Date: November 6, 2014

To: Jeff Telander, EPA/OAQPS/SPPD

From: Thomas Holloway, RTI International

Subject: Methodology and Assumptions Used to Estimate the Model Costs and Impacts of 

BSCP Air Pollution Control Devices

I. Introduction

In accordance with section 112 of the Clean Air Act (CAA), the U.S. Environmental 

Protection Agency (EPA) established national emission standards for hazardous air pollutants 

(NESHAP) on May 16, 2003 for the brick and structural clay products (BSCP) manufacturing 

industry. The NESHAP regulated emissions of hydrogen fluoride (HF), hydrogen chloride (HCl), 

and particulate matter (PM)—a surrogate for hazardous air pollutant (HAP) metals—from tunnel 

kilns located at BSCP facilities. On March 13, 2007, the D.C. Circuit Court vacated the emission 

standards for BSCP manufacturing due to issues associated with the methodology used to 

determine the minimum regulatory “floors” for new and existing units.1 Therefore, the EPA is 

proposing new standards for BSCP manufacturing, including standards for HF, HCl, chlorine 

(Cl2), mercury (Hg), and non-Hg HAP metals (or PM surrogate). The purpose of this 

memorandum is to present the methodology and assumptions used in estimating the model costs 

and environmental and energy impacts for the control technologies used to meet these new 

standards.

II. General Model Parameters

Model costs and impacts were developed for two sizes of BSCP control devices—large 

control devices (LCD) and small control devices (SCD), reflecting the size subcategories of the 

BSCP NESHAP, which are based on a kiln capacity threshold of 10 tons per hour (tph). The 

model costs and impacts were estimated based on a variety of model parameters—(1) general 

parameters such as production rate, operating hours, gas flow rate, electricity and waste disposal 

unit costs, labor wage rates, and uncontrolled emissions; and (2) control-specific parameters such 

as control device horsepower (hp) requirements, sorbent requirements, and sorbent unit cost. 

This section discusses the basis for the general model parameters, which are presented in 

Appendix A at the end of this memorandum.

 1 Sierra Club v. EPA, 479 F.3d 875 (D.C. Cir. 2007).
2

The model production rates (in tph) and operating hours (in hours per year [hr/yr]) were 

based on data from the BSCP inventory (Holloway, 2014). The BSCP inventory is a combination 

of (1) industry responses to the 2008 BSCP section 114 survey; (2) responses to a survey similar 

to the 2008 BSCP section 114 survey that was administered by the Brick Industry Association;

and (3) industry data from the 2003 BSCP database (from the original 2003 BSCP NESHAP) for 

plants not included in the 2008 surveys. The average kiln production rate (7.0 tph) and operating 

hours (7,300 hr/yr) for the small model were calculated from those tunnel kilns with a kiln 

capacity less than 10 tph. The average kiln production rate (15 tph) and operating hours 

(7,800 hr/yr) for the large model were calculated from those tunnel kilns with a kiln capacity of 

10 tph or greater. The model kiln production rates were based on a mix of permitted and design 

capacities, i.e., those capacities to which the kilns are actually limited. The model kiln operating 

hours were based on a mix of actual kiln operating hours from industry responses to the 2008 

BSCP survey (Holloway, 2014) and facility operating hours from the 2003 BSCP database for 

those facilities not included in the 2008 survey. Since the kiln is the center of the production 

process at the BSCP facility, it is reasonable to assume facility operating hours would be the 

same as kiln operating hours.

The model exhaust gas flow rates (in actual cubic feet per minute [acfm]) were based on 

data from BSCP stack tests (Raymond, 2014), with the model flow rate for the small model 

(23,100 acfm) calculated from stack test data for tunnel kilns with a kiln capacity less than 10 

tph, and the model flow rate for the large model (38,700 acfm) calculated from stack test data for 

tunnel kilns with a kiln capacity of 10 tph or greater. In those cases where flow rate data were 

only available in units of dry standard cubic feet per minute (dscfm), those flow rates were 

converted to units of acfm using Equation 1 below, based on stack temperature and moisture 

content data from the stack test (assuming a stack pressure equivalent to standard atmospheric 

pressure):

Equation 1—Flow rate conversion

(100% )

100%

T tan %H O

T Q Q

s dard 2

stack

acfm dscfm − = × ×

where:

Qacfm = exhaust flow rate (acfm),

Qdscfm = exhaust flow rate (dscfm),

Tstack = stack temperature (converted from degrees Fahrenheit [°F] to degrees Rankine 

[°R]),

Tstandard = standard temperature (528°R), and

% H2O = moisture content (percent [%]).

Unit costs for electricity ($0.073/kilowatt-hour [kWh]) and waste disposal ($40/ton 

waste) were based on the average of those unit costs from the 2008 BSCP survey responses

(Holloway, 2014). The operator wage rate ($22.67/hr) was based on mean hourly wage data from 
3

the May 2011 Bureau of Labor Statistics for NAICS 327100 (Clay Product and Refractory 

Manufacturing) for an Industrial Engineering Technician (BLS, 2012). Wage rates from the 

Bureau of Labor Statistics were used because they were more conservative than those provided 

by BSCP survey respondents. The maintenance wage rate ($24.94/hr) was assumed to be 10 

percent higher than the operator wage rate, similar to the ratio of maintenance to operator wage 

rates provided by one BSCP company in its response to the 2008 survey (Holloway, 2014).

The capital recovery factor (0.0944) was calculated using Equation 2 below, assuming a 

7 percent interest rate and 20-year equipment life for the control devices expected to be used to 

comply with the new standards for BSCP manufacturing:

Equation 2—Capital recovery factor:

(1 ) 1

(1 )

+ −

× + = n

n

i

i i CRF

where:

i = interest rate (%) and

n = payment period, e.g., equipment life (yrs).

Model uncontrolled emissions estimates (in pounds per ton [lb/ton]) were used to 

estimate the amount of material captured by the control devices, based on each device’s control 

efficiency. The pollutants of interest were HF, HCl, chlorine (Cl2), PM, HAP metals, and sulfur 

dioxide (SO2). The model uncontrolled emissions estimates for HF, HCl, PM, Cl2, and SO2 were 

based on the average of uncontrolled emissions data from BSCP stack tests (Raymond, 2014).

The model uncontrolled emissions estimate for total HAP metals was assumed to be 1.1 percent 

of the PM estimate, based on the average ratio of metals to PM emissions in BSCP stack tests

(Raymond, 2014).

III. Model Costs

This section discusses the methodology and assumptions used to estimate the model costs 

for the new or retrofit emission control devices that BSCP facilities are expected to install in 

order to comply with the new standards for the BSCP industry. The cost estimates are presented

in 2011 dollars. The model cost tables for new and retrofit control devices are presented in 

Appendices B and C, respectively. (Note: The annual operating costs for replacement control 

devices presented in this memorandum are a conservative estimate. The operating costs for 

control devices to be replaced have not been subtracted out.)

Dry sorbent injection/fabric filter (DIFF). Dry sorbent injection followed by a fabric filter 

(DIFF) can be used to reduce emissions of both particulates and acid gases from BSCP tunnel 

kilns. This type of control system is already in use in the BSCP industry (Holloway, 2014) and is 

expected to be installed on uncontrolled kilns or retrofitted to replace less efficient kiln controls

to enable facilities to comply with the new BSCP standards.
4

The DIFF costs were estimated using the cost algorithms from the original BSCP 

rulemaking (Shrager, 2003), which were generated following guidelines in the OAQPS Control 

Cost Manual (EPA, 2002). The algorithms were updated to include more recent model 

parameters, including the general parameters discussed previously and the following parameters 

specific to DIFF control devices:

• Control efficiency (e.g., 99.5% HF, 94% PM)

• Fan horsepower (150 hp [small]/190 hp [large])

• Total horsepower for other motors (30 hp)

• Stoichiometric ratio of hydrated lime (2.65 [small], 1.79 [large])

• Bag life (5 yrs)

• Gas-to-cloth ratio (3.4 feet per minute [ft/min])

• Bag area (28 square feet [ft2

])

• Compressed air (0.9 cubic feet [ft3

] of compressed air/1,000 ft3 of gas)

• Time to replace bags (2.25 hr/bag)

• Hydrated lime unit cost ($160/ton)

• Bag fabric cost ($8.15/ft2

)

• Compressed air unit cost ($0.24/1,000 ft3

)

• Bag capital recovery factor (0.244, based on 5-yr bag life and 7% interest)

With two exceptions, the values of the model DIFF parameters were determined based on 

averages of industry responses to the 2008 BSCP survey (Holloway, 2014). The DIFF control 

efficiencies and stoichiometric ratios of hydrated lime were determined differently, as discussed 

below.

The control efficiencies for new and retrofit DIFF were estimated based on the average of 

those stack tests with better efficiencies than the baseline control efficiency (which was 

determined based on the average of all available stack tests with control efficiency data)

(Raymond, 2014). For example, the baseline HF control efficiency for a DIFF is estimated to be 

98 percent; in stack tests with HF control efficiencies better than 98 percent, the average HF 

control efficiency is 99.5 percent.

