OAR Box 1115 

Prepped by Ryan Dugan 

Document Number: 

76) ll-A-8 

Docket Number: 

A-84-22 

Printed 4/18/2008 10:52:08 AM 

_______________________________________^____^___ 

Sheet 76 of 94 

p.1 
ir 

P.2 

EPA-450/2-74-023 

NOVEMBER 1974 

EPA RESPONSE TO REMAND 

ORDERED BY U.S. COURT OF APPEALS 

FOR THE DISTRICT OF COLUMBIA 

IN PORTLAND CEMENT 

ASSOCIATION V. RUCKELSHAUS 

(486 F. 2d 375, JUNE 29, 1973) 

^ PRO^° 

U.S. ENVIRONMENTAL PROTECTION AGENCY 

Office of Air antl Waste Management 

Office of Air Quality Planning and Standards 

Research Triangle Park, North Carolina 27711 
P.3 

EPA-450/2-74-023 

EPA RESPONSE TO REMAND 

ORDERED BY U.S. COURT OF APPEALS 

FOR THE DISTRICT OF COLUMBIA 

IN PORTLAND CEMENT 

ASSOCIATION V. RUCKELSHAUS 

(486 F. 2d 375, JUNE 29, 1973) 

Emission Standards and Engineering Division 

U.S. ENVIRONMENTAL PROTECTION AGENCY 

Office of Air and Waste Management 

Office of Air Quality Planning and Standards 

Research Triangle Park, North Carolina 27711 

November 1974 
P.4 

This report is issued by the Environmental Protection Agency to report 

technical data of interest to a limited number of readers. Copies are 

available free of charge to Federal employees, current contractors and 

grantees, and nonprofit organizations -as supplies permit - from the 

Air Pollution Technical Information Center, Environmental Protection 

Agency, Research Triangle Park, North Carolina 27711; or for a fee, 

from the National Technical Information Service, 5285 Port Royal Road, 

Springfield, Virginia 22161. 

mm 

Publication No. EPA-450/2-74-023 

i i 
P.5 

EPA Response to Remand Ordered by 

U. S. Court of Appeals for the 

District of Columbia in Portland Cement Association 

v. Ruckelshaus (486 F.2d 375, June 29, 1973) 

On June 29, 1973, the U. S. Court of Appeals for the District 

of Columbia remanded to EPA the new source performance standards for 

Portland cement plants (40 C.F.R. 60.60 et seq.) promulgated by EPA 

under §111 of the Clean Air Act. EPA has reviewed its standards 

for these plants pursuant to the remand and has concluded that the 

standards other than the opacity standard should not be revised. 

The bases for these standards are set forth in full below. 

This description of the bases for the standards responds to concerns 

expressed by the Court in its opinion explaining the bases for the 

remand. In order to assure that all of the Court's concerns are 

addressed, Appendix I is provided which lists the questions raised 

by the Court and EPA's responses to these questions. 

••.-•sia->»f 

111 
•wTi P.6 

EPA sought and received corrments from the public and 

the affected industry in developing the challenged standards 

prior to proposal and during the proposal period prior to 

promulgation. Criticisms of these standards were again 

raised by petitioners and intervenors in connection with 

the legal challenge to these standards and were also carefully 

reviewed. EPA has, of course, carefully considered the 

comments as well as the order of the U.S. Court of Appeals 

for the District of Columbia Circuit in responding to this 

remand. However, to further insure that the affected industries 

had an opportunity to comment on EPA's response to the remand 

and to insure that a reviewing court would have the benefit 

of EPA's response to such comments, a proposed remand response 

was submitted for comment to the petitioner and intervenors 

in this case. 

At the request of Appalachian Power Co. and Essex Chemical 

Corporation, petitioners in another case in which new source 

performance standards were remanded, Essex Chemical Corp. v. 

EPA and Appalachian Power Co. v. EPA, 486 F.2d 427 (C.A.D.C. 1973), 

copies of the remand response were also submitted to these 

companies for comment. The remanded issues in the latter 

decision included an issue raised in this case, i.e. reliability 

of opacity readings, and EPA believed it appropriate to obtain 

iv 

$£!£$ 
P.7 

the comments of these companies with respect to this issue. 

Comments were received from both companies. 

The comments received were carefully reviewed and have 

persuaded the agency that no revision should be made to the 

standards other than the opacity standard. Because it was 

not found necessary or desirable to revise the standards in 

any other respect as a result of the comments received, the 

proposed response as submitted to petitioners is set forth 

as a final response. (Minor corrections have been made to the 

text of the response on pages 8, 26, and 39.) The comments 

received with respect to issues other than opacity and EPA's 

response to these comments are set forth in Appendix II. 

Because substantial revisions were deemed necessary to EPA's 

draft remand response on the issue of opacity, EPA's 

discussion of opacity and justification for the revised 

opacity standard are set forth in full in Appendix III of 

this response. 

Copies of documents referenced herein are available from 

Emission Standards and Engineering Division, Environmental 

Protection Agency, Research Triangle Park, North Carolina 27711, 

Attention: Mr. Don R. Goodwin. 

Date / /yActino Administrator 

-_iJi«';::<v.^.' 
P.8 

CONTENTS 

Section Page 

HISTORY OF CONTROL TECHNIQUES 1 

COMPARISON OF WET PROCESS AND DRY PROCESS EMISSION CONTROLS 4 

TESTING 7 

CONTROL EQUIPMENT VENDOR STATEMENTS 15 

OPACITY STANDARD 16 

COSTS 29 

ADVERSE ENVIRONMENTAL IMPACTS 30 

SUMMARY 34 

APPENDICES 

I. EPA RESPONSES TO SPECIFIC ISSUES RAISED BY THE COURT 37 

REFERENCES FOR BODY OF RESPONSE AND APPENDIX I 59 

II. EPA RESPONSE TO PETITIONERS' COMMENTS REGARDING EPA 

RESPONSE TO REMAND 61 

REFERENCES FOR APPENDIX II . 82 

III. PORTLAND CEMENT REMAND RESPONSE. 83 

PART A: OPACITY STANDARD 85 

REFERENCES FOR APPENDIX III, PART A 124 

PART B: PREAMBLE AND AMENDMENTS TO REGULATIONS 127 

TECHNICAL REPORT DATA SHEET 152 

\%iW& 

vn 
P.9 

HISTORY OF CONTROL TECHNIQUES 

Prior to December 19 70 when the Clean Air Act was 

amended, EPA and its predecessor agencies had acquired 

extensive knowledge of portland cement operations. A 

study of the industry had been made by the U. S. Department of Health, Education, and Welfare and in 19 67 a report was published entitled, "Atmospheric Emissions from 

the Manufacture of Portland Cement", PHS Publication No. 

1/ 

999-AP-17. Engineers from EPA's predecessor agencies had 

inspected numerous plants and discussed control technology 

with vendors and knowledgeable individuals within the 

cement industry and had provided technical assistance to 

State and local air pollution control agencies regarding 

air pollution problems associated with cement plants. 

Further information regarding cement plants was developed 

by EPA engineers for publications concerning cement plant 

cont-rol technology, e.g., AP-51, "Control Techniques for 

V Particulate Air Pollutants", 1969. In addition, a report 

dated September 30, 1970, relating to the establishment of 

national emission standards for portland cement manufacturing 

plants had been prepared under contract by the Research 

3/ Triangle Institute and Pedco-Environmental, Incorporated.-

These references were used to obtain general knowledge 

of cement plant operation, control and nature and quantity 

1 

•jix_s:Viri.*:iS> 
""wi -ip p i n..j***!-pi! P.10 

of emissions. They were also used for their enumeration 

of cement plants in the United States. 

It was recognized that at portland cement plants, 

there are several sources of dust,- v/ith some more difficult 

and more costly to control than others. Kilns were 

recognized as the most difficult and costly to control. 

Exhaust gases from kilns are hot, contain heavy concentrations of very fine dust, and often large fractions of water 

vapor. Clinker coolers which are used-to cool the product 

from the kiln were considered easier to control because 

they contain more coarse particulates and less moisture. 

Other equipment in cement plants was generally operated at X^-*: 

ambient temperature, and therefore easier to control. For 

instance, grinders and conveyors often produced heavy concentrations of very fine particulates, but since this dust 

is handled at room temperature, it can be collected in 

fabric filters or baghouses which the cement industry acknowledged to be extremely effective in controlling dust. 

For those sources operated at ambient temperature, 

there has never been an argument with the cement industry 

as to how they should be controlled. The industry acknowledged that baghouses were the most effective devices and 

since they collected a larger fraction of their product— 

cement—than any other available device, the industry 
P.11 

readily used such devices. In the case of clinker coolers, 

many cement plants had used only centrifugal collectors 

to remove the coarse particulate from exhaust gases. However, 

in 1970, it was observed that several plants were installing 

more effective devices, usually electrostatic precipitators 

or baghouses. EPA observations indicated that both electrostatic precipitators.and baghouses appeared to be effective 

in controlling particulate emissions. 

In the case of cement kilns, by 1970 industry had 

generally supplemented centrifugal, collectors with electrostatic precipitators or baghouses. (Centrifugal collectors '$01$% 

are not capable of collecting the very fine particulates 

that are released from the kilns and would not therefore 

be acceptable in most communities in the United States.) 

There are many more kilns in the United States equipped 

with precipitators than with baghouses but baghouses have 

been applied to both wet and dry process kilns. Precipitators 

can be designed to achieve extremely high efficiencies but the 

higher the efficiency the more costly the unit. 

Because precipitators can be purchased which will operate 

over a range of efficiencies, plant operators that wished 

to control emissions but not necessarily to the high 

efficiency that baghouses achieve generally selected lower 

efficiency, and thus lower cost, precipitators, As public 
P.12 

pressure and local regulations .caused plant operators 

to install higher efficiency equipment, more plant 

operators chose to install baghouses. The best controlled 

kilns observed and -tested by EPA were controlled by baghouses. 

Later data v/hich v/ill be discussed below shov/ that precipitator 

controlled plants can also meet the standards. 

COMPARISON OF WET PROCESS AND DRY PROCESS EMISSION CONTROLS 

Both precipitators and baghouses are used on wet 

process as well as dry process kilns. The only difference 

between controlling emissions from the two processes is that the 

gases from the v/et process kiln contain 25-40 percent moisture 

by volume whereas those from a dry process kiln contain less 

than 5 percent moisture. At one time, plant operators feared 

that this additional moisture v/ould clog bags and cause 

shutdowns. It was also feared that baghouses could not be 

used on wet process plants in cold climates because of condensation. This apprehension is why there are fewer baghouses on wet process plants than on dry process plants. 

However, at actual installations these problems have been 

resolved by insulating and if necessary heating the exhaust 

emissions to keep the moisture from condensing. There are 

presently wet process plants with baghouses operating 

successfully in such cold and moist climates as Thomaston, 

%§&0i® 
P.13 

Maine (Dragon Cement Company), Lake Oswego, Oregon 

(Oregon Portland Cement Company), and Northampton, 

Pennsylvania (Universal Atlas Company). 

The existence of the greater moisture content in-v/et 

process gases means that a greater volume of emissions 

must be controlled at such plants. Thus, controlling emissions from wet process kilns will cost more, both for heating and insulation as well as treating the additional 

volume of gases, than will controlling emissions from dry 

process plants. The cost of insulating a wet process baghouse or precipitator would depend on the external temperature range. Nevertheless, the differential cost of insulating P^ip 

a wet as opposed to a dry process plant is not significant 

compared to other dust control costs. 

The greater volume of gas from a wet process plant requires an equivalent increase in baghouse or precipitator 

size. For a 10,000 bbl per day plant, the cost of a wet 

process baghouse would be approximately $890,000 as opposed 

to approximately $730,000 for a dry process baghouse. Corresponding costs for an electrostatic precipitator are estimated as $750,000 and $650,000 for wet and dry process plants, 

4/ respectively.-

However, these additional costs for a v/et process plant 

are largely offset by the fact that a wet process plant 

does not need to control -.aissions from the grinding 
P.14 

"1 

process before the raw material is put in the kilns. This 

emission control equipment for a 10,000 bbl a day dry process 

4/ 

plant costs approximately $90,000 , 

Achieving the same mass particulate limit per ton of 

cement produced is more difficult for a v/et process plant 

than a dry process plant because of the greater volume of 

emissions and because of inherent limitations of dust 

collectors, Baghouses and precipitators can only reduce 

concentrations of particulates of gas emissions down to 

certain levels. Since wet process kilns emit greater 

volumes of gas than dry process kilns of equivalent size, 

a given concentration of particulates emitted will result in 

a greater total amount of particulates being emitted from a 

wet process kiln per unit of cement produced. 

For example, if a baghouse or precipitator can reduce 

concentrations of particulates down to a certain number of 

grains per actual cubic foot of gas emitted, the total emissions of particulates from a wet process plant per unit of 

cement produced will be 25-40 percent higher than the total 

emissions of particulates from a dry process plant because 

of the 25-40 percent greater volume of gases which wet process 

plants emit. Thus, the highest level of particulate control, 

expressed in pounds per ton of dry feed, which a wet process 

plant can achieve would result in about 25-40 percent more 

emissions than that from a dry process plant. As will be 

discussed later, EPA took this into account in setting the 

standard. 

6 

:t:Wti&m. 
P.15 

TESTING 

While EPA was knowledgeable in 19 70 regarding applicable control devices for cement plants, they possessed very 

little source test information with regard to the emission 

of particulates from cement plants. Most of the test data had 

been collected using the American Society of Mechanical 

Engineers (ASME) Power Test Code'. This is considerably less 

specific and as a result different from the EPA particulate 

sampling method v/hich had been utilized to a large' degree 

with incinerators and combustion sources. It was recognized that an appreciable effort would be required to survey 

and select plants demonstrating best control technology 

and to evaluate the emissions from these sources using 

the EPA particulate sampling method. 

Early in 1971, EPA engineers contacted the Portland 

Cement Association, the Bureau of Mines, and knowledgeable 

vendors of air pollution control equipment. They procured 

pertinent information regarding what appeared to be the 

better controlled plants and arranged inspection tours to 

evaluate the apparent efficiency of the air pollution control 

equipment at various plants. During these inspections, EPA 

engineers observed that those plants—both dry and wet 

process—equipped with baghouses appeared to operate with 

less particulate emissions than did those plants at which 

a~? The ASME code is broadly defined such that it covers several 

techniques including even the EPA method with and without 

impingers. However, most ASME tests have been conducted 

with a different filter and under different conditions than 

EPA Method 5 such that results are not normally comparable 

to the EPA method. 
P.16 

\ 

the kilns were equipped with precipitators. Nevertheless, some 

precipitator-equipped kilns also exhibited what appeared to be 

good control of particulates. The basis for the initial judgment 

of the effectiveness of control was the amount of visible emissions 

emanating from stacks and leaks in ductwork, etc., as well as 

observation of the quantity of dust deposited on surfaces of roofs, 

floors, equipment, etc., within the plant. Four plants were inspected 

where kilns equipped with baghouses had minimum dust emissions and 

appeared to be operated in an extremely clean manner. These four 

plants were operated by Ideal Cement at Tijeras, New Mexico; Dragon 

Cement at Northampton, Pennsylvania; Oregon Portland Cement at Lake 

Oswego, Oregon; and Cop!ay Cement Company at Nazareth, Pennsylvania. 

There were four plants where kilns equipped with precipitators also 

appeared to be well operated and with minimum dust emissions. These 

kilns were at plants operated by the Ideal Cement Company in Seattle, 

Washington; the Maule Industries plant at Hialeah, Florida; the Lone 

Star Cement plant at Greencastie, Indiana; and the Ideal Cement plant 

at Castle Hayne, North Carolina. Cement plants equipped with both 

types of control devices were observed which exhibited heavy concentrations 

of dust in and around the buildings and in the gases being discharged 

from stacks serving the kilns. The latter instances appeared to be the 

result of inadequate maintenance and/or dust collection equipment 

deficiencies. 

•?*$&£-»•?$ 
P.17 

As a result of plant visits, EPA selected plants for its 

testing program of kilns, clinker coolers, and finish mills. 

Five kiln installations were tested as well as three clinker 

coolers, one raw mill, and three finish mills. These included 

a wet process kiln with a baghouse at Harleyville, South 

Carolina which appeared tb be so poorly maintained that 

results would be questionsable. Nevertheless, with the time 

constraints in the Clean Air Act, it. was deemed necessary 

to test these installations to gather information for setting our standards. It is emphasized that the selection of 

test sites was a compromise between what appeared to be best 

available control and the ability to conduct representative 

source tests. Four plants had to be discounted because the 

kiln control devices were not constructed in a manner that 

would allow them to be tested. These were the Ideal Cement 

Company in Tijeras, New Mexico; the Universal Atlas plant in 

Northhampton, Pennsylvania; the Lone Star Cement Company in 

Greencastie, Indiana; and the Coplay Cement Company in Nazareth, 

Pennsylvania. These included open discharge baghouses and 

precipitators in which the configuration of the ductwork 

made testing impossible. The kilns that were tested before 

proposal were operated by Dragon Cement Company in Northampton, 

Pennsylvania (dry process with baghouse, Emission Testing Report 

5/ 

ETB Test Number 71-MM-05); by Ideal Cement Company in 

Seattle, Washington (wet process with precipitator, ETB Test 

Number 71-MM-03); by Maule Industries in Hialeah, Florida 

JJ 

(wet process with precipitator, ETB Test Number 71-MM-01); 

0M$!$$i 
P.18 

1 

and by'Giant Portland Cement in Harleyville, South Carolina 

8/ 

(wet process with baghouse, ETB Test Number 71-MM-07)T 

The test data .obtained from these kiln.*"., include the 

amount of particulates collected in both the front half and 

the back half of the EPA sampling train. At the time EPA 

proposed these standards, it was anticipated- that compliance 

with the standards would be determined by measuring particulates captured in the total train (front half plus the back 

half of the sampling train). Howeyer, the standard as promulgated requires that compliance be determined by measuring 

only the particulates collected in the front half of the 

train. This change in sampling techniques required for 

compliance in no way brings the test data into question since 

EPA obtained data on the catch in the front half of the train, 

The only effect of the change is that back half test results 

are no longer used for compliance purposes. All particulate 

emission data referred to in this Notice refers to the front 

half catch unless otherwise noted. 

The test results for the four plants showed the following averages: 

Dragon Cement Company 0,07 lbs/ton 

Ideal Cement Company 0,88 lbs/ton 

*M?W;-S 

10 
P.19 

Maule Industries 1.15 lbs/ton 

Giant Portland Cement 0.52 lbs/ton 

As these results show, the Dragon Cement dry process 

kiln equipped with a baghouse was operating well below the 

__/ 

standard but none of the other three plants, all of which 

were wet process operations, met the eventual limit of .3 

pound of particulate per ton of feed. However, the control 

devices on these plants did not appear to be operating at 

optimum effectiveness during the test period. For example, 

the baghouse at the Giant Portland Cement Company plant in 

Harleyville, South Carolina v/as actually a 24-compartment 

unit with 12 separate stacks. EPA tested each of the 12 

stacks and averaged the results'. P.esults showed emissions ^".KSwell in excess of the proposed standard; however, visible 

emissions from some stacks looked better than others indicating 

that the bags in some of the compartments were in better condition than in others. There was considerable evidence of poor 

maintenance in that dust was observed on the roof of the 

baghouse and on other horizontal surfaces in proximity to 

the baghouse discharges. 

Taking into account that the only difference between 

the emissions of wet and dry process plants is the higher 

moisture content of the wet process emissions, EPA estimated 

Lw7 Subsequent to the EPA tests, the plant operators conducted 

comparison tests using a somewhat different test procedure. 

Results were similar, averaging 7 percent lov/er than EPA 

measurements. The company, Martin Marietta Cement, has stated 

that they believe the two test procedures give the same resuits and requested that EPA certify its particulate test met., 

equivalent to Method 5. No action was taken on the request 

because EPA had not established guidelines for determining 

equivalency and felt that more comparative testing was needed 

before the method could be deemed equivalent. 

11 
from the dry process test that wet process plants could 

achieve the standard by a reasonable margin. The Dragon 

test showed that particulate concentrations in gases could 

be controlled to approximately .00 5 grains per actual 

cubic foot of air emitted. If the volume of air emitted 

from a wet process kiln were 40% greater per ton of feed 

due to greater moisture content, the same concentration, 

.005 grains per actual cubic foot of air emitted, would 

result in 40% more pounds of particulate per ton of feed 

or, based on the Dragon test, would be about 0.1 pounds 

per ton of feed. This would be well below the standard. 

Although it was EPA's judgment based on this estimate 

and statements of control equipment vendors that wet as 

well as dry process plants could be controlled to meet the 

standards, EPA decided to conduct another test on a v/et 

process plant. A wet process kiln equipped with a baghouse 

at the Oregon Portland Cement installation at Lake Oswego, 

2/ 

Oregon, was selected and a test was run in August of 19 71 

shortly after the standards were proposed. During the test, 

it was observed that there were visible emissions from the 

stack at somewhat greater opacities than had been observed 

during the initial inspection. The process was upset during 

testing and EPA engineers believe that bags were broken. Subsequent evaluation of the data shov/ed that emissions were considerably greater than emissions from 

12 
P.21 

the Dragon Cement 'Company—averaging .60 pound per ton of 

feed. Discussions v/ere held with company personnel and it 

was agreed that efforts would be made to repair the system 

such that it would operate in a more representative manner. 

Such repairs were made although it must be emphasized that 

the repairs v/ere still not of the type that would be considered good operating and maintenance practice. In most 

instances, the broken bags were merely blocked or tied off 

in the system such that they no longer served as filter 

media. The EPA engineer supervising the test estimated 

15 percent of the bags v/ere tied off during the test. This 

effectively removed some of the fabric filter area from the 

system and meant that the remaining bags were required to 

perform the task that the entire baghouse would perform 

under well maintained conditions. This decreased filter 

area tended to cause greater wear on the bags and could have 

resulted in greater particulate emissions. Nevertheless, 

tests on this plant were run in October of 1971, which 

showed average emissions of 0.28 lbs/ton (Emission Testing 

Report ETB Test Number 71-MM-15)V Thus, at the time EPA 

promulgated the standard both a wet and a dry process plant 

had shown in tests that they could meet the standard. 

0$rWk 

13 
Since the standard was promulgated, summary test data 

on other Portland cement plant kilns have been obtained by 

EPA from a State air pollution control agency. One test 

was conducted by a private testing firm commissioned by the 

plant operator and the other test was conducted by plant 

personnel. The data may be obtained from EPA. They show 

the following: 

Test Date Name of Company flmissions in 

lbs/ton of dry feed 

4/18-25/72 Lehigh Portland Cement 0.125 

Company, Union Bridge, 

Md., dry process,electrical 

precipitator jo/ £$A0% 

7/11-14/73 Marquette Cement Manufacturing 0.087 

Company, Hagerstown, Md., dry 

process,electrical precipitator —' 

Thus, tv/o additional portland cement plant kilns appear 

capable of meeting the standard. To date, therefore, both 

a wet and dry process plant using a baghouse have been shown 

by EPA tests to have achieved the standard and data submitted 

to a State air pollution control agency indicates that two 

additional dry process plants using precipitators have 

achieved the standard. 

