MEMORANDUM 

TO: Portland Cement NSPS Docket 

FROM: Keith Barnett, USEPA/OAQPS/SPPD/MMG 

DATE: February 17, 2010 

SUBJECT: February 16, 2010 meeting with Representatives of Ash Grove Cement and 

Lehigh Cement. 

Meeting Participants 

Keith Barnett, USEPA 

Elineth Torres, USEPA 

Sharon Nizich, USEPA 

Curtis Lesslie, Ash Grove Cement 

Yim Matz, Lehigh Hanson Cement 

Information discussed in the Meeting 

This meeting was to discuss dust shuttling as a mercury control technique. Information 

presented at the meeting is attached. 
 

 Follow Up Information from February 16, 2010 Meeting 

 Curtis Lesslie 

 to: 

 Peter Tsirigotis 

 02/26/2010 10:56 PM 

 Cc: 

 "Matz, Tim", "Richard Wilson", "Fran Streitman", Keith Barnett 

 Show Details 

Peter: 

 

Thank you for taking the time to meet with us on 2/16/10 to discuss the 

innovative mercury reduction efforts being developed and implemented at 

Ash Grove’s Durkee plant and Lehigh’s Union Bridge plant. 

 

Both Ash Grove and Lehigh are very interested in sharing more ideas with 

EPA, however at this time I simply wanted to provide the presentation we 

gave during the meeting and a couple of documents that were promised 

during the meeting. 

 

I have attached the EERC paper on the role of selenium versus mercury 

that 

I mentioned to Keith. I have also attached the PCA scrubber report and a 

B&W paper showing re-emissions of mercury from wet scrubbers. Keeping in 

mind that both Durkee and Tehachapi are located in arid regions, have a 

high fraction of elemental mercury in the exhaust, and have insufficient 

water rights to accommodate a wet scrubber, I wanted to reiterate that a 

wet scrubber would not provide any significant added benefit for mercury 

control at either of these plants. Activated carbon is the only viable 

control option. 

 

We look forward to sharing additional ideas in the near future. In the 

meantime, please let us know if we can provide any additional information 

that may be useful. 

 

Sincerely, 

Curtis 

 

 

Curtis Lesslie, P.E. 

Vice President of Environmental Affairs 

Ash Grove Cement Company 

11011 Cody Street 

Overland Park, Kansas 66210 

Desk (913) 319-6065 

Cell (785) 550-6330 

Fax (913) 451-1686 

 
Selenium’s Importance in R

Issues Regarding Mer

Laura Raymond

Energy & Environmental Resea

Grand Forks, ND

September 24, 2007
History

• Minimata Bay, Japan, 1950s

– From 1932 to 1968, Chisso 

Corporation dumped an estimated 27 tons of mercury compounds into Minamata Bay.

– Hundreds of people died.– Over 3000 victims have been 

recognized as having "Minamata Disease."

– Fish Hg levels <50 ppm

(typical ocean fish <1 ppm)

• Iraq 1971–1972

– Grain treated with mercury 

containing fungicide.

– 459 people died.– Hospitalization of over 6000.– Hair Hg levels up to 674 ppm 

(today <1.4 ppm)
Two Major Epidemiolo

Studies

• Faroe Island study

– Neurological defects in children neonatally e

from fish and whale consumption.

• Seychelles Island study

– No adverse effects in children born to mothe

eating fish.

– Fish consumption levels are 10–20X higher th

consumption. 
Reference Dose 0.1 

μg/k

• WHO - estimate a Benchmark Dose (B

– Increased prevalence to adverse respo

• Benchmark Lower Limit (BMDL)

– No Adverse Effects Level (NOAEL)– At least 2 standard deviations below B– 1.2 -2.4 ug/Hg/kg/d

• Add a 10 fold “safety factor”.

– 0.4 ug/Hg/kg/d

• EPA calculated the RfD - Safe daily in

– Faroes data– Includes an additional 10 fold “safety f– results in 4 fold reduction from WHO N– 0.1 ug/Hg/kg/d

• Reference dose –

– 135-lb woman: 1.5 oz of swordfis– 50-lb child: 0.5 oz of swordfish o

• Centers for Disease Control and Prev

in the United States tests anywhere ne
Reference Dose 0.1 

μg/k

Safe daily intake for lifetime ex

• The 2000 National Research Council report stated 

that 60,000 newborns annually are born at riskbecause of methylmercury. 

– Assuming that women eating the most fish (the top 

5%) are risking their babies’ health. 

• 2002 government hearing – this number was 

assumed to be increased to 400,000 pregnancies per year. 

• July 2006 national survey conducted by Opinion 

Research Corporation found that 40% of Americans believe at least 10,000 childhood cases of mercury poisoning are documented by scientists each year.

• There are NO documented cases of mercury 

poisoning from fish consumption. 
Third Study

United Kingdom St

• Increased risks for neurodevelopmental 

decreased fish consumption: 

– Maternal compliance with the EPA RfD increased risks of 

the lowest quartile for verbal IQ and increased risks for pafine motor, communication, and social skills compared to RfD recommendation.

– Children of mothers that avoided fish during pregnancy sh

impairments of a magnitude estimated to be 60 times grecase impairments associated with the highest pilot whale Faroes. 

Huh?????