The stoichiometric ratio of hydrated lime for new and retrofit DIFF was estimated based 

on average reagent rates from industry responses to the 2008 BSCP survey (Holloway, 2014), 

average uncontrolled emissions data from stack tests (Raymond, 2014), and molecular weight 

information for the primary pollutants and hydrated lime, scaled up from baseline using the ratio 

of the aforementioned control efficiencies (99.5 percent/98 percent).

The model DIFF capital costs were estimated by taking DIFF capital cost data from 

industry responses to the 2008 BSCP survey (Holloway, 2014), escalating the costs to 2011 

dollars using the Chemical Engineering Plant Cost Index (CEPCI) (CE, 2011), scaling the costs 

to the large and small model sizes using the six-tenths cost rule (see Equation 3 below), taking 

the average of the scaled costs for each model size, and rounding the results to three significant 

figures.
5

Equation 3—Six-tenths cost rule:

0.6

2

1

2

1















 = Q

Q

C

C

where:

C = capital cost and

Q = capacity parameter (e.g., exhaust gas flow rate).

For retrofits, the capital costs were further adjusted using a retrofit factor of 1.4, which is 

in the middle of the range of retrofit factors for emission control devices, according to guidance 

from the OAQPS Control Cost Manual (EPA, 2002).

The model DIFF annual costs were estimated based on the aforementioned cost 

algorithms, and include the following cost items:

• Operating labor (assumed to be twice the maintenance labor hours at $22.67/hr)

• Supervisory labor (estimated at 15% of operating labor)

• Maintenance labor (estimated based on 1.25 hr/shift from BSCP survey 

responses and an assumed $24.94/hr wage rate)

• Maintenance materials (estimated at 100% of maintenance labor)

• Electricity (estimated based on hp requirements, 0.745 kW/hp, and 

$0.073/kWh)

• Lime (estimated based on hydrated lime makeup and $160/ton hydrated lime 

unit cost)

• Compressed air (estimated based on 0.9 ft3

/1,000 ft3 compressed air 

requirements and $0.24/1,000 ft3 compressed air unit cost)

• Replacement bags (estimated based on 3.4 ft/min gas-to-cloth ratio, $8.15/ft2

bag fabric, and 0.244 bag capital recovery factor)

• Bag replacement labor (estimated based on 3.4 ft/min gas-to-cloth ratio, 28 ft2

bag area, $29.94/hr maintenance wage rate, and 0.244 bag capital recovery 

factor)

• Waste disposal (estimated based on waste generated and $40/ton waste)

• Overhead (estimated at 60% of labor and maintenance materials)

• Property taxes, insurance, and administrative charges (estimated at 4% of total 

capital cost)

• Capital recovery (estimated as the product of a 0.0944 capital recovery factor 

and total capital cost, minus the cost of capital recovery for replacement bags 

and bag replacement labor)

Fabric filter. Fabric filters can be used to reduce emissions of particulates from BSCP 

tunnel kilns at plants that already have acid gas control or have inherently low acid gas emissions 

(e.g., due to low fluoride and chloride content in the raw materials). Stand-alone fabric filters are 
6

not currently used by the BSCP industry to control tunnel kiln emissions, although DIFF are used 

to control emissions from the larger tunnel kilns (Holloway, 2014). The BSCP industry has 

expressed the following concerns about using stand-alone fabric filters (Holloway, 2013b):

• Without the dry lime injection that reduces the acid gas, there will not be 

enough particulates in the kiln exhaust to coat the bags and get good 

performance from the fabric filter.

• The uncontrolled acid in the exhaust stream could rot the bags.

• The exhaust gas temperatures from BSCP tunnel kilns can be high (about 400°F 

on average, as high as 668°F).

• The use of membrane bags on low inlet loadings.

In response to these concerns, we contacted two major fabric filter vendors—Solios 

Environment and McGill AirClean—and a major filter bag vendor—W.L. Gore & Associates—

to determine the feasibility of using stand-alone fabric filters in the BSCP industry.

A representative from one of the fabric filter vendors (Solios Environment) agreed with 

industry concerns that that the lack of a dust cake would negatively impact total outlet emissions 

and that the dust cake serves an important function for acid gas neutralization. He noted that the 

bag choices for high-temperature applications are limited to fiberglass, with an upper 

temperature limit of 500°F, and that fiberglass degrades rapidly in the presence of HF acid gas. 

While PTFE (Teflon) fabric also has a limit of 500°F and is impervious to most acid gases, he 

noted that it carries a very significant price premium. He indicated that Aramid, Ryton, and P-84 

fabrics are generally limited to 400°F operation, but noted that these fabrics are sensitive to 

degradation not only by the acid gases but also the relatively high oxygen concentration in brick 

kiln gases (Hansen, 2013).

A representative from the other fabric filter vendor (McGill AirClean) stated that a brick 

plant should be able to use a stand-alone baghouse to control just filterable particulate emissions 

from a brick kiln. According to the vendor, if the concern is low dust load and not being able to 

establish a good dust cake, then bags with an expanded PTFE membrane could be used. He noted 

that membrane bags usually control outlet particulate emissions to very low levels and are not 

cost prohibitive any more. Like Solios, he stated that the base fabric for the membrane can be a 

woven fiberglass fabric, which is good for a 500°F continuous operating temperature. If there is 

HF in the gas stream, he said that this could damage the fiberglass, so scrubbing would be a good 

idea, depending on the amount of HF present. He said that acid gases in moderate concentrations 

usually do not cause fabric degradation if the bags are continuously operated above the acid gas 

dewpoints. Regarding operating temperatures above 500°F, he said there are some fabrics that 

are available for continuous operation at these temperatures but none with a membrane. He noted 

that the plant could consider flue gas cooling using a dry-bottom evaporative cooler or a gas-toair heat exchanger to reduce the gas temperature to a level where conventional fabrics could be 

used safely (Childress, 2013b).

A representative from the bag fabric vendor (W.L. Gore & Associates) noted that his 

company had done business with the brick industry before and that they have two kinds of bags 

that could be used for the industry: (1) high-temperature fiberglass bags, and (2) hightemperature PTFE (Teflon) bags. Both are rated to 500°F. He indicated that a ceramic style bag 
7

would be needed for temperatures above 500°F. He could not speak to the concern regarding PM 

loading, but did say that there would be no problem with PM loadings as low as 1 to 2 grains per 

cubic foot. He noted that HF destroys fiberglass, so PTFE bags would be needed if HF emissions 

are a concern. He noted that PTFE bags, unlike fiberglass bags, are chemically inert, but are very 

expensive, about 2 to 5 times more expensive than fiberglass. He also noted that PTFE bags have 

high chemical and thermal resistance and would control PM but not acid gas (Holloway, 2013c).

Based on the information obtained from vendors, we believe fabric filters can potentially 

be an effective control option, if acid gas levels (especially HF) are already inherently low or 

effectively controlled and exhaust gas temperatures are not too high. The fabric filter costs were 

estimated using the DIFF cost algorithms, minus the capital cost for a dry sorbent injection 

system and annual cost for sorbent, and with a revised annual cost for waste disposal that 

excludes any acid gas control.

Activated carbon injection (ACI). Injecting activated carbon before the particulate control 

device (e.g., fabric filter) has been demonstrated to improve the removal efficiency of mercury 

from a variety of combustion devices (e.g., waste incinerators, industrial boilers, cement kilns). 

In the absence of a national mercury standard for the BSCP industry, there are currently no 

BSCP plants that use ACI. However, given the effective mercury control performance achieved 

in these other industries, we believed it prudent to explore this control technology as an option to 

reduce the mercury emissions from the BSCP industry.

To obtain information on the feasibility and cost of adding an ACI system to an existing 

DIFF control system for BSCP kilns, we first contacted a fabric filter vendor, McGill AirClean. 

While a representative from the vendor indicated that his company does not have data on control 

of mercury emissions from BSCP kilns (all of the company’s mercury control experience is with 

municipal waste incinerators), he indicated that it should not be difficult or expensive to add an 

ACI system to an existing DIFF control system on a BSCP kiln. He said that a simple bag dump 

system with a blower could be used and would require little additional space at the site. He also 

noted that the slight increase in inlet PM loading to the baghouse should not affect the 

performance of the baghouse (Childress, 2013a).

We then contacted an ACI vendor (Cabot Norit Activated Carbon) to obtain information 

on the feasibility and cost of installing an ACI system for control of mercury emissions from 

BSCP kilns. A representative from the company stated that he thought ACI would work well 

with BSCP kilns. He indicated that it would cost about $0.80 to $0.90/lb for carbon (Holloway,

2013a). He also indicated that, for applications using baghouses (e.g., a DIFF), an activated 

carbon feed rate of 0.5 to 3 pounds per million actual cubic feet (lb/MMacf) is typical; he 

suggested using 2 lb/MMacf as a baseline (Thompson, 2013).