The EPA tests which showed emissions above the standard 

do not shov/ that those sources could not meet the standard. 

They only showed that they were not meeting it when tested, 

whether due to inadequate maintenance, inadequate control 

equipment, temporary upset, or some other reason. 

14 
P.23 

CONTROL EQUIPMENT VENDOR STATEMENTS 

Control equipment vendors have stated that their 

equipment will permit the attainment of the standards. 

Mr. T. A. Brown of the Koppers Company in a letter to EPA 

dated September 30, 19 71, said that he saw no problem meeting the standard with electrostatic precipitators. 

Wheelabrator-Frye in a letter dated A.pril 7, 1972, said it 

would guarantee Medusa Portland Cement Company that its 

precipitators and baghouses would limit emissions belov/ the 

standard. Buell Environ-tech in a letter dated May 10, 

1972, and Kaiser Engineers in a letter dated May 10, 1972, 

said their precipitators would limit emissions from wet 

process plants to the standard. 

EPA believes that these statements are useful supplementary evidence confirming that the standards can be met. 

While considerations of self interest could lead a control 

equipment vendor to advocate a stringent standard, it would 

be contrary to the self-interest of such a vendor to repre*-

sent that his equipment could meet the standard if it could 

not. It would be especially contrary to the" self-interest 

of the vendor to represent or guarantee to a potential 

purchaser of his equipment that it could meet the standard 

since the vendor would be liable for failure to satisfy his 

obligations. Furthermore, all of these vendors have good 

15 

?S\y^TJfe.;i*f, 
m n j wpi i 11 P.24 

reputations and they would not have achieved nor could 

they maintain their reputations if they misrepresented 

the capability of their equipment. Because of these 

factors and because the vendor statements supplement the 

source tests rather than serve as a sole basis for the 

standard, EPA believes that the expenditure of time and 

resources needed to independently verify the vendors' 

statements is not warranted. 

One of the factors which several of the vendors and 

many cement plant operators expressed doubt about was 

whether the standard could be rrtet at all times including 

periods of startup, shutdown, and upset. EPA has promulgated regulations which make it clear that EPA's mass emission limits apply only during performance tests rather than 

at all times. The standards do not apply during periods of 

startup, shutdown, and malfunction. (38 F.R. 25864, 

October 15, 1973). 

OPACITY STANDARD 

EPA promulgated opacity limits as well as mass emission limits because opacity limits provide an effective and 

easily utilized means of determining relative mass emissions 

as well as wether control equipment is being properly maintained and operated. EPA personnel observed during testing 

that tv/o plants v/hich met the mass emission standard did 

not exceed 10 percent opacity during emission test periods. 

16 

(_$$&$ 
P.25 

An additional cement kiln v/as observed that had no visible 

emissions, but it could not be tested for mass emissions 

due to physical limitations. A summary of mass particulate 

emissions and observed opacities for cement kilns investigated by EPA is shown in Table 1. 

i&TsJft 

17 
P.26 

Table 1. PARTICULATE MATTER AND OPACITY OF EMISSIONS 

FROM CEMENT KILNS 

Cement Plant 

Measured Parti- Opacity of 

culate Emissions, Visible 

lbs/ton feed, Emissions, %, 

from kiln from kiln 

Dragon Cement Company 0.0705 5-1 0 

Northhampton, Pa. 

Oregon Portland Cement 

Lake Osv/ego, Oregon 

Test No. 1, August 1971 0.56 10 - 30 

Test No. 2, October 1971 0.272 0-1 0 

Giant Portland Cement 0.574 0-3 5 

Harleyville, S. C. 

Ideal Cement Company 0.883 20 

Seattle, Washington eii.ji.;:&:j 

Ideal Cement Company 0 

Tijeras, New Mexico 

18 
P.27 

EPA has given adequate consideration to the problems 

of measuring opacity by use of the trained and qualified 

observer. Use of a human observer to measure stack opacity 

entails essentially the same considerations that would 

be given to use of a mechanical instrument, i.e., the 

calibration, accuracy, and precision of the instrument. 

Calibration of any instrument is achieved by comparing 

the test instrument's output against a known standard. 

Similarly, a human observer must be qualified or "calibrated" 

by comparing his observations of 25 white and 25 black 

plumes with the measurements of a calibrated smoke indicator 

or light transmission meter. See Appendix to 40 C.F.R. Part 

60, Test Method 9 (36 FR 24895, December 23, 1971). 

EPA has evaluated the accuracy and the precision of 

the qualified observer. Precision of an instrument refers 

to the ability to consistently produce essentially the 

same measurement or response when subjected to the same set 

of test conditions. A precise instrument is not necessarily 

accurate because interferences or improper test conditions 

may produce a bias that would cause the measurement to be 

consistently in error when compared with the "true" value 

of the quantity being measured. In the document 

entitled, Optical Properties and Visual Effects of Smoke 

!_i^t&? 

12/ 

Stack Plumes (Public Health Service Publication No. 999-AP-30.), 

19 
P.28 

a description is given of tests designed to evaluate the 

precision and accuracy of the qualified observer (section 

title: Evaluation of Plumes by Trained Observers, pages 

23-29). The evaluation showed that the., precision of the 

qualified observer was reasonably good, i.e., "Group assessments showed good agreement for similar sun-plume-viewer 

geometries" (p. 25), however tiie accuracy of the observation 

was greatly affected by the position of the observer with 

respect to the sun and plume due to light scattering effects 

of the plume (Figures 16, 17, and 19, and Tables 1 and 2) . This 

light scattering interference v/as essentially nullified ^H* ' 

by positioning the observer v/ith his back to the sun as 

is shown in Figure 16 (East: 9:30, 10:00, 10:30 a.m.) and 

Figure 17 (East: 9;45, 10:15, 10:45 a.m.). Figures 16 

and 17 show that a qualified observer with the sun at his 

back was able to determine the opacity of both white and 

black plumes with very good agreement (accuracy) with the 

in-stack light transmission meter measurements. 

Thus petitioners miscited test data in Table 2 of 

the Optical Properties report as indicating that opacity 

tests are unreliable. Data in this table were developed 

without regard to the placement of observers with respect 

to the sun and plume. As discussed previously, the sun 

must be to the observer's back to accurately determine 

20 
P.29 

opacity of a plume. The EPA test method for opacity 

specifically requires that "The qualified observer stands 

at approximately two stack heights, but not more than a 

quarter of a. mile from the base of the stack with the sun 

to his back." (40 CFR Part 60 Appendix, Test Method 9) . 

EPA periodically conducts smoke reading courses for 

the purpose of qualifying candidates as smoke observers in 

accordance with the requirements of Test Method 9. In the 

smoke school, an observer is shown and"assigns opacity readings to 25 different black plumes and 25 different white 

plumes. The readings, which are recorded on data sheets, W0). 

are assigned in even 5 percent increments. In order to 

qualify, no single reading may be in error by more than 15 

percent opacity; the average error may not exceed 7.5 percent opacity in each category. 

In order to assess the accuracy and precision with 

which qualified observers read plumes, the results of 50 

individuals v/ere selected at random from candidates in nine 

smoke school courses conducted in 1972 and 1973. This 

provided a total of 2500 observations for analysis. These 

results are available in a report titled Average Observational 

19/ 

Error Associated with Smoke Plumes at Levels- of Known Opacity. — 

The analysis of these observations considered two 

parameters: 

21 
P.30 

1 . the average, error made in observation of plumes 

of known opacity, and 

2. the precision of individual observations 

of plumes of known opacity. 

The results of these analyses are described belov/. 

For each smoke plume which v/as observed the error or 

difference between the observed opacity and the actual 

opacity (observed opacity minus actual opacity) v/as recorded. 

For plumes of 0%, 5%, 10%, and 15% opacity, these errors 

were tabulated separately for the respective plume. Above 

this level plumes were combined into 10% opacity intervals 

for convenience of calculation. Thus a 5% error associated \8$M& 

with a plume of either 20% or 25% was tabulated under the 

actual opacity of "20% or 25%." 

Two calculations were made using the above data: the 

"average error," and the "average absolute error." The 

following example illustrates these calculations: 

Data for a plume of 

actual opacity =10 % 

- 5% error = 2 

0% error = 31 

+5% error = 31 

+10% error = 23 

+15% error = _6_ 

9 3 total observations 

2(-5%) + 31(5%) + 23(10%) + 6(15%) 

Average error =9 3 = +5.0% 

2(5%) + 31(5%) + 23,(10%) 4 6(15%) 

Average absolute error = 9"3 = 5.2 

22 i 
P.31 

The "average error" indicates the overall bias of the 

group with respect to a particular plume. A positive value 

would indicate that the average observation is greater than 

the actual plume, and vice-versa. As example, a -5% error 

and a +5% error v/ould result in an "average error" of 0%. 

The "average absolute error" indicates the average 

absolute accuracy attained by the observers. As example, 

a -5% error and a +5% error would result in an average 

absolute error of 5%. 

The results of these calculations are shov/n in Table 2. 

Table 2. AVERAGE OBSERVATIONAL ERROR 

Average Absolute 

Actual Number of Average Error Error 

Opacity* Observations % Opacity % Opacity 

0 12 +3.3 3.3 

5 12 +2.5 2.5 

10 93 +5.0 5.2 

15 96 +2.8 5.4 

20 or 25 331 +2.5 5.0 

30 or 35. 409 +0.1 5.1 

40 or 45 606 -0.1 5.5 

50 or 55 393 -0.1 6.0 

60 or 65 235 -0.2 6.2 -

70 or 75 185 -1.2 6.1 

80 or 85 120 -2.4 6.0 

90 or 95 96 -2.6 4.6 

100 12 -5.8 5.8 

•Measured with a photoelectric transmissometer located in the 

smoke generator stack. 

t A review of Table 2 shows that on the average, the smoke 

readings can be made with good accuracy. With two exceptions, 

23 

ij^jil?^ 
P.32 

the average accuracy is within +3.3 percent. At two 

levels of opacity, 10% and 100%, the average error was 

noted to be 5% and 5.8% respectively. 

No test method is invariably perfectly accurate. 

Water vapor does not cause major problems in opacity testing. 

When stack emissions contain appreciable water vapor, the 

vapor becomes visible when the gases are cooled below the 

dew point and water condenses in fine droplets. Some water 

plumes are detached v/hile others are visible as released 

from the stack. However, since ambient air is normally 

much drier than stack emissions' containing visible water 

vapor, dilution causes the gases at some point to become 

unsaturated. At this point, condensed water evaporates and 

visually disappears from the plume. Trained smoke observers 

can discriminate between condensed water vapor and visible 

pollutants by determining the opacity at or after that point 

in the plume where the water vapor dissipates. 

Under relatively warm and dry conditions, the visible 

water plume evaporates and becomes invisible within a 

short distance of the stack. In cold weather, air has 

much less capacity to carry water vapor, the water plume 

Q/ The phenomenon of a "detached plume" is often observed 

when a warm moist gas stream is released into a cooler 

atmosphere, e.g., when hot, v/et exhaust gases from a wet 

process kiln are released to the atmosphere. Here the 

gases are clear at the point of discharge but become 

opaque as the wet gases mix with cooler air in the atmosphere. 

24 

W&M 
from a given source is usually much more pronounced and 

has a longer path. Due to the character of the dust and 

atmospheric conditions existing at a given point in time, 

i.e., humidity, cloud cover, rain, snow, etc., it may not 

be possible in some cases to evaluate opacities of the 

particulate fraction with sufficient precision to warrant 

enforcement action. In such cases, it is necessary to make 

multiple observations under varying atmospheric conditions. 

Opacity and v/ater vapor phenomena are shov/n photographically 

in the EPA report entitled, "A Report on Contaminated Water 

18/ 

Vapor Plumes". The proper place to deal with such small 

variations is at the time of enforcement. For example, the 

agency would not take, and the courts v/ould not sustain, 

enforcement action based upon opacity observations that 

do not exceed the standard by more than the average opacity 

error associated with the particular opacity standard. It 

is important to note in this connection that under §113(c)(1)(C) 

of the Clean Air Act criminal sanctions can only be imposed 

on persons who "knowingly" violate §111 standards. Also 

orders issued under §113(a)(4) must take into account "the 

seriousness of the violation and any good faith efforts to 

comply with applicable requirements." 

25 
P.34 

Opacity standards have been tested by time, experience, 

and litigation. California enacted a statutory opacity 

requirement in 1947. California Health and Safety Code 

24242, Stats. 1947, ch. 63251. In an analysis prepared 

for EPA by L. J. Duncan of The Mitre Corporation titled 

Analysis of Final State Implementation Plans - Rules and 

16/ 

Regulations, (APTD-1334, July 1972), Table XVI (p. 51-52) 

shows that every State has equivalent opacity restrictions 

applicable to particulate emissions. These range from 0% 

opacity ("no visible discharges") to 40% opacity during 

normal operations with most restrictions being 20% opacity. 

Botti Maryland (in two Air Quality Control Regions) and the 

District of Columbia have no visible discharge limitations. 

Various courts have upheld the validity of opacity 

requirements. See, e.g. State v. Fry Roofing Co., 495 F.2d 

751, 4 ERC 1116 (Oregon Court of Appeals 1972); People v. 

Plywood Manufacturers, 291 F.2d 587 (Superior Court of Los 

Angeles, California, 1955). 

Opacity standards are a necessary supplement to mass 

emission standards. Opacity standards help assure that 

sources and emission control systems continue to be properly 

maintained and operated so as to comply with mass emission 

standards. Particulate testing by EPA Method 5 and most 

other techniques requires an expenditure of $3,000 to $10,000 

26 

M&&L 
P.35 

per test including about 300 man-hours of technical personnel. 

Furthermore, scheduling and preparation are required such 

that it is seldom possible to conduct a test with less than 

two weeks notice. Therefore, Method 5 particulate tests 

can be conducted only on an infrequent basis. 

If there were no standards other than mass emission 

standards, operators could inadequately operate or maintain 

pollution control equipment at all times except during periods 

of performance testing. Operators are aware that two weeks 

or longer are necessary to schedule a typical stack test. 

If only small repairs were required, e.g., pump or fan repair 

or replacement of fabric filter bags, the operator could 

delay such remedial action and continue to pollute until 

shortly before the test is conducted. For some types of 

equipment such as scrubbers, the operator could reduce the 

energy input (the pressure drop through the system) when 

stack tests weren't being conducted and could release significantly more particulate than normal. Therefore, EPA has 

required that operators properly maintain air pollution control equipment at all times (40 CFR 60.11(d)) and meet 

opacity standards at all times except periods of startup, 

shutdown, malfunction, and as otherwise provided in the 

applicable standard (40 CFR 60.11(c)). 

d_7 Cost applicable to retests only. Initial performance test 

is usually more costly because of need to erect platforms, 

scaffolding, or other sampling facilities. 

27 

§Mm 
» i r '• • 

P.36 

Opacity of emissions is indicative of whether control 

equipment is properly maintained and operated. However, it 

is established as an independent enforceable standard, rather 

than an indicator of maintenance and operating conditions 

because information concerning the latter is peculiarly 

within the control of the plant operator. Furthermore, the 

time and expense required to prove that proper procedures 

have not been followed are so great that the provisions of 

40 CFR 60.11(d) by themselves (without opacity standards) 

would not provide an economically feasible means of insuring 

on a day-to-day basis that emissions of pollutants are within 

allowable limits. Opacity standards require nothing more 

than a trained observer and can be performed with no prior 

notice. However, in some cases, including times when opacity 

standards may not be violated, a full investigation of 

operating and maintenance conditions will be desirable. Accordingly, EPA has requirements for both opacity limits and 

proper operating and maintenance procedures. 

For the foregoing reasons, EPA believes that opacity 

standards are such an indispensible air pollution control 

tool for the States and Federal government, and that the range 

of uncertainty in applying such standards is so small that 

this type of standard should continue to be used by EPA as 

well as the States. 

28 

m$&% 
P.37 

COSTS 

The only cost issue v/hich the Court remanded to EPA_ 

was whether the costs of a standard which precluded the 

use of wet process kilns and precipitators were reasonable. 

EPA's standard will not preclude use of wet process kilns 

nor of precipitators. This issue v/as discussed above 

along with -the relative costs of control equipment for wet 

and dry process kilns. 

For purposes of this remand, it is sufficient to state 

that EPA continues to believe that tlie economic costs 

associated with the standard are reasonable. This conclusion is based primarily on the reports: "The Financial 

Impact of Air Pollution Control Upon the Portland Cement 

4/ Industry" by J. R. Elias and J. M. Demenfand "The Cement 

Industry: Economic Impact of Pollution Control Costs" by 

13/ 

the Boston Consulting Group. 

29 
P.38 

ADVERSE ENVIRONMENTAL IMPACTS 

The new source performance standards for Portland cement 

plants are not expected to result in significant adverse 

environmental impact. The possible areas of adverse environmental impact are: 1) increased pollution from generation, 

of electricity required to operate precipitators, 2) water 

pollution from disposal of collected particulate matter. 

Neither of these is a serious problem. 

The electric power rate required to operate a precipitator 

that would meet the new source standard on a typical v/et 

process kiln would be approximately 115 kilowatts. This 

should be compared with the total electric power rate consumption of a typical cement plant which approximates 5300 

kilowatts and with the 500,000 kilowatt output of a typical new 

steam generating electric power plant. The additional 

115 kilowatts v/ill thus have little incremental impact on 

pollution created by electric power generation generally 

and that created by electric power generation for Portland 

cement plants specifically. 

The above figures were developed on the following 

assumptions: A typical cement plant producing 2.5 million 

bbl of cement annually would exhaust gases at a rate of 

230,000 cfm. (Robert Elias and John Dement, "Financial 

Impact of Air Pollution Control Upon the Portland Cement 

i/ 

Industry"). In order to meet the new source performance 

30 

J3?i>S^ 
P.39 

standards of 0.3 pound per ton kiln 

feed (1.6 ton feed per ton product), based on an emission 

factor of 235 pounds per.ton of cement product, a precipitator 

would have to have a collection efficiency of approximately 

99.92 percent. A study conducted by Southern ResearchInstitute shows that precipitators recently installed on tv/o 

wet process plants which have collection efficiencies of 

99.92 and 99.95 percent had power rates of 440 watts per 

1000 cfm and 520 watts per 1000 cfm respectively. (A manual 

of Electrostatic Precipitator Technology, Contract CPA 

22-69-73 for NAPCA, Figure 18.10, Part II - Application 

Areas)WAt a power rate of 500 watts per 1000 cfm, a 

precipitator handling 230,000 cfm at a collection efficiency 

of 99.92 percent would require 115 kilov/atts. 

The total electrical consumption (excluding fuel) of 

a cement plant is 120 kilowatts per metric ton product. 

For the typical plant producing 44-45 metric tons per hour 

(2.1 million bbl per year), the total plant energy consumption 

approximates 5 300 kilowatts. (Southern Research Institute, 

"Development Document for Effluent Limitations Guidelines 

and Standards of Performance: Cement Manufacturing Industry," 

• 15 / 

Contract 68-01-0599) ~ 

State implementation plan requirements would require 

up to 81 kilowatts to be consumed in the precipitator of 

the typical cement kiln even if there were no 

t"s?i*f?£ 

31 
P.40 

applicable nov/ source standards. State implementation 

plans require controls cn the emission of particulate 

matter by cement plants ranging from 0.36 to 0.89 lb. per 

ton feed. ("Analysis of Final State Implementation Plans -

16/ 

Rules and Regulations," APTD-1334). These standards require 

collection efficiencies of 99.76-99.9U percent. The 

pov/er rates associated with these efficiencies are betv/een 

125-350 v/atts per cfm. A precipitator with an approximate 

size of 230,000 cfm would thus require between 29 and 81 

kilowatts to meet State Implementation "Plan standards. 

Although higher efficiency dust collectors will increase 

the amount of material collected, the new source performance 

standards v/ill not substantially increase the land disposal 

problems faced by cement plants. Furthermore, it will 

require the collection of dust v/hich would otherwise be 

vented to the atmosphere and indiscriminately deposited on 

land in the vicinity of the cement plant. The present 

practice in the cement industry is to dispose of the collected 

kiln dust that cannot be returned to the kiln. The waste 

dust is hauled or slurried to an unused part of the quarry 

from which the raw material came or is landfilled. Table 

3 summarizes the methods employed by 80 cement plants to 

dispose of kiln dust. 

!*•>'$**• * 

32 
P.41 

Table 3. METHODS OF DISPOSAL OF COLLECTED KILN DUST 

BY CEMENT PLANTS

 (a) 

Method Number of Percent of 80 

Plants Reporting Plants Reporting(D 

all dust returned to kiln 27 34 

surface piling (dry) 29 36 

returned to quarry (dry) 11 14 

leached 9 11 

slurried and discarded 7 9 

some sold or hauled away 8 10 

by contractor 

(a) Source: Southern Research Institute, "Development Document 

for Effluent Limitations Guidelines and Standards of Performance: Cement Manufacturing industry," Contract 6 8-01-

0599.15/ 

(bj Percentage total is greater than 100 because some plants 

report more than one method. 

State implementation plans require controls on the 

emi-: sion of particulate matter by cement plants ranging 

from 0.36 to 0.89 lb. per ton feed. Compliance with these 

standards will require cement plants to dispose of substantial 

amounts of material. The amount of additional dust collected 

to meet the new source performance standards of 0.30 lb. 

per ton feed will not be significantly greater than that 

collected to meet the state implementation plan standards. 

33 
P.42 

For similar reasons, the increased amount of material 

collected by higher efficiency dust collectors will not 

substantially increase the risk of water pollution. Present 

land disposal methods could permit dust v/ith a high 

alkaline content to-cause potential v/ater pollution problems 

from rainfall runoff or by percolation into streams and 

rivers. If alkalai dust were not controlled but instead 

were released to the atmosphere, it would also find its 

way into streams and rivers. However, containment and 

treatment of runoff from kiln-dust piles will eliminate 

the danger of water pollurion resulting from alkalai cement 

dust. The Southern Research Institute study previously cited 

15/ (EPA Contract 68-01-0599r^indicates that technology exists 

to treat the contaminated water resulting from leaching 

and describes that technology. 

In any event, the increase in the collection of 

particulate due to new source performance standards as 

compared to the collection of particulates resulting 

from the application of state implementation plan 

requirements will be insignificant. 

SUMMARY 

EPA thus concludes that the standards are achievable 

and have been achieved by both wet and dry process kilns, 

that the economic costs are reasonable and that the adverse 

environmental impact is minimal. EPA further concludes 

34 

«$#&•& 
P.43 

that the opacity standard is a valid and necessary standard 

which meets the requirements of §111 of the Clean Air Act. 

Therefore, EPA, after reconsidering the standards pursuant to the 

remand of the U. S. Court of Appeals for the Distric t of Columbia, 

has concluded that the standards should not be changed. 

SfSS^SS 

35 
P.44 

APPENDIX I 

EPA RESPONSES TO SPECIFIC ISSUES RAISED BY THE COURT 

37 
P.45 

APPENDIX'I 

This appendix contains responses to specific issues 

raised by the U.S. Court of Appeals for the District of 

Columbia in the Portland Cement case. References are to 

the Slip Opinion. 