• The Great Debate

Neurological defects – Faroe Island studyNo adverse effects – Seychelles Island studyIncreased risks with decreased fish consumption – 
Health Benefits of 

• Health effects

– Neurodevelopment– Fetal development

• Decreased preterm deliveries and longer gesta

weight, lower prevalence of pregnancy-induced 

– Cardiovascular health

• Stroke, atrial fibrillation, arrhythmias, congestiv

blood pressure

– Mood disorders and PMS– Memory loss, Alzheimer’s disease

• Nutrients

– Omega 3 fatty acids– Lean protein– Micronutrients– SELENIUM
Selenium Physiolo

21st amino acid – Selenocys

• Development • Thyroid homeostasis• HIV and other viruses• Cancer• Immune system• Cardiovascular disease• Reproduction• Mood• Disease links

– Congenital muscular dystrophy– Autism– Alzheimer's, Downs syndrome– Brain tumors– Diabetes– Liver diseases– Any condition associated with increased oxidative stress 

(rheumatoid arthritis, pancreatitis, asthma, obesity, septic 
Selenium Is a Merc

Antagonist

• “Protective effect” of selenium.• Numerous reports indicating seleni

supplementation counteracts the neimpacts of exposure to mercury.

– Neurotoxicity– Fetotoxicity– Developmental toxicity

• Protective effects of selenium again

have been shown in all investigated mammals, birds, and fish.
Se-Hg

H2Se

+

MeHg

Protective Effect of Se

Binding Affinity ~1045Extremely low solubility ~10-58 to 10- 65

Se binds to mercury, so mercury is unavailab
Hg-Se

MeHg

+

H2Se

Or Is It the

Thieving Effect of Mer

Hg is binding to selenium, so selenium is unavailable 

During Se depletion, there is retention and redistribution endocrine organs, and reproductive organs.Mercury has the ability to cross the placental and blood–diminish selenoenzyme activities!
Effects of MeHg in rats f

normal, and selenium-ric

Objective: To investigate the effects of dietary exposure in rats fed varying concentrations of 
All of these rats were fed diets prepared with 10 ppm 

methylmercury added. The rat on the left has been fed a selenium-deficient diet, the center rat was fed a selenium-adequate diet, and the rat on the right was fed a selenium-rich diet. 

Effects of MeHg in Rats F

Adequate, and Selenium-R

100200300400500

0 14 28 42 

Body Weight (g) 

0.1 μmol Se/kg1.0 μmol Se/kg10 μmol Se/kg
Effects of MeHg on Neuro

This rat, fed a seleni10 ppm methylmercusigns of neurotoxicity(hind limb crossing, uneveand loss of balance). 

This rat, fed a selenium-rich diet with 10 ppm methylmercury, showed no signs of neurotoxicity.
SELENIUM’S THERAP

EFFECT

To examine potential therapeutic effects of selenium, a11 the toxicity group was further divided into three grou

• No change in diet• Same amount of Hg with added Se • No Hg with added Se
Results Show...

• Hair and blood Hg levels accurately reflect expo

– Increased Hg in hair, blood, and brain was associ

toxicity.

– The lowest Hg concentrations in hair, blood, and 

with the highest toxicity.

– It was the molar ratios of Hg to Se that determined 

• MeHg toxicity was only apparent with Se-deficie

– The increased molar excess of Hg:Se indicated to

• Se therapy effects were nearly identical in treatm

regardless of whether MeHg exposure was disco
Why Is This Import

05

101520

Sole

Flounder

Salmon 

Tuna 

Pollock

Halibut

Cod

Snapper 

Grouper

Swordfish

US average

Pilot Whale 

nmol/g

MercurySelenium

• Fish are among the richest sources of nutritiona

American diet. 

• Out of 1100 foods commonly consumed in the U

of the top 25 sources of dietary selenium are fro

Fish data depicted from Hall et al. (1978); pilot whale from Julshaand swordfish from Friedman et al. (1978).
Can Selenium Expl

“The Great Debate

• Faroe Island study

– Neurological defects in children neonatally ex

fish and whale consumption.

• Seychelles Island study

– No adverse effects in children born to mothe

eating fish:

– Fish consumption levels are 10–20X higher th

consumption. 

• United Kingdom Study

– Increased risks for neurodevelopmental defe

fish consumption.
Se Health Benefit V

• Seafood safety criterion• Considering fish health benefits• Levels of selenium 

– Antagonistic to mercury– Selenium health benefits

Se-HBV =

(Se:Hg molar ratio × total Se) 

− (Hg:Se molar ra
Se Health Benefit V

• Freshwater fish 0.1–0.4 ppm

• Ocean fish 0.6–0.8 ppm• Predator fish >1.0 ppm

• Fish in “polluted” water >10 ppm

• Fish from Minamata Bay ~50 ppm• Whale meat ~4 ppm

• Whale liver >1000 ppm
Selenium Level

• Wor

sele

– – – – – – A
FDA and EPA Mess

• The reference dose and risk assessme

on mercury levels only.

•

“Avoid shark, swordfish, golden bass, 

mackerel. Limit your fish intake to two 

week and choose low mercury containing 

• 74% of women of childbearing age and 85% of pr

consume <6 oz/wk. 

• By focusing only on MeHg exposure without cons

measurements of additional nutrients in fish, thes

statements are inadequate, inaccurate, misleadindangerous.
Time for New Mess

• It is essential that the beneficial effects a

and integrated into the evaluation of risk regarding seafood consumption. 

– Avoidance of fish consumption may be detrim

development and cardiovascular health. 