The model ACI costs for BSCP kilns were estimated based on ACI cost algorithms for a 

similarly-sized combustion device, specifically hazardous waste combustors (HWCs). We used 

the cost algorithms in the 2005 technical support document (TSD) for the HWC MACT 

replacement standards (EPA, 2005), using the general parameters discussed in the previous 

section and the carbon injection rate (2 lb/MMacf [Thompson, 2013]) and carbon unit cost 

(average of $0.85/lb [Holloway, 2013a]) from the ACI vendor. To determine the purchased 

equipment cost (PEC), the total equipment cost from the TSD was scaled to the large and small 
8

BSCP model sizes using the six-tenths cost rule, sales tax and freight charges were added, the 

resulting cost was escalated to 2011 dollars, and a retrofit factor of 1.15 was applied (CE, 2011;

EPA, 2005). To determine the total direct capital costs, installation costs were added to the total 

PEC (EPA, 2005). In addition to these direct costs, indirect costs of engineering, construction 

and field expense, contractor fees, startup, performance test, model study, and contingencies 

were also estimated (EPA, 2005).

The model ACI annual costs were also estimated based on the aforementioned cost 

algorithms (EPA, 2005) and include the following cost items:

• Operating labor (assumed based on 1 hour/day at $22.67/hour)

• Supervisory labor (estimated at 15% of operating labor)

• Maintenance labor (estimated based on 0.5 hour/shift and an assumed $29.94/hr 

wage rate)

• Maintenance materials (estimated at 5% of the PEC)

• Electricity (estimated based on hp requirements, 0.9 fan efficiency, 0.745 

kW/hp, and $0.073/kWh)

• Carbon (estimated based on carbon feed rate and $0.85/lb)

• Waste disposal (estimated based on waste generated and $40/ton waste)

• Overhead (estimated at 60% of labor and maintenance materials)

• Property taxes, insurance, and administrative charges (estimated at 4% of total 

capital cost)

• Capital recovery (estimated as the product of a 0.1098 capital recovery factor 

and total capital cost, assuming a 15-year equipment life and 7% interest)

Dry limestone adsorber (DLA). Instead of installing control equipment such as a DIFF to 

meet the new BSCP standards, some BSCP facilities may choose to install less expensive DLA 

systems on one or more of their uncontrolled tunnel kilns to reduce facility emissions below the 

threshold for major sources of HAP—10 tons per year (tpy) or more of any single HAP or 25 tpy 

or more of any combination of HAP. By obtaining a federally enforceable limit reducing 

emissions below major source thresholds, those BSCP facilities would become synthetic area 

sources and would not be subject to the major source BSCP NESHAP. Only those BSCP 

facilities that would be impacted under the new BSCP standards and that could reduce their HAP 

emissions below the major source threshold using a DLA system are expected to install such 

controls on their uncontrolled tunnel kilns.

Dry limestone adsorbers are designed to control HF emissions and also provide limited 

control of HCl and Cl2 emissions. The systems do not provide a mechanism for controlling PM 

emissions and would be expected to get only incidental PM control. This type of control system 

is already in use in the BSCP industry (Holloway, 2014). The DLA costs were estimated using 

the cost algorithms from the original BSCP rulemaking (Shrager, 2003), which were generated 

following guidelines in the OAQPS Control Cost Manual (EPA, 2002). The algorithms were 

updated to include more recent model parameters, including the general parameters discussed 

previously and the following parameters specific to DLA control devices:
9

• Control efficiency (e.g., 95% HF, 30% HCl)

• Fan horsepower (60 hp [small]/90 hp [large])

• Total horsepower for other motors (10 hp [small]/40 hp [large])

• Limestone rate (85 lb/hr [small]/120 lb/hr[large])

• Limestone unit cost ($40/ton)

The model DLA control efficiencies for HF, HCl, and other pollutants were estimated 

based on averages of data from BSCP stack tests (Raymond, 2014), while the values of the other 

model DLA parameters were determined based on averages of industry responses to the 2008 

BSCP survey (Holloway, 2014).

The model DLA capital costs were estimated by taking DLA capital cost data from 

industry responses to the 2008 BSCP survey (Holloway, 2014), escalating the costs to 2011 

dollars using the CEPCI (CE, 2011), scaling the costs to the large and small model sizes using 

the six-tenths cost rule (see Equation 3), taking the average of the scaled costs for each model 

size, and rounding the results to three significant figures.

The model DLA annual costs were estimated based on the aforementioned cost 

algorithms, and include the following cost items:

• Operating labor (assumed to be twice the maintenance labor hours at $22.67/hr)

• Supervisory labor (estimated at 15% of operating labor)

• Maintenance labor (estimated based on 0.75 hr/shift from BSCP survey 

responses and an assumed $24.94/hr wage rate)

• Maintenance materials (estimated at 100% of maintenance labor)

• Electricity (estimated based on hp requirements, 0.745 kW/hp, and 

$0.073/kWh)

• Limestone (estimated based on limestone rate and $40/ton limestone unit cost)

• Waste disposal (estimated based on waste generated and $40/ton waste)

• Overhead (estimated at 60% of labor and maintenance materials)

• Property taxes, insurance, and administrative charges (estimated at 4% of total 

capital cost)

• Capital recovery (estimated as the product of a 0.0944 capital recovery factor 

and total capital cost)

Summary. Table 1 presents the model costs for the DIFF, fabric filter, ACI, and DLA

control options discussed above for the small and large BSCP control devices. For additional 

information, see Appendix B and C at the end of this memorandum.
10

Table 1. Summary of Control Option Model Costs

Control Option Cost parameters SCD LCD

Install new DIFF Total capital investment $2,000,000 $2,730,000

Total annual cost $613,297 $797,096

Install new fabric filter Total capital investment $1,200,000 $1,500,000

Total annual cost $437,845 $526,006

Replace with DIFF Total capital investment $2,800,000 $3,820,000

Total annual cost $720,811 $943,585

Retrofit fabric filter Total capital investment $1,680,000 $2,100,000

Total annual cost $502,354 $606,642

Retrofit ACI system

 MACT floor Total capital investment $102,224 $146,697

Total annual cost $70,589 $96,482

 Beyond the floor Total capital investment $102,224 $146,697

Total annual cost $79,480 $112,768

Install DLA Total capital investment $1,060,000 $1,440,000

Total annual cost $306,593 $405,045

IV. Model Impacts

This section discusses the methodology and assumptions used to estimate the model 

environmental and energy impacts associated with new or retrofit emission control devices that 

BSCP plants are expected to install in order to comply with the new standards for the BSCP 

industry. The model impacts parameters and calculations are presented in Appendix D. The 

model impacts tables for new and retrofit control devices are presented in Appendices E and F, 

respectively.

A. Emission Reductions

Model emission reductions were estimated for the major pollutants emitted from BSCP 

tunnel kilns, including both HAP (HF, HCl, Cl2, and HAP metals) and non-HAP (PM and SO2). 

In most cases, we were able to determine the model emission reductions (tpy) by multiplying the 

model uncontrolled emission factors (lb/ton) in Appendix A by the model production rate (tph) 

and operating hours (hr/yr) in Appendix A and the appropriate control efficiency (%) in 

Appendix D, and dividing by a conversion factor of 2,000 lb/ton.

B. Energy Impacts

To determine the annual amount of electricity (in kilowatt-hours per year [kWh/yr])

needed to power the control device, the horsepower requirements (hp) of the control device were 

multiplied by a conversion factor of 0.745 kW/hp and the annual operating hours (hr/yr). The 

annual amount of energy (in million British thermal units per year [MMBtu/yr]) needed to 

generate this electricity was then determined by dividing the electricity requirements (kWh/yr) 

by the nationwide average power plant efficiency (35 percent) and multiplying by a conversion 

factor of 3,415 British thermal units per kilowatt hour (Btu/kWh).
11

The efficiency for each type of power plant was determined by dividing the heat content 

of electricity (3,415 Btu/kWh) by the heat rate for each type of plant (10,415 Btu/kWh for coal; 

8,185 Btu/kWh for natural gas; 10,452 Btu/kWh for nuclear power; and 9,756 Btu/kWh for 

renewable energy). The nationwide average power plant efficiency was determined as a 

weighted average of these power plant efficiencies, based on the projected fuel mix for 2015 

from Version 3.0 of EPA’s Integrated Planning Model (IPM), which is a forecast model of the 

U.S. electric power sector (EPA, 2011). The projected fuel mix is 53 percent coal, 22 percent 

natural gas/other, 17 percent nuclear, and 8 percent renewable/hydroelectric (EPA, 2011).