Issue 1 

On page- 21, the Court asks EPA to respond to petitioner's 

comments concerning possible adverse environmental impact 

of the standards. 

Response 

These impacts are discussed in the text above. 

Issue 2 

On page 23 and 24 and again on page 41, the Court asks 

EPA to consider the justification for and economic impact 

of standards that would terminate the use of wet process 

kilns and precipitator control of both wet and dry process 

emissions. 

Response 

EPA's standards do not preclude the use of either wet 

process kilns or precipitators. Test results show both have 

met the standards. This is discussed in the text above, 

along with economic considerations. 

39 

S®"*^ 
P.46 

Issue 3 

In footnote 5 5 the Court s?id: 

"If the same technology is now available and 

in use for incinerators, steam power plants and 

cement plants, the Administrator on remand may wish 

to offer some further explanation of the difference 

in standards set simultaneously for the three 

industries." 

Response 

At the time the cement, incinerator and steam generator 

standards were promulgated, EPA had data showing that baghouses would enable both wet and dry process Portland cement 

kilns to achieve concentration levels of .03 grains per dry 

standard cubic foot (gr/dscf) or less. EPA judged but $$#$&?$ 

had not confirmed that a precipitator could achieve the 

same levels. EPA also suspected but had inadequate data 

to confirm that incinerators and steam generators could 

use baghouses to achieve concentration levels approximating 

those achieved by cement kiln baghouses. 

Because different types of sources emit gases of 

different composition at different velocities, it cannot 

be assumed that a device that removes particulates will 

be equally effective in removing every type of particulate 

from every type of source. Furthermore, different types 

of sources may emit substances v/hich will interfere with 

the operation of the control equipment. 

40 
Thus EPA based its incinerator, steam generator and 

cement standards primarily on applying baghouses to cement 

plants and assumed less efficient precipitators would be 

used for incinerators' and steam generators, although EPA 

had indications that baghouses could be applied to incinerators 

and steam generators and that precipitators could achieve 

emission concentrations similar to those of baghouses. 

As noted in the text above, precipitators on cement 

kilns do achieve the standards. As data is gathered showing precipitators, baghouses, or other dust collectors on 

incinerators and steam generators also can achieve similar 

concentration levels, the standards for these sources will 

be revised. Any data the cement industry has on the emission 

levels which can be achieved by incinerators and steam 

generators should be submitted to EPA to facilitate the 

review of the standards for these two source classes. 

:W*K? 

41 
ISSUE 4 

On page 37 the Court directs EPA to consider contentions presented in briefs to this Court, though not previously raised, unless EPA explains why they are not 

material. 

RESPONSE 

• The above text and these responses to questions raised 

by the Court effectively respond to the points raised 

by petitioners. 

ISSUE 5 

In footnote 73 the Court says it is uncertain whether 

the test v/as referred to in the Background Document as not 

available at the time this document was published v/as of 

one of the two kilns tested at the Dragon Plant or v/as 

located at still another plant. 

RESPONSE 

The missing test was that of the Giant Portland Cement 

plant in Harleyville, South Carolina, a wet process plant 

with a baghouse. 

ISSUE 6 

On page 40, the Court questions whether a single 

test is an adequate basis for inferring that all new 

cement plants would be able to meet the proposed standards. 

42 

$8? 
P.49 

RESPONSE 

At the time the standard was promulgated, EPA had 

tested two plants which met the standard (The Dragon and 

Oregon plants). Each test consisted of three repititions 

of two hour sampling periods or six total hours of testing. 

EPA has since obtained test results from two other plants 

which show emissions v/e 11 belov/ the standard: The Lehigh 

Portland Cement Co. and Marquette Cement Manufacturing Co. 

tests referenced in the text above. 

The Court in raising this issue referred to a letter 

from Mr. Kreichelt which v/as critical of EPA's basing the 

standard on tests which showed the standard was met at 

only one plant. As three additional plants have since been 

tested v/hich meet the standard, Mr. Kreichelt's criticism 

is no longer applicable. However, even if it were, the 

following considerations should be taken into account in 

evaluating his criticism. First it was based on the assumption, correct at that time, that EPA's test method would 

include particulates collected in the impinger portion of 

the sampling train. Upon this assumption, the one test 

result (Dragon Cement) referred to by Mr. Kreichelt showing 

the standard could be met would show an average of .184 

pounds per ton compared with the standard of .3 pounds per 

ton. However, the deletion in the promulgated standard of 

43 
P.50 

the requirement that impinger catch must be included-means 

that the Dragon plant in fact tested at .07 pounds per ton 

or less than one-fourth of the standard. 

Second, as noted, test results have since become 

available v/hich shov/ three more plants, including a wet 

process plant, have met the standard. 

Third, even if EPA did not have these additional test 

results, the Agency is not constrained to accept Mr. Kreichelt's 

definition of v/hat is "achievable." The greater the number 

of tests required to prove a standard can be met before the 

standard can be promulgated, the greater the likelihood the 

new source performance standards v/ould reflect only the feS-'^'i? 

technology and maintenance requirements v/hich existing 

plants have chosen to apply. However, EPA was testing to 

determine the best levels of control being achieved at 

existing plants. Engineering judgment was. then applied by 

EPA to determine whether new plants could be constructed to 

perform at control efficiencies equal to or better than that 

observed at the tested existing plants. EPA was not attempting to determine the statistical average performance of 

existing plants. 

ISSUE 7 

On page 41, the Court questions whether validity of 

standard is affected by the different testing method 

44 
P.51 

required by EPA in the promulgated standards and that 

used by EPA in its tests in developing the standards. 

The Court first refers to the elimination of the requirement in the pr-"--' .lighted standard that the impinger catch 

of the sampling train be included in determining the particulate emissions. 

RESPONSE 

In EPA's proposed standards the particulate sampling 

method required that both the front half (probe, cyclone 

and filter) and back half (impinger) catches of the sampling 

train be measured. When EPA tested the Dragon and Oregon 

plants, it calculated the pounds of particulate per ton of ^iJUt 

feed by adding the amounts collected in both the front 

and back half of the sampling train. However, EPA separately 

measured both front and back half catches. (See Summaries 

of Test Data for Standards of Performance for New Stationary 

UJ 

Sources, August 19 71.) Thus, the change in test methods in 

no way invalidated EPA's test results. It only rendered 

some of the data valueless. Based only on the probe,cyclone 

and filter catch data, the Dragon Cement plant emitted an 

average of 0.0 7 pounds per ton during the test of that plant 

(See Summaries of Test Data and Emission Testing Report, 

5/ 

ETB Test Number 71-MM-05T and the Oregon plant emitted an 

average of 0.28 pounds per ton (See Emission Testing Report, 

9/ 

ETB Test Number 71-MM-15). 

45 
P.52 

ISSUE 8 

On page 42, the Court asks the Administrator to explain' 

why compliance v/ith the standard is based on a two-hour 

test while the data base v/as developed on 30-minute tests? 

RESPONSE 

There were four ports to be sampled at Dragon 

Cement; during each of the three tests each port was 

tested for 30 minutes for a total sampling time of 2 

hours, the time required for compliance test. Thus, 

there are inevitable time periods during which no 

sampling will be done as it takes time to correctly ^,-»y; 

position and adjust the sampler at each traverse point. 

The Sources subject to this standard will also have such 

gaps in their own tests, which gaps will not invalidate 

their tests. 

The general provisions of 40 CFR 60 are being revised 

to clarify the fact that a run or repetition may be either 

continuous or intermittent, consistent with good engineering 

practice. This revision does not alter the test method; it 

only makes clear the fact that the normal practice of interrupting runs for such purposes as moving sampling equipment 

or sampling cyclic processes is, in fact, expected and is 

an accepted procedure which is within the scope of the test 

method. 

46 
P.53 

issur: 9 

On page 42, the Court raises the question on the 

basis of a handwritten note made by the EPA contractor, as 

to whether the tested plant v/as operating at maximum performance during testing. The contractor had noted, "Baghouse is undersize and production is held back due to this." 

Compliance tests under the regulation require, however, 

that "All performance tests shall be conducted while the 

affected facility is operating at or above the maximum 

production rate. ... " 

RESPONSE 

The handwritten note of the EPA_ contractor refers to 

a presurvey note of an EP/-_ engineer. That note referred 

to the potential production capacity of the plant as reported by plant personnel and did not indicate that the 

Dragon Cement kiln was being operated at an abnormally low 

production rate. 

A cement plant's production rate is related to many 

variables in the system. A few of the variables that could 

influence or limit the production rate are: the capacity 

of the grinders, the size of the kiln, the size of the fans 

or pumps in the system or the size of control equipment 

installed to control particulate emissions from the kiln. 

In addition,.variables such as kiln temperature, pressure, 

Btu content of fuel, excess air for combustion and moisture 

content of the feed could all directly or indirectly affect 

the production rate Of the cement plant. 

47 

S&£i_is <Sp£$6 p 
The baghouse installed at Dragon Cement was sized for 

the production rate desired by the company taking into 

account the other variables -in the system. During the test 

period, the plant was operated at its normal maximum production 

rate. 

ISSUE 10 

On page 42 and 43, the Court restated petitioner's 

contention that EPA erred in the Dragon test in (a) not 

using observed measured values, (b) substituting lower 

reading from another test run for a reading based on contamination of the sampler by solids, and (c) pouring [&&?*#?; 

liquid obtained from one run into the beaker used to hold 

liquid from another run. The Court went on to say 

"However, deviations from prescribed measurement techniques 

are not necessarily significant as to testing results, 

and if petitioners press this point on remand they must 

establish that such test deviations bear significant consequences." Nevertheless, in the interest of providing a 

complete response to the Court's remand EPA v/ill respond 

to this issue. 

RESPONSE 

Petitioner's comments v/ere based on comments made bv 

5/ 

EPA on page 7 of the Dragon Test Report, ETB Test No. 71-MM-G5. 

EPA has to test existing plants as they are. The Dragon 

plant had allov/ed solids to build up in the duct downstream 

of the baghouse. These solids, v/hich EPA was unaware of 

48 
P.55 

until after Test Run 1, contaminated the probe and cyclone 

and also reduced the cross section of the duct. In order 

to correct for these solids, EPA had to compute the cross 

section of the duct through which air could pass*. 

The catch of the front half of the sampling train 

is measured by adding together the probe and cyclone catch 

and the filter catch. The probe and cyclone capture large 

particles and the filter catches smaller particles. It 

was observed that the probe and cyclone in Test Run 1 

captured 9 8.1 mg of particulates while the probe and cyclone 

catch in Run 2 v/as 15.9 mg and'in Run 3 was 18.0 mg. It 

was also observed that at one sampling point in the duct the 

gas velocity was zero. This led to an inspection of the 

duct which showed that solids v/ere in fact deposited on 

the bottom. The probe and cyclone had obviously collected 

some of these particles. Therefore, the catch of the probe 

and cyclone v/as assumed to be 17.0 mg, the average of Runs 

2 and 3. The actual filter catch in Run 1, 38.6 mg, v/as 

used. Thus a part of the Run 1 results were calculated 

rather than measured. However, the possible error introduced in this one portion of one Test Run at the Dragon 

plant was so small that in the opinion of EPA it does not 

substantively prejudice the results of the Dragon test 

and certainly not the standard, v/hich was based on other 

tests in addition to the Dragon tests. 

49 

\ffl&&$ 
P.56_ 

The mistake in pouring liquid obtained in one run in the 

wrong beaker is now irrelevant since the liquid was impinger water. 

The promulgated standard deleted the requirement that impinger 

catch be added in ascertaining compliance. 

ISSUE 11 

On pages 43-44, the Court directs EPA to respond to criticisms 

expressed by Mr. Striker to the effect that EPA underestimated the 

stack gas flow rate, and thus the amount of particulates emitted, by 

a factor of two. 

RESPONSE 

Before responding to specific allegations of error made by 

Mr. Striker, it is important to note that even if Mr. Striker were 

correct in his allegations, and EPA believes that he is not, the 

tests would still show that the Dragon Cement Plant met the EPA 

promulgated new source performance standard. Mr. Striker concluded 

that the "correct emission of particulate matter is in the neighborhood 

of .404 pounds per ton of kiln feed." But this figure was reached 

by using 0.2 lbs/ton based on the entire train for the first, and 

maximum, of three tests. After changing to a front-half catch only, 

(the terms of the promulgated new source performance standard), the 

result from this test was 0.11 lbs/ton and even if the error that 

Mr. Striker claims had been possible and had occurred, test results 

from this maximum test would be 0.22 lbs/ton and average test results 

would change from .07 lbs/ton to .14 lbs/ton, well below the standard 

of 0.3 lbs/ton. 

50 

*#%M*.& 
'.57 

It is this average of three tests that is to be used for 

compliance with the new source performance standard. This plant 

would still be well below new source performance standards of .30 

lbs/ton. 

In any event, EPA has thoroughly considered Mr. Striker's 

specific allegations of error and disagree with him. Mr. Striker's 

allegations are well summarized by the Court as follows: 

Finally, engineer Striker claims significant errors of 

measurement were made in determining the measurement of the 

cubic feet of stack gas per minute, and a resulting understatement of the true volume of calcining carbon dioxide 

included in total stack gas. He states that commonly "35% 

(plus or minus 1%) of raw feed is converted into carbon 

dioxide in the burning process." He then notes that an 

accurate measure of raw feed is the volume of calcining 

carbon dioxide appearing in stack gas, which in turn depends 

on an accurate measure of the volume of stack gas. His own 

calculations, based on EPA data showing a stack flow rate 

of 51,187 cubic feet per minute of dry gas, indicate that 

there were 2,153 cubic feet per hour of stack gas in the 

test attributable to calcining carbon dioxide coming from 

the raw feed and that "as a matter of basic chemistry" 

2153 cubic feet of calcining carbon dioxide "comes only 

from 22.11 tons of raw feed." This was at variance from 

the kiln rate of 44.03 tons of raw feed per hour reported 

in the test. He concludes that the error lay not in the 

measurement of the raw feed, but in the test data reported 

on the stack gas volume -- flow rate of 51,187 -- which in 

his judgment requires more sophisticated equipment for 

recording than does the raw feed which is easily measureable. 

Having corrected the stack gas figure, he states his opinion 

that the EPA assumption of emissions' satisfying its ultimate 

0.30 standard was in error. He concluded: 

It is my personal opinion that the particulate 

matter emissions of .202 pounds in test 1 per ton of 

kiln feed reported .. . is grossly erroneous and 

that the correct emission of particulate matter is 

in the neighborhood of .404 pounds per ton of kiln 

feed. 

51 
P.58 

We are not competent to decide if Mr. Striker's methodology 

and conclusions are correct. We can note, however, that 

he claims that as a matter of "basic chemistry" two test 

values, for feed and gas volume, cannot co-exist. This is 

certainly the type of criticism EPA should be required to 

discuss on remand. 

The possible error in measurement of dry stack gas volume has 

been gone over repeatedly by EPA engineers and Mr. Striker. Basically 

the situation is this: Mr. Striker claims that the C0? does not 

balance in the system, i.e., that the calculated C0? from combustion 

plus C0? driven off from the calcium carbonate is not equal to the 

COp calculated from Orsat (gas composition) readings and stack gas 

flow measurement. Mr. Striker's C0? calculations on the C0? balance 

appear to be essentially correct. Mr. Striker's error lies in his 

assumption of the cause of this C0? discrepancy. There is no conceivable 

source of error in measurement of the stack gas flow rate that could 

even approach 100%. Moreover the gas flow rate was measured consistently 

during twelve traverses at a total of 180 points. Nowhere does Mr. Striker 

say where such an error could occur. 

A flow rate as suggested by Mr. Striker was impossible because of 

the plant design. Neither the fan nor the baghouse could have possibly 

handled such a volume. This has been confirmed with the plant management. 

Further evidence of the correctness of EPA measurements (and the 

52 
P.59 

incorrectness of Mr. Striker's assertions) is contained in 

later test resul-s from the Dragon Cement plant cited by 

Edward Klein of Martin-Marietta (owners of Dragon Cement Co.). 

These results shov/ flow rates very close to those measured 

20/ 

by EPA at full production (as in EPA tests). The summary of 

these test results supplied by Mr. Klein is available from 

EPA. Thus Mr. Striker's allegations would violate the basic 

laws of nature had they been correct. Mr. Striker assumes 

that everything measured v/as correct except for a 100% error 

in stack gas volume. Under that assumption our number when 

expressed as pounds per ton of feed should have been twice 

that stated. As shown above, this could not be the case. 

There are tv/o other possible sources of this C02 error: 

feed rate and Orsat (gas composition) analyses.' Mr. Striker 

agrees that kiln feed rate is not in error. The plant was 

operating steadily at full production rate. A check with 

plant personnel shows our feed rate and their records to 

be in agreement. It should be pointed out that Orsat 

analysis for oxygen, carbon dioxide, and other combustion 

gases were only incidential to particulate testing. They 

in no way affect results. Kiln feed is the chief variable 

of cement production and careful control is maintained. 

Any substantial variation v/ould have been noticed by the 

plant. 

Thus, the only possibility is that the error was in 

the Orsat analysis (% of each gas in effluent). Calculations 

53 

W$*m 
P.60 

performed by EPA experts on this indicate that the CO2 

absorbing solution in the Orsat was exhausted and C02 in 

the stack gases v/as not measured as CO2 but rather as 

oxygen. Checks with EPA emission testing engineers who 

supervised the test confirm tiiat this v/as the source 

of discrepancy in the C02 balances. 

In order to determine the pounds of particulate 

per ton of feed it is necessary to sample the amount of 

particulates per unit of gas emitted and then multiply 

this figure by the total amount of gas emitted during 

the period a measured amount of feed is consumed. This 

is what EPA did in calculating the emission rates from 

the plants tested. If, Mr. Striker's allegations were 

correct, the emission rate would indeed need to be changed. 

The error in the Orsat analysis explains the apparent 

violation of the laws of "basic chemistry" but does not 

necessitate any change in the test results reported. 

ISSUE 12 

On page 44 and 45 and in footnote 90, the Court 

suggests that if their study of the matter is correct, the 

Oregon wet process kiln test results to be compared with 

the standard, i.e. front half catch only, are .247, .309 

and .261 lbs/ton rather than .535, .361 and .291 lbs/ton. 

RESPONSE 

The court is correct. The average test results for 

the Oregon test v/hich should be compared with the standard 

is .28 lbs/ton. 

54 

mm 
P.61 

ISSUE 13 

On pages 45 to 47, the Court expresses concern that 

problems at the Oregon plant caused interruptions in the 

sampling. The Court suggests that a provision allowing 

for malfunctions could be taken into account in considering this issue on remand. 

RESPONSE 

The testing of the Oregon plant is described in the 

test above. During the testing period ."it Oregon Portland 

Cement plant, a test was begun on 10/7/71 and discontinued 

due to kiln shutdown. The test was resumed and completed 

on 10/8/71. Two additional tests v/ere run on 10/8/71 v/ith 

only short interruptions to change ports as required by 

the test method. On October 5 and 6, 19 71, two earlier 

attempts were made at measurement of emissions but conditions 

prevented meaningful measurements. The important things 

to note are that process operation was extremely upset 

during these attempts and did not represent normal operating 

conditions and that the manner in which the early attempts 

at testing were- performed v/as an attempt to make a test at 

normal operating conditions. The second and third tests 

recorded were at normal operating conditions (not artificially 

ideal conditions) to be expected during normal cement plant 

operation. No stop-start testing, as described in the 

55 
P.62 

petitioners' quote, was used (except as noted in the response 

to Issue 8). The first test recorded had only one 

interruption (other-than port changes) due to the kiln 

shutting down. The circumstances described above are 

9/ 

in ETB Test Report Number 71-MM-15, (pages 16 and 47), 

the same report quoted by petitioner. 

The fact that the Oregon plant v/as not being properly 

operated or maintained does not limit EPA to standards 

based on tests conducted during periods of malfunction. 

EPA attempts to determine the best levels that a plant 

can achieve. In any event, the testing at the Oregon 

Portland Cement plant v/as consistent with the manner of 

conducting performance tests under the proposed revision 

to §60.8(c) of Title 40, Code of Federal Regulations. 38 

Fed. Reg. 10820-21 (May 2, 1973). That section provides 

that compliance tests shall be based upon representative 

performance, which shall not include periods of startup, 

shutdov/n, and upset. EPA has promulgated regulations 

which make it clear that EPA's mass emission limits apply 

oniy during performance tests rather than at all times. 

(38 Fed. Reg, 28565, October 15, 1973). 

ISSUE 14 

On page 48, the Court directs EPA to state with 

specificity v/hat literature is relied on to support the 

standard. 

56 

••j-» 7 •>•*•••• 
P.63 

RESPONSE 

This is discussed in the text above. As indicated in 

the text, a principal literature source was a government 

publication, resulting from a study conducted in cooperation 

with representative companies manufacturing portland cement 

entitled, "Atmospheric Emissions from the Manufacture of 

Portland Cement". This principal literature source provided 

basic information regarding cement plan.ts, including process 

details, process equipment, types of control equipment 

utilized, and documentation that baghouses could be used 

for the control of particulates from both v/et and dry process 

kilns, i.e. that baghouse control is "adequately demonstrated." 

In addition, the names of cement companies - location and 

size of cement plants were listed and this information was 

utilized by locating the best controlled plants to be 

considered for inspection and possible source testing in 

conjunction with the development of new source performance 

standards. Source test data included in the report were 

not relied on by EPA to show that the standard was being 

met. 

ISSUE 15 

In footnote 9 5, the Court states that if vendor representations are to be relied on, more might be required than 

mere comments. 

57 
P.64 

RESPONSE 

The relevance cf vendor statements is discussed in 

the text above. The tests EPA conducted v/ere sufficientlysupportive of EPA's standards that vendor representations, 

although relevant to confirm the standard can be met, are 

not of such crucial importance that the time and effort 

required to go beyond their professional representations 

is warranted. 

ISSUE 16 

On pages 49-52, the Court directs EPA to reconsider 

the opacity standard. '*'iSfe* 

RESPONSE 

This is discussed in the text above. 

58 
P.65 

BODY OF RESPONSE AND APPENDIX I 

Atmospheric Emissions from the Manufacture of Portland 

Cement, U. S. Dlj-7'7 ?I-"S, National Center for Air Pollution Control, Cincinnati, Ohio, PHS Publication No. 

999-AP-17, 1967. 

Control Techniques for Particulate Air Pollutants, U.S. 

DHEW, PKS, CPEHS, National Air Pollution Control Administration, Washington, D. C , NAPCA Publication No. AP51, 1969. 

Establishment of National Emission Standards for Stationary 

Sources, Volume VI, Portland Cement Manufacturing Plants, 

Contract No. CPA-70-16 4, Task Order No. 2, Prepared for 

the National Air Pollution Control Administration, Durham, 

N. C , by Research Triangle Institute and PEDCo Environmental Specialists, Incorporated, 1970. 

The Financial Impact of Air Pollution Control Upon the 

Portland Cement Industry, Internal document, Environmental Protection Agency, Raleigh, North Carolina, 1971 

l^'-V--" - ?"^ -

Emission Testing Report, Environmental Protection Agency, 

ETB Test Number 71-MM-05, Dragon Cement Company, 

Northampton, Pennsylvania. 

Emission Testing Report, Environmental Protection Agency, 

ETB Test Number 71-MM-0 3, Ideal Cement Company, Seattle, 

Washington. 

Emission Testing Report, Environmental Protection Agency, 

ETB Test Number 71-MM-01, Maule Industries, Hialeah, 

Florida. 

9. 

10 

Emission Testing Report, Environmental Protection Agency, 

ETB Test Number 71-MM-07, Giant Portland Cement Company, 

Harleyville, South Carolina. 

Emission Testing Report, Environmental Protection Agency, 

ETB Test Number 71-MM-15, Oregon Portland Cement Company, 

Lake Oswego, Oregon. 

Emission Testing Report, Lehigh Portland Cement Company, 

Union Bridge, Maryland, dry process, electrical precipitator, Union Bridge No ' ' '" " ' 

Inc., 1972. 

4 kiln, Tested by Resources Research, 

59 
P.66 

11. Emission Testing Report, Marquette Cement Manufacturing 

Company, Hagors •*: ov;n, Marylrnd, dry process, electrical 

precipitator, T;;.. Led by Marquette Cement Manufacturing 

Company, 19 72. 

12. Optical Properties and Visual Effects of Smoke-Stack 

Plumes, U. S. DHIIW, PHS, Bureau of Disease Prevention 

and Environmental Control, Cincinnati, Ohio, PHS Publication No. 999-AP-30, 1967. 

13. The Cement Industry: Economic Impact of Pollution Control Costs, Volume I, Contract No. EQC-20 4, Prepared 

for the Council on Environmental Quality and tlie Environmental Protection Agency, Washington, D. C., by the 

Boston Consulting Group, 1971. 

14. A Manual of Electrostatic Precipitator Technology, 

Part II—Application Areas, Contract No. CPA 22-69-73, 

Parepared for the National Air Pollution Control 

Administration, Cincinnati,'Ohio, by Southern Research 

Institute, pp. 609-640, 1970. 

15. Development Document for Effluent Limitations Guidelines and Standards of Performance, Cement Manufacturing 

Industry, Contract No. 68-01-0599, Draft report prepared 

for the U. S. Environmental Protection Agency, Washington, 

D. C , by Southern Research Institute, 1973. 

16. Analysis of Final State Implementation Plans—Rules 

and Regulations, Contract No. 68-02-0248, Prepared 

for the U. S. Environmental Protection Agency, Research 

Triangle Park, N. C. by the Mitre Corporation, Office 

of Air Programs, Publication No. APTD-1334, 1972. 

17. Standards of Performance for New Stationary Sources, 

Summaries of Test Data, Internal document, U. S. Environmental Protection Agency, Durham, N. C., 1971. 

18. A report on Contaminated Water Vapor Plumes, Internal 

document, U. S. Environmental Protection Agency, Durham, 

N. C , 1973. 

19. Average Observational Error Associated With Smoke Plumes At Levels 

Of Known Opacity, Internal Document, U. S. Environmental Protection 

Agency, Durham, N.C. 1973. 

20. Letter From Martin Marietta Cement Company (Formerly Dragon Cement 

Company), Confirming Gas Flow Rates As Measured By EPA During 

Test No. 71-MM-05, Dated August 24, 1972. 

60 
APPENDIX II 

EPA RESPONSE TO PETITIONERS'tCOMMENTS 

REGARDING EPA RESPONSE TO REMAND 

0%P&3ii 

61 
APPENDIX II 

Portland Cement Association Comments 

P.68 

Adverse Environmental Impact 

Portland Cement Association (PCA) objected to the draft response 

to the issue of the environmental impact associated with the electricity 

required to operate the control technology. In particular, PCA objected 

that the Agency should not have compared the electricity required to 

operate the control technology needed to meet EPA standards with the 

electricity required to meet State pollution control standards. PCA 

believed that State regulations "do not furnish a valid basis to excuse 

EPA from its statutory duty because most of those regulations, were in 

effect, mandated by EPA itself." EPA did not mandate specific State 

particulate emission limitations. 

Prior to the date that new source performance standards and 

implementation plans were proposed, many progressive State and local 

air pollution control agencies had promulgated rules and regulations 

that were as strict or stricter than those required by EPA to assure 

that national ambient air quality standards would be met. For example, 

the State of Maryland had promulgated regulations— that allowed no 

visible emissions and mass emission standards that are as stringent 

as EPA new source performance standards. 

After the Clean Air Act was signed into law, EPA was required to 

review State implementation plans to determine whether they would achieve 

and maintain national ambient air quality standards, including standards 

Bj^SS^ft 

63 
P.69 

for particulates. In some cases, EPA promulgated emission limits where 

the State plans did not adequately achieve or maintain the national 

ambient standards. However, the State was free to determine which 

emission sources should be reduced to meet the ambient standards or 

to achieve more stringent ambient levels. It is, therefore, incorrect 

that EPA "mandated" specific State particulate emission limitations. 

Furthermore, EPA did not limit its consideration of the adverse 

environmental impact of the electricity required to operate the control 

equipment to a comparison of the impact of EPA's standards with the 

impact of State standards. EPA in its remand response compared the 

approximately 115 kilowatts required to operate a precipitator that 

would meet the new source performance standards with the total electric 

power rate consumption of a typical cement plant which approximates f#*-*->>*'*« 

5,300 kilowatts and with the 500,000 kilowatt output of a typical new 

steam generating electric power plant. EPA believes that this comparison 

alone indicates that a detailed discussion of the incremental and environmental 

impact associated with the additional 115 kilowatts required to meet the 

new source performance standards is unwarranted. Furthermore, EPA would 

note that the 115 kilowatt increment is based upon the assumption that 

emissions would otherwise be totally uncontrolled. It is nearly inconceivable 

that States and/or local governments would permit Portland cement plants to 

be operated without any particulate control whatsoever but for EPA's requirement of such control. 

PCA also objects that EPA's consideration of the environmental impact 

of water pollution from the run-off from kiln dust piles has been 

inadequately considered. First, it should be noted that water 

64 
P.70 

pollution resulting from particulate matter is not a question of whether 

water pollution occurs, but where it occurs. Uncontrolled emissions 

deposit the particulates throughout the countryside where it then washes 

into water supplies. On the other hand, removing particulates from exhaust 

gases enables the source to collect the particulate matter and thus control 

water run-off of the particulate matter should it occur. 

Second, much of the particulate matter collected by emission control 

devices can be used by Portland cement plants. Thus, the total amount of 

particulates disposed of will be less if collected by emission control 

devices than if vented uncontrolled into the atmosphere. 

The technology for control of water run-off from dust piles is 

similar to that required for coal pile drainage, yard drains, and run-off 

from construction. These streams must be wholly or partially detained during 

storm events in order to minimize overall treatment costs. Diking, ditching, 

and holding technology can practically be utilized in conjunction with 

facilities for sedimentation or filtration for solids removal and for pH 

8/ 

control.- EPA does not believe that water run-off from piles of particulate 

emissions from Portland cement plants is a major problem. To the extent 

there is a problem, it is the judgment of the Administrator that the 

problem of water run off from collected piles of particulate matter is 

less than the problem of uncontrolled releases of particulate matter into 

the atmosphere. 

Cost-Benefit Analysis 

PCA argues that EPA should do a cost benefit analysis. Such an 

analysis has not been made because reasonable means for doing so do not 

yet exist, in the opinion of EPA. An emission limitation on a specific 

type of emission source will have different effects on ambient levels in 

different places. Ambient levels are affected not only by emission 

P§i#S 
P.71 

levels of specific sources but also-the placement of such sources 

relative to other sources and to meteorological conditions around 

each of such sources. Furthermore, sources vary in their geographical 

relationships to populations, wildlife, vegetation and other factors 

which would be impacted by the emission source. Thus relating the 

cost of control to the benefits of the control at least at this time 

is a practical impossibility. 

We believe that Congress intended §111 to be used to establish 

emission limitations which are the lowest that can be achieved by that 

industry. Where the cost of meeting such standards would be so great 

that the industry could not bear the costs and survive, such standards 

could not be implemented by the industry regardless of technological •».,*,>.._*, 

ifl'St''.-)?--**.''''-

feasibility. There are also cases where a reduction in emissions that 

would be achieved by a particular control technique would be so grossly 

disproportionate to the cost of the control technique that it would not 

be required. However, these determinations are necessarily judgmental 

and are left specifically to the Administrator in §111. EPA does not 

believe that cost benefit analysis can be established for standards 

under §111 nor does it believe that Congress intended that standards be 

established or justified on the basis of such an analysis. 

Although EPA has not conducted a cost benefit analysis for these 

standards, we have considered PCA's criticisms of the standards based 

on cost benefit analysis. PCA relies heavily on a conceptual chart 

published in an HEW publication: Control Techniques for Particulate 

Air Pollutants, Pub. No. AP-51. This chart shows a smooth curve relating 

"Capital Costs" (although no units are shown on the chart) to efficiency 

of the control techniques. The chart shows the curve rising asymptotically 

as efficiency approaches 100 percent. However, this chart does not represent 

66 I 
the realities of control of particulate emissions ir. the Portland cement 

industry. The primary method of control relied on by EPA at the time the 

standards were developed was control by baghouses. Baghouses when properly 

designed, installed, and maintained operate at nearly the same collection 

efficiency, thus the relationship between cost and efficiency is somewhat 

inelastic. It is well established that properly designed and maintained 

baghouses can limit emissions to .03 grains per actual cubic foot (ACF) 

of emission air and gases. EPA tests confirmed that baghouses already 

installed on Portland cement plants were capable of achieving .03 gr/acf 

if properly maintained and operated. In fact, EPA believes and recent 

tests confirm that baghouses can achieve higher removal efficiencies. 

However, at some point of control where emission levels are less than 

.03 gr/acf the removal efficiencies will not increase to any great extent l^f^S 

regardless of the cost of the equipment. It is only coincidental that 

the standard for Portland cement plants results in costs that fall below 

the level where costs rise sharply compared to increased removal efficiency. 

This type of cost-effectiveness analysis was neither the basis for setting 

the Portland cement standard nor any other new source performance standard. 

In general, a standard will not be established at a level at which the cost 

of compliance would result in the inability of new plants to compete with 

established firms in the industry. This type of analysis is not based upon 

cost effectiveness but rather upon the economic structure of the industry as 

a whole. 

PCA commented that if cost benefit comparisons were made between the 

standards for Portland cement plants on the one hand and coal-fired power plants 

and incinerators on the other, they would indicate that the Portland cement 

standards should be loosened and the others should be tightened to achieve a 

cost benefit equality. The particulate standards for coal-fired power 

plants and incinerators were based on the use of precipitators. Although 

67 
P.73 

there were indications at the time the standards were promulgated that 

precipitators could be used on Portland cement plants and baghouses 

could be used on coal-fired power plants and incinerators, EPA. based 

its standards on the methods which had been established as applicable 

to the source subject to the standard. Furthermore, EPA based its 

particulate standards for power plants and incinerators on emission 

levels being achieved at existing plants. Because the removal efficiencies 

being achieved by properly maintained and operated baghouses on Portland 

cement plants were superior to those being achieved by power plants and 

incinerators, the effective emission concentration limits were more 

restrictive for Portland cement plants. 

It now appears that precipitator technology may achieve the same 

levels of control, i.e., below .03 gr/acf, required of the Portland 

cement industry and that baghouses can be applied to the other two 

industries. EPA will consider whether the particulate standards for 

the other two industries should be tightened. However, EPA does not 

believe that inequalities between the effective emission concentration 

limits between these three types of sources should be eliminated by 

loosening the standards applicable to Portland cement plants as urged by 

PCA to permit such plants to emit an additional "10,000 tons per year" 

(PCA1s figure) of particulate matter to the atmosphere. 

Cost Estimate 

PCA commented that EPA underestimated the cost of achieving the 

standards. PCA particularly objected that EPA did not use cost figures 

supplied by the industry. EPA does not agree with the industry's cost 

estimates. The costs presented by PCA did not speak specifically to the 

costs resulting from the standard of performance for new cement plants. 

The estimates reflect the total costs necessary to meet State emission standards 

68 

£&-$$! 
P.74 

and the Federal standard. It is not possible to separate the two cost 

estimates in the submittal by PCA. In addition, PCA spoke only to the 

investment cost for pollution control and did not present any costs for 

operating and maintaining the equipment. As a result, the cost estimates 

submitted by PCA were of no value in estimating the costs resulting from 

the standard of performance. 

A study of the economic impact of pollution control costs upon the 

cement industry was performed by the Boston Consulting Group and 

2/ published in 1971.— One of the conclusions reached was as follows: 

"The combined effects of plant size advantage, required 

pollution control expenditures on existing plants, and 

labor cost pressure will motivate a rate of plant construction in excess of the rate of demand growth, which itself 

. will exceed that of the past decade. The consequence will 

be a substantial increase in plant construction, virtually 

all of which will be in plants with kiln sizes of 2.5 million 

barrels and above." 

Although the costs used in this study were supplied by EPA, the report 

goes on to state: 

"If the industry estimates of total and anticipated pollution 

control costs were used, instead of the EPA figures, the foregoing conclusions would not be changed, but would be intensified." 

In summary, the Boston Consulting Group study forecasts an increase in 

new construction, not a decrease. 

PCA further argues that inflation will change the cost figures. 

It is true that inflation will change the absolute magnitude of the cost 

figures. It is also true, however, that cement prices have risen at a 

rate at least equal to the overall rate of inflation. The existence 

of inflation is not a factor that invalidates the cost impact originally 

presented since it tends to affect all items, revenues as well as costs, 

5**-*_3R£: 

69 
P.75 

and leaves the relative impact unchanged. 

PCA also criticizes the Boston Consulting Group study on the basis 

that it considered a model plant rather than "widely ranging 

variations in raw material availability fuel costs and availability, 

and regional marketing considerations." PCA argues that EPA should show 

that capital will be obtainable to finance pollution control equipment. 

Raising capital does not appear to be much of a problem for cement 

plants, even for pollution control equipment. The following comments are 

taken from the January 1974 volume of Pit and Quarry, an edition that 

highlighted past and future developments in the cement industry: "No 

new plants went into operation in 1973. There were, however, eight major 

expansions involving new kilns, at least three of which might be considered 

as a new plant alongside an older one. In all, seven new kilns and 17 

grinding mills are known to have been installed during the year." Obviously, 

capital was available for these expansions. 

Specifically with regard to pollution control equipment, the Pit and 

Quarry article mentioned above states that "1973 was another record year 

for the installation of dust collectors. At least 34 electrostatic precipitators. 

17 baghouses, and 2 gravel bed filters are known to have been installed, most 

of them on kilns, but some also on coolers. These figures are far above 

those in 1972 and 1971, which were record installation years. The rate 

of installation of smaller collection units was also undoubtedly ahead of 

any previous year." In light of the above, we find it difficult to believe 

that capital availability is a problem in the cement industry. 

EPA believes it has adequately considered cost even though it has not 

conducted an analysis of the costs for pollution control for each and every 

projected new plant and has not shown where and how the capital for pollution 

70 

;^-<r¥* ? 
P.76 

control equipment is to be raised by such plants. The cost of pollution 

control is one of several factors that might affect a company's decision 

to locate a plant at a given site. EPA does not believe that §111 demands 

the finely tuned cost analysis demanded by PCA. Furthermore, the agency 

believes that a plant by plant analysis is impractical and that the model 

plant representing average facilities is the best approach. 

Demonstration of Achievability 

PCA criticizes the testing procedures which EPA used to determine that 

the standard can be achieved. PCA admits the standards can be achieved. 

They state that: 

"Petitioner does not contend that the .03 gr/scf Standard 

cannot be achieved. Indeed, as stated in Section II above, it 

is believed that efficiencies in excess of 99.9 percent can be 

achieved with existing technology and available equipment applied 

to many traditional stationary sources of particulate pollutants, 

including cement plants." (PCA Comments to EPA draft response, 

p. 13, note 7.) 

This should be dispositive of this issue. However, EPA has considered 

each specific criticism of PCA on this issue and for purposes of developing 

a complete response, will address each issue here. 

Apparently the bases of PCA's criticisms are that some tests showed 

the standards were not being met, that each test that showed the standards 

could be met had some defect or was not adequately verified by EPA and in 

particular that EPA discontinued testing one plant (the Oregon plant) that 

was poorly maintained until broken bags were tied off. 

PCA apparently construes §111 as requiring EPA to set a standard of 

performance for new sources that is the lowest emission level achieved 

at any existing plant regardless of how poorly the pollution control 

equipment is maintained or operated. The purpose of §111 is clearly to 

require new sources to use the best pollution control equipment which 

new sources can obtain. In order to determine what emission levels 

71 
P.77 

'new sources can obtain, EPA is required to look at the best equipment 

used by existing plants, not the average and certainly not the worst. 

Furthermore, §111 standards are not required to permit new sources to 

use inadequate maintenance simply because some existing plants are 

inadequately maintained. 

Turning now to specific criticisms by PCA of EPA's testing, PCA 

argues that at the Dragon cement plant test the admitted presence of 

settled dust in the duct at the test point raises further doubts as 

to the accuracy of the results obtained. The Dragon cement plant test 

was conducted by expert source test personnel. The settled dust in the 

duct was recognized. The layer of dust reduced the cross-sectional 

area and this was considered in calculations for the total volumetric 

flow rate. 

PCA objects that the location of the test point in the Dragon cement 

plant did not comply with the EPA test procedures set forth in Federal 

Register Vol. 36, No. 247, Section 60.85. 

The test conducted at Dragon Cement plant was conducted before test 

procedures were detailed in the Federal Register for new plants. It must 

further be realized that testing had to be conducted at existing plants 

to show what levels of emission control were achievable by new plants. 

EPA could not construct well-controlled plants with proper duct configurations 

solely for standard-setting purposes. It is conceded that ductwork at the 

plant was not ideal; however, in order to compensate for this, sampling 

was conducted at a larger number of traverse points than would normally 

be used at a test location with a suitable ductwork configuration and 

a precision low-range inclined manometer was used for the velocity 

measurements. This type of manometer permitted a higher standard of 

precision by expanding the scale to improve readibility and sensitivity 

$?$$$ 
P.78 

of the velocity head measurements. In addition, three separate test 

runs were conducted, each of which indicated compliance with the standard. 

If results of each test run had varied widely, then there could have 

been serious doubts concerning the test results. This was not the case. 

PCA objects that the Orsat analysis which EPA admits was inaccurate 

affects the results of the source test conducted at the Dragon Cement 

plant. While petitioner is technically correct, the inaccurate Orsat 

analysis introduced only a small error due to the slightly different 

density of the gases. It appears that the actual carbon dioxide content 

in Test No. 1 was 15.4 percent instead of 7.5 percent as reportedr Therefore, the dry molecular weight of the gases would have been 30.93 pounds 

per cubic foot rather than 29.82 pounds per cubic foot. This factor 

could have introduced an error of no more than 1.8 percent in reported s'fs*S&j? 

emission levels. EPA relied on measured values as the critical parameters 

in the Dragon test. The fact that one measured value which was not critical 

and which is strongly suspect to be in error, would lead to calculated values 

which.disagree with the measured values does not support excluding the Dragon 

test from consideration of whether the standard can be achieved. 

PCA objects that the Oregon Portland Cement plant had an estimated 

15 percent of the bags tied off thus creating an unrepresentative operating 

condition. EPA was faced with the necessity of testing existing Portland 

cement plants to set a standard for new sources. The record shows that 

most existing plants were poorly maintained. Although the plant operators 

had been notified that their plants were going to be source tested for new 

source performance standards, both the Oregon Portland Cement plant and the Giant 

Portland Cement plant operations were being operated with holes in their baghouse, bags at the time that source testing was scheduled. Abnormalities 

a_/ As noted on page 1-12 of the proposed response to remand order bv U.S. 

Court of Appeals for the District of Columbia, even if Mr. Striker'were 

correct, the particulate emission test results for the maximum test would 

be 0.22 lbs/ton, 30 percent less than the standard. 

73 
in their baghouse operation were detected by visible emissions. In 

both cases, EPA engineers recognized these excessive emissions, stopped 

the testing, and requested plant maintenance personnel to enter the 

baghouse and tie off bags that were leaking excessive emissions of dust 

through holes in the bags. 

In the case of the Oregon Portland Cement plant, it was estimated 

that 15 percent of the bags were tied off; however, even with this 

relatively large number of bags tied off, the baghouse control system 

was capable of>being operated (with the kiln in normal operation) within 

the limits of the proposed mass emission and visible emission standards. 

PCA argues further on this point that: 

"Special repairs made for the purpose of this test . . . 

present an ethical issue similar to the Ford Motor Company 

maintenance procedures for which Ford was prosecuted. ..." 

(PCA Comments, p. 15, note 9). 

EPA believes that the ethical distinctions between adjusting equipment 

at EPA's request and unauthorized tampering with cars undergoing certification 

tests are self evident. 

PCA criticized reliance on the Marquette and Lehigh tests in Maryland 

because they were performed on new facilities just brought up to production 

rate. PCA believes that these were ideal, rather than representative, 

conditions and therefore shouldn't be relied on. It is pointed out that the 

cover letter from the State of Maryland states that the equipment for both 

plants was installed new in 1970. The source tests were not conducted until 

1972. 

Source tests for compliance with new source performance standards 

will be conducted on new or substantially modified facilities. There 

is no reason that control equipment cannot be installed, maintained, 

and operated as necessary to meet the standard long after the plant has 

74 
P.80 

been in operation. Tests of the Dragon and Oregun plants confirm this. 

PCA argues that EPA did not conduct the source tests on the Marquette 

and Lehigh plants. They claim EPA shouldn't rely on the report of another 

agency. The test reports for the Marquette and Lehigh Portland Cement 

plants were official documents submitted by the companies to a State air 

pollution control agency. The test reports state that the tests were conducted 

following EPA test methods and test results indicated compliance with the 

NSPS. Tests to determine compliance with the standards in question would 

be conducted in essentially the same manner. 

Subsequent to November 26, 1973, the U. S. Environmental Protection 

Agency has received additional source test data and information indicating 

that additional Portland cement plant kilns and clinker coolers are capable Itllfli 

of being operated in compliance with new source performance standards. 

It is pointed out that this data and information has not been presented 

to the petitioners because of the time element involved; however, because 

of its relevancy, the data are summarized in Table I. 

Table I 

Emissions in Lbs/Ton 

Test Date Name of Company of Dry Feed 

6/25-27/74 United Cement Company^ 0.209 

Artesia, Mississippi, 

kiln, wet process, 

electrical precipitator 

8-20-74 United Cement Company,-/ 0.04 

Artesia, Mississippi, 

clinker cooler, cyclone and 

wet scrubber. 

5/23-24/74 Santee Portland Cement Company--7 0.107 

Holly Hill, South Carolina, 

kiln, wet process, two 

electrical precipitators 

75 
P.81 

Emission in Lbs/Ton 

Test Date Name of Company of'Dry Feed 

6/12-14/74 Monarch Cement Company- 0.196 

Humboldt, Kansas, kiln 

No. 4, dry process, 

baghouse 

6/12-14/74 Monarch Cement Company 1/ 0.0174 

Humboldt, Kansas, clinker 

cooler, No. 4 kiln system, 

baghouse 

$2&5^ 

76 
NORTHWESTERN STATES PORTLAND 

CEMENT COMPANY COMMENTS 

Comments on Affidavit of Mr. Striker 

Mr. Striker commented rather extensively on the Orsat analysis used 

at the Dragon Cement plant test. Both Mr. Striker's comments on this 

issue and EPA's response-&re highly technical and are not included here. 

Copies of both of these documents may be obtained from the Emission 

Standards and Engineering Division, Research Triangle Park, North 

Carolina 27711, Attention: Mr. Don R. Goodwin. It will only be noted 

here that EPA disagrees with Mr. Striker's conclusions. Furthermore, 

even if Mr. Striker's conclusions were correct, the Dragon test still 

met the standard as did the tests taken at three other plants, as noted 

in the text of this response. 

Mr. Striker comments as follows: "The standard is inferentially based on 

the premise that all cement plants are essentially alike although this 

is not the case. Every plant is custom designed and a 

unique operation." Nearly every stationary source is a "unique operation". 

Availability of local materials and local labor force as well as siting 

and other unique constraints vary with each plant. It would be infeasible 

and Congress did not intend for EPA to set a different standard for each 

new Portland cement plant. However, it is the judgment of EPA that all 

new plants can meet the standard regardless of raw materials used. 

Control equipment installed to minimize particulate emissions from Portland 

cement plant kilns are not off-the-shelf type items. Each unit must be 

carefully engineered and consideration must be given to all variables 

that can affect the efficient operation of the equipment. 

77 
P.83 

Mr. Striker hasn't shown that the four plants which were found 

to meet the particulate standard were unique in any respect. Neither 

has he shown that new plants which install equally effective controls 

won't meet the standard. Operators have reasonable options in 

choosing sites and raw materials for new plants. If operators were 

in fact convinced that there were factors which adversely affected 

particulate emissions, these could be avoided in the building of new 

plants. 

Mr. Stt'ker claims that independent source tests and summary test 

data submitted to EPA by Dragon Cement Company are of little value. 

It is EPA's opinion that summary test data submitted by Dragon Cement 

Company showing the results of a test conducted independently by the 

Company which tend to support the standard are of great value. Furthermore, the volume of gases, the dust concentration, and emissions reported 

in the summary agree favorably with EPA test results. 

Mr. Striker believes the Dragon Cement test should be free from all 

doubts and should stand up under critical inspection from any standpoint. 

The Dragon Cement results are as free from doubt as almost any other 

source test. Examination shows that the configuration of the ductwork 

was not ideal but that EPA modified the sampling procedure as much as 

possible to offset these conditions. In addition, all reasonable analysis 

including information and tests supplied by the operating company confirm 

that the exhaust volume rate is as measured in the EPA test,not the much 

larger value predicted by Mr. Striker. We believe the operating company 

is much more knowledgeable of the kiln system than Mr. Striker. 

Mr. Striker suggests the Lehigh Portland Cement tests on No. 4 kiln 

at Union Bridge, Maryland, appear erroneous. Mr. Striker has provided 

78 

&S» 
P.84 

no basis for this conclusion. As in other instances, it appears that 

estimates were used to make theoretical determinations that do not 

agree with the measured values. Mr. Striker has submitted no factual 

information to prove that his determinations are correct. 

m& 

79 
P.85 

Comments of Mr. Photiades 

Mr. Photiades commented that manufacturer's warranties are limited. 

The inference of this comment is that such warranties should not be 

greatly relied on to support the standard. As EPA noted in the text of 

its response, vendor representations were not of critical importance in 

supporting the standard. However, since a vendor has a reputation 

to maintain as well as a financial obligation to meet the strict terms of 

a warranty, representations of a reputable vendor that its equipment will 

meet the standard is of some value in supporting the standard even if the 

warranty of its equipment is limited. Vendors usually limit their warranties 

not because of doubt about the reliability of the equipment so much as due 

to the fact that they have no control over operation and maintenance of &$?$;$ 

the equipment. 

Mr. Photiades also comments that inflation and other factors have 

caused prices to increase since the time EPA promulgated the standard. 

Mr. Photiades cites bids made on a Northwestern baghouse to support 

his contention. EPA cannot disagree that costs have risen due primarily 

to inflation over the 1971-1974 period; however, it is also pointed out 

that the costs of other cement plant components as well as the revenues from 

y 

the cement sold have likewise risen over the same period. No information 

or data have been presented that EPA estimates of costs as shown in 

the document entitled, "The Financial Impact of Air Pollution Control 

Upon the Portland Cement Industry" by R. J. Elias and J. M. Dement are 

grossly in error. The bids made on one baghouse neither prove the study 

is invalid nor that the standard should be changed, particularly when 

the normal variability in capital expenditures is considered. It is 

also important to note that Mr. Photiades did not provide sufficient 

b/The average cement price rose from $3.52/bbl in 1971 (Minerals Yearbook, 

—1972 Edition, page 259) to $5.79/bbl in 1974 (Engineering News-Record, 

80 
P.86 

detail in his estimate to enable EPA to separate the financial impact 

resulting from the State Implementation Plans from the impact resulting, 

from new source performance standards. 

Comments of Mr. Shepard 

Mr. Shepard, counsel for Northwestern criticizes EPA's reliance 

on the Oregon test because EPA stopped the test until broken bags 

were tied off. He believes that this prejudiced the test because 

in his opinion broken bags represent "normal operating procedure" 

which must be reflected in the test and therefore the standard. He 

also expressed concern that EPA did not state that tests were not 

under normal operating procedures until he saw the draft EPA response 

dated November 26, 1973. fei$§ 

EPA did not and does not consider inadequate maintenance or kiln 

operation fixed at a lower than normal feed rate as normal operating 

procedure which must be permitted under the standard. As for Mr. Shepard's 

comment that he didn't know that EPA discontinued the test until broken 

bags were tied off, even if that were material he has had an opportunity 

to comment on this issue as his clients' comments on the draft of this EPA 

response to the remand were solicited. Indeed he has commented on the issue,so it 

is not clear how his clients were prejudiced by any alleged failure of EPA 

to supply information at some point in the past. 

Mr. Shepard also suggests that EPA's request to the Oregon operator 

to tie off its bags is equivalent to Ford Motor Company's unauthorized 

tampering with cars undergoing Federal pollution control tests for which 

Ford was fined $7,000,000. As noted earlier in this Appendix (page 74), :;~ 

the distinction between the activities is self-evident. 

81 
P.87 

REFERENCES FOR APPENDIX II 

1. State of Maryland, 43P04 regulations governing the control of air 

pollution in area III (as amended through December 23, 1971). 

2. The Cement Industry - Economic Impact of Pollution Control Costs, 

Boston Consulting Group, November 1971, Vol. 1, p. 11. 

3. Emission Testing Report, United Cement Company, Artesia, Mississippi, 

kiln, wet process, electrical precipitator, tested by company personnel, 1974. 

4. Emission Testing Report, United Cement Company, Artesia, Mississippi, 

clinker cooler, cyclone and wet scrubber, tested by company personnel , 1974. 

5. Emission Testing Report, Santee Portland Cement Corporation, Holly 

Hill, South Carolina, kiln No. 2, wet process, two electrical 

precipitators, tested by Pollution Control-Walther, Inc., 1974. 

6. Emission Testing Report, Monarch Cement Company, Humboldt, Kansas, 

kiln, dry process and clinker cooler, two baghouses, tested by the 

Fuller Company, 1974. 

7. Memorandum from Roger T. Shigehara and Clyde E. Riley to Robert T. 

Walsh, dated April 23, 1974, corrected July 26, 1974. 

8. Development Document for Effluent Limitations Guidelines and New 

Source Performance Standards for the Cement Manufacturing Category, 

U.S. Environmental Protection Agency, EPA-440/l-74-005-a, 1974. 

*?&!$# 

82 
P.88 

APPENDIX II I 

PORTLAND CEMENT REMAND RESPONSE 

&rS5&T 

83 
PORTLAND CEMENT REMAND RESPONSE: 

APPENDIX III, PART A: OPACITY STANDARD 

P.89 

In the case of other points at issue in this Remand Response, 

it has been necessary only to supplement the November, 1973 Draft 

Response to deal with the comments of the Portland Cement Association 

and others on that Draft Response. In order to respond fully to the 

comments with respect to opacity, it has been necessary to prepare the 

rewritten, extensive response found in this Appendix III. The response 

contained herein should therefore be considered to supercede that portion 

of the Draft Response dealing with the opacity standards, and the 

present Appendix III constitutes the Administrator's full and complete 

position with regard to this issue. 

EPA promulgated opacity limits as well as mass emission limits 

primarily because EPA believes that opacity limits provide the only 

effective and practical method for determining whether emission 

control equipment, necessary for a source to meet the mass emission 

limits, is continuously maintained and operated properly. It has 

not been EPA's position that a single, constantly invariant and 

precise correlation between opacity and mass emissions must be identified for each source under all conditions of operation. Such a 

correlation is unnecessary to the opacity standard, since the 

Administrator consistently develops opacity standards for each class 

of sources at a level no more restrictive than the corresponding mass 

emission limitation with due consideration given to all conditions 

§0$J& 

85 
P.90 

1 2 3 

of operation. ' Any source which is meeting the mass limit will therefore also be meeting the opacity limit; if a source is not meeting 

the opacity limit, this will be due to the failure of that source to 

properly maintain and operate its emission control equipment. And if 

the equipment necessary to meet the mass emission standard is not 

properly maintained and operated, the source will also fail to meet 

the mass emission standard. 

Opacity standards are a necessary supplement to mass emission 

standards, since there is no reliable instrument to directly 

measure mass emissions currently available. If only mass emission 

standards were in effect, operators would not be compelled to assure 

proper maintenance and operation of pollution control equipment at 

times other than during periods of performance testing. Two weeks 

or longer are necessary to schedule a typical stack test, due to the 

preparation involved. If relatively minor repairs were all that 

were needed in a given case, such as pump or fan repair or replacement of fabric filter bags, a plant operator could delay such 

repairs and continue to pollute until shortly before the stack test 

was conducted. For some types of control equipment, such as 

scrubbers, the operator could reduce the input of energy (the pressure 

drop through the system) thereby partially or totally defeating the 

air pollution control system when stack tests were not being 

conducted and through such action could release significantly more 

particulate matter than permissible under the mass emission standards. 

&*§&&$;• 

86 
P.91 

Furthermore, stack tests can only be conducted with limited frequency, 

since they often cost up to $10,000 to perform. Therefore, EPA has 

required that operators properly maintain and operate air pollution 

control equipment at all times [40 CFR 60.11(d)] and meet opacity 

standards at all times except during periods of startup, shutdown, 

malfunction, and as otherwise provided in the applicable standard [40 

CFR 60.11(d)]. Opacity is established as an independent, enforceable 

standard, rather than merely as an indicator of maintenance and 

operating conditions, because information regarding those conditions 

is peculiarly within the control of the operator. The time and expense 

required to prove that proper procedures have not been followed are so 

great that the provisions of 40 CFR 60.11(d) by themselves (without 

opacity standards) would not provide a practical means for ensuring 

that on a day-to-day basis the pollution control equipment is maintained and operated in the way necessary to meet the mass emission 

limitations. Opacity standards, in contrast, require only a qualified 

observer and can be performed with no prior notice. In some cases, of 

course, a full investigation of operating and maintenance conditions 

will be desirable. Accordingly, the opacity standards and maintenance 

requirements were both promulgated, and work in tandem to guarantee 

that proper maintenance and operation of pollution control equipment, 

the sine qua non of continuous compliance with emission limits, can in 

fact be required and monitored. 

Two primary aspects of the opacity standards, raised by Petitioner 

Portland Cement Association, were identified by the Court of Appeals as 

87 
P.92 

the bases of its concern: 1) .the inherent reliability of opacity 

standards, i.e. whether measurements of opacity can be made with 

reasonable accuracy, and 2) the achievability of the opacity standard 

set for portland cement plants. 

RELIABILITY OF OPACITY STANDARDS 

Accuracy of Opacity Measurements in Detecting Violations 

The Portland Cement Association (PCA) contends that opacity 

measurements cannot be made with reasonable accuracy. PCA indicates, 

in particular, that individual observer readings under certain conditions are often in error by 10 percent opacity or more, and therefore 

that "equivalent opacity—at any level — is an inherently inadequate 

and invalid measure to determine compliance with, or violation of an 

anti-pollution law." In support of this contention, PCA argues that 

observed opacity may be affected by such factors as: dark nights, 

contaminated water vapor or detached plumes, lack of contrasting background (e.g., white plume viewed against an overcast sky), and wind 

velocity. 

The PCA and other commentators contend also that EPA smoke school 

requirements and procedures are inadequate to ensure that qualified 

observers will make accurate readings. The procedure whereby training 

plumes are shown in advance of certification runs, and under which 

observers are allowed to use fixed (non-sky) contrasting backgrounds 

are noted as specific deficiencies. 

In response to the questions raised by the Court and the PCA, 

EPA has reviewed available data concerning the accuracy of qualified 

88 
P.93 

4 5 6 observers; ' ' has reviewed the theory of equivalent opacity, 

particularly concerning the effect of variable viewing conditions on 

5 6 

accuracy; ' has reviewed the smoke school certification procedures; 

and has conducted extensive field tests involving both specially 

generated plumes and industrial plumes. On the basis of this extensive 

review, EPA concludes that the accuracy of Reference Method 9 has been 

well established, that its error tolerance is reasonable and is within 

limits considered normal by the scientific and engineering community, 

and that when that error tolerance is accounted for in assessing the 

results of opacity readings, the method is valid and reliable for 

determining compliance with prescribed opacity standards. EPA also 

concludes that the smoke school certification procedures are adequate 

to assure proper qualification and accuracy of qualified observers. The 

basis for these conclusions is set forth below. 

PCA contends that plumes of the same actual opacity will appear 

to have somewhat different opacities under dissimilar conditions of 

viewing. EPA agrees that this is true. A plume will appear most 

visible to an observer when the plume is viewed against a contrasting 

5 6 background. ' A white plume therefore will be more visible when 

viewed against a black background or a blue sky than it will when 

5 

viewed against a hazy or overcast sky. Indeed, a white plume viewed 

against a white background may well be invisible. PCA concludes that 

because a plume will appear of lesser opacity under less contrasting 

conditions, EPA's opacity standards, which limit allowable opacity 

89 
P.94 

even under conditions of maximum apparent opacity, are inaccurate 

and unreliable. It is with this illogical conclusion that EPA 

disagrees. Cement plant operators are in no way prejudiced by the 

fact that under less contrasting conditions the opacity of their plume 

may be read at less than its actual value; obviously, this is to their 

advantage. Their only real concern, therefore, is with the accuracy 

of opacity readings under viewing conditions of highest apparent opacity. 

Since opacity appears greatest under conditions of high background 

contrast, it is under such conditions that the potential for positive 

observer error (observed opacity greater than true opacity) is 

greatest. This is verified by the available data, which show that 

positive observer error (average of 25 readings) can approach + 7.5 &&# § 

percent under relatively high contrast conditions such as are 

encountered at a smoke school, when a training plume is observed 

4 7 against a contrasting background. ' Against a less contrasting 

background, a plume will be less visible and observer errors will tend 

to be negative (observed opacity less than true opacity). A collaborative test performed at a power plant where a white plume was 

observed on an overcast day confirmed that this downward bias can be 

significant, to the extent that the probability of positive errors 

even in single readings is essentially non-existent under such 

4 

conditions. 

It is clear therefore that in assessing the reliability of the 

opacity standards, the possibility of positive errors is of primary 

concern, since such errors could in theory result in the determination 

90 
P.95 

of a violation when true opacity was below the standard. While 

negative errors are undesirable from an enforcement point of view, 

they do not place a complying source in jeopardy. It is only necessary 

therefore to quantify the positive error, which may occur under high 

contrast viewing conditions, to demonstrate that the method does 

measure opacity with the reasonable accuracy required of an enforceable 

standard. As the Court of Appeals notes in Amoco Oil Company v. E.P.A., 

501 F2d 722_. (6ERC 1481, May 1, 1974, slip op. at pp. 38-39): 

Petitioners also contend that any test methods adopted 

will involve a certain capacity for statistical error. 

We fail to appreciate the force of this argument. The 

possibility of statistical measurement error, which is 

often unavoidable where regulations set quantitative 

standards, does not detract from an agency's power to 

set such standards. It merely deprives the agency of 

the power to find a violation of the standards, in 

enforcement proceedings, where the measured departure 

from them is within the boundaries of probable measurement error. (Emphasis in original.) 

The following data provide a basis for such quantification and 

lead to the conclusion that, using an average of 25 readings obtained 

under the conditions prescribed in Method 9, qualified observers are 

able to consistently assign opacity values under relatively ideal 

conditions, with a positive error seldom exceeding 7.5 percent opacity. 

(a) October 1973 report titled "Average Observation Error Asso4 

dated with Smoke Plumes at Levels of Known Opacity". This report in 

addition to showing that each observer met the +_ 7.5 percent requirement, shows that when the readings of all observers are averaged, the 

largest positive error associated with a given opacity level was 5.0 

8,9 

«Sf mm* 

91 
P.96 

percent opacity which occurred when the true opacity was 10 percent. 

For plumes between 15 percent and 90 percent opacity, the average error 

did not exceed + 2.8 percent opacity. This is a clear demonstration of 

the inherent accuracy of the technique of determining plume opacity 

through observation by qualified observers. 

(b) In a test conducted November 19-20, 1973, nine qualified 

observers were shown plumes generated by a smoke generator. The plumes 

were presented in runs of 25 each during which each observer assigned 

opacity using the procedures set forth in Method 9. A total of 133 

sets of 25 observations using black smoke and 170 sets of 25 observations using white smoke were made. The results of this test are as 

follows. For white plumes, 99 percent (168 of 170) of the sets of 

observations were made with an error of less than + 7.5 percent opacity. 

Ninety-five percent of the sets of observations were made with an error 

of less than +5. 8 percent opacity. For black plumes, the accuracy was 

even better: 99 percent of the sets of observations were made with an 

error of less than + 5 percent opacity; 95 percent were made with an 

error of less than +2. 7 percent opacity. 

(c) A test was conducted at a power plant in Charlotte, North 

Carolina, on September 30, and October 1, 1974. In this test, 8 

qualified observers made a total of 168 sets of 25 observations and 

»;'vyit'.-._. 

92 
P.97 

assigned opacity according to the procedures of Method 9.* Each run 

consisted of 25 individual readings. All observers had been certified 

according to Method 9. Two of the 8 observers had not had previous 

field experience and two had only limited field experience. The power 

plant plume (which was monitored with an in-stack transmissometer) was 

white in appearance and was viewed against a constrasting clear blue 

sky (no condensed water vapor was present in the plume). The plume was 

held relatively constant during some runs and was varied during other 

runs in order to simulate the various conditions which could be 

encountered in the field. The test results showed that 99 percent 

(166 of 168) of the observations (average of 25 readings) were made with 

an error of less than +6.2 percent opacity; 95 percent with an error of 

less than + 4.7 percent opacity, and 90 percent with an error of less 

than +2.6 percent opacity. 

(d) A test was conducted at a sulfuric acid plant on January 29-30, 

1974. The plant was equipped with an in-stack transmissometer.** 

ft^fi 

* This test was conducted with the 8 observers divided into two groups 

of 4 each. One group, the control group, made all readings from an 

optimum viewing location. The second group made readings under differing 

conditions. Only the readings which were made according to Method 9 

criteria are reported here, except that 32 sets of readings are also 

included which did not conform precisely to Method 9. In these sets, 

observers were located at an optimum location and assigned opacity in 

1 percent increments, not 5 percent increments as specified in the 

method. The only other data collected but not included in the totals 

shown here, was read with the sun outside the 140° sector to the observer's 

back. This is not acceptable under Method 9. 

** Not required at sulfuric acid plants by EPA standards. 

93 
P.98 

^PHT'i n j-Mh-f I IJP m , 

Observer readings were made according to Method 9 against a contrasting 

background and were compared with the transmissometer readings. The 

results are as follows: A total of 298 sets of 25 readings were made. 

Two sets of readings were made with an average error of + 8 percent 

opacity. A total of nine sets of readings were made with an average 

error of + 5 percent opacity or greater. The remaining 289 sets of 

readings were made with errors of less than + 5 percent opacity. 

In summary, a total of 636 runs of 25 readings each were made 

using white plumes and 133 runs of 25 readings each using black plumes 

for the specific purpose of quantifying the degree of positive error 

possible in Method 9. The readings were made against contrasting 

backgrounds, the condition under which a plume is most visible and is 

most conducive to positive observer errors. The results show that 

single observers, on the basis of single sets of 25 readings, are able 

to assign opacity with errors of less than +7.5 percent with good 

consistency (630 of 636 for white plumes; 133 out of 133 for black 

plumes). Errors in excess of -t 7.5 percent can occur, although very 

infrequently. In short, on the basis of this extensive research of 

the very sort demanded by PCA, observer readings of opacity have been 

shown to be within an error tolerance of + 7.5 opacity with a frequency 

of approximately 99.3 percent (763 of 769 total sets of observations). 

This indicates clearly that opacity observers do in fact meet the + 7.5 

percent opacity accuracy limit which is specified explicitly in the 

introduction to (amended) Reference Method 9. 

'&#&& 

94 
P.99 

Finally with regard to observer accuracy and the inherent reliability of opacity readings, much of the concern of the Court of Appeals 

is related to PCA's contention, based on an HEW study, that at low 

levels opacity readings cannot be made reliably. The Court notes that 

PCA's claim that Table 2 on page 28 of that study shows that the six 

trained observers rated a plume known to have 0 percent opacity at more 

than 0 percent opacity, and three rated it at more than 20 percent. 

The Court notes further that a plume known to be 20 percent opacity was 

rated higher than 20 percent by five of the six observers, based also 

on Table 2. 

A close reading of Table 2 shows, however, that Petitioners have 

wholly misconstrued the nature of that test and the data presented in 

Table 2. In fact, the study specifies that 

"tests of trained observers show that the observers that 

viewed white plumes on a clear day facing the sun assessed 

the plumes at a higher Ringelmann number (lower transmittance) than did observers that viewed the plumes with 

the sun to their backs. For darker, plumes the effect was 

less pronounced. Group assessments showed good agreement 

for similar sun-plume-viewer geometries'^ (emphasis added). 

EPA agrees that viewing plumes while facing the sun may produce inaccurate 

g 

readings. It is for this very reason that Reference Method 9 requires 

observations to be made with the sun at the viewer's back. 

When Table 2 is examined in this regard, the "good agreement" for 

apparent similar geometries divides the observers into two groups. The 

first, consisting of Inspectors 1, 2, and 3, had similar readings among 

[&&_--£_-* 

95 
themselves. The second group, consisting of Inspectors 4, 5, and 6, 

also had good agreement among themselves. The levels of the second 

group are significantly higher than those of the first group, indicating 

that the second group was viewing into the sun, while the first group (1, 

2, and 3) was viewing with the sun to their backs. This probability is 

confirmed by the report itself, which states that no restriction was 

placed on viewing direction. Since only Inspectors 1, 2, and 3 appa.-

ently made their observations with the sun at their backs, it is only 

their results that are at all relevant to the question of observational 

reliability or accuracy. These results, for the low levels of opacity 

concerning the Court, are reproduced below: 

Table 2. AP-30, Evaluation of White Plumes6 $0&m 

In-stack transmittance, percent 75% 90% 

Eguiv. Ring. No. 1.00 0 . 

Insp. No. 1 1.03 0.03 

Insp. No. 2 1.13 0.16 

Insp. No. 3 0.97 0.17 

It is at once apparent that the observations of Inspectors 1,2 , 

and 3 reflect a very high degree of accuracy, contrary to PCA's contentions. Closer examination of this table, moreover, shows that the 

data itself is presented in a way not corresponding with EPA's 

standards. It will be noted that each column is headed by two 

figures: the "equivalent Ringelmann No.", and the "In-stack Transmittance, Percent." Transmittance, of course, represents the 

percentage of light not blocked by the smoke, so the 75 percent 

mittance is a 10 percent opacity. As the Court notes, the presently 

96 
P.1 

accepted equivalency between Rinqelmann numbers and opacity of white 

smoke is 20:1, i.e. Ringelmann No. 2 = 40 percent opacity, Ringelmann 

No. 1 = 20 percent opacity, Ringlemann No. .5 = 10 percent opacity, 

Ringelmann No. 0 = 0 percent opacity, etc. The Table 2 column headings, 

however, reflect a different equivalency: there, Ringelmann No. 1 

corresponds to 25 percent opacity (75 percent transmittance), and 

Ringelmann 0 corresponds to 10 percent opacity (90 percent transmittance), 

Since EPA's opacity standards are predicated upon and expressed in terms 

of the transmission and obscuration of light, it is therefore only the 

transmittance figures which are at all relevant to evaluating EPA's 

standards. 

The discrepancy between the equivalency used in Table 2 and the 

presently accepted Ringelmann-opacity equivalency exists because during 

the middle nineteen-sixties when the data were obtained, there was little 

interest in reading low opacity plumes, since visible emissions standards were generally at about forty percent opacity. The tests were 

conducted with smoke readers at a smoke school where^the Ringelmann 

Chart was considered the'primary standard, and the school's smoke generator transmissometers were calibrated in terms of Ringelmann numbers (a 

procedure not used today). This nonlinear calibration resulted in 

white plumes below thirteen percent opacity being assigned a Ringlemann 

number of zero. Black plumes below five percent opacity were also 

assigned a Ringelmann number of zero. It is clear therefore that this 

equivalency (now replaced by the standard 20:1 ratio) was not intended 
P.2 

to deal with low opacity plumes, since all six inspectors in fact 

reported seeing smoke at "what was supposed to be Ringlemann zero. 

As a result of these flaws, the data in Table 2 can only be 

partially converted to opacity percentages for purposes of evaluating 

observer accuracy and are not completely reliable for this purpose as 

the observations were not made in accordance with current procedures 

specified by Method 9. Since a definite ratio of 25:1.00 was used to 

calibrate the observers at the 25 percent level, those figures 

can be expressed as opacity percentages. The conversion for the 10 

percent opacity column is less exact, but the fact that all observers 

did observe smoke with a known 10 percent opacity plume allows the use 

of the standard ratio (Ringelmann .5 = 10 percent opacity) as a close 

approximation for purposes of conversion. The results of this conversion 

appear below. 

Table 2. AP-30, Evaluation of White Plumes6 

In-stack transmittance, percent 75% 90% 

Opacity, percent 25% 1 <0 

Inspector No. 1 

Ringelmann observed 1.03 0.03 

Equivalent opacity 25.75% 0.6% 

Inspector No. 2 

Ringelmann observed 1.13 0.16 

Equivalent opacity 28.25% 3.2% 

Inspector No. 3 

Ringelmann observed 0.97 0.17 

Equivalent opacity 24.25% 3.4% 

It is apparent from this more properly presented data that Table 

2 in fact refutes, rather than supports, PCA's claims of unreliably 98 

i<P$ ^ 
P.3 

high readings at low levels o* opacity. Indeed, the column which PCA 

treated as 0 percent opacity is in fact 10 percent opacity; in this 

column all three inspectors rated the opacity at well below its actual 

value. Likewise, the column which PCA treated as 20 percent is actually 

25 percent opacity. In that column, all observers rated the opacity at 

values very close to the actual level, and well within the 7.5 percent 

opacity tolerance to which observers are limited by Method 9. 

Because of the fundamental differences in the method of relating 

and calibrating Ringelmann numbers with equivalent opacity between the 

method used at the smoke school where the above data v/ere gathered and 

the present approach used by EPA (as reflected in Method 9) , the 

author of AP-30 states that the data in Table 2 cannot be used to 

5 

assess the reliability of EPA's method or opacity readings in general. 

The above discussion is therefore presented solely to demonstrate that, 

contrary to PCA's belief, those data do not in any way indicate the 

unreliability of EPA's use. of qualified observers. The Agency is not 

relying on those data as part of its demonstration of the accuracy of 

Method 9. 

In accordance with the Amoco case discussed above, this error 

tolerance of + 7.5 percent opacity must be accounted for in the enforcement process, so that no source which is in fact 1n compliance with the 

applicable opacity standard is cited for a violation due merely to 

normal observational error. EPA has consistently maintained that it 

does in fact take this error tolerance into account in the enforcement 

99 
P.4 

process. In an earlier draft response to this remand (November, 1973), 

for example, the Administrator stated that "the agency would not take, 

and the courts would not sustain, enforcement action based upon opacity 

observations that do not exceed the standard by more than the average 

opacity error associated with the particular opacity standard." PCA, 

however, has been unsatisfied by this assurance, apparently fearing that 

EPA in its enforcement decisions would ignore the established error 

tolerance. To provide the certainty desired by PCA and others, EPA is 

therefore now amending the applicable regulations (40 CFR 60, Appendix 

A, Reference Method 9) by adding an introductory section which discusses 

the concept of visible emission readings and describes the effect of 

variable viewing conditions. This section presents pertinent portions &$&$$ 

of the above data and notes specifically that the accuracy of the method 

must be taken into account when determining possible violations of 

applicable opacity standards. A copy of the revised regulation appears 

in Part B of Appendix III of this Response. 

EPA is also now amending the provisions of Reference Method 9 to 

make clear that the determination of an opacity level reportable as a 

violation involves averaging 24 readings taken at 15-second intervals. 

This will make clear that a single high reading will not be cited as a 

violation. It will also ensure, as PCA requests, that such individual 

readings, which may result under normal plant operations from brief 

events such as shaking of fabric filter bags in baghouses or rapping 

of electrodes in electrostatic precipitators, will not result in 

100 
P.5 

determinations of violation. This amendment to Reference Method 9 is 

set forth in Part B of Appendix III. (This approach is a satisfactory 

means of enforcing opacity standards in cases where the violation is a 

continuing one and time exceptions are not part of the applicable 

opacity standard. However, the opacity standards for steam electric 

generators in 40 CFR 60.42 and fluid catalytic cracking unit catalyst 

regenerators in 40 CFR 60.102 and numerous opacity standards in State 

Implementation Plans specify various time exceptions. Many State and 

local air pollution control agencies use a different approach in 

enforcing opacity standards than the six-minute average period specified 

in this revision to Method 9. EPA recognizes that certain types of 

opacity violations that are intermittent in nature require a different 

approach in applying the opacity standards than this revision to Method 

9. It is EPA's intent to propose an additional revision to Method 9 

specifying an alternative method to enforce opacity standards. It is 

our intent that this method specify a minimum number of readings that 

must be taken, such as a minimum of ten readings above the standard in 

any one hour period prior to citing a violation. EPA is in the process 

of analyzing available data and determining the error involved in 

reading opacity in this manner and will propose this revision to Method 

9 as soon as this analysis is completed. The Agency solicits comments 

and recommendations on the need for this additional revision to Method 

9 and would welcome any suggestions particularly from air pollution 

control agencies in how we might make Method 9 more responsive to the 

needs of these agencies.) 

;

;i?7/;>,7;9*;V,S 

j

u*5'>J^!V';^?._- -j 

101 
P.6 

PCA also contends that the wind velocity during a given set of 

observations can affect the opacity levels read by observers. EPA 

agrees that this is true. However, as is the case with lack of contrasting background in viewing a plume, the result of high winds is a 

negative error in reading the opacity of the plume; this results from 

the dissipation of the plume caused by the wind. Since a negative 

error in reading the opacity of the plume cannot prejudice an operator, 

this consideration is not relevant to the reliability of the method for 

assessing violations of the opacity standards. 

PCA contends that the viewing angle of the observer with respect 

to the sun and the plume can produce erroneously high readings; if the 

observer reads the plume while facing the sun, PCA says, such high 

reading may result. EPA agrees, as was noted above, and for this reason 

Reference Method 9 has always required the observer to read the plume 

with the sun at his back. Reference Method 9 is now being amended to 

include even more, specific criteria concerning observer position with 

respect to the sun. The method will now require that the sun shall be 

within a 140° sector to the observer's back. This amendment appears in 

Part B of Appendix III. 

The final aspect of opacity observations with which PCA and the 

Court of Appeals were concerned is the procedure employed by qualified 

observers to evaluate plumes containing condensed (visible) water vapor, 

or "steam plumes." When stack emissions contain appreciable water vapor, 

the vapor becomes visible when the gases are cooled below the dew point 

<wmi102 
P.7 

and water condenses in fine droplets. Some steam plumes are detached 

•kick 

while others are visible as released from the stack. However, 

since ambient air is normally much drier than stack emissions containing 

visible water vapor, dilution causes the gases at some point to become 

unsaturated. At this point, condensed water evaporates and is no 

longer visible in the plume, PCA contends that these plumes cannot be 

read properly, and the Court of Appeals also notes concern over the way 

in which steam plumes are to be read. This issue was addressed in part 

24 in the report titled "A Report on Contaminated Water Vapor Plumes." As 

EPA has previously noted, instruction is given in the smoke school as 

to how such plumes are to be read; the above report illustrates how 

qualified observers can readily distinguish the point at which all visible 

water vapor has evaporated from the plume. It is this point at which 

the opacity reading is made. Since the plume has been somewhat dissipated by that point, the reading is often lower than that which would 

have been found at the lip of the stack, had the plume been free from 

visible water vapor. This error is negative, however, and in no way 

prejudices the plant operator. EPA agrees, however, that the prior 

language of Method 9 did not sufficiently make this procedure clear. 

Method 9 is therefore now being amended to remedy that deficiency; 

*** The phenomenon of a "detached plume" is often observed when a warm, 

moist gas stream is released into a cooler atmosphere, e.g. when hot, 

wet exhaust gases from a wet process kiln are released to the atmosphere. 

Here the gases are clear at the point of discharge but become opaque as 

the wet gases mix with cooler air in the atmosphere. 

103 
P.8 

when the new guidelines are adhered to (as they were in the past, though 

not formally articulated in the Method), any errors due to the presence 

of water vapor can be eliminated. These amendments appear in Part B of 

Appendix III. 

In addition to proposing specific procedures, EPA is currently 

investigating techniques which could be employed in the smoke school to 

further enhance an observer's capability to accurately identify 

contaminated water plumes. This investigation is being undertaken by 

a contractor—Pacific Environmental Services, Inc.--and by EPA staff 

as part of an overall program to develop further guidelines concerning 

12 opacity training and field observation. Procedures used by State and 

local regulatory agencies to observe contaminated water vapor plumes *'••#>& 

are being reviewed, and the use of such training aids as movies and 

apprenticeship training will be considered. 

The basic question involved is not whether an observer can accurately 

assign opacity to a contaminated water plume, but rather is whether an 

observer can distinguish between condensed water vapor and visible 

particulate matter. To accurately evaluate wet plumes pursuant to 

revised Method 9, it is necessary only for an observer to distinguish 

between condensed water vapor and visible particulate air pollutants. 

In no case is the observer required to assign an opacity to a plume 

13 which contains visible (condensed) water droplets. 

As noted in the previously cited report, water plumes present an 

entirely different appearance to an observer than a dust plume. A 

104 
P.9 

trained air pollution inspector is familiar with both types of plumes, 

and has no difficulty distinguishing between the two. While much of 

his ability in this area stems from smoke school training, his background 

in inspecting industrial processes is also a factor. Inspectors 

employed by control agencies are required to become familiar with a 

broad spectrum of sources and to evaluate opacities from them under 

all weather conditions. For instance they know which sources employ 

scrubbers, which cement plants employ wet and dry process systems and 

generally which sources tend to produce wet plumes. They also know that 

extreme weather conditions can create visible water plumes at sources 

which release only negligible particulate matter, e.g. natural gas-fired 

boilers and water heaters. Thus, when a trained air pollution inspector W%&& 

evaluates a wet plume source he relies on all of this background in 

making a judgment. In following Method 9 he first identifies that 

portion of the plume which contains condensed water. As explained in 

the previously cited report, fluffy water plumes may trail 100 feet or 

24 

more from the stack. When the water plume disappears, he evaluates the 

opacity of the remaining dust plume which, if of violating opacity, will 

persist for a much longer distance. At this point, when water droplets 

evaporate and cease to be visible, the dust plume has been diluted 

considerably below the concentration at the stack exit. Only if the 

dust plume is still of greater than allowed opacity at the point of 

complete evaporation can an inspector consider a citation of violation. 

His normal procedure is to enter the plant and evaluate the process 

105 
P.10 

•** • I pp I I 

operation before in fact issuing the notice of violation. Thus it is 

obvious that the procedure allows a great deal of latitude to the 

operator of a wet plume process. Far from citing unjustly for violative 

visible emissions, the air pollution inspector will often be forced to 

ignore periods of marginal violations simply because the visible dust 

plume is masked by visible water droplets. 

The revisions in Reference Method 9 make clear that the above 

o 

procedure is to be followed. For attached steam plumes, the observer 

is to make his readings at the point where all visible water vapor has 

evaporated and only particulates remain in the plume. He is to. record 

the reading made at that point in the plume, and is not (as PCA fears) 

to extrapolate back to any hypothetical value at the lip of the stack. 

For detached steam plumes, the observer is to read the opacity value as 

usual at the lip of the stack, providing that no visible water vapor is 

present there, i.e. providing that there is a gap between the lip of the 

stack and the point of initial condensation into steam. 

•-•lily''*"'1"' 

106 
P.11 

EVALUATION OF SMOKE SCHOOL PROCEDURES 

The purpose of a smoke school is two-fold. It provides a 

means for training an observer, and for certifying that an observer 

is, in fact, capable of making opacity observations with reasonable 

accuracy. In this sense, the school serves to calibrate (or re-calibrate) 

observers, and rejects candidates who are not capable of accurately 

reading opacity. The question of whether the school adequately serves 

these purposes cannot primarily be answered by examining the procedures 

used. Rather, it is necessary to examine the accuracy of observers 

who have been trained and certified in the school, i.e., the results 

of those procedures. If, as the data discussed earlier demonstrate, 

qualified observers can read plumes with reasonable accuracy, the 

procedures and instruction used at the smoke school must, by 

definition, be accomplishing the desired results. 

With regard to PCA's criticism concerning the ability of an 

observer to accurately read emissions under various field conditions 

which were not encountered in the training school, it is necessary 

to refer again to the factors affecting apparent opacity. As discussed 

above, observations made under conditions of high contrast are most 

conducive to positive errors. To the extent possible, observers employ 

contrasting backgrounds during qualification. It is true that this 

procedure may tend to limit the accuracy of an observer under less than 

ideal conditions. However, since a plume will present an appearance of 

lower opacity under such conditions, the resulting,bias will be negative. 

As discussed above, this effect is confirmed by theory and by field 

observation. 

107 

^Ht 
P.12 

PCA has noted the fact that smoke school trainees are given 

repeated opportunities to pass the certification test. Thus, an 

observer may be certified on one run even though the certification 

criteria were not met on previous runs. Presumably, he could 

also fail to meet the criteria on subsequent runs. Petitioners 

are correct in this description—particularly when new or relatively 

inexperienced persons are being tested. It does not follow, however, 

that the smoke school procedures are deficient or inadequate in this 

respect. First, as noted above, the adequacy of the smoke school 

cannot be determined solely by reviewing the procedures; evaluation 

can also be made by testing the ability of observers who have 

passed the certification test. Secondly with respect to the 

certification procedures, it should be recognized that the +7.5% 

criterion is particularly restrictive in that it involves the absolute 

error, not simply the average taken over 25 readings. Thus, negative 

and positive errors are not compensating (i.e;, a -5% error and 

a +7 error result in an average absolute error of +6%). This is 

unlike the field observation procedure where negative and positive 

errors are compensating (a -5% error and a +7 error result in an 

average error of +1%). During an EPA smoke school conducted on 

October 9, 1974, a record was kept for all observers who attended and 

g 

were certified. This record includes both runs during which the 

observers passed the certification criteria and during which observers 

failed to meet the criteria. These data show that even on these 

runs when observers failed to qualify, over two-thirds of them met 

W$$k108 
P.13 

g 

7.5% average error limit imposed by Method 9. Since the Reference 

Method 9 involves an average of 24 readings as a means of determining 

plume opacity, failure to continuously meet the more stringent 

certification requirements is relatively unimportant as long as 

the average reading is consistently within the prescribed criterion 

of less than +7.5% average opacity. For example, the requirement 

that no single reading be missed by more than +15 percent is somewhat 

arbitrary, and could be relaxed to +20 percent to reduce the number 

of observers failing the certification test. EPA has concluded, 

however, that the stringent certification criterion serves the intended 

purpose of forcing a trainee to learn to assign opacity within a 

reasonable range of precision and therefore should not be relaxed. $&&$& 

EPA has further concluded, in summary, that while any changes 

recommended by the contractor Pacific Environmental Services will 

be carefully considered, the training program does in fact effectively 

train observers to read plumes under field conditions with 

reasonable accuracy. 

Summary 

EPA believes that the above data have convincingly demonstrated 

that the opacity standards are inherently reliable.**** The data show 

that observers can, with a very high confidence level, read plumes 

to within the certified error tolerance of 7.5%. That tolerance 

is taken into account in the enforcement process, as provided 

**** A New Jersey court has recently reached the same conclusion. See 

New Jersey v. LLoyd A. Fry Roofing Co., Docket no. C-3682-72 

(Superior Court, Sept. 30, 1974). 

109 
P.14 

explicitly by the (amended) regulations. EPA further believes that 

the effectiveness of the training program is well proven by the 

resulting accuracy of its graduates under actual field conditions. 

In those few situations where the language of the regulations or 

Reference Method 9 was insufficiently clear or inadequate, those 

regulations are being or have been amended to remedy such deficiencies. 

The Administrator concludes, therefore, that since the concerns of 

the Court of Appeals and the Portland Cement Association in this 

regard have all been satisfactorily dealt with, the Agency should 

continue to use opacity standards for new sources under Section 111 

of the Clean Air Act. EPA does, however, recognize that some 

operators of Portland cement plants may install in-stack transmissometers 

14 for the purpose of continuous monitoring of particulate emissions. 

EPA will therefore accept as probative (though not conclusive) 

evidence the results of such continuous monitoring by transmissometer which indicate that the opacity at the time readings 

were taken by Reference Method 9 was not in excess of the standard, 

provided that the source shall meet the burden of proving that the 

instrument used meets (at the time of the alleged violation) the 

14 applicable technical specifications, has been properly maintained 

and (at the time of the alleged violation) calibrated, and that the 

resulting data have not been tampered with in any way. The applicable 

regulations are being amended to reflect this provision and appear in 

Part B of Appendix III. 

j£t&Bg&£ 

110 
P.15 

EPA will of course continue to review the degree of accuracy 

and need for opacity measurements as new data and information are 

acquired. For example, at the request of the Department of Commerce, 

EPA solicited such information in the preamble to new source 

performance standards recently proposed (39 FR 37466). However, at 

this time the data and information available to EPA support the 

position taken in this response. 

ACHIEVABILITY OF THE OPACITY STANDARDS FOR PORTLAND CEMENT PLANTS 

Under Section 111 of the Clean Air Act, EPA has established 

10 percent opacity as the standard which may not be exceeded by 

new kilns at Portland cement plants. PCA contends that some new 

plants will or may be unable to achieve compliance with this 

visible emissions limit. EPA policy is that opacity limits should 

be set at such levels that any source which meets the mass emission 

limits will also meet the opacity limits. EPA has conducted an 

intensive review of its opacity standards, including conducting new 

tests and gathering new data, and has concluded that although the 10% 

opacity standard is achievable by almost all new Portland cement plants, 

that standard should nevertheless be relaxedNto 20% opacity to accomodate certain extreme circumstances. EPA further concludes that at this 

new level, practical circumstances under which any combination of the 

factors cited by PCA or the Court as having a possible effect on opacity 

(transmittance) of smoke plumes that could cause a new source to be 

unable to meet the opacity standard is exceedingly rare. The 

111 
P. 16 

reasons for these conclusions are set forth below. 

PCA contends that the opacity standards for Portland cement 

plants are unachievable for two primary reasons, both related to 

the theory of transmittance of light through a plume. PCA states, 

first, that opacity varies with particle size and shape, so that 

a given mass concentration of particles — which could be composed 

of various combinations of different size and shape particles — 

could result in differing opacities. EPA agrees that this correctly 

states the theory of plume transmittance (opacity) as it relates 

to particle dimensions. PCA concludes from this statement of theory, 

disregarding the results of the application of the theory to operation 

of Portland cement plants, that such plants might have widely varying 

opacities while still meeting the mass emission limits. It is with 

PCA's conclusion that EPA disagrees. The relevant question is what 

variations in opacity are in fact produced by the particle size-shape 

distributions actually present in Portland cement plants under normal 

operation and with praper maintenance and operation of pollution control 

equipment. It is this question which is next addressed. 

It is known from various studies and experience that uncontrolled 

gases vented from cement kilns contain heavy concentrations of coarse 

as well as fine partic!ate, i.e., in the range of 5 to 15 grains 

15 

per standard cubic foot. Standards of performance for new sources 

requiring best available technology, necessitate the installation of 

high efficiency collectors. Collectors of 99.4 to 99.8 percent 

efficiency are necessary to reduce exit concentrations to approximately 

112 
P.17 

0.03 grains per standard cubic foot which is necessary to meet 

the mass emission standard.' ..These collectors, fabric filters or 

electrostatic precipitators, are more effective in removing coarse 

particles than fine particles. Thus emissions from collectors, i.e., 

visible emissions, tend to be made up of much greater fractions 

of fine particulates than coarse particulates. 

In typical high efficiency collector exhaust gases there are 

generally few particulates larger than 40 microns diameter. ' The 

predominant number of particles are between 0.5 and 10 microns with 

2 17 the average size being about 2-4 microns. ' Maximum light scattering 

is generally acknowledged to be caused by particles in the size range 

of 0.2 to 2.0 micron. ' Available data indicate that the size dis- ?$?$$$. 

tribution of particulates released from well controlled cement kilns 

are similar within a narrow range (approximately 2 to 6 microns) from 

one kiln to another, and therfore from one plant to another. 

What the above data and studies indicate, in short, is that the 

size of particles emitted by plants with such control equipment varies 

only within a very narrow range. This variability in average size 

is theoretically not sufficient to cause more than a + 5 percent 

variation in opacity for typical cement kilns. These data are 

wholly incompatible with PCA's speculation that widely varying particle sizes might produce much larger variations in opacity at cement 

plants meeting the mass emission standard. 

The shape of particles emitted from well-controlled 

portland cement plants may vary as PCA contends. However, we disagree 

with their conclusions that such variations in shape would affect the 

113 
P.18 

opacity of emissions perceived by a qualified observer or in-stack 

transmissometer. Any irregularly shaped particles would be randomly oriented thereby smoothing or averaging out any significant variations of 

opacity that could possibly result. In addition, it is likely that the 

particles will be abraded or will condense into spherical shapes for the 

following reasons: 1) feed materials are ground to less than 75 microns 

in almost all cases; 2) further attrition and size reduction occurs 

as the feed material passes through the high temperature rotating 

kiln; and 3) alkaline material tends to vaporize and condense as 

a fume.1 5 -

1 6 '1 7 

Also, the recent microscopic examination of particles from 

the exhaust gases of a precipitator controlled kiln showed that 

2 

almost all particles were approximately spherical in shape. 

Given that particle size and shape do not vary to the extent 

necessary to substantiate PCA's speculation, it is apparent that 

normal operations even from plant to plant will not produce variations sufficient to significantly affect the opacity observed 

at the point of emission from the stack. Therefore, if the opacity 

standards are set in accordance with the opacity actually produced 

by normal operations, then with proper maintenance and operation 

of control equipment the very slight variations which may occur 

from plant to plant or from time to time within an individual plant 

will not cause the source to exceed the opacity standard. And if, 

for any reasons, some unusual design feature of a given plant 

caused it to exceed the opacity standard but not the mass emission 

114 
P.19 

standard, the variance procedure described below would eliminate any prejudice to such source. 

The second major factor which PCA claims affects opacity 

(transmittance) to the extent that some plants may exceed the 

opacity standard while meeting the mass emission standard is 

the diameter of the duct involved; i.e., the path length through 

which the light must pass. EPA agrees that the greater the path 

length through which the light must pass, the more light will be 

attenuated, and the greater will be the opacity. EPA again disagrees, however, with PCA's conclusion, which is again in disregard 

of the actual circumstances cf plant design and operation, that 

some plants will therefore be unable to meet the opacity standards, 

though meeting the mass standard. EPA believes that the proper 

issue in this regard is the actual range of stack diameters 

resulting from the engineering and economic necessities of plant 

design. This question is addressed below. 

Stack diameter affects opacity directly because it governs the 

length of the path through which the light is attenuated before it 

reaches the observer viewing the plume. The larger the diameter 

of the stack, and therefore the plume, the more light will be 

attenuated as it passes through the plume, and the greater will 

be the opacity of the plume. Stacks venting high efficiency control 

equipment, such as that serving kilns at portland cement plants, are 

designed to ventilate the process to the degree necessary with the 

minimum pressure drop and at the lowest cost. These engineering 

and economic factors result in the construction of stacks in which 

115 

r$$3t2?? 
P.20 

the gas velocities approximate 30 to 100 feet per second, since at 

higher velocities friction losses become excessive, necessitating 

much larger horsepower fans. At lower velocities, the size of the 

stack required would result in disproportionately large capital 

costs. Thus, stack diameter tends to be directly related to and 

characteristic of plant size, varying only within a relatively 

limited range. 

Stack gas exit velocity is controlled by stack diameter. 

Exit velocity is directly proportional to the volume of gases 

vented from a kiln and inversely proportional to the cross-sectional 

area of the stack. For plumes of a given cross-section, velocity 

has no effect upon opacity, since opacity is a function of path 

length and is proportional to the concentration and characteristics of particles in the gas stream. The velocity at which the 

gas stream moves through the viewer's line of vision has no 

effect on opacity. 

It follows, therefore, that an extremely large diameter 

stack could theoretically be installed at a cement plant, even 

though its cost would be much greater than normal. Ih the course 

of EPA's survey of the cement industry, the largest size kiln 

stack that has come to our attention is 15 foot in diameter. In 

the unlikely event that larger stacks were used or other abnormal 

conditions of design or operation were encountered that could 

cause a violation of an applicable opacity standard, EPA would evaluate 

opacity during the performance tests for the mass emission standard. 

If it were shown necessary, a suitable opacity level greater than 

116 
P.21 

20 percent would be established for that specific kiln installation. 

Although such an eventuality is highly unlikely, appropriate language is being promulgated in the general provisions of the regulation 

to accomodate such situations and appears in Part B of Appendix III . 

EPA concludes, on the basis of the actual stack diameters 

employed by the industry, that stack diameter will not cause a 

plant meeting the mass emission standard to exceed the opacity 

standard. To deal with the uncertainties cited by PCA as to 

how plumes from baghouses with stub stacks are to be read, EPA is 

revising Method 9 to specify that a row of such stub stacks, or 

any non-circular stack, is to be read along its shortest axis 

(perpendicular to its longer axis). This ensures that the 

shorter path length will be used to determine opacity, and will 

eliminate any concern that a long row of stub stacks, common on 

baghouses, might be read along its long axis, producing higher 

opacity. 

Given that particle size-shape and stack diameter do not produce opacity variations sufficient to cause a source which might 

otherwise meet the opacity standard, and which is meeting the mass 

standard, to exceed the opacity standard, the only remaining issue 

is whether well-controlled portland cement plants can, in fact, 

meet the opacity standard. EPA has accumulated data for portland 

cement plant kilns that are vented to high efficiency control 

equipment that is properly designed, operated and maintained. These 

data are summarized in Table I. Opacity readings were also taken of 

•K&Bsii* 

117 
P.22 

Table I 

Name of the Company, 

Date of Test and 

Type Control Equipment 

Dragon Cement Co. 

Northampton, Pa. 

4/29-30/71 

Baghouse 

Oregon Portland Cement Co. 

Lake Oswego, Oregon 

10/7-8/71 

Baghouse 

Santee Portland Cement Co. 

Holly Hill , S. C. 

5/23-25/74 

Electrical Precipitator 

United Portland Cement Co. 

Artesia, Miss. 

6/25-27/74 

Electrical Precipitator 

Monarch Cement Co. 

Humboldt, Kansas 

6/12-14/74 

Baghouse 

Marquette Cement Co. 

Neville Island, Pa. 

6/19-21/74 

Electrical Precipitator 

Particulate Emissions 

Test Duration 

2,19-23 

9 hours -

0 minutes 

lbs/ton 

of dry 

feed 

6 hours 0.070 

6 hours 0.272 

8 hours - 0.107 

2 minutes 

8 hours - 0.209 

23 minutes 

12.5 minutes 0.196 

0.339 

Stack Dia. 

1T0" 

4'4" 

(velocity 

cone) 

12'0" 

1T3' 

7'0" 

12'6" 

Max. 

Average Single 

Opacity Reading 

<10 <10 

<10 <10 

<5 <5 

3.8 

18* 

*Based on transmissometer data. 

118 
several additional well controlled portland cement plant kiln stacks 

I Q 

by an EPA contractor. Mass emission tests were not conducted in 

these instances, however, in light of the petitioners contention 

that the mass standards ars overly restrictive, it would seem 

unlikely that these plants would be operating significantly below 

the mass emission standard. A summary of these installations is 

shown in Table II . 

Table II 

Opacity of Visible Emissions from Cement Kilns Controlled by Fabric Filters 

13 

Name of Company 

Date of Test and 

Control Equipment 

Whitehall Cem 

Cementon, Pa. 

7/29 & 8/1/74 

Baghouse 

Coplay (Egypt) 

Cement Co. 

Egypt, Pa. 

7/29-31/74 

Baghouse 

Hercules Cement Co. 

Stockerton, Pa. 

7/29 & 8/2/74 

Duration 

of Test 

(hours, min.) 

8h 2m 

7h 15m 

Stack Size 

(feet) 

15' dia. 

(1 stack) 

4' 10" dia. each. 

(7 stacks) 

Average 

Opacity 

(percent) 

Maximum 

6-Minute 

Average 

Opacity 

0.2 

3.8 

Maximum 

Single 

Reading 

5h 16m 

Penn-Dixie Cement Co.* 7h 55 m 

Nazareth, Pa. 

7/29-30/74 

Baghouse 

13' dia. 

(1 stack) 

2'xV each. 

(12 stacks) 

5'xll' each with 

center divider. 

(8 stacks) 

0 

0 

10-15 

0 

0 

15 

0 

0 

25 

W&M& 

*These observations were taken across the shorter axis of .the eight stacks (40' pathlength). If the observations had been taken across the longer axis of any one stack, the 

pathlength would have been 11 feet. The estimated maximum 6-minute average opacity 

under these latter conditions would be 4.4 percent rather than 15 percent. Likewise, the maximum single reading would be 7.5%. Reference Method 9 now requires 

these observations to be made across the 11' axis. 

119 
P.24 

With the exception of Marquette Cement' Co. all of the kilns 

identified in Table I were- operating below the mass and opacity 

standards promulgated in 1971 (i.e., 0.3 lb/ton of dry feed and 

10%). The data for Marquette Cement Co. indicate that the kiln 

was not in compliance with the mass emission standard (0.339 

versus 0.3 lb/ton of dry feed). The opacity data were collected 

with an in-stack transmissometer. The stack diameter is 12'6", the 

average opacity during the mass emission tests was 18%, and the 

average size of emitted particles was determined to be approximately 

2 2 microns diameter. If the stack diameter were 15', which is the 

largest diameter stack EPA has observed on cement plants, the average 

opacity would have been 21%. The mass emission tests for Marquette %<$$•'* 

Cement Co. consisted of three separate runs. The results of the three 

runs are: 

Table III 

2 3 Opacity and Mass Emissions for a Kiln * 

Particulate Average opacity Average opacity 

Emissions, (percent) at (percent) extrapRun lbs/tons of actual stack con- olated to 15' diameter 

Number dry kiln feed ditions (12'6") stack conditions 

25 

20 

18 

The particulate matter emissions from Marquette Cement Co. were 

analyzed to determine the particle size distribution. This analysis 

indicated that the average particle diameter was approximately 2 microns 

1 

2 

3 

0.386 

0.339 

0.292 

22 

17 

15 

120 
P.25 

which is very low for portland cement plants. These data indicate 

that for a plant with an unusually large stack diameter and 

with particulate emissions having very small average particle diameter 

properties, a 20% opacity standard is more reasonable than a 10% standard. 

The achievability of a 20 percent standard is amply demonstrated by 

the data in Tables I and II which illustrate that most portland cement 

kilns have no difficulty in meeting even a 10 percent opacity standard. 

The Marquette Cement Company test results illustrate that even under 

the combination of conditions that would produce the maximum obscuration 

of light (i.e., large stack diameters, small average particle sizes, 

and concentrations near the mass emission standard), a 20 percent 

standard (Table III, run number 3) would be achieved. It should be 

additionally noted that the combination of conditions for maximum 

opacity, even though accommodated by the 20 percent standard, will 

occur infrequently. Therefore, it is concluded that a plant with a 15' 

diameter stack which meets the mass emission standard will also meet a 

20% opacity standard and when it exceeds the mass emission standard 

will exceed the opacity standard. For stacks smaller than 15 feet in 

diameter, a portland cement kiln that violates a 20% opacity 

standard will also violate the mass emission standard by a substantial amount. Data in Table II show that in several cases, 

opacity of emissions from well controlled cement kilns are 

appreciably less than 20% even where larger stacks are employed 

e.g., 0.2% from a 15 foot diamater stack and zero from a 13 foot 

diameter stack. Based on these-data and EPA's policy that opacity 

standards be established at levels which require proper operation 

121 

#$?t* 
P.26 

and maintenance of control systems, the opacity standard for 

portland cement plant kilns is being changed from 10 to 20 percent. 

This change appears in Part B of Appendix III. 

In addition to considerations of the average opacity standards, 

EPA has evaluated the need for possible time exemptions in the 

opacity standard. It is recognized that during normal operation of 

portland cement kilns, process variations, shaking of bags in baghouses, rapping of electrodes in electrical precipitators, etc., 

can produce mass emissions that are not perfectly constant. It 

follows that slight variations in opacity can also occur under 

these conditions. However, with the clarification to Method 9 

whereby a minimum of 24 opacity readings must be taken at 15 &&$• 

second intervals over a 6 minute period and with the averaging 

of observations for determining compliance with the opacity 

standard, it is apparent that such instantaneous opacity readings 

will not constitute a violation of the standard. Changing the opacity 

standard for portland cement kilns from 10 to 20 percent further 

ensures that such temporary incidents will not cause the opacity 

standard to be exceeded. Since the change in the opacity standard 

merely represents a relaxation of the standard, it will be applicable to all sources which commenced construction subsequent to 

the promulgation of the original, more stringent level. To an even 

greater degree than the 10% standard, this 20% standard is 

significantly less stringent than the mass emission limit for 

portland cement kilns. 

122 
P.27 

As discussed in this remand response, the change of the 

opacity standard from 10 percent to 20 percent was made to insure 

that no plant that is meeting the mass emission standard is cited 

for violating the opacity standard. It does not change the 

degree of particulate control required of new portland cement 

plants. Accordingly, this relaxation of the opacity standard 

does not require an environmental impact statement. 

123 
P.28 

APPENDIX III 

References 

1. K.W. Buhne and L. Duwel. Recording Dust Emission Measurements in 

the Cement Industry with the RM4 Instrument. Staub. Vol.32, No. 19. 

1972 (in English). 

2. Preliminary Test Results of Marquette Cement Manufacturing 

Company for Task Number 11. Cottrell Environmental Sciences. 

EPA Contract No. 68-02-0239. August 26, 1974. 

3. Robert L. Ajax. Memo to Jack R. Farmer, Credibility of Emission Test 

Data Contained in the Marquette Cement Manufacturing Company's Report. 

October 24, 1974. 

4. Average Observational Error Associated with Smoke Plumes at Levels ofKnown Opacity. EPA, OAWP, OAQPS, ESED Report. October 1973. 

5. W. D. Conner. Memo to R. L. Ajax, Measurement of Opacity by 

Transmissometer and Smoke Readers. October 16, 1974. 

6. Optical Properties and Visual Effects of Smoke Stack Plumes. PHS 

Publication No. 999-AP-30. 

7. Henry F. Hammill, Richard E. Thomas, and Nollie F. Swynnerton. 

Evaluation and Collaborative Study of Method for Visual 

Determination of Opacity of Emissions from Stationary Sources: 

Interim Report. October 1974. 

8. Federal Register: 39 FR 32857, September 11, 1974. 

9. Evaluation of EPA Smoke School Results. EPA, OAWM, OAQPS, ESED Report. 

October 9, 1974. 

10. Portland Cement Association v. Ruckelshaus. 486 F.2d 375, No. 72-1073. 

June 29, 1973. 

11. Coons, J. D., et al. Development, Calibration, and Use of a Plume 

Evaluation Training Unit. Journal of Air Pollution Control Association. 

Vol. 15. May 1965. pp. 199-205. 

12. Task Order: Preparation of Guideline for Evaluation of Visible 

Emission Opacity by Trained Observers. EPA Contract No. 68-02-1390, 

Task 2, June 5, 1974. 

13. Federal Register: 39 FR 32854, September 11, 1974. 

14. Federal Register: 39 FR 32852, September 11, 1974. 

15. R. Emmet Doherty. Current Status and Future Prospects - Cement Mill 

Air Pollution Control. Proceedings, The Third National Conference 

on Air Pollution, Washington, D. C. December 12-14, 1966. 

124 

rn**?TM 
P.29 

16. A Manual of Electrostatic Precipitator Technology, Part II--

Application Areas. Southern Research Institute. Contract No. 

22-69-73. 1970. pp. 609-640. 

17. Particulate Pollutant System Study, Volume II--Fine Particulate 

Emissions. Midwest Research Institute. Contract No. CPA 22-69-104. 

1971. 

18. Visible Emission Testing at Four Portland Cement Plants. Scott 

Environmental Technology, Inc. Contract No. 68-02-1400. 1974. 

19. Emission Testing Report (tested by company personnel). United 

Cement Company, Artesia, Mississippi. 1974. 

20. Emission Testing Report (kiln No. 2) . Santee Portland Cement 

Corporation, Holly Hill, South Carolina. Pollution ControlWalther Inc. 1974. 

21. Emission Testing Report. Monarch Cement Company, Humboldt, Kansas. 

Fuller Company. 1974. 

22. Emission Testing Report. Dragon Cement Company, Northampton, _?!*«&#/ 

Pennsylvania. EPA, OAWM, OAQPS, ESED Report. March 1972. 

23. Emission Testing Report. Oregon Portland Cement Company, 

Lake Oswego, Oregon. EPA, OAWM, OAQPS, ESED Report. March 1972. 

24. Contaminated Water Plumes. EPA, OAWM, OAQPS, ESED Report. 1973. 

125 
PORTLAND CEMENT REMAND RESPONSE 

APPENDIX III, PART B 

PREAMBLE AND AMENDMENTS 

TO REGULATIONS 

127 
P.31 

Title 40--Protection of the Environment 

CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY 

Subchapter C--Air Programs 

PART 60—STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES 

Opacity Provisions 

On June 29, 1973, the United States Court of Appeals for the 

District of Columbia in Portland Cement Association v. Ruckelshaus, 

486 F. 2d 375 (1973) remanded to EPA the standard of performance for 

Portland cement plants (40 CFR 60.60 e_t. seq.) promulgated by EPA 

under section 111 of the Clean Air Act. In the remand, the Court 

directed EPA to reconsider among other things the use of the opacity 

standards. EPA has prepared a response to the remand. Copies of 

this response are available from the Emission Standards and Engineering 

Division, Environmental Protection Agency, Research Triangle Park, 

N. C. 27711, Attn: Mr. Don R. Goodwin. In developing the response, 

EPA collected and evaluated a substantial amount of information which 

is summarized and referenced in the response. Copies of this information are available for inspection during normal office hours at EPA's 

Office of Public Affairs, 401 M Street, S.W., Washington, D. C. EPA 

determined that the Portland cement plant standards generally did 

not require revision but did find that certain revisions are appropriate to the opacity provisions of the standards. The provisions 

promulgated herein include a revision to §60.11, Compliance with 

Standards and Maintenance Requirements, a revision to the opacity 

iMsp 

129 
P.32 

standard for Portlant cement plants, and revisions to Reference 

Method 9. The bases for the revisions are discussed in detail in 

the Agency's response to the remand. They are summarized below. 

The revisions to §60.11 include the modification of paragraph (b) 

and the addition of paragraph (e). Paragraph (b) has been revised 

to indicate that while Reference Method 9 remains the primary and 

accepted means for determining compliance with opacity standards in 

this part, EPA will accept as probative evidence in certain situations 

and under certain conditions the results of continuous monitoring by 

transmissometer to determine whether a violation has in fact occurred. 

The revision makes clear that even in such situations the results of 

opacity readings by Method 9 remain presumptively valid and correct. &>$&•& 

The provisions in paragraph (e) provide a mechanism for an owner 

or operator to petition the Administrator to establish an opacity 

standard for an affected facility where such facility meets all 

applicable standards for which a performance test is conducted under 

§60.8 but fails to meet an applicable opacity standard. This provision 

is intended primarily to apply to cases where a source installs a 

very large diameter stack which causes the opacity of the emissions 

to be greater than if a stack of the diameter ordinarily used 

in the industry were Installed. Although this situation is considered 

to be very unlikely to occur, this provision will accommodate such 

a situation. The provision could also apply to other situations 

where for any reason an affected facility could fail to meet opacity 

standards while meeting mass emission standards, although no such 

situations are expected to occur. 

130 
A revision td the opacity standard for Portland cement plants 

is promulgated herein. The revision changes the opacity limit 

for kilns from 10 percent to 20 percent. This revision is based 

on EPA's policy on opacity standards and the new emission data 

from Portland cement plants evaluated by EPA during its reconsideration. The preamble to the standards of performance which were promulgated on March 3, 1974 (39 FR 9308) sets forth EPA's policy on 

opacity standards: (1) opacity limits are independent enforceable 

standards; (2) where opacity and mass/concentration standards are 

applicable to the same source* the mass/concentration standards are 

established at a level which will result in the design, installation, 

and operation of the best adequately demonstrated system of emission 

reduction (taking costs into account); and (3) the opacity standards 

are established at a level which will require proper operation and 

maintenance of such control systems. The new data indicate that 

Increasing the opacity limit for kilns from 10 percent to 20 percent 

is justified, because such a standard will still require the design, 

installation, and operation of the best adequately demonstrated 

system of emission reduction (taking costs into account) while 

eliminating or minimizing the situations where it will be necessary 

to promulgate a new opacity standard under §60.11(e). 

In evaluating the accuracy of results from qualified observers 

following the procedures of Reference Method 9, EPA determined that 

some revisions to Reference Method 9 are appropriate. The evaluation 

showed that observers trained and certified in accordance with the 

procedures prescribed under Reference Method 9 are consistently able 

to read opacity with errors not exceeding +7.5 percent based upon 

131 
P.34 

single sets of the average of 24 readings. The revisions to 

Reference Method 9 include the following: 

1. An introductory section is added. This includes a discussion of the concept of visible emission reading and describes 

the effect of variable viewing conditions. Information is also 

presented concerning the accuracy of the method noting that the 

accuracy of the method must be taken into account when determining 

possible violations of applicable opacity standards. 

2. Provisions are added which specify that the determination of 

opacity requires averaging 24 readings taken at 15-second intervals. 

The purpose for taking 24 readings is both to extend the averaging 

time over which the observations are made, and to take sufficient 

readings to insure acceptable accuracy. 

3. More specific criteria concerning observer position with 

respect to the sun are added. Specifically, the sun must be within 

a 140° sector to the observer's back. 

4. Criteria concerning an observer's position with respect to 

the plume are added. Specific guidance is also provided for reading 

emissions from rectangular emission points with large length 

to width ratios, and for reading emissions from multiple stacks. In 

each of these cases, emissions are to be read across the shortest 

path length. 

5. Provisions are added to make clear that opacity of contaminated water or steam plumes 1s to be read at a point where water does 

not exist in condensed form. Two specific instructions are provided: 

132 

-»!&£$• 
one for the case where opacity can be observed prior to the 

formation of the condensed water plume, and one for the case 

where opacity is to be observed after the condensed water plume 

has dissipated. 

6. Specifications are added for the smoke generator used 

for qualification of observers so that State or local air pollution 

control agencies may provide observer qualification training 

consistent with EPA training. 

In developing this regulation we have taken into account the 

comments received in response to the September 11, 1974 (39 FR 35852) 

notice of proposed rulemaking which proposed among other things 

certain minor changes to Reference Method 9. This regulation represents the rulemaking with respect to the revisions to Method 9. 

The determination of compliance with applicable opacity standards 

will be based on an average of 24 consecutive opacity readings taken 

at 15 second intervals. This approach is a satisfactory means of 

enforcing opacity standards in cases where the violation is a continuing one and time exceptions are not part of the applicable 

opacity standard. However, the opacity standards for steam electric 

generators in 40 CFR 60.42 and fluid catalytic cracking unit catalyst 

regenerators in 40 CFR 60.102 and numerous opacity standards 1n State 

implementation plans specify various time exceptions. Many State 

and local air pollution control agencies use a different approach 

1n enforcing opacity standards than the s1x-minute average period 

specified in this revision to Method 9. EPA recognizes that certain 

133 
P.36 

types of opacity violations that are intermittent in nature 

require -a different approach in applying the opacity standards 

than this revision to Method 9. It is EPA's intent to propose 

an additional revision to Method 9 specifying an alternative 

method to enforce opacity standards. It is our intent that this 

method specify a minimum number of readings that must be taken, 

such as a minimum of ten readings above the standard in any one 

hour period prior to citing a violation. EPA is in the process 

of analyzing available data and determining the error involved in 

reading opacity in this manner and will propose this revision to 

Method 9 as soon as this analysis is completed. The Agency solicits 

comments and recommendations on the need for this additional revision 

to Method 9 and would welcome any suggestions particularly from air 

pollution control agencies on how we might make Method 9 more 

responsive to the needs of these agencies. 

These actions are effective on (date of publication). The Agency 

finds good cause exists for not publishing these actions as a notice 

of proposed rulemaking and for making them effective immediately 

upon publication for the following reasons: 

(1) Only minor amendments are being made to the opacity standards 

which were remanded. 

(2) The U. S. Court of Appeals for the District of Columbia 

Instructed EPA to complete the remand proceeding with respect to the 

Portland cement plant standards by November 5, 1974. 

(3) Because opacity standards are the subject of other litigation, it is necessary to reach a final determination with respect to 

134 

•••••*:: ' 
P.37 

the basic issues involving opacity at this time in order to properly 

respond to this issue with respect to such other litigation. 

These regulations are issued under the authority of sections 111 

and 114 of the Clean Air Act, as amended (42 U.S.C. 1857c-6 and 9) . 

DltF Administrator 

135 
P.38 

Part 60 of Chapter I, Title 40 of the Code of Federal Regulations is amended as follows: 

1. Section 60.11 is amended by revising paragraph (b) and 

adding paragraph (e), reading as follows: 

* * * * . * 

(b) Compliance with opacity standards in this part shall be 

determined by conducting observations in accordance with Reference 

Method 9 in Appendix A of this part. Opacity readings of portions 

of plumes which contain condensed, uncombined water vapor shall not 

be used for purposes of determining compliance with opacity standards. 

The results of continuous monitoring by transmissometer which 

indicate that the opacity at the time visual observations were 

made was not in excess of the standard are probative but not 

conclusive evidence of the actual opacity of an emission, provided 

that the source shall meet the burden of proving that the instrument 

used meets (at the time of the alleged violation) Performance 

Specification 1 in Appendix B of this part, has been properly 

maintained and (at the time of the alleged violation) calibrated, 

and that the resulting data have not been tampered with in any way. 

* * * * * 

(e)(1) An owner or operator of an affected facility may 

request the Administrator to determine opacity of emissions from the 

affected facility during the initial performance tests required by §60.8. 

136 
(2) Upon receipt from such owner or operator of the written 

report of the results of the performance tests required by §60.8, 

the Administrator will make a finding concerning compliance with 

opacity and other applicable standaro... If the Administrator finds 

that an affected facility is in compliance with all applicable 

standards for which performance tests are conducted in accordance 

with §60.8 of this part but during the time such performance tests 

are being conducted fails to meet any applicable opacity standard, 

he shall notify the owner or operator and advise him that he may 

petition the Administrator within 10 days of receipt of notification 

to make appropriate adjustment to the opacity standard for the 

affected facility. WJJA 

(3) The Administrator will grant such a petition upon a demonstration by the owner or operator that the affected facility and 

associated air pollution control equipment was operated and maintained in a manner to minimize the opacity of emissions during the 

performance tests; that the performance tests were performed under 

the conditions established by the Administrator; and that the 

affected facility and associated air pollution control equipment 

were Incapable of being adjusted or operated to meet the applicable 

opacity standard. 

(4) The Administrator will establish an opacity standard for 

the affected facility meeting the above requirements at a level at 

which the source will be able, as indicated by the performance and 

opacity tests, to meet the opacity standard at all times during 

which the source is meeting the mass or concentration emission standard. 

137 
The Administrator will promulgate the new opacity standard in 

the Federal Register. 

2. In §60.62, paragraph (a)(2) is revised to read as follows 

§60.62 Standard for particulate matter 

* 

* * 

(a) * * * 

(2) Exhibit greater than 20 percent opacity. 

3. Appendix A-Reference Methods is amended by revising 

Reference Method 9 as follows: 

138 

\<-MW. 
P.41 

METHOD 9--VISUAL DETERMINATION OF THE 

OPACITY OF EMISSIONS FROM STATIONARY SOURCES 

Many stationary sources discharge visible emissions into the 

atmosphere; these emissions are usually in the shape of a plume. 

This method involves the determination of plume opacity by qualified 

observers. The method includes procedures for the training and certification of observers, and procedures to be used in the field for 

determination of plume opacity. The appearance of a plume as viewed 

by an observer depends upon a number of variables, some of which may 

be controllable and some of which may not be controllable in the field. 

Variables which can be controlled to an extent to which they no longer 

exert a significant influence upon plume appearance include: angle of i^&jii 

the observer with respect to the plume; angle of the observer with respect 

to the sun; point of observation of attached and detached steam plume; and 

angle of the observer with respect to a plume emitted from a rectangular 

stack with a large length to width ratio. The method includes specific 

criteria applicable to these variables. 

Other variables which may not be controllable in the field are 

luminescence and color contrast between the plume and the background 

against which the plume is viewed. These variables exert an influence 

upon the appearance of a plume as viewed by an observer, and can affect 

the ability of the observer to accurately assign opacity values to the 

observed plume. Studies of the theory of plume opacity and field studies 

have demonstrated that a plume 1s most visible and presents the greatest 

apparent opacity when viewed against a contrasting background. It follows 

139 
P.42 

from this, and is confirmed by field trials, that the opacity of a 

plume, viewed under conditions where a contrasting background is present 

can be assigned with the greatest degree of accuracy. However, the 

potential for a positive error is also the greatest when a plume 1s 

viewed under such contrasting conditions. Under conditions presenting 

a less contrasting background, the apparent opacity of a plume is less 

and approaches zero as the color and luminescence contrast decrease 

toward zero. As a result, significant negative bias and negative errors 

can be made when a plume is viewed under less contrasting conditions. 

A negative bias decreases rather than increases the possibility that a 

plant operator will be cited for a violation of opacity standards due to 

observer error. 

Studies have been undertaken to determine the magnitude of positive 

errors which can be made by qualified observers while reading plumes under 

contrasting conditions and using the procedures set forth in this method. 

The results of these studies (field trials) which involve a total of 769 

sets of 25 readings each are as follows: 

(1) For black plumes (133 sets at a smoke generator), 100% of the 

sets were read with a positive error* of less than 7.5% opacity; 99% were 

read with a positive error of less than 5% opacity. 

(2) For white plumes (170 sets at a smoke generator, 168 sets at a 

coal-fired power plant, 298 sets at a sulfuric acid plant), 99% of the 

sets were read with a positive error of less than 7.5% opacity; 95% were 

read with a positive error of less than 5% opacity. 

*r~or a set, positive error = average opacity determined by observer's 

25 observations - average opacity determined from transmissometer's 

25 recordings. 

$m& 

140 
The positive observational error as'sociated with an average 

of twenty-five readings 1s therefore established. The accuracy of 

the method must be taken into account when determining possible 

violations pf applicable opacity standards. 

1. Principle and applicability. 

-1.1 Principle. The opacity of emissions from stationary sources 

1s determined visually by a qualified observer. 

1.2 Applicability. This method 1s applicable for the determination 

of the opacity of emissions from stationary sources pursuant to 

§60.11(b) and for qualifying observers for visually determining 

opacity of emissions. 

2. Procedures. The observer qualified in accordance with paragraph 3 

of this method shall use the following procedures for visually 

determining the opacity of emissions: 

2.1 Position. The qualified observer shall stand at a distance 

sufficient to provide a clear view of the emissions with the sun oriented 

1n the 140 sector to his back. Consistent with maintaining the above . 

requirement, the observer shall, as much as possible, make his observations 

from a position such that his line of vision is approximately 

perpendicular to the plume direction, and when observing opacity of 

emissions from rectangular outlets (e.g. roof monitors, open baghouses, 

noncircular stacks), approximately perpendicular to the longer axis of 

the outlet. The observer's line of sight should not include more than 

one plume at a time when multiple stacks are involved, and in any case 

mmm 

141 
P.44 

the observer should make his observations with his line of sight perpendicular to the longer axis of such a set of multiple stacks (e.g. 

stub stacks on baghouses). 

2.2 Field records. The observer shall record the name of 

the plant, emission location, type facility, observer's name and 

affiliation, and the date on a field data sheet (Figure 9-1). The 

time, estimated distance to the emission location, approximate wind 

direction, estimated wind speed, description of the sky condition 

(presence and color of clouds), and plume background are 

recorded on a field data sheet at the time opacity readings are 

initiated and completed. 

2.3 Observations. Opacity observations shall be made at the 

point of greatest opacity in that portion of the plume where 

condensed water vapor is not present. The observer shall not look 

continuously at the plume, but instead shall observe the plume 

momentarily at 15-second intervals. 

2.3.1 Attached steam plumes, when condensed water vapor is 

present within the plume as it emerges from the emission outlet, opacity 

observations shall be made beyond the point in the plume at which condensed water vapor 1s no longer visible. The observer shall record the 

approximate distance from the emission outlet to the point in the plume 

at which the observations are made. 

2.3.2 Detached steam plume. When water vapor in the plume condenses 

and becomes visible at a distinct distance from the emission-outlet, the 

opacity of emissions should be evaluated at the emission outlet prior to 

142 
P.45 

the condensation of water vapor and the formation of the steam plume. 

2.4 Recording observations. Opacity observations shall be recorded 

to the nearest 5 percent at 15-second intervals on an observational record 

sheet. (See Figure 9-2 for an example.) A minimum of 24 observations 

shall be recorded. Each momentary observation recorded shall be deemed 

to represent the average opacity of emissions for a 15-second period. 

2.5 Data Reduction. Opacity shall be determined as an average of 

24 consecutive observations-recorded at 15-second intervals. Divide the 

observations recorded on the record sheet into sets of 24 consecutive 

observations. A set is composed of any 24 consecutive observations. 

Sets need not be consecutive in time and in no case shall two sets 

overlap. For each set of 24 observations, calculate the average by 

summing the opacity of the 24 observations and dividing this sum by 24. 

If an applicable standard specifies an averaging time requiring more than 

24 observations, calculate the average for all observations made during 

the specified time period. Record the average opacity on a record sheet. 

(See Figure 9-1 for an example.) 

3. Qualifications and testing. 

3.1 Certification requirements. To receive certification as a 

qualified observer, a candidate must be tested and demonstrate the 

ability to assign opacity readings in 5 percent increments to 25 

different black plumes and 25 different white plumes, with an error 

not to exceed 15.percent opacity on any one reading and an average 

error not to exceed 7.5 percent opacity 1n each category. Candidates 

shall be tested according to the procedures described 1n paragraph 3.2. 

Smoke generators used pursuant to paragraph 3.2 shall be equipped with 

a smoke meter which meets the requirements of paragraph 3.3. 

143 
P.46 

The certification shall be valid for a period of 6 months, at which 

time the qualification procedure must be repeated by any observer in 

order to retain certification. 

3.2 Certification procedure. The certification test consists of showing the candidate a complete run of 50 plumes--25 black plumes and 25 white 

plumes—generated by a smoke generator. Plumes within each set of 25 

black and 25 white runs shall be presented in random order. The 

candidate assigns an opacity value to each plume and records his 

observation on a suitable form. At the completion of each run of 50 

readings, the score of the candidate is determined. If a candidate fails 

to qualify, the complete run of 50 readings must be repeated in any 

retest. The smoke test may be administered as part of a smoke school •%#»' 

or training program, and may be preceded by training or familiarization 

runs of the smoke generator during which candidates are shown black and 

white plumes of known opacity. 

3.3 Smoke generator specifications. Any smoke generator used for 

the purposes of paragraph 3.2 shall be equipped with a smoke meter 

installed to measure opacity across the diameter of the smoke generator 

stack. The smoke meter output shall display in-stack opacity based upon 

a pathlength equal to the stack exit diameter, on a full 0 to 100 percent 

chart recorder scale. The smoke meter optical design and performance 

shall meet the specifications shown in Table 9-1. The smoke meter shall 

be calibrated as prescribed in paragraph 3.3.1 prior to the conduct 

of each smoke reading test. At the completion of each test, the zero 

and span drift shall be checked and if the drift exceeds +1 percent 

144 
P.47 

opacity, the condition shall be corrected prior to conducting .any 

subsequent test runs. The smoke meter shall be demonstrated, at the 

time of installation, to meet the specifications listed 1n Table 9-1. 

This demonstration shall be repeated following any subsequent repair 

or replacement of the photocell or associated electronic circuitry 

including the chart recorder or output meter, or every 6 months, whichever occurs first. 

TABLE 9-1 SMOKE METER DESIGN AND PERFORMANCE SPECIFICATIONS 

Parameter Specification 

a. Light source 

Spectral response 

of photocell 

c. Angle of view 

d. Angle of projection 

e. Calibration error 

f. Zero and span drift 

g. Response time 

Incandescent lamp operated at 

nominal rated voltage 

Photopic (Daylight spectral 

response of the human eyereference 4.3) 

15° maximum total angle 

15° maximum total angle 

+_ 3% opacity, maximum 

+_ 1% opacity, 30 minutes 

< 5 seconds 

3.3.1 Calibration. The smoke meter 1s calibrated after allowing a minimum of 30 minutes warmup by alternately producing simulated 

opacity of 0 percent and 100 percent. When stable response at 0 

percent or 100 percent is noted, the smoke meter is adjusted to 

produce an output of 0 percent or 100 percent, as appropriate, this 

calibration shall be repeated until stable 0 percent and 100 percent 

readings are produced without adjustment. Simulated 0 percent and 100 

145 
P.48 

percent opacity values may be produced by alternately switching the 

power to the light source on and off while the smoke generator is not 

producing smoke. 

3.3.2 Smoke meter evaluation. The smoke meter design and performance are to be evaluated as follows: 

3.3.2.1 Light source. Verify from manufacturer's data and 

from voltage measurements made at the lamp, as Installed, that the 

lamp 1s operated within +_ 5 percent of the nominal rated voltage. 

3.3.2.2 Spectral response of photocell. Verify from manufacturer's data that the photocell has a photopic response; i.e., 

the spectral sensitivity of the cell shall closely approximate the 

standard spectral-luminosity curve for photopic vision which is is^aa 

referenced in (b) of Table 9-1. 

3.3.2.3 Angle of view. Check construction geometry to ensure 

that the total angle of view of the smoke plume, as seen by the 

photocell, does not exceed 15°. The total angle of view may 

be calculated from: o = 2 tan" d/2L, where e= total angle of view; 

d = the sum of the photocell diameter + the diameter of the limiting 

aperture; and L = the distance from the photocell to the limiting 

aperture. The limiting aperture is the point in the path between the 

photocell and the smoke plume where the angle of view is most 

restricted. In smoke generator smoke meters this is normally an 

orifice plate. 

3.3.2.4 Angle of projection. Check construction geometry 

to ensure that the total angle of projection of the lamp on the smoke 

146 
P.49 

plume does not exceed 15°. The total angle of projection may be 

calculated from: e- 2 tan" d/2L, where e = total angle of projection; 

d = the sum of the length of the lamp filament + the diameter of the 

limiting aperture; and L = the distance from the lamp to the limiting 

aperture. 

3.3.2.5 Calibration error. Using neutral-density filters of 

known opacity, check the error between the actual response and the 

theoretical linear response of the smoke meter. This check is 

accomplished by first calibrating the smoke meter according to 3.3.1 

and then inserting a series of three neutral-density filters of 

nominal opacity of 20, 50, and 75 percent 1n the smoke meter pathlength. 

Filters calibrated within +2 percent shall be used. Care should be 

taken when inserting the filters to prevent stray light from affecting 

the meter. Make a total of five nonconsecutive readings for each 

filter. The maximum error on any one reading shall be 3 percent opacity. 

3.3.2.6 Zero and span drift. Determine the zero and span 

drift by calibrating and operating the smoke generator 1n a normal 

manner over a 1-hour period. The drift 1s measured by checking the 

z e ^ and span at the end of this period. 

3.3.2.7 Response time. Determine the response time by producing 

a series of five simulated 0 percent and 100 percent opacity values 

and observing the time required to reach stable response. Opacity 

values of 0 percent and 100 percent may be simulated by alternately 

switching the power to the light source off and on while the smoke 

generator 1s not operating. 

147 
P.50 

4. References. 

4.1 Air Pollution Control District Rules and Renulations, 

Los Angeles County Air Pollution Control District, Regulation IV, 

Prohibitions, Rule 50. 

4.2 Weisburd, Melvin I., Field Operations and Enforcement Manual 

for Air, U. S. Environmental Protection Agency, Research Triangle Park, 

N. C , APTD-1100, August 1972, pp. 4.1-4.36. 

4.3 Condon, E. U., and Odishaw, H., Handbook of Physics, 

McGraw-Hill Co., N. Y., N. Y., 1958, Table 3.1, p. 6-52. 

$$wp 

148 
COMPANY 

LOCATION 

TEST NUMBER_ 

DATE 

TYPE FACILITY 

CONTROL DEVICE 

Figure 9-1. Field data sheet. 

HOURS'OF OBSERVATION, 

OBSERVER 

OBSERVER CERTIFICATION DATE_ 

OBSERVER AFFILIATION 

POINT OF EMISSIONS 

HEIGHT OF DISCHARGE POINT 

CLOCK TIME 

OBSERVER LOCATION 

Distance to Discharge 

Direction from Discharge 

Height of Observation Point 

BACKGROUND DESCRIPTION 

WEATHER CONDITIONS 

Wind Direction 

Wind Speed 

Ambient Temperature 

SKY CONDITIONS (clear, 

overcast, % clouds, etc.) 

PLUME DESCRIPTION 

Color 

Distance Visible 

OTiica INTONATION 

Initial Final SUMMARY OF AVERAGE OPACITY 

Readings ranged from to 

Set 

Number 

Time 

Start--End 

0pacit> ' 

Sum 'verage ! 

! 

i 

i 

i 

i 

'! 

i 

% opacii.y 

The source was/was not in compliance with 

the time evaluation was made. 

at 
COMPANY 

LOCATION _ 

TEST NUMBER" 

DATE 

P.52 

FIGURE 9-2 OBSERVATION RECORD PAGE OF 

OBSERVER 

TYPE FACILITY 

POINT OF EMISSIONS 

Hr. 

1 

Min. 

0 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

Seconds 

TT 15 30 45 

STEAM PLUME 

(check if anplicable) 

Attached Detached COMMENTS 

^ 

150 
P.53 

FIGURE 9-2 OBSERVATION RECORD 

(Continued) 

PAGE OF 

COMPANY 

LOCATION 

TEST NUMBER 

DATE 

OBSERVER 

TYPE FACILITY 

POINT OF EMISSIONS 

Hr. 

, 

Min. 

30 

31 

32 

33 

34 

35 

36 

37 

38 

39 

40 

41 

42 

43 

44 

45 

46 

47 

48 

49 

50 

51 

52 

53 

54 

55 

56 

57 

58 

59 

Seconds 

0 15 30 45 

STEAM PLUME 

(check if applicable). 

Attached Detached COMMENTS 

151 
TECHMICAL REPORT DATA 

{Please read Instructions on the reverse before completing) 

1. REPORT NO. 

EPA-450/2-74-023 

3. RECIPIENT'S ACCESSION NO. 

4. TITLE AND SUBTITLE 5. REPORT DATE 

EPA Response to Remand Ordered by U.S. Court of Appeals 

for the Distric t of Columbia in Portland Cement Association v. Ruckelshaus (486 F. 2d 375, June 29, 1973). 

6. PERFORMING ORGANIZATIO N CODE 

7. AUTHOR(S) 8. PERFORMING ORGANIZATIO N REPORT NO. 

9. PERFORMING ORGANIZATION NAM E AN D ADDRESS 

Environmental Protection Agency 

Office of Air Quality Planning and Standards 

Research Triangle Park, N. C. 27711 

12. SPONSORING AGENCY NAME AN D ADDRESS 

November 1974 

10. PROGRAM ELEMENT NO. 

1 1 . CONTRACT/GRAN T NO. 

13. TYPE OF REPORT AN D PERIOD COVERED 

14. SPONSORING AGENCY CODE 

15. SUPPLEMENTARY NOTES 

16. ABSTRACT 

On June 29, 1973, the U.S. Court of Appeals for the District of Columbia remanded 

to EPA the standards of performance for Portland cement plants promulgated under 

section 111 of the Clean Air Act, directing the Agency to reconsider the standards 

and provide additional explanation of the action taken. EPA has reviewed the standards 

for these plants pursuant to the remand and has concluded that the standards other 

than the opacity standard should not be revised. This document is a detailed technical 

justification and explanation of the actions taken by the Administrator in 

promulgating the standards for Portland cement plants. Included is the justification 

for revising the opacity standard. 

KEY WORDS AN D DOCUMENT ANALYSIS 

DESCRIPTORS 

Air pollution 

Opacity standards 

Visual observations 

Portland cement plants 

Particulate matter 

Emissions 

IS. DISTRIBUTION STATEMENT 

Unlimited 

b.IDENTIFIERS/OPEN ENDEDTERM S c. COSATI l7

icld/Group 

Air pollution control 

19. SECURITY CLASS (This Report) 

Unclassified 

20. SECURITY CLASS {This page) 

Unclassified 

2 1 . NO. OF PAGES 

152 

EPA Form 2220-1 (9-73) 

752 

$&$$ • 
IO 

ENVIRONMENTAL PROTECTION AGENCY 

Technical Publications Branch 

Office of Administration 

Research Triangle Park. N.C. 27711 

POSTAGE ANO FEES PAID 

ENVIRONMENTAL PROTECTION AGENCY 

EPA - 335 

OFFICIA L BUSINESS 

AN EQUAL OPPORTUNITY EMPLOYER 

Return this sheet if you do NOT wish to receive this material H.-!, 

or if change of address is needed JA). (Indicate change, including 

ZIP code.). 

PUBLICATION NO. EPA-450/2-74-023