• Se-HBV criterion provides an improved s

– More comprehensive and meaningful.– Differentiates between seafood and freshwate

a rich source of selenium from those that are because they contain an excess of mercury. 

– May be used to establish a rank order of ocea

nutritional benefits.

– Promote healthy choices rather than unneces

nutrient-rich, low-mercury fish. 
The Babcock & Wilcox Company 7

Role of Sulfides in the Sequestration of Mercury

by Wet Scrubbers

BR-1787

Technical Paper

Presented to:

EPRI-DOE-EPA-AWMA

Combined Power Plant Air Pollutant Control

Mega Symposium

August 28-31, 2006

Baltimore, Maryland, U.S.A.

B. Ghorishi, B. Downs, and S. Renninger

The Babcock & Wilcox Company

Barberton, Ohio, U.S.A.
Copyrighted page/s removed. Copyrighted material is not available in 

Regulations.gov since it may not be reproduced without consent of 

the copyright holder. 

Contact the EPA Docket Center’s Public Reading Room to view 

or receive a copy of this document. 

Requests for copies may be made as follows: 

In person/writing: 

Environmental Protection Agency, Docket Center 

1301 Constitution Ave NW, 2822T, Room 3334 

Washington, DC. 20004 

Telephone: 

202-566-1744 

Fax: 

202-566- 9744 

Email: 

docket-customerservice@epa.gov 
PORTLAND CEMENT ASSOCIATION 

SCRUBBER TESTING PROGRAM 

TO DETERMINE 

MERCURY CONCENTRATION 

AND REMOVAL 

SUMMARY REPORT 

October 2008 

Emission Monitoring Inc. 

8901 Glenwood Ave. 

Raleigh NC 

27617 

919.781.3824 

 
ii

Key Words 

Elemental Mercury, Flue Gas Adsorbent Mercury (FAMS) Sampling, Limestone Scrubber, 

Method 30B, National Emission Standards for Hazardous Air Pollutants (NESHAP), Oxidized 

Mercury, Percent Removal, Sulfur Dioxide, Total Mercury 

Abstract 

The Portland Cement Association (PCA) sponsored a test program of five scrubber controlled 

kilns located at four Portland cement plants. The scrubbers were installed downstream of 

particulate matter removal device (i.e., fabric filter baghouses and/or ESPs) to control sulfur 

dioxide and other acid gases. These five scrubber controlled kilns were identified by EPA as 

potential maximum controlled sources for mercury in their review 2006 of the Portland cement 

NESHAP. 

Testing for mercury compounds in the flue gas was conducted simultaneously upstream and 

downstream of the limestone scrubbers to determine the effects on the mercury compounds. 

Concentration testing using EPA Method 30B and the “FAMS” method were performed 

concurrently along with diluent oxygen measurements. Mercury results are reported as μg/m3

normalized to 7% oxygen. A percent removal for the individual mercury compounds (as well as 

total mercury) was calculated using the average inlet and outlet normalized concentrations. 

The results were analyzed using a bias correction combined with the standard deviation of the 

paired results to determine the significance of the percent removal calculation. 

 
iii

TABLE OF CONTENTS 

1.0 INTRODUCTION 1 

2.0 EXECUTIVE SUMMARY 3 

3.0 DISCUSSION OF FINDINGS 4 

3.1 Method Comparisons 4

 3.2 Effect of Raw Mill Operation 4

 3.3 Effect of Limestone Scrubber 5

4.0 METHOD 30B RESULTS AND RANGE OF Hg REMOVAL 5 

Table 4-1 Method 30B Tabulated Results 6

5.0 FAMS RESULTS 7 

Table 5-1 FAMS Speciated Results 7

6.0 PROJECT CONCLUSIONS 8 

APPENDIX A Analyses of Mill On Results – Bias Correction and 

Statistics 

APPENDIX B EXAMPLE CHARTS 

 
1

1.0 INTRODUCTION 

The U.S. EPA (EPA) published a Federal Register Notice on December 20, 2006 (Vol. 71, No. 

244, Pg.76553) that directly affected the Portland cement industry. In this Federal Register 

Notice, the EPA requested speciated mercury (Hg) testing on scrubber equipped cement kilns to 

understand more fully Hg speciation and emissions at Portland cement plants. Data from this 

testing program were expected to be used by EPA, in part, to determine what (if any) mercury 

standard would apply to the Industry during a subsequent rulemaking. 

In response to EPA’s Notice of Reconsideration identified in the December 20, 2006 Federal 

Register Notice, the Portland Cement Association (PCA) and its member companies sponsored a 

test program to quantify mercury concentrations upstream and downstream of limestone 

scrubbers. 

Many rounds of discussions were held between PCA, Emission Monitoring Inc. (EMI) and EPA 

regarding which test method would be employed. Final negotiations resulted in the selection of 

two methods to be used simultaneously to provide the requisite information; Method 30B, and a 

method referred to as “FAMS”. Both methods employ adsorbent media to collect mercury. 

Method 30B produces a total mercury result and the FAMS method produces results for 

particulate, oxidized and elemental mercury species. (PM bound Hg was quantified by FAMS, 

but not really of concern to the overall project.) 

Four individual plants having a total of five scrubber controlled kilns were tested from July 

through December 2007. Air Sampling Associated Inc. (ASA - Lewisville, TX) performed the 

testing under the direction of Dr. Laura Kinner of EMI. 

The facilities, and geographic locations presented in the order of testing are as follows: 

 Lehigh North (1-kiln, SNCR, ESP, Scrubber) Mason City, Iowa, July 2007 

 Holcim US (1-kiln, FF, Scrubber), Florence, Colorado, July 2007 

 Holcim Texas LP (2-kilns, SNCR, FF, Scrubber) Midlothian, Texas, October 2007 

 Texas Industries (1-kiln, FF, Scrubber, RTO*) Midlothian, Texas, December 2007 

o Testing did not involve RTO 

All of the plants were contemporary pre-heater/precalciner pyroprocessing systems having inline raw mills. All facilities used a fabric filter system for PM removal upstream of the scrubber 

with the exception of Lehigh North which uses an ESP. The scrubbers were installed by the 

facilities to control sulfur dioxide and other acid gases. The Lehigh and the Holcim Midlothian 

facilities also employed SNCR for NOx abatement during these tests. 

Testing was conducted during two distinct process operating conditions; with the in-line raw mill 

operating and while not operating. Testing using EPA Method 30B and the FAMS method for 
2

speciated mercury compounds was conducted simultaneously upstream and downstream of the 

scrubbers. 

Complete reports including descriptions of the sampling locations, results of all quality assurance 

activities and supporting data for each plant were prepared by ASA and reviewed by EMI. 

These reports were submitted to the PCA as they became finalized, and entire report package 

was submitted in February 2008 to Keith Barnett of the US EPA. 

This document presents an overall summary of the results and provides conclusions from the 

testing program that are not provided in the ASA reports. 

 
3

2.0 EXECUTIVE SUMMARY 

Testing was performed to determine the total mercury and speciated mercury concentrations 

upstream and downstream of the limestone scrubbers, and to determine the scrubber’s affect on 

the mercury speciation and removal. Two distinct modes of process operation were tested; inline raw mill on and off. 

During raw mill on operation, four of the five kilns tested had total Hg concentration levels of 

less than 10ug/m3

 at the stack or scrubber outlet. Raw mill off operation always produced higher 

stack concentration levels which ranged from15 ug/m3

 to 50 ug/m3 for the facilities tested. 

The following presents the pertinent results and observations from this testing program. 

1. During raw mill on operation, 

a. the Lehigh North facility and the Holcim Portland facility exhibited negative HgT 

removal across the scrubber indicating oxidized mercury conversion to elemental 

mercury with subsequent re-emission of elemental mercury, 

b. the Holcim Midlothian Kiln #2 exhibited minimal HgT

 removal in the range of 4-

11%, 

c. the Holcim Midlothian Kiln #1 and the TXI kiln had HgT removal efficiencies of 

from 22-38%, 

d. The cement plants operate with raw mill on approximately 80-90% of the time, 

and the scrubbers were observed to have minimal effect on mercury control 

during this process condition. 

2. During raw mill off operation, 

a. All kilns exhibit some amount of Hg removal which is directly proportional to the 

inlet Hg+2 concentration levels. 

b. The amount of removal ranged from 58% (TXI) to 93% (Holcim Portland) 

reflective of corresponding inlet Hg+2 concentration levels. 

c. The cement plants operate with raw mill off approximately 10-20% of the time, 

and much of the oxidized mercury captured during this process condition is 

gradually reconverted back to elemental mercury and released back to the 

atmosphere during raw mill on operation. 

 
4

3.0 Discussion of Findings

3.1 Method Comparison 

Comparisons between EPA Method 30B and the FAMS method based on total mercury catch 

were comparable for inlet locations. 

Because of the design of the FAMS probes, the method was found to be better suited for dry 

stack sampling. 

Inlet sample results for the FAMS are not in question except for TXI (which was a “wet” sample 

location due to its proximity to the scrubber itself), but some of the outlet FAMS results for the 

kilns tested are in question either because of water droplets entering the probe, or because the 

probes had to be operated at elevated temperature to prevent water droplet entrainment which 

caused problems with mercury capture on the appropriate section of the trap. 

3.2 Effect of Raw Mill Operation 

Overall, oxidized mercury was observed to be captured by the scrubbers during raw mill off 

operation (positive removal), and elemental mercury was observed to be released during raw mill 

on operation (in many cases negative removal for total Hg was observed across the scrubber). In 

most cases, elemental Hg was higher at the scrubber outlet than scrubber inlet during raw mill on 

testing. 

The in-line raw mill has a tremendous affect on both mercury speciation and concentration. The 

in-line raw mill acts as a dry scrubber for oxidized mercury much as it does for sulfur dioxide 

and certain other compounds. When the raw mill is operating, the kiln feed materials adsorb the 

oxidized mercury and thus reduce mercury levels at the stack exit. When the raw mill is not 

operating (i.e., periods of routine maintenance or malfunction), the natural scrubbing does not 

occur. Additionally, previously silo’d material is used for kiln feed thus releasing previously 

sequestered mercury. 

Scrubber inlet concentrations for raw mill off versus raw mill on were observed to be 40-50 

times greater in some circumstances. The in-line raw mill and silo system sequester the 

oxidized mercury and subsequently release much of it back to the effluent during raw mill 

off conditions. 
5

3.3 Effect of Scrubbers 

The scrubbers were observed to reduce the amount of oxidized mercury during raw mill off 

operation since this compound is water soluble. In most cases, re-emission was observed across 

the scrubbers during raw mill on operation as observed by higher elemental mercury at the outlet 

than at the inlet to the scrubber. Re-emission is a phenomena encountered in the utility industry 

as well1

. It occurs when oxidized mercury captured by the scrubber is reduced back to elemental 

mercury in the alkaline conditions encountered in the scrubber liquor. The elemental mercury is 

not water soluble and thus it is stripped out of the scrubber liquor and released back into the 

effluent. The scrubber system sequesters the oxidized mercury, with release of elemental 

mercury back to the stack effluent. This is particularly evident during mill on conditions. 

Together the two competing phenomena create a dynamic equilibrium between capture and 

release of mercury compounds. 

4.0 SUMMARY OF TOTAL MERCURY RESULTS – METHOD 30B

Table 4-1 presents the results for each facility in terms of total mercury, and range of calculated 

mercury removal. These results are derived from Method 30B results only, FAMS speciated 

results are presented in Section 5. 

For raw mill on operation the results have been: 1) corrected for spike recovery and, 2) the 

precision of the paired results were used to present the range of possible percent Hg removal. 

The apparent removal during mill on operation was either a negative number of a very low 

percentage removal. 

The correction of raw mill on results for bias based on spike recovery is possible and plausible 

since the spike levels were very close to the actual effluent concentrations. Appendix A 

presents the application of spike correction, and the statistical analyses employed. Note that in 

some cases the precision was excellent and therefore contributed little in the error analyses 

presentation. 

Raw mill off operation did not employ a spike correction or statistical analyses of the data for 

two reasons. First the spike correction for bias could not be determined at the stack 

concentrations encountered during mill off (spike levels were simply too low to employ for this 

purpose), and secondly, there appears to be actual Hg removal during raw mill off operation due 

to the elevated Hg+2 observed during this process condition.   

                                                           

1

  Ghorishi, B., Downs, B., & Renninger, S., “Role of Sulfides in Sequestration of Mercury by Wet Scrubbers,”

EPRI/DOE/EPA/AWMA Combined Symposium on Power Plant Air Pollution Control, Baltimore, MD. August 28‐31,

2006.   
6

TABLE 4-1 PCA-Hg Scrubber Project Results Summary 

MILL ON 

Method 30 B Results 

Inlet 

HgT

Outlet 

HgT % Removal % Removal Range 

Facility ug/m3

 ug/m3 ug/m3 2-SIGMA 

Lehigh North 16.7 18.8 -13% 

Spike Corrected 17.5 21.1 -20% - 56% to 9% 

Holcim Portland 1.2 2.8 -133% 

Spike Corrected 1.2 2.7 -120% - 188% to -72% 

Holcim Midlothian - K#1 4.2 2.9 31% 

Spike Corrected 4.1 2.6 38% 31% to 38% 

Holcim Midlothian - K#2 7.3 6.5 11% 

Spike Corrected 6.6 6.4 4% 4% to 11% 

TXI 4.9 3.6 27% 

Spike Corrected 4.8 3.6 26% 23% to 29% 

MILL OFF 

Method 30 B Results 

Inlet 

HgT

Outlet 

HgT % Removal 

Facility ug/m3 ug/m3 ug/m3

Holcim Portland 193.0 14.0 93% 

Holcim Midlothian - K#1 182.0 22.0 88% 

Holcim Midlothian - K#2 180.0 50.0 72% 

TXI 96.0 40.0 58% 

Note that all concentration results are normalized to 7% oxygen 
7

5.0 FAMS Results 

Table 5-1 presents the FAMS testing results for speciated mercury on a plant-by-plant basis. 

Suspect data are highlighted in yellow. 

Some of the FAMS outlet data were questionable for two reasons; 1) liquid water droplets 

solublized oxidized mercury from the potassium chloride (KCl) media and transported it through 

the trap as was noted in the Lehigh North scrubber outlet data, and 2) elevated temperatures 

employed to eliminate water droplet collection resulted in oxidized mercury being transported 

through the trap. This phenomenon was noted in the Holcim Midlothian and TXI scrubber outlet 

data where there is an apparent reduction of elemental mercury as indicated by the FAMS data. 

This occurs when the mercury originally captured on the KCl section (designed to capture 

oxidized mercury) of the FAMS trap is desorbed at elevated temperature and then carried 

through to the carbon (section of the trap for elemental Hg) and thus counted as inappropriately 

counted elemental mercury. 

Questionable FAMS data are flagged in yellow. 

Table 5-1 Results Summary 

Mill On 

ug/m3

 at 7% O2 Inlet Results Outlet Results Removal 

Facility Hg p

 Hg +2 Hg 0 Hg p Hg +2 Hg 0 Hg p Hg +2 Hg 0

Lehigh North 0.06 0.61 11.60 0.50 5.51 20.17 -804% 

-

800% -74% 

Holcim Portland 0.03 0.48 0.48 0.05 0.13 1.74 -61% 74% -258% 

Holcim Midlothian - K#1 0.04 1.31 2.94 0.05 0.02 3.06 -20% 99% -4% 

Holcim Midlothian - K#2 0.05 4.06 1.85 0.01 0.04 3.90 83% 99% -111% 

TXI 0.05 0.42 3.49 0.02 0.05 2.25 67% 88% 36% 

Mill Off 

ug/m3

 at 7% O2 Inlet Results Outlet Results Removal 

Facility Hg p

 Hg +2 Hg 0 Hg p Hg +2 Hg 0 Hg p Hg +2 Hg 0

Holcim Portland 2.74 165.52 0.67 0.50 2.20 6.51 82% 99% -865% 

Holcim Midlothian - K#1 0.29 59.22 93.27 0.02 0.01 17.80 94% 100% 81% 

Holcim Midlothian - K#2 0.78 73.16 33.26 0.05 0.08 38.81 93% 100% -17% 

TXI 0.03 0.33 84.68 0.11 0.18 27.24 -229% 46% 68% 

Yellow at inlet indicates a suspect error in speciated results. Likely that it is mostly oxidized 

based on the percent removal indicated.
8

6.0 CONCLUSIONS 

 The in-line raw mill acts as a dry scrubber for oxidized mercury, 

 During raw mill off operation, oxidized mercury is not captured in the raw mill, but is 

removed by the limestone scrubber, 

 During raw mill on operation, mercury (captured by the scrubber during mill off 

operation) is released back to the atmosphere because of mercury reduction (Hg+2 Hg0

) 

and re-emission, 

 Together, the in-line raw mill, raw feed storage system, and limestone scrubbers 

sequester and release mercury from the process in a complex equilibrium. 

 Method 30B and the FAMS test methods provided comparable results where good FAMS 

data were available for comparison, 

 Some simple modifications to the FAMS method could improve its function in wet stack 

applications. For example, a probe that heats uniformly and that is designed to reject 

water droplets could be designed. 
A

APPENDIX A 

Analyses of Mill On Results – Bias Correction and Statistics 
PCA Scrubber Test Program - Accuracy and Precision Results

MILL ON 

Facility Lehigh North Holcim PD Holcim TX #1 Holcim TX #2 TXI

Avg. Stack Concentration ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 16.7 1.2 4.2 7.3 4.9

Outlet 18.8 2.8 2.9 6.5 3.6

Apparent % Removal -13% -133% 31% 11% 27%

Spike Accuracy Percentage Percentage Percentage Percentage Percentage

Inlet % Recovery 95 97 102 109 102

Outlet % Recovery 88 103 112 102 101

Spike Levels (conc. Eq.) ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 32 5 13 13 6.7

Outlet 13 5 13 13 6.7

Precision

Average of Paired Differences ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 1.6 0.0 0.0 0.0 0.1

Outlet 2.0 0.0 0.2 0.0 0.1

Stdev of Pair Differences ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 1.0 0.1 0.0 0.0 0.0

Outlet 1.6 0.1 0.0 0.0 0.1

Standard Error of Pair Differences ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 0.45 0.05 0.00 0.00 0.01

Outlet 0.72 0.05 0.00 0.00 0.02

2 Sigma (95% coverage)

Inlet 2.00 0.22 0.00 0.00 0.04

Outlet 3.20 0.22 0.00 0.00 0.11

Analyses done with duplicates analyses ("Pairs") from five trains (10 samples)

Pair difference is absolute amount each results differs from pair average = abs(X-Y)/Avg.

Note - all concentration results are normalized to 7% oxygen
LEHIGH NORTH - MILL ON - Error Analyses of Results Error Bars Error Bars Worst Case Best Case

Lehigh North Corrected for Spike SE 2 Sigma Range of Possible Results

Avg. Stack Concentration ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 16.7 17.5 0.45 2.00 15.5 19.5

Outlet 18.8 21.1 0.72 3.20 24.3 17.9

Apparent % Removal -13% -20% -56% 9%

Spike Accuracy Percentage

Inlet % Recovery 95

Outlet % Recovery 88

Spike Levels (conc. Eq.) ug/m 3

Inlet 32

Outlet 13

Precision

Average of Paired Differences ug/m 3

Inlet 1.6

Outlet 2.0

Stdev of Pair Differences ug/m 3

Inlet 1.0

Outlet 1.6

Error Bars

Standard Error of Pair Differences ug/m 3

Inlet 0.45

Outlet 0.72

2 Sigma (95% coverage)

Inlet 2.00

Outlet 3.20
Holcim Portland - MILL ON - Error Analyses of Results

Error Bars Error Bars Worst Case Best Case

Holcim PD Corrected for Spike SE 2 Sigma Range of Possible Results

Avg. Stack Concentration ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 1.2 1.2 0.04 0.22 1.0 1.5

Outlet 2.8 2.7 0.04 0.22 2.9 2.5

Apparent % Removal -133% -120% -188% -72%

Spike Accuracy Percentage

Inlet % Recovery 97

Outlet % Recovery 103

Spike Levels (conc. Eq.) ug/m 3

Inlet 5

Outlet 5

Precision

Paired Results Difference from Avg. ug/m 3

Inlet 0.0

Outlet 0.1

Stdev of Pair Differences ug/m 3

Inlet 0.1

Outlet 0.1

Standard Error of Pair Differences ug/m 3

Inlet 0.04

Outlet 0.04

2 Sigma (95% coverage)

Inlet 0.22

Outlet 0.22

Analyses done with paired run results from six trains (12 samples)

Difference from average is the difference between results of each pair (n = 6 pairs)

Variance is the square of the standard deviation and is a value that can be added and subtracted

Subtracting the variance of the paired sample results from the variance of the paired differences allows 
Holcim Midlothian #1 - MILL ON - Error Analyses of Results

Error Bars Error Bars Worst Case Best Case

Facility Holcim TX #1 Corrected for Spike SE 2 Sigma Range of Possible Results

Avg. Stack Concentration ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 4.2 4.1 0.00 0.00 4.1 4.1

Outlet 2.9 2.6 0.00 0.00 2.6 2.6

Apparent % Removal 31% 38% 38% 38%

Spike Accuracy Percentage

Inlet % Recovery 102

Outlet % Recovery 112

Spike Levels (conc. Eq.) ug/m 3

Inlet 13

Outlet 13

Precision

Paired Results Difference from Avg. ug/m 3

Inlet 0.0

Outlet 0.2

Stdev of Pair Differences ug/m 3

Inlet 0.0

Outlet 0.0

Standard Error of Pair Differences ug/m 3

Inlet 0.00

Outlet 0.00

2 Sigma (95% coverage)

Inlet 0.00

Outlet 0.00

Analyses done with paired run results from five trains (10 samples)

Difference from average is the difference between results of each pair (n = 5 pairs)

Variance is the square of the standard deviation and is a value that can be added and subtracted

Subtracting the variance of the paired sample results from the variance of the paired differences allows 
Holcim Midlothian #2 - MILL ON - Error Analyses of Results

Error Bars Error Bars Worst Case Best Case

Facility Holcim TX #2 Corrected for Spike SE 2 Sigma Range of Possible Results

Avg. Stack Concentration ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 7.3 6.6 0.00 0.00 6.6 6.6

Outlet 6.5 6.4 0.00 0.00 6.4 6.4

Apparent % Removal 11% 4% 4% 4%

Spike Accuracy Percentage

Inlet % Recovery 109

Outlet % Recovery 102

Spike Levels (conc. Eq.) ug/m 3

Inlet 13

Outlet 13

Precision

Paired Results Difference from Avg. ug/m 3

Inlet 0.0

Outlet 0.0

Stdev of Pair Differences ug/m 3

Inlet 0.0

Outlet 0.0

Standard Error of Pair Differences ug/m 3

Inlet 0.00

Outlet 0.00

2 Sigma (95% coverage)

Inlet 0.00

Outlet 0.00

Analyses done with paired run results from five trains (10 samples)

Difference from average is the difference between results of each pair (n = 5 pairs)

Variance is the square of the standard deviation and is a value that can be added and subtracted

Subtracting the variance of the paired sample results from the variance of the paired differences allows 
TXI - MILL ON - Error Analyses of Results

Error Bars Error Bars Worst Case Best Case

Facility TXI Corrected for Spike SE 2 Sigma Range of Possible Results

Avg. Stack Concentration ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3 ug/m 3

Inlet 4.9 4.8 0.01 0.04 4.8 4.8

Outlet 3.6 3.6 0.02 0.11 3.7 3.5

Apparent % Removal 27% 26% 23% 29%

Spike Accuracy Percentage

Inlet % Recovery 102

Outlet % Recovery 101

Spike Levels (conc. Eq.) ug/m 3

Inlet 6.7

Outlet 6.7

Precision

Paired Results Difference from Avg. ug/m 3

Inlet 0.1

Outlet 0.1

Stdev of Pair Differences ug/m 3

Inlet 0.0

Outlet 0.1

Standard Error of Pair Differences ug/m 3

Inlet 0.01

Outlet 0.02

2 Sigma (95% coverage)

Inlet 0.04

Outlet 0.11

Analyses done with paired run results from five trains (10 samples)

Difference from average is the difference between results of each pair (n = 5 pairs)

Variance is the square of the standard deviation and is a value that can be added and subtracted

Subtracting the variance of the paired sample results from the variance of the paired differences allows 
B

APPENDIX B

Select Charts
0

5

10

15

20

25

30

Lehigh North Holcim Portland Holcim Midlothian - K#1 Holcim Midlothian - K#2 TXI

ug/m3@7% O2

Facility

Mill On Comparisons

Total Hg Concentrations

30B INLET

FAMS INLET

30B OUTLET

FAMS OUTLET
0

20

40

60

80

100

120

140

160

180

200

Holcim Portland Holcim Midlothian - K#1 Holcim Midlothian - K#2 TXI

ug/m3 @ 7% O2

Facility

Mill Off Comparisons

Total Hg Concentrations

30B INLET

30B OUTLET

FAMS INLET

FAMS OUTLET
0.00

2.00

4.00

6.00

8.00

10.00

12.00

Lehigh North Holcim Portland Holcim Midlothian - K#1 Holcim Midlothian - K#2 TXI

ug/m3 @ 7% O2

Facility

Inlet Speciated FAMS Results

Hg p

Hg 0

Hg +2
0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

18.00

20.00

Lehigh North Holcim Portland Holcim Midlothian - K#1 Holcim Midlothian - K#2 TXI

ug/m3 @ 7% O2

Facility

Speciated Outlet Mill On

Hg p

Hg 0

Hg +2

Suspect due to water droplets
0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

160.00

Holcim Portland Holcim Midlothian - K#1 Holcim Midlothian - K#2 TXI

ug/m3 @ 7% O2

Facility

Speciated Inlet Mill Off

Hg p

Hg 0

Hg +2
0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

Holcim Portland Holcim Midlothian - K#1 Holcim Midlothian - K#2 TXI

ug/m3 @ 7% O2

Facility

Speciated Outlet Mill Off

Hg p

Hg 0

Hg +2
Goals of Meeting

• The facts of dust shuttling as we know 

– What we know– What we don’t know

• Actual Dust Shuttling Experience

– Data on shuttling for mercury from Germa

– Lehigh Union Bridge

– Lehigh Tehachapi

– Ash Grove Durkee

• Implications for the final PC MACT 

standard
There are many variables 

influence mercury co

• Oxidized vs. Elemental• Raw Mill Temperature

• Baghouse Dust to Raw Material R

• Dust Shuttling Limitations to Cem

• Others?
Lehigh Experience

• Union Bridge

– Shuttling (<3%) results in ~40% mer

– ACI into the main baghouse, plus sh

demonstrated

• If carbon added when raw mill on, exp

mercury concentration in the baghous

• Tehachapi

– Shuttling expected to result in <10% 

removal

– ACI not yet tried
Durkee Raw Material to D

• Durkee BH dust Raw Mill (RM) on is 50 

• Durkee Raw Feed (RF) is about 1.2 ppm

• Durkee Dust/RF ratio is 42 which indica

mercury enrichment factor

• Enrichment Factor = Hg conc. Raw Mill 

Hg conc. In Raw F
Gossman Data vs. PCA 

• Schreiber PCA study(1) indicated 3

system removal efficiency(SRE) ‐ 1

various types

• Gossman paper indicates one kiln 

as 99% but study done with most

data at hazardous waste combust

(1) Inherent Mercury Controls within the Portland Cement Kiln System, 
Dr. Clark Mercury Sem

• Model based on Chlorine Alkali buildup 

• If 99% SRE in Raw Mill then up to 75‐8

wasting 3% dust

• If 90% SRE in Raw mill then 30% remov

3 % dust

• Schreiber model of Durkee indicates ap

30% removal at a 3% dust shuttling

• Both models tend to agree when perc

defined
Critical Factor in Dr. Clark’s 

• 99% SRE would mean a ratio of 10

mercury enrichment factor

• EPA 114 data shows this is rare
PH Kilns with Enrichm

Factor<350

0

50

100150200250300350

0 10 20 30 40
All PH Kilns ‐ Enrichmen

0

100200300400500600700

0 10 20 30 40 

Union Bridge =625Durkee = 42Tehachapi = 7.5 
All Kilns Enrichment Fact

0

50

100150200250300350

0 20 40 60 80 100

A
All PH Kilns Statisti

• Average ratio is 85

• Median ratio is 12

• St deviation is 168

• Most ratios below 40
Durkee Shuttling Mod

• 2.14% or 2.7 tph

• 25% reduction from shuttling

• Adjusted for 66% ground onsite

• Yields 16.5

% reduction

• Uncertainty remains on best shutt

– Raw Mill On average 50 ppm (range 

– Raw Mill Off average 23 ppm (range 
Durkee Effective Mercur

• 1000 pounds mercury per year

• Less 16.5% control from shuttling

• 835 pounds balance• 85% control by activated carbon

• Balance 125.25 pounds mercury p

• 87.5% effective control
Amount of Dust That Can Be Shuttled 

The range of dust shuttling at Ash Grove’s pla3.0% based on meeting quality specificationsare limited by IR, two plants are limited by LOare limited by Alkali limitations.
Current Situation

• We are concerned that EPA may b

towards setting a standard withoutechnology demonstration neede

a specific level of control

• Optimization study needed to dem

actual control that can be achieve

shuttling

• We agree that shuttling will contr

but extent of control is currently u
Dust Shuttling Summ

• Shuttling will provide additional c

ACI alone

• How much will vary significantly b

• Technology is still under developm

• Industry can agree to maximize its 

efficiency at each plant

• Industry cannot support a specific 

control at this time
Control Options Consi

• Selective Quarrying

• Limestone Scrubbing

• Oxidizing Techniques (SCR, Haloge

Carbon)

• Importing Limestone

• Scrubbers• CKD Treatment/FLSmidth Limesto

• ACI• Dust Shuttling
Best Beyond the Floor Pac

• >225 ppb subcategory must instal

– 75% minimum SRE

– Implement Control Enhancement Ac

maximize benefits of ACI

• Require all reasonable measures to ma

performance

• Recurring assessment of whether SRE 

– Duty to reassess injection rates and 

reasonable measures

• Ensures continuous improvement effo
Best Beyond the Floor Pac

• Reduce Hg entering cycle from off

materials

– Require Mercury Minimization Plan

• Prohibit use of fly ash in raw feed

• Evaluate and minimize Hg in other imp

• Require dust shuttling up to maxim

achievable without impacting pro

– Require site specific evaluation:

• Document maximization of shuttling• Document optimal timing of dust bleed
Best Beyond the Floor Pac

• Could result in 90%+ SRE

– Until optimized at individual plant, n

combination can achieve

– This approach puts emphasis on opt

possible Hg reduction at each plant
Best Beyond the Floor Pac

• This approach enables Ash Grove 

– Employ “the best control technolog

available so far as is known”

– Employ the only control technology 

effective on all forms of Hg

– Keep jobs in the U.S.

– Avoid emissions associated with imp
Conclusions

• Proposed resolution ensures:

– Protection of environment– Compliance with Clean Air Act– Protection of jobs and community

• Avoids offshoring jobs to country’s wit

• If plants such as Durkee & Tehachapi c

U.S. will meet cement demand through 

• What is EPA thinking about this ap

• What additional information does 

• Next steps
Questions?