C. Secondary Air Emissions

Once the model energy impacts were determined, the associated model secondary air 

emissions were estimated. Secondary emissions typically include the criteria air pollutant 

emissions—PM, carbon monoxide (CO), nitrogen oxides (NOX), and SO2—that result from the 

generation of electricity used to operate the control devices. For purposes of this analysis, the 

electricity was assumed to be purchased from offsite power plants. The secondary emissions 

were estimated by multiplying emission factors for the pollutants by the energy impacts, 

assuming a specific mix of fuels to generate the needed electricity. (EPA, 2011)

We used a variety of information sources to obtain the emission factors used to estimate 

the secondary emissions. For natural gas combustion, we used emission factors (in pounds per 

cubic foot [lb/ft3

] of natural gas) from the AP-42 chapter on natural gas combustion to estimate 

the secondary emissions for PM, CO, NOX, and SO2 (EPA, 1998a). We used the AP-42 

conversion factor of 1,020 Btu/ft3 of natural gas to convert the emission factors to pounds per 

million British thermal units (lb/MMBtu) to facilitate estimating the secondary emissions for 

these pollutants from natural gas (EPA, 1998a).

For solid fuel (coal) combustion, we used emission limits (in lb/MMBtu) from the new 

source performance standards (NSPS) for utility plants (40 CFR part 60, subpart Da; 2006 CFR 

edition) to estimate the secondary emissions for PM and SO2 (EPA, 2006). We used emission 

factors (in lb/ton coal) from the AP-42 chapter on coal combustion to estimate the secondary 

emissions for NOX and CO; we specifically used the AP-42 emission factors for 

bituminous/subbituminous coal combustion/spreader stokers (EPA, 1998b). The NOX emission

factor was based on an average of the AP-42 emission factors for spreader stoker type boilers

burning bituminous (11 lb/ton) and subbituminous (8.8 lb/ton) coal. We used the AP-42 

conversion factor of 13,000 Btu/lb of coal to facilitate estimating the secondary emissions for 

NOX and CO from coal (EPA, 1998b).

All secondary air impacts were attributed to the combustion of coal, natural gas, or 

“other” fuels at offsite power plants. We attributed no secondary air impacts to nuclear, 

hydroelectric, or renewable energy generation. The secondary air impacts for “other” fuels were 

assumed to be equivalent to those for natural gas.
12

D. Solid Waste and Wastewater Impacts

We estimated the solid waste impacts by calculating the amount of material captured by 

the control device. The material captured by the fabric filter includes just PM from the kiln, 

while the material captured by the DIFF includes:

• Reaction products from the reaction of the lime with the acid gases,

• Unreacted lime, and

• Particulate matter from the kiln.

In the absence of information, the amount of solid waste captured by a spray 

dryer/electrostatic precipitator (ESP) (the control system currently employed at one BSCP 

facility) was assumed to be the same as that captured by a DIFF, since both emission control 

systems include a combination of acid gas and PM controls, unlike a stand-alone fabric filter 

(which captures only PM) or a DLA (which captures mostly acid gases, primarily HF).

We estimated the wastewater impacts associated with using a spray dryer/ESP by 

calculating the amount of water usage for the spray dryer, using the equation shown in Appendix 

E. There are no wastewater impacts for the other control devices.

E. Model Impacts for Control Options

Model impacts were estimated for the following control scenarios and are presented in 

the appendix tables cited below:

• Installation of new DIFF on uncontrolled kiln (see Table E-1)

• Installation of new fabric filter on uncontrolled kiln (where acid gas levels and 

exhaust gas temperatures are low) (see Table E-2)

• Retrofit of fabric filter after an existing acid gas control (e.g., DLA) (see Table 

E-2)

• Installation of DLA on uncontrolled kiln(s) to become synthetic area source (see 

Table E-3)

• Retrofit of ACI system to an existing control system (e.g., DIFF) (see Table 

F-1)

• Replacement of existing DLA with a new DIFF (see Table F-2)

• Replacement of existing spray dryer/ESP with a new DIFF (see Table F-3)

• Replacement of existing DIFF with a new, more efficient DIFF (see Table F-4)

To estimate the incremental impacts for replacement control devices, the impacts 

associated with baseline controls were subtracted from the impacts associated with new controls. 

For DLA and spray dryer/ESP controls being replaced with a DIFF, the incremental impacts 

include the emission reductions, energy impacts, secondary air impacts, solid waste impacts, and 

wastewater impacts (spray dryer/ESP controls only). For those cases where a facility replaces an 

existing DIFF with a new, more efficient DIFF to comply with the new standards, we assumed 

no change in energy requirements or the associated secondary emissions, but we estimated the 

difference in emissions and solid waste impacts that would accompany the improved control of 

PM and acid gases.
13

Because we had no control efficiency data for spray dryer/electrostatic precipitator (ESP), 

we used stack test data for the kilns equipped with this emission control as the baseline emissions 

and subtracted the baseline emissions for the DIFF to determine the incremental emissions 

reduction from replacing a spray dryer/ESP with a DIFF.

Tables 2 through 4 present the model impacts for the DIFF, fabric filter, and ACI control 

installation/retrofit options and control replacement options discussed above for the small and 

large BSCP control devices. For additional information, see the aforementioned tables in 

Appendices E and F at the end of this memorandum.

Table 2a. Summary of Model Emission Reductions for Control Installation/Retrofit 

Options

Control option Pollutant

Emissions reductions, tpy

SCD LCD

Install new DIFF Hydrogen fluoride 15.1 34.6

Hydrogen chloride 1.72 3.94

Chlorine 0.0789 0.181

HAP metals 0.0855 0.196

Particulate matter 7.78 17.8

Sulfur dioxide 40.2 92.1

Install/retrofit fabric filter HAP metals 0.0855 0.196

Particulate matter 7.78 17.8

Install new DLA Hydrogen fluoride 14.4 33.0

Hydrogen chloride 0.620 1.42

Chlorine 0.0371 0.0850

HAP metals 0.0182 0.0417

Particulate matter 1.65 3.79

Sulfur dioxide 9.90 22.7

Retrofit ACI system

 MACT floor Mercury 0.00136 0.00311

 Beyond the floor Mercury 0.00152 0.00347
14

Table 2b. Summary of Model Emission Reductions for Control Replacement Options

Control option Pollutant

Net emissions reductions, tpy

SCD LCD

Replace dry limestone adsorber 

with new DIFF

Hydrogen fluoride 0.683 1.56

Hydrogen chloride 1.10 2.52

Chlorine 0.0418 0.0958

HAP metals 0.0673 0.154

Particulate matter 6.12 14.0

Sulfur dioxide 30.3 69.4

Replace spray dryer/ESP with new 

DIFF

Hydrogen fluoride 17.5 37.3

Hydrogen chloride 3.93 8.35

Chlorine 0.534 1.14

HAP metals 0.00 0.00

Particulate matter 0.00 0.00

Sulfur dioxide 0.606 1.39

Replace existing DIFF with new, 

more efficient DIFF

Hydrogen fluoride 0.228 0.521

Hydrogen chloride 0.0259 0.0594

Chlorine 0.00119 0.00272

HAP metals 0.0200 0.0458

Particulate matter 1.82 4.17

Sulfur dioxide 0.606 1.39

Table 3a. Summary of Model Energy and Solid Waste Impacts for Control 

Installation/Retrofit Options

Control option Type of impact SCD LCD

Install new DIFF Energy impacts, MMBtu/yr 9,620 12,563

Solid waste impacts, tpy 372 604

Install/retrofit fabric filter Energy impacts, MMBtu/yr 9,620 12,563

Solid waste impacts, tpy 7.78 17.8

Install new DLA Energy impacts, MMBtu/yr 3,741 7,424

Solid waste impacts, tpy 306 457

Retrofit ACI system

 MACT floor Energy impacts, MMBtu/yr 309 553

Solid waste impacts, tpy 10.2 17.9

 Beyond the floor Energy impacts, MMBtu/yr 309 553

Solid waste impacts, tpy 15.3 27.3
15

Table 3b. Summary of Model Energy, Solid Waste, and Wastewater Impacts for Control 

Replacement Options

Control option Type of impact

Increase in impacts1

SCD LCD

Replace dry limestone adsorber 

with new DIFF

Energy impacts, MMBtu/yr 5,879 5,139

Solid waste impacts, tpy 66.8 147

Replace spray dryer/ESP with new 

DIFF

Energy impacts, MMBtu/yr -7,749 -24,555

Solid waste impacts, tpy 7.22 12.9

Wastewater impacts, gpy -1,901 -4,063

Replace existing DIFF with new, 

more efficient DIFF

Energy impacts, MMBtu/yr 0 0

Solid waste impacts, tpy 7.22 12.9

1 A negative increase in impacts would be equivalent to a reduction in impacts.

Table 4a. Summary of Model Secondary Impacts for Control Installation/Retrofit Options

Control option Secondary pollutant1

Secondary air impacts, tpy

SCD LCD

Install new DIFF Particulate matter 0.0710 0.0927

PM2.5 0.0238 0.0311

Carbon monoxide 0.120 0.156

Nitrogen oxides 0.951 1.24

Sulfur dioxide 2.77 3.62

Install/retrofit fabric filter Particulate matter 0.0710 0.0927

PM2.5 0.0238 0.0311

Carbon monoxide 0.120 0.156

Nitrogen oxides 0.951 1.24

Sulfur dioxide 2.77 3.62

Install new DLA Particulate matter 0.0276 0.0548

PM2.5 0.00925 0.0184

Carbon monoxide 0.0465 0.0923

Nitrogen oxides 0.370 0.734

Sulfur dioxide 1.08 2.14

Retrofit ACI system

(MACT floor/beyond the floor)

Particulate matter 0.00228 0.00408

PM2.5 0.000765 0.00137

Carbon monoxide 0.00385 0.00688

Nitrogen oxides 0.0306 0.0547

Sulfur dioxide 0.0891 0.159

1 PM2.5 = PM with particles less than 2.5 micrometers in diameter.
16

Table 4b. Summary of Model Secondary Impacts for Control Replacement Options

Control option Secondary pollutant2

Increase in secondary air 

impacts, tpy1

SCD LCD

Replace dry limestone adsorber 

with new DIFF

Particulate matter 0.0434 0.0379

PM2.5 0.0145 0.0127

Carbon monoxide 0.0731 0.0639

Nitrogen oxides 0.581 0.508

Sulfur dioxide 1.69 1.48

Replace spray dryer/ESP with new 

DIFF

Particulate matter -0.0572 -0.181

PM2.5 -0.0192 -0.0607

Carbon monoxide -0.0964 -0.305

Nitrogen oxides -0.766 -2.43

Sulfur dioxide -2.23 -7.07

Replace existing DIFF with new, 

more efficient DIFF

Particulate matter 0 0

PM2.5 0 0

Carbon monoxide 0 0

Nitrogen oxides 0 0

Sulfur dioxide 0 0

1 A negative increase in secondary air impacts would be equivalent to a reduction in secondary air impacts.

2 PM2.5 = PM with particles less than 2.5 micrometers in diameter.

V. References

BLS (U.S. Department of Labor, Bureau of Labor Statistics). 2012. Occupational Employment 

Statistics: May 2011 National Industry-Specific Occupational Employment and Wage 

Estimates. NAICS 327100 - Clay Product and Refractory Manufacturing. Industrial 

Engineering Technician. March 27, 2012. Available at: 

http://www.bls.gov/oes/2011/may/naics4_327100.htm.

CE (Chemical Engineering). 2011. Plant Cost Index.

Childress, J. 2013a. “RE: From McGill AirClean Web Site.” E-mail from Jerry Childress, 

McGill AirClean LLC, to Thomas Holloway, RTI International. April 18, 2013.

Childress, J. 2013b. “RE: From McGill AirClean Web Site.” E-mail from Jerry Childress, 

McGill AirClean LLC, to Thomas Holloway, RTI International. June 27, 2013.

EPA (U.S. Environmental Protection Agency). 1998a. Compilation of Air Pollutant Emission 

Factors. Volume 1: Stationary Point and Area Sources. AP-42, Section 1.4: Natural Gas 

Combustion. July 1998.

EPA (U.S. Environmental Protection Agency). 1998b. Compilation of Air Pollutant Emission 

Factors. Volume 1: Stationary Point and Area Sources. AP-42, Section 1.1: Bituminous and 

Subbituminous Coal Combustion. September 1998.
17

EPA (U.S. Environmental Protection Agency). 2002. EPA Air Pollution Control Cost Manual. 

Sixth Edition. Office of Air Quality Planning and Standards, Research Triangle Park, NC. 

Publication No. EPA/452/B-02-001. January 2002.

EPA (U.S. Environmental Protection Agency). 2005. Technical Support Document for the HWC 

MACT Replacement Standards, Volume V: Emissions Estimates and Engineering Costs. 

Office of Solid Waste and Emergency Response, Washington, DC. September 2005.

EPA (U.S. Environmental Protection Agency). 2006. “Subpart Da—Standards of Performance 

for Electric Utility Steam Generating Units for Which Construction is Commenced After 

September 18, 1978.” Code of Federal Regulations, Title 40, Part 60. Published by Office of 

the Federal Register, National Archives and Records Administration. As of July 1, 2006.

EPA (U.S. Environmental Protection Agency). 2011. Regulatory Impact Analysis for the Final 

Mercury and Air Toxics Standards. Table 3-6: Generation Mix with the Base Case and the 

MATS, 2015 (Thousand GWh). Publication No. EPA-452/R-11-011. December 2011.

Hansen, L. 2013. “RE: Question regarding use of fabric filters for brick kilns.” E-mail from Lars

Hansen, Solios Environment Corp., to Thomas Holloway, RTI International. July 2, 2013.

Holloway, T. 2013a. Telephone Contact Summary: Jeff Thompson, Cabot Norit Activated 

Carbon. Contacted by Thomas Holloway, RTI International. May 16, 2013.

Holloway, T. 2013b. “RE: From McGill AirClean Web Site.” E-mail from Thomas Holloway, 

RTI International, to Jerry Childress, McGill AirClean LLC. June 26, 2013.

Holloway, T. 2013c. Telephone Contact Summary: Chris Polizzi, W.L. Gore & Associates, Inc.

Contacted by Thomas Holloway, RTI International. July 16, 2013.

Holloway, T. 2014. Updated BSCP Inventory Database and Documentation. Memorandum from 

Thomas Holloway, RTI International, to Jeff Telander, EPA/OAQPS/SPPD. November 6, 

2014.

Raymond, G. 2014. Test Data Used in BSCP Proposed Rule. Memorandum from Gabrielle 

Raymond, RTI International, to Jeff Telander, EPA/OAQPS/SPPD. November 6, 2014.

Shrager, B. 2003. Final Rule: Costs for Air Pollution Control Devices on Kilns. Memorandum 

from Brian Shrager, RTI International, to Mary Johnson, U.S. Environmental Protection 

Agency. February 25, 2003.

Thompson, J. 2013. “FW: Cabot Norit Activated Carbon–question.” E-mail from Jeff Thompson, 

Cabot Norit Activated Carbon, to Thomas Holloway, RTI International. May 31, 2013.
Appendix A

Model Parameters
A-2

Table A-1. General Parameters for BSCP Model Control Devices

Parameters SCD LCD Footnotes

Process parameters

Production rate, ton/hr 7.0 15.0 1

Operating hours, hr/yr 7,300 7,800 1

Exhaust flow, acfm 23,100 38,700 2

Unit costs

Electricity cost, $/kwh 0.073 0.073 1

Waste disposal cost, $/ton 40 40 1

Operator wage rate, $/hr 22.67 22.67 3

Maintenance wage rate, $/hr 24.94 24.94 4

Capital recovery factor--system 0.0944 0.0944 5

Molecular weights

HF 20 20

HCl 36.5 36.5

SO2 64 64

CaF2 78 78 6

CaCl2 111 111 6

CaSO3 120 120 6

Ca(OH)2 74 74 7

Uncontrolled emissions, lb/ton

HF 0.594 0.594 2

HCl 0.081 0.081 2

Cl2 0.00346 0.00346 2

Non-Hg HAP Metals 0.00356 0.00356 8

PM 0.324 0.324 2

SO2 3.23 3.23 2

Uncontrolled emissions, lb/hr

HF 4.16 8.91 9

HCl 0.566 1.21 9

Cl2 0.0242 0.0519 9

Non-Hg HAP Metals 0.0249 0.0534 9

PM 2.27 4.86 9

SO2 22.6 48.5 9

1. Average from section 114 survey responses.

2. Average from test data.

3. Mean hourly wage, from Bureau of Labor Statistics, May 2011 National Industry-Specific Occupational 

Employment and Wage Estimates, NAICS 327100, Industrial Engineering Technician. Website: 

http://www.bls.gov/oes/2011/may/naics4_327100.htm. Wage rates from Bureau of Labor Statistics were used 

because they are more conservative than those provided by section 114 survey respondents.

4. 10 percent higher than operator rate.

5. Based on equipment life of 20 years and 7 percent interest.

6. Reaction product; CaF2 = calcium fluoride; CaCl2 = calcium chloride; CaSO3 = calcium sulfite.

7. Hydrated lime.

8. Assume 1.1 percent of PM.

9. Calculated from lb/ton times production rate.
Appendix B

Installation Model Costs
B-2

Table B-1. Model Costs to Install New DIFF

Parameters SCD LCD Footnotes

Control efficiency, percent

HF 99.5% 99.5% 1

HCl 83.3% 83.3% 2

Cl2 89.3% 89.3% 3

Non-Hg HAP Metals 94% 94% 4

PM 94% 94% 1

SO2 48.7% 48.7% 5

Design and operating parameters

Fan hp 150 190 6

Total hp for other motors 30 30 6

Hydrated lime, fraction of stoichiometric amount 2.65 1.79 7

Operator labor, hr/shift 2.5 2.5 8

Maintenance labor, hr/shift 1.25 1.25 6

Bag life, yr 5 5 6

Gas-to-cloth ratio (gross), ft/min 3.4 3.4 6

Bag area, ft2 28 28 6

Compressed air, ft3/1,000 ft3 0.9 0.9 6

Time to replace bags, hr/bag 2.25 2.25 6

Added cooling air, ft3/min 0 0 9

Calculated parameters

Hydrated lime makeup, lb/hr 91.4 132.0

Reaction products, lb/hr 29.4 63.1 10

Reacted lime, lb/hr 20.9 44.7

Particulate matter, lb/hr 2.1 4.6

Waste, lb/hr 102.1 154.9 11

Cost factors

Hydrated lime, $/ton 160 160 6

Bag fabric cost, $/ft2 8.15 8.15 6

Compressed air, $/1,000 ft3 0.24 0.24 12

Capital recovery factor--bags 0.244 0.244 13

Capital costs

Total capital investment 2,000,000 2,730,000 14

Annual costs

Operating labor 51,716 55,258

Supervisory labor 7,757 8,289 15

Maintenance labor 28,444 30,392

Maintenance materials 28,444 30,392 16

Electricity 71,462 93,325 17

Lime 53,348 82,337

Compressed air 2,185 3,912

Annualized replacement bags 13,505 22,625

Annualized bag replacement labor 3,320 5,563 18

Cage replacement 0 0 19
B-3

Parameters SCD LCD Footnotes

Waste disposal 14,900 24,162

Overhead 69,817 74,598 20

Administrative charges 40,000 54,600 21

Property taxes 20,000 27,300 22

Insurance 20,000 27,300 22

Capital recovery 188,399 257,044

Total annual cost, $/yr 613,297 797,096

1. Average from test data with better efficiency than baseline.

2. Based on ratio of enhanced HF reduction and baseline HCl reduction.

3. Based on ratio of enhanced HF reduction and baseline Cl2 reduction.

4. Assume same as PM.

5. Based on ratio of enhanced HF reduction and baseline SO2 reduction.

6. Average from section 114 survey responses.

7. Assume hydrated lime is 2.65/1.79 times the stoichiometric amount needed to get additional control re baseline 

(from 98% to 99.5%).

8. Assume 2 times maintenance labor (EPA, 2002).

9. Assume none.

10. CaF2 (calcium fluoride), CaCl2 (calcium chloride), and CaSO3 (calcium sulfite).

11. Inlet lime minus reacted lime plus reaction products and PM.

12. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the 

Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. 

Web site: http://www.p2pays.org/ref/40/39536.pdf.

13. Based on equipment life of 5 years and 7 percent interest.

14. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), escalated to 2011 

dollars, and rounded.

15. 15 percent of operator labor.

16. 100 percent of maintenance labor.

17. Based on conversion factor of 0.745 kW/hp.

18. Performed by maintenance personnel.

19. Maybe no need to replace.

20. 60 percent of labor and maintenance materials.

21. 2 percent of TCI.

22. 1 percent of TCI.
B-4

Table B-2. Model Costs to Install New Fabric Filter

Parameters SCD LCD Footnotes

Control efficiency, percent

Non-Hg HAP Metals 94% 94% 1

PM 94% 94% 2

Design and operating parameters

Fan hp 150 190 3

Total hp for other motors 30 30 3

Operator labor, hr/shift 2.5 2.5 4

Maintenance labor, hr/shift 1.25 1.25 3

Bag life, yr 5 5 3

Gas-to-cloth ratio (gross), ft/min 3.4 3.4 3

Bag area, ft2 28 28 3

Compressed air, ft3/1,000 ft3 0.9 0.9 3

Time to replace bags, hr/bag 2.25 2.25 3

Added cooling air, ft3/min 0 0 5

Calculated parameters

Waste, lb/hr 2.1 4.6 6

Cost factors

Bag fabric cost, $/ft2 8.15 8.15 3

Compressed air, $/1,000 ft3 0.24 0.24 7

Capital recovery factor--bags 0.244 0.244 8

Cost of dry injection system 800,907 1,230,278 9

Capital costs

Total capital investment 1,200,000 1,500,000 10

Annual costs

Operating labor 51,716 55,258

Supervisory labor 7,757 8,289 11

Maintenance labor 28,444 30,392

Maintenance materials 28,444 30,392 12

Electricity 71,462 93,325 13

Compressed air 2,185 3,912

Annualized replacement bags 13,505 22,625

Annualized bag replacement labor 3,320 5,563 14

Cage replacement 0 0 15

Waste disposal 311 712

Overhead 69,817 74,598 16

Administrative charges 24,000 30,000 17

Property taxes 12,000 15,000 18

Insurance 12,000 15,000 18

Capital recovery 112,884 140,940

Total annual cost, $/yr 437,845 526,006

1. Assume same as PM.

2. Average from test data with better efficiency than baseline.

3. Average from section 114 survey responses.

4. Assume 2 times maintenance labor (EPA, 2002).
B-5

5. Assume none.

6. Particulate matter.

7. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the 

Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. 

Web site: http://www.p2pays.org/ref/40/39536.pdf.

8. Based on equipment life of 5 years and 7 percent interest.

9. Based on cost equations in the June 19, 2009 memorandum Revised Baseline Operating Costs for Existing 

HMIWI, in Docket ID No. EPA-HQ-OAR-2006-0534 for the hospital/medical/infectious waste incinerator (HMIWI)

rule.

10. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), subtracted cost of 

dry injection system, escalated to 2011 dollars, and rounded.

11. 15 percent of operator labor.

12. 100 percent of maintenance labor.

13. Based on conversion factor of 0.745 kW/hp.

14. Performed by maintenance personnel.

15. Maybe no need to replace.

16. 60 percent of labor and maintenance materials.

17. 2 percent of TCI.

18. 1 percent of TCI.
B-6

Table B-3. Model Costs to Install New DLA

Parameters SCD LCD Footnotes

Control efficiency, percent

HF 95% 95% 1

HCl 30% 30% 1

Cl2 42% 42% 1

Non-Hg HAP Metals 20% 20% 2

PM 20% 20% 1

SO2 12% 12% 1

Design and operating parameters

Fan hp 60 90 3

Total hp for other motors 10 40 3

Limestone, lb/hr 85 120 3

Operator labor, hr/shift 1.5 1.5 4

Maintenance labor, hr/shift 0.75 0.75 3

Calculated parameters

Reaction products, lb/hr 13.1 28.0 5

Reacted limestone, lb/hr 14.4 30.8

Particulate matter, lb/hr 0.1 0.1

Waste, lb/hr 83.8 117.3 6

Cost factors

Limestone, $/ton 40 40 3

Capital costs

Total capital investment 1,060,000 1,440,000 7

Annual costs

Operating labor 31,030 33,155

Supervisory labor 4,654 4,973 8

Maintenance labor 17,066 18,235

Maintenance materials 17,066 18,235 9

Electricity 27,791 55,146 10

Limestone 12,410 18,720

Waste disposal 12,230 18,295 11

Overhead 41,890 44,759 12

Administrative charges 21,200 28,800 13

Property taxes 10,600 14,400 14

Insurance 10,600 14,400 14

Capital recovery 100,057 135,926

Total annual cost, $/yr 306,593 405,045

1. Average from test data.

2. Assume same as PM.

3. Average from section 114 survey responses.

4. Assume 2 times maintenance labor (EPA, 2002).

5. CaF2 (calcium fluoride), CaCl2 (calcium chloride), and CaSO3 (calcium sulfite).

6. Inlet limestone minus reacted limestone plus reaction products and PM.

7. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), escalated to 2011 

dollars, and rounded.
B-7

8. 15 percent of operator labor.

9. 100 percent of maintenance labor.

10. Based on conversion factor of 0.745 kW/hp.

11. Some facilities have minimal waste disposal costs.

12. 60 percent of labor and maintenance materials.

13. 2 percent of TCI.

14. 1 percent of TCI.
Appendix C

Retrofit/Replacement Model Costs
C-2

Table C-1. Model Costs to Replace Existing Control Device with DIFF

Parameters SCD LCD Footnotes

Control efficiency, percent

HF 99.5% 99.5% 1

HCl 83.3% 83.3% 2

Cl2 89.3% 89.3% 3

Non-Hg HAP Metals 94% 94% 4

PM 94% 94% 1

SO2 48.7% 48.7% 5

Design and operating parameters

Fan hp 150 190 6

Total hp for other motors 30 30 6

Hydrated lime, fraction of stoichiometric amount 2.65 1.79 7

Operator labor, hr/shift 2.5 2.5 8

Maintenance labor, hr/shift 1.25 1.25 6

Bag life, yr 5 5 6

Gas-to-cloth ratio (gross), ft/min 3.4 3.4 6

Bag area, ft2 28 28 6

Compressed air, ft3/1,000 ft3 0.9 0.9 6

Time to replace bags, hr/bag 2.25 2.25 6

Added cooling air, ft3/min 0 0 9

Calculated parameters

Hydrated lime makeup, lb/hr 91.4 132.0

Reaction products, lb/hr 29.4 63.1 10

Reacted lime, lb/hr 20.9 44.7

Particulate matter, lb/hr 2.1 4.6

Waste, lb/hr 102.1 154.9 11

Cost factors

Hydrated lime, $/ton 160 160 6

Bag fabric cost, $/ft2 8.15 8.15 6

Compressed air, $/1,000 ft3 0.24 0.24 12

Capital recovery factor--bags 0.244 0.244 13

Retrofit factor 1.4 1.4 14

Capital costs

Total capital investment 2,800,000 3,820,000 15

Annual costs

Operating labor 51,716 55,258

Supervisory labor 7,757 8,289 16

Maintenance labor 28,444 30,392

Maintenance materials 28,444 30,392 17

Electricity 71,462 93,325 18

Lime 53,348 82,337

Compressed air 2,185 3,912

Annualized replacement bags 13,505 22,625

Annualized bag replacement labor 3,320 5,563 19
C-3

Parameters SCD LCD Footnotes

Cage replacement 0 0 20

Waste disposal 14,900 24,162

Overhead 69,817 74,598 21

Administrative charges 56,000 76,400 22

Property taxes 28,000 38,200 23

Insurance 28,000 38,200 23

Capital recovery 263,913 359,932

Total annual cost, $/yr 720,811 943,585

1. Average from test data with better efficiency than baseline.

2. Based on ratio of enhanced HF reduction and baseline HCl reduction.

3. Based on ratio of enhanced HF reduction and baseline Cl2 reduction.

4. Assume same as PM.

5. Based on ratio of enhanced HF reduction and baseline SO2 reduction.

6. Average from section 114 survey responses.

7. Assume hydrated lime is 2.65/1.79 times the stoichiometric amount needed to get additional control re baseline 

(from 98% to 99.5%).

8. Assume 2 times maintenance labor (EPA, 2002).

9. Assume none.

10. CaF2 (calcium fluoride), CaCl2 (calcium chloride), and CaSO3 (calcium sulfite).

11. Inlet lime minus reacted lime plus reaction products and PM.

12. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the 

Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. 

Web site: http://www.p2pays.org/ref/40/39536.pdf.

13. Based on equipment life of 5 years and 7 percent interest.

14. Average for various control devices (EPA, 2002).

15. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), escalated to 2011 

dollars, multiplied by retrofit cost factor, and rounded.

16. 15 percent of operator labor.

17. 100 percent of maintenance labor.

18. Based on conversion factor of 0.745 kW/hp.

19. Performed by maintenance personnel.

20. Maybe no need to replace.

21. 60 percent of labor and maintenance materials.

22. 2 percent of TCI.

23. 1 percent of TCI.
C-4

Table C-2. Model Costs to Retrofit Fabric Filter to Existing Control Device

Parameters SCD LCD Footnotes

Control efficiency, percent

Non-Hg HAP Metals 94% 94% 1

PM 94% 94% 2

Design and operating parameters

Fan hp 150 190 3

Total hp for other motors 30 30 3

Operator labor, hr/shift 2.5 2.5 4

Maintenance labor, hr/shift 1.25 1.25 3

Bag life, yr 5 5 3

Gas-to-cloth ratio (gross), ft/min 3.4 3.4 3

Bag area, ft2 28 28 3

Compressed air, ft3/1,000 ft3 0.9 0.9 3

Time to replace bags, hr/bag 2.25 2.25 3

Added cooling air, ft3/min 0 0 5

Calculated parameters

Waste, lb/hr 2.1 4.6 6

Cost factors

Bag fabric cost, $/ft2 8.15 8.15 3

Compressed air, $/1,000 ft3 0.24 0.24 7

Capital recovery factor--bags 0.244 0.244 8

Cost of dry injection system 800,907 1,230,278 9

Retrofit factor 1.4 1.4 10

Capital costs

Total capital investment 1,680,000 2,100,000 11

Annual costs

Operating labor 51,716 55,258

Supervisory labor 7,757 8,289 12

Maintenance labor 28,444 30,392

Maintenance materials 28,444 30,392 13

Electricity 71,462 93,325 14

Compressed air 2,185 3,912

Annualized replacement bags 13,505 22,625

Annualized bag replacement labor 3,320 5,563 15

Cage replacement 0 0 16

Waste disposal 311 712

Overhead 69,817 74,598 17

Administrative charges 33,600 42,000 18

Property taxes 16,800 21,000 19

Insurance 16,800 21,000 19

Capital recovery 158,193 197,576

Total annual cost, $/yr 502,354 606,642

1. Assume same as PM.

2. Average from test data with better efficiency than baseline.

3. Average from section 114 survey responses.
C-5

4. Assume 2 times maintenance labor (EPA, 2002).

5. Assume none.

6. Particulate matter.

7. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the 

Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. 

Web site: http://www.p2pays.org/ref/40/39536.pdf.

8. Based on equipment life of 5 years and 7 percent interest.

9. Based on cost equations in the June 19, 2009 memorandum Revised Baseline Operating Costs for Existing 

HMIWI, in Docket ID No. EPA-HQ-OAR-2006-0534 for the HMIWI rule.

10. Average for various control devices (EPA, 2002).

11. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), subtracted cost of 

dry injection system, escalated to 2011 dollars, multiplied by retrofit cost factor, and rounded.

12. 15 percent of operator labor.

13. 100 percent of maintenance labor.

14. Based on conversion factor of 0.745 kW/hp.

15. Performed by maintenance personnel.

16. Maybe no need to replace.

17. 60 percent of labor and maintenance materials.

18. 2 percent of TCI.

19. 1 percent of TCI.
C-6

Table C-3. Model Costs to Retrofit ACI System to Existing Control Device

Parameters

MACT Floor Beyond the Floor

SCD LCD SCD LCD Footnotes

Design and operating parameters

Carbon injection rate (lb/MMft3) [CIR] 2 2 3 3 1

Injection blower fan power (hp) [Powerfan] 5.2 8.7 5.2 8.7 2,3

Projected equipment life (yrs) [n] 15 15 15 15 2

Interest rate (%) [i] 7 7 7 7

Calculated parameters

Carbon feed rate (lb/hr) [CFR] 2.8 4.6 4.2 7.0 4

Cost factors

Carbon unit cost ($/lb) [CC] 0.85 0.85 0.85 0.85 5

Escalation factor [EF] 1.78 1.78 1.78 1.78 2,6,7

Capital recovery factor [CRF] 0.1098 0.1098 0.1098 0.1098 2,8

Retrofit factor [RF] 1.15 1.15 1.15 1.15 2

Direct capital costs

Purchased equipment costs

Total equipment [TEC] (see Note) $24,294 $34,864 $24,294 $34,864 2,9

Sales tax $729 $1,046 $729 $1,046 2,10

Freight $1,215 $1,743 $1,215 $1,743 2,11

Purchased equipment with tax and freight $26,238 $37,653 $26,238 $37,653 2,12

Purchased equipment with escalation $46,784 $67,138 $46,784 $67,138 2,13

Purchased equipment with retrofit factor [PEC] $53,802 $77,209 $53,802 $77,209 2,14

Installation cost [IC] $16,141 $23,163 $16,141 $23,163 2,15

Total direct costs [TDC] $69,942 $100,371 $69,942 $100,371 2,16

Indirect capital costs

Engineering $10,760 $15,442 $10,760 $15,442 2,17

Construction and field expense $10,760 $15,442 $10,760 $15,442 2,17

Contractor fees $5,380 $7,721 $5,380 $7,721 2,18

Start-up $538 $772 $538 $772 2,19

Performance test $538 $772 $538 $772 2,19

Model study $1,076 $1,544 $1,076 $1,544 2,20

Contingencies $3,228 $4,633 $3,228 $4,633 2,21
C-7

Parameters

MACT Floor Beyond the Floor

SCD LCD SCD LCD Footnotes

Total indirect costs [TIC] $32,281 $46,325 $32,281 $46,325 2,22

Total capital cost

Total capital investment [TCI] $102,224 $146,697 $102,224 $146,697 2,23

Annual costs

Operating labor $6,895 $7,368 $6,895 $7,368 2,24

Supervisory labor $1,034 $1,105 $1,034 $1,105 2,25

Maintenance labor $11,378 $12,157 $11,378 $12,157 2,26

Maintenance materials $2,690 $3,860 $2,690 $3,860 2,27

Electricity cost $2,298 $4,108 $2,298 $4,108 2,28

Carbon cost $17,374 $30,498 $26,061 $46,410 2,29

Solid waste disposal cost $409 $718 $613 $1,092 2,30

Overhead $13,198 $14,694 $13,198 $14,694 2,31

Administrative charges $2,044 $2,934 $2,044 $2,934 2,32

Property tax $1,022 $1,467 $1,022 $1,467 2,33

Insurance $1,022 $1,467 $1,022 $1,467 2,33

Capital recovery $11,224 $16,107 $11,224 $16,107 2,34

Total annual cost $70,589 $96,482 $79,480 $112,768 2,35

Note: Total equipment includes storage silo, feed bin, gravimetric feeders, pneumatic conveyor, and injection ports.

Footnotes:

1. Thompson, 2013. Suggested carbon concentration of 2 lb/MMft3.

2. EPA, 2005, Appendix J.

3. Scaled HWC hp estimate using ratio of exhaust flow rates: (15 hp) x Q / (66,870.6 acfm).

4. Equal to CIR / 1E6 x exhaust flow x (60 min/hr).

5. Holloway, 2013a. Indicated carbon price would be $0.80 to $0.90/lb. Used average of $0.85/lb.

6. Escalating costs from 2004 (HWC) to 2011 (BSCP) using the following factors: (HWC escalation factor, 1.1319 x 1.064) x (BSCP escalation factor, 1.4805).

7. Chemical Engineering Plant Cost Index.

8. Equal to = [i x (1 + i)n

] / [(1 + i)n - 1], where i = 7 percent interest and n = 15-year equipment life.

9. Equal to 90,000 x (exhaust flow/150,000)0.7.

10. Equal to 0.03 x TEC.

11. Equal to 0.05 x TEC.
C-8

12. Equal to TEC + (sales tax) + (freight).

13. Equal to EF x (purchased equipment with tax and freight).

14. Equal to RF x (purchased equipment with escalation).

15. Equal to 0.3 x PEC.

16. Equal to PEC + IC.

17. Equal to 0.2 x PEC.

18. Equal to 0.1 x PEC.

19. Equal to 0.01 x PEC.

20. Equal to 0.02 x PEC.

21. Equal to 0.06 x PEC.

22. Equal to sum of indirect costs.

23. Equal to TDC + TIC.

24. Equal to (1 hr/d) x operating hr/yr / (24 hr/d) x operator wage rate ($/hr).

25. Equal to 0.15 x (operator labor cost).

26. Equal to (0.5 hr/shift) x (3 shifts/d) x operating hr/yr / (24 hr/d) x maintenance wage rate ($/hr).

27. Equal to 0.05 x PEC.

28. Equal to Powerfan / (1.34 hp/kW) / (0.9 Efficiencyfan) x operating hr/yr x electricity unit cost ($/kWh).

29. Equal to CFR x operating hr/yr x carbon unit cost ($/lb).

30. Equal to CFR x operating hr/yr / (2000 lb/ton) x waste disposal unit cost ($/ton).

31. Equal to 0.6 x (operating labor cost + maintenance cost).

32. Equal to 0.02 x TCI.

33. Equal to 0.01 x TCI.

34. Equal to CRF x TCI.

35. Equal to sum of annual costs.
Appendix D

Model Impacts Equations
D-2

Table D-1. Equations Used to Estimate Model Energy and Secondary Impacts

Parameters Value Notes, units, and equations

Energy impacts

Heat factors

Heat content of electricity 

(HCelec)

3,415 Btu/kWh

Heat rate

 Coal (HRcoal) 10,415 Btu/kWh

 Natural gas (HRgas) 8,185 Btu/kWh

 Nuclear power (HRnuclear) 10,452 Btu/kWh

 Renewable energy (HRrenew) 9,756 Btu/kWh

Percent of generation

Coal (% coal) 48% Used for solid fuel

Oil/natural gas (% gas) 18% Used for natural gas

Nuclear (% nuclear) 20% No secondary emissions estimated

Hydroelectric (% hydro) 7% No secondary emissions estimated

Renewable (% renew) 6% No secondary emissions estimated

Other (% other) 1% Used for natural gas (assumed equivalent)

Power plant efficiency (E)

Coal (Ecoal) 33% % = HCelec / HRcoal * 100

Natural gas/other (Egas) 42% % = HCelec / HRgas* 100

Nuclear (Enuclear) 33% % = HCelec / HRnuclear * 100

Renewable/hydroelectric (Erenew) 35% % = HCelec / HRrenew * 100

Average (Eavg) 35% % = (Ecoal x % coal) + (Egas x % gas/other) + (Enuclear x % 

nuclear) + (Erenew x % renew/hydro)

Energy impacts calculations

Electricity requirements model-specific kWh/yr = total hp x (0.745 kW/hp) x operating hr/yr

Energy impacts model-specific MMBtu/yr = (kWh/yr) x (HCelec) x (MMBtu/1E6 Btu) / Eavg

Secondary emissions

Emission factors, natural gas

Particulate matter/PM2.5 1.9 lb/MM ft3 natural gas

0.00186275 lb/MMBtu natural gas

Carbon monoxide 84 lb/MM ft3 natural gas

0.0824 lb/MMBtu natural gas

Nitrogen oxide 100 lb/MM ft3 natural gas

0.0980 lb/MMBtu natural gas

Sulfur dioxide 0.6 lb/MM ft3 natural gas

0.00059 lb/MMBtu natural gas

Emission factors, solid fuel

Particulate matter 0.03 lb/MMBtu solid, liquid, gaseous fuel

PM2.5 0.00957 lb/MMBtu solid, liquid, gaseous fuel

Carbon monoxide 0.19 lb/MMBtu bituminous coal

Nitrogen oxide 0.38 lb/MMBtu solid fuel

Sulfur dioxide 1.2 lb/MMBtu solid fuel
D-3

Parameters Value Notes, units, and equations

Secondary emissions calculation

Secondary emissions, for each 

pollutant

model-specific lb/yr = MMBtu/yr x [(lb/MMBtu natural gas) x (% 

gas/other) + (lb/MMBtu solid fuel) x (% coal)]

Solid waste and wastewater impacts

Solid waste impacts model-specific tpy = waste (lb/hr) x operating hr/yr / (2,000 lb/ton)

Wastewater impacts model-specific gpy = water usage (gpd) x operating hr/yr / (24 hr/d)

1. gpy = gallons per year; gpd = gallons per day.

2. Assume electricity generated using the above mix (from IPM Version 3.0 for the year 2015), as determined from 

Table 3-6 of Regulatory Impacts Analysis for the final Mercury and Air Toxics Standards. IPM = EPA Integrated 

Planning Model, which is a multi-regional, dynamic, deterministic linear programming model of the U.S. electric 

power sector that provides forecasts of least-cost capacity expansion, electricity dispatch, and emission control 

strategies for meeting energy demand and environmental, transmission, dispatch, and reliability constraints.

3. For natural gas, used PM, CO, NOX, and SO2 emission factors from AP-42 chapter on natural gas combustion.

Assumed 1,020 Btu/ft3 of natural gas in estimating PM, CO, NOX, and SO2 secondary emissions. Also assumed 

that 100% of PM is PM2.5, based on statement in AP-42 that PM from natural gas combustion is estimated to be 

less than 1 micron in size.

4. For solid fuel, used PM and SO2 emission limits for solid fuel-fired boilers from 2006 CFR edition of NSPS for 

electric utility plants (40 CFR part 60, subpart Da) and used NOX and CO emission factors from AP-42 chapter on

coal combustion (bituminous/subbituminous coal). The NOX emission factor was based on average of NOX

emission factors for PC dry-bottom wall-fired NSPS boilers burning bituminous (12 lb/ton) and subbituminous (7.4 

lb/ton) coal. Assumed 13,000 Btu/lb of coal in estimating NOX and CO secondary emissions. According to AP-42, 

the percentage of PM that is PM2.5 for dry-bottom coal-fired boilers is 29% with ESP, 53% with FF, and 6% if 

uncontrolled. Assumed 84% of utility boilers controlled with ESP and 14% with FF, leaving 2% uncontrolled, based 

on information from EPA document on control of emissions from coal-fired utility boilers.
Appendix E

Installation Model Impacts
E-2

Table E-1. Model Impacts of Installing New DIFF

Parameters SCD LCD

Control efficiency

HF 99.5% 99.5%

HCl 83.3% 83.3%

Cl2 89.3% 89.3%

Non-Hg HAP metals 94% 94%

PM 94% 94%

SO2 48.7% 48.7%

Parameters

Fan hp 150 190

Total hp for other motors 30 30

Waste, lb/hr 102.1 154.9

Emissions reductions, tpy

HF 15.1 34.6

HCl 1.72 3.94

Cl2 0.0789 0.181

Non-Hg HAP metals 0.0855 0.196

PM 7.78 17.8

SO2 40.2 92.1

Energy impacts, MMBtu/yr 9,620 12,563

Secondary air impacts, tpy

Particulate matter 0.0710 0.0927

PM2.5 0.0238 0.0311

Carbon monoxide 0.120 0.156

Nitrogen oxides 0.951 1.24

Sulfur dioxide 2.77 3.62

Solid waste impacts, tpy 372 604
E-3

Table E-2. Model Impacts of Installing/Retrofitting Fabric Filter

Parameters SCD LCD

Control efficiency

Non-Hg HAP metals 94% 94%

PM 94% 94%

Parameters

Fan hp 150 190

Total hp for other motors 30 30

Waste, lb/hr 2.1 4.6

Emissions reductions, tpy

Non-Hg HAP metals 0.0855 0.196

PM 7.78 17.8

Energy impacts, MMBtu/yr 9,620 12,563

Secondary air impacts, tpy

Particulate matter 0.0710 0.0927

PM2.5 0.0238 0.0311

Carbon monoxide 0.120 0.156

Nitrogen oxides 0.951 1.24

Sulfur dioxide 2.77 3.62

Solid waste impacts, tpy 7.78 17.8
E-4

Table E-3. Model Impacts of Installing New DLA

Parameters SCD LