms close,

that would still be closure of 14% to 21% ofthe small lime firms in the domestic industry. This

seems to be such a significant economic impact that it should encourage the EPA to seriously

consider additional ways to minimize the impact on small businesses.

Response

It is unclear what the basis for the first part ofthis comment is (it seems the same claims

they are making for small firms would also apply to large firms). As far as the second part, to the

extent that actual costs differ from EPA estimates, it is possible that the actual losses experienced

by firms would be higher or lower than presented in the EIA. However, the costs of

implementation currently used for analysis reflect EPA's best estimate of actual costs. The

assertion that lime prices cannot increase in response to an increase in production costs is not

credible (see comments above).

We also disagree that the number ofsmall firms at risk of closure, 2 to 3, can be

considered a significant number in the context of SBAR. In any case, we have seriously

considered ways to minimize the impact on small businesses based on comments from industry

and has substantially reduced the costs ofthis rule relative to pervious versions. As previously

discussed, EPA, along with the Small Business Administration and the Office ofManagement

and Budget, convened a panel under the authority of SBAR to talk with small business

representatives on how to mitigate potential impacts to small businesses associated with the lime

manufacturing NESHAP. This panel yielded a report that included many recommendations on

how potential impacts to small businesses from the proposed rulel could be mitigated. These

recommendations are also reflected in the final rule.

Comment

One commenter (IV-D-06) claims that the EIA assumption that production costs will go

down with decreases in production is wrong. The commenter claimed that they maintains a

close watch on cost of production stated in cost per ton oflime produced. Simple economics

dictates that an increase in dollar cost associated with a decrease in production results in a higher

cost of production, which is a higher cost per ton oflime.

Response

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I

\

(

(

Presumably, the commenter's statement that there is an increase in dollar cost refers to

the compliance costs, but those costs are shown separately from production costs in the EIA. The

EIA does not say that the total cost per ton oflime including compliance costs will decrease, it

indicates that total production costs (not including compliance costs) will decrease in response to

a reduction in use ofvariable inputs as production falls.

Comment

One commenter (IV-D-06) stated they are already trying to control costs while over the

past several years our workers' compensation insurance, group health insurance, natural gas,

maintenance parts, and liability insurance costs have continued to increase by double digit

percentages, while sales prices have not increased to this extreme. Trade and economic

predictions indicate more similar increases can be expected. These factors should be important

considerations ofthe economic analysis.

Response

EPA gathered baseline data for the lime industry to inform the economic analysis. It is

possible that market conditions for the lime industry have worsened over time. However, the

focus ofthe economic analysis is the incremental impacts ofthe lime manufacturing MACT

standard, which may be relatively small compared with other changes that are occurring within

the lime industry.

3.12 Risk Analysis

Comment

One commenter (IV-D-01) was concerned over EPA's use of the Acute Exposure

Guideline Level (AEGL) in assessing the health risk associated with HCI. While not

directly objecting to the conclusions reached by EPA, the commenter noted that the

intended use of the AEGL, according to the National Research Council, is in

conjunction with "once in a lifetime" exposures for emergency exposures ranging from

10 minutes to 8 hours. Because the AEGL values are intended to be used in

conjunction with a single lifetime exposure, they can be higher than short term limits

recommended for populations with repeated exposures. It is not clear in the description

of the NLA analysis, if NLA in their use of AEGL was contemplating a once in a lifetime

exposure Ofwhether exposures would be occurring repeatedly. The commenter stated

that EPA should explicitly state how they believe AEGL values should be used in their

risk assessment process and what are the possible exposure levels to the public. The

commenter was also troubled by the use in the rationale of both the RfC (estimated

daily exposure that over a lifetime is not likely to result in significant non cancer effect in

humans) and the AEGL (once in a lifetime exposure).

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The commenter asked that EPA clarify their position on the use of AEGL values

for environmental risk assessments, and whether its use represents a "reasonable

methodology" and "consistent with EPA methodology" as claimed in the preamble.

Response

This analysis evaluated only risks based on offsite exposure to the general

population. EPA does not assess risks associated with occupational exposures, not do

we have the authority to address occupational issues.

In our evaluation of the NLA risk analysis, EPA reviewed the available acute

dose-response values for this compound. Among these, the CalEPA reference

exposure level (REL) and AEGL-1 values (2.1 and 2.7 mg/m3

, respectively) were found

to be the most health-protective. Since these benchmarks were effectively the same,

and AEGL values are products of a Federal effort in which EPA participates, we gave

priority to the AEGL. Therefore, the AEGL-1 selected for analysis represented the

most appropriate value.

Although there are relatively protective acute dose-response assessment values

for hydrochloric acid, protective assessments for other hazardous air pollutants may not

exist. In such cases we may have to rely on less-conservative analyses, perhaps

based on endpoints at mild effect levels. Nevertheless, EPA believes that the use of

less-protective values (e.g., AEGL-2) is better than omitting acute exposure from the

risk assessment.

3.13 Applicability

Comment

One commenter (IV-D-03) requested that the rule be revised to exempt lime kilns

operated in conjunction with public water treatment facilities. The commenterexplained

that the kilns are used to recover the calcium carbonate sludge from their water

softening process. The recovered lime is used on-site in the water treatment process

thereby reducing demand for these resources, avoiding the air emissions that would

otherwise be associated with the transport of this material to a disposal site, and

reducing the amount of solid waste generated. Under the existing language of the rule,

the lime recovery kilns located at the water treatment plant would be subject to the rule

because the treatment facility operates air stripping towers which are permitted to emit

over 10 tons of a single HAP and over 25 tons per year of multiple HAP.

The commenter states that unlike lime kilns that process raw limestone

materials, which contain metal HAP, the sludge from the water softening process, the

only calcareous material fed to the kilns, does not contain metal HAP in any

appreciable quantity. The elements and compounds found in the calcareous sludge

from the water softening process are representative of those found in the treatment

plants raw water source and the chemicals that are added as part of the water softening

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( process. As the public's water supply, neither the source water, sodium silicate, nor the

lime added prior to the kiln should have significant levels of metal HAP.

The commenter also stated that EPA did not review lime kilns at water treatment

facilities in developing the proposed rule. Nor did the NLA include these lime kilns in

their modeling of HCI emissions. The inclusion of lime kilns operated as part of water

treatment facilities would be arbitrary and capricious and not based on any research or

analysis.

The commenter suggests EPA revise 63.7081(a) to include public water

treatment plants in the list of lime producing facilities exempt from the rule. The

commenter also suggests revising 63.7143 by modifying the definition of "Stone feed"

by adding the following: "Stone feed does not include calcareous solids that are

generated by and recovered in the water softening process at water treatment plants."

Response

The lime recovery operation described by the commenter was not the intended

target of the rule. The EPA has revised the rule to exclude lime kilns that are operated

as part of a publicly owned water treatment facility to recover lime from water softening

processes.

( 3.14 General Comments

Comment

One commenter (IV-D-16) notes that in the proposal preamble, EPA asked for

comments on a two-tiered approach for compliance monitoring. The commenter

agrees that the rule should contain a threshold limit to initiate corrective action (which if

corrected within a given time period would not constitute a violation). In many cases,

entering a baghouse to perform maintenance on a broken bag poses a significant

hazard to the maintenance personnel due to temperature, lack of oxygen, and high

levels of sulfur oxides and nitrogen oxides. Thus the time period for corrective action

must consider the critical time necessary to cool down and purge a compartment, so

that the danger to maintenance personnel can be minimized.

Response

For baghouses monitored using BLD systems and for ESP monitored using PM

CEM, alarm systems may be used to alert operators when preset levels have been

have been exceeded indicating that corrective actions may be necessary. Only after

the alarm time has exceeded 5 percent of the total operating time in a 6-month period

has a violation of an operating limit occurred. Alarm time is counted by how long it

takes it takes from the onset of a BLD or PM CEM alarm to the time that corrective

<: action is initiated. By not counting the time required to correct the problem, the plant

owner or operator can take the time necessary to address the cause of the alarm in a

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safe and efficient manner without incurring additional alarm time. Procedures to be

followed in inspecting control devices for the cause of alarms or malfunctions should be

incorporated into a facility's OM&M plan and SSM plan.

For other parametric compliance monitoring options, the rule requires that the

owner/operator define the compliance parameters to be monitored in their OM&M plan.

During the initial performance tests, they are required to monitor and establish the

value or range of the parameters. EPA believes that the initial performance tests will be

designed to give the owner or operator flexibility in adhering to the established range for

monitored parameters. These values must be reported in the results of the test and

notification of compliance status to the permitting authority and must be approved by

the permitting authority. During subsequent operations, if the monitored parameters

exceed the values or fall outside the range determined during the initial performance

test, it is a violation of the operating requirements of the standard (unless it is the result

of a malfunction to which the facility responds to in accordance with the SSM plan).

The EPA has no basis for allowing deviations before considering the facility to be in

violation. The owner/operator has ample opportunity to establish a range for the

operating parameters and must thereafter operate within that range.

Comment

Several commenters (IV-D-04, IV-D-05, and IV-D-08) believe the rule should not

require HCI testing of all kilns. Commenter IV-D-04 believes the rule should provide

state agencies with the discretion to not require HCI testing of all kilns. Commenters IV0-05 Western and IV-D-08 Engineering believe the rule itself should allow flexibility in

HCI testing.

The commenters note that in recent years, many lime plants have been forced to

idle or infrequently operate kilns at operating plants due to increased fuel cost, reduced

customer demand, etc., and start up of every kiln for the purpose of conducting HCI

testing would require significant expenditures. Commenter IV-D-04 notes that this

would also result in PM and other emissions that otherwise would not be generated.

Commenter IV-D-04 uses the example of an idled kiln of the same type as an active kiln

at the plant, fired with the same fuel and stone; it may be reasonable for a state agency

to conclude that HCI emissions testing from the active kiln can be used to estimate

emissions from the idled kiln. Furthermore, the commenters note that testing may not

be warranted on kilns that represent small fractions of the plant's total capacity. As a

result, Commenter IV-D-04 requests that the rule be revised to provide state agencies

with the discretion to determine whether testing of all kilns at a lime plant is necessary

in order to demonstrate that a plant is an area source. Commenter IV-D-05 requests

that the rule state that plants which desire to claim area source status be required to

test a sufficient number of kilns so that 70 percent or more of the potential production

capacity of the plant is tested for HCI. Or, as an alternative, EPA could allow HCI test

results from one kiln to be extrapolated to estimate emissions from comparable kilns at

the same plant.

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( Response

A lime manufacturing plant's status as an area source or a major source is not

addressed by this rule. If there are questions regarding whether a source is an area

source or a major source, the owner or operator should refer to the General Provisions,

in particular, section 63.2, and contact the appropriate permitting authority if additional

clarification is needed. We believe this is the best approach for major source

determinations because every site may have different issues, and attempting to

address these site specific issues in this rule would be inappropriate. We believe

allowing the permitting authority to evaluate these issues on a case-by-case basis is the

best approach.

Comment

Several commenters (IV-D-04, IV-D-17, IV-D-11, and IV-D-13) state that the rule

should allow lime plants to use the following emission factors to estimate HAP metal

emissions: 0.15 percent of PM emissions from kiln stacks and 0.07 percent from stone

handling operations. Commenters IV-D-04 and IV-D-17 believe that the quantity of

metal HAP emitted from lime plants is sufficiently low that it is highly unlikely that such

metals will be present in quantities that would have any effect on whether a commercial

lime plant exceeds the 25 ton per year major source threshold for all HAP. According to

commenter IV-D-04, Docket Item No. 11-8-43 establishes the HAP metal content of lime

( kiln emissions to be 0.15 percent, and Docket Item No. 11-8-77 establishes the HAP

metal content of fugitive stone emissions to be 0.07 percent. Commenter IV-D-16

Refractories also commented that the rule should allow for the use of emissions factors

for HAP metals.

Commenter IV-D-04 notes that the cement MACT allows cement plants to

assume that HAP metals emissions constitute 1 percent of PM emissions for the

purpose of area source determinations. This commenter believes the quantities of

metal HAP from lime plants are so small they will not affect the area/major source

determination, and thus measurement of the metal emissions is unnecessary.

Response

The rule, as proposed, contained no requirement to measure HAP metals in the

emissions from kilns or stone handling operations and we see no reason to add such

provisions. The final rule does not require that lime manufacturing plants perform

emissions testing for HAP metals. Therefore, we see no reason to establish a specific

ratio in the rule. However, nothing in the rule would preclude these ratios from being

used.

Comment

( Several commenters (IV-D-04, IV-D-16, IV-D-11, and IV-D-13) comment that

testing for HAP organics should not be required because it is highly unlikely that such

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compounds will be present in quantities that would have any effect on whether a

commercial lime plant exceeds the 25 ton per year major source threshold for all HAP.

Commenter IV-D-04 notes that lime kilns are not expected to emit significant quantities

of organic HAP because inorganic limestone is the only feed material processed, and

EPA's testing of 10 commercial lime kilns detected virtually no organic HAP (Docket

Item No. 11-8-121). This commenter also notes that lime kilns at sugar beet facilities

have been exempted from the lime MACT, and no analysis of organic emissions from

lime kilns at sugar beet facilities has been conducted (Docket Item Nos. 11-8-44 and

81).

Response

EPA agrees with the commenters, the rule does not require that emission testing

for HAP organics be conducted.

Comment

One commenter (IV-D-04) states the requirement in § 63.7142(b) to use FTIR,

Method 18 or ASTM D6420-99 if organics testing is conducted for area source

determinations should be deleted. The commenter notes that the proposed

requirement creates the inference that organics testing should be conducted, and that

testing beyond the 36 volatile organics specified in the ASTM method is necessary,

when the chance that organics will cause lime plants to be a major source is highly

remote.

Response

As stated in the previous response, the final rule does not require emission

testing for HAP organics. However, we do not believe it is appropriate to specifically

state that organics testing is not required. It is possible that a permitting authority may

wish to have a facility perform organic HAP testing due to site specific considerations.

If this occurs, we believe that EPA-approved test methods should be used.

Comment

One commenter (IV-D-02) believes the final rule should include an alternative

limit based on the quantity of HAP metals released. For example, "a lime

manufacturing plant with a dry collector and a particulate release greater than 0.12

Ib/tsf should not be required to meet a MACT surrogate particulate value when its

release of HAP metals is equal to or less than that of EPA's basis for establishing the

0.12 1b PM/tsf limit...a lime plant that has a stone feed stock low in heavy metals and/or

fires with natural gas can have a lower HAP metals release than a plant meeting the

proposed MACT particulate limit. Since the intent of the proposed regulation is to

control the release of HAP metals, whether a company complies via operating practices

or particulate control equipment should be irrelevant." In the case of wet scrubbers, the

commenter recommends an alternative HAP limit of 1.5 Ibs/1000 tons of stone feed

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(based on a particulate release of 1.0 Ib/tsf and a HAP metals concentration of 1,500

ppm in the particulate).

Response

We do not have, and the commenter did not provide, sufficient HAP metal

emission information on which to establish a metal HAP emission limit as an alternative

to the PM emission limit. We commonly use PM emissions as a surrogate for metal

HAP emissions, finding that controlling PM emissions will control the non-volatile and

semi-volatile metal HAP. At-the-stack controls used at lime manufacturing plants, i.e.,

baghouses, ESPs, and wet scrubbers, capture non-volatile and semi-volatile metal

HAP non-preferentially along with other PM, making PM a permissible indicator for HAP

metals. We believe using PM as a surrogate is preferred by most sources as the cost

of emissions testing and monitoring that would be required to demonstrate compliance

with the otherwise numerous standards that would apply to individual HAP metals

would be much higher than testing for and monitoring for PM emissions.

Comment

Several commenters (IV-D-04, IV-D-16, IV-D-11, and IV-D-13) state that

performance testing should be conducted under "representative" conditions rather than

under the "highest production level reasonably expected to occur." Commenter IV-D-11

notes that there are inconsistencies between what is proposed in Table 4 of the rule

and what is required under the General Provisions at 40CFR 63.7(e)(1). EPA has

recently amended the Cement MACT to fix similar inconsistencies, and the commenter

suggests the Lime MACT be similarly revised.

Response y~

We have changed the requirement in the final rule to require testing under

representative conditions, which is in agreement with the language in the General

Provisions.

Comment

One commenter (IV-D-04) notes that reports should be required only for

malfunctions, not startups and shutdowns. The commenter states that in recent

proposed amendments to the General Provisions in Subpart A of Part 63, EPA has

determined that requiring reporting of startups and shutdowns is "unnecessary and

burdensome" (67 Fed. Reg. 72,881).

Response

Section 63.7121(b) requires that deviations from operating, VE, and opacity

limits, including periods of startup, shutdown, or malfunction be reported. EPA intends

for this requirement to be consistent with the General Provisions and has revised this

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paragraph to clarify that reports of startups, shutdowns, and malfunctions are to be

made in accordance with section 63.10(d) of the General Provisions.

Comment

Two commenters (IV-D-04 and IV-D-16) believe the final rule should provide a

risk-based exemption from the entire rule (not just from HCI standards) for plants at

which modeled risks are below health based thresholds. Commenter IV-D-04 notes that

EPA recently solicited comment on providing risk-based exemptions in proposed MACT

standards for several sources categories. This commenter strongly supports the view

that such exemptions should be provided in MACT standards that impose substantial

costs while achieving negligible reductions in risks to public health, and believes the

lime MACT fits this description.

Response

Other than the decision to not regulate emissions of HCI from lime

manufacturing, EPA did not consider and did not request comments on providing riskbased exemptions for lime manufacturing facilities. Although EPA is aware that riskbased exemptions were being discussed in other proposed rules, no decisions have

been made by the Agency regarding risk-based exemptions and application to industry

groups or individual plants. Due to the uncertainty of how these exemptions would be

structured, we do not believe that it would be appropriate to include these site specific

risk based exemptions in the final rule. We also believe that including such a

substantive change in the final rule without allowing the general public an opportunity to

comment would be a violation of the Administrative Procedures Act, especially in light of

the fact that their inclusion in other proposed rules have generated significant negative

comment from the public.

Comment

One commenter (IV-D-04) states the Benefits Analysis is based on inaccurate

assumptions, and presents conclusions regarding reductions in metal HAP that are

greatly overstated.

The commenter submitted comments to the Small Business Advocacy Review

(SBAR) Panel explaining that the emission factor for uncontrolled existing kilns is 27

times smaller than the emission factor used by EPA to calculate baseline emissions.

The commenter notes that its emission factor is based on actual test data from these

kilns.

The commenter also notes that the emission factor for existing uncontrolled

stone handling operations is also overstated; it was derived using AP-42 emission

factors with liE" ratings. The commenter states that it also presented to the SBAR

Panel a more reliable emission factor for these units that is rated "C" and was revised in

1995.

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In addition, the commenter claims that EPA overstated the amount of new

capacity and the emissions from new rotary kilns. The commenter states, "EPA should

either reflect (our) estimates in the preamble to the final rule, or provide a reasoned

response to our comments that EPA's estimates are overstated...we believe the best

estimate of metal HAP reductions is 3.5 tons (7,000 pounds) per year. Based on the 56

lime plants predicted to be subject to the MACT rule, this translates into an annual

reduction in metal HAP per lime plant of 124 pounds.

Response

EPA reviewed the new information on PM emissions presented by the

commenter as well as their calculations of baseline emissions and emission reductions

resulting from the rule and finds them to be reasonable. The preamble to the final rule

reflects these revised estimates. However, even with these revised estimates, we still

note that the estimated benefits are still significantly higher than the costs for the final

rule.

Comment

One commenter (IV-D-22) states that EPA should clarify that PM from nuisance

dust collectors that service coolers are not included in the collective PM limit for

kilns/coolers. The commenter notes that nuisance dust collectors, commonly

associated with coolers, (called the cooler duct collector in some plants) collect dust

generated in the transfer from the cooler to the material handling system, and PM from

the nuisance dust collector should not be included in the kiln PM limit, but instead

should be exempt as part of the lime handling system.

Response

The standard only applies to air used for cooling that is exhausted from the

cooler to the kiln or that is exhausted separately to the atmosphere. Operations that

process only lime product, lime kiln dust, or fuel are excluded from coverage. The rule

was revised to clarify that dust emitted in the transfer from the cooler to the material

handling system is not included in the calculation of the PM emission rate.

Comment

One commenter ( Docket No. OAR-2002-0052, item 530) states that clean air is

essential, and requests that the companies that pollute the air be made to clean it up.

Response

EPA acknowledges the comment and believes this and other standards

\ promulgated under the CAA are effective at reducing HAP emissions.

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Comment

One commenter (IV-D-15) requests that EPA withdraw the proposed Lime

manufacturing NESHAP and publish a new draft that is substantially more

environmentally protective of PM1 O.

Response

The degree to which emissions of any substance can be reduced by regulation

are a reflection of the statutory basis of those regulations. Under section 112 of the

CAA, EPA is directed to establish MACT standards which are based on the emission

reduction being achieved by the top performing, currently operating facilities. The

standard for lime manufacturing plants used this approach and we believe that the

result of the standard will be a substantial reduction in total PM emissions (over 3,880

tons per year), including PM10 emissions.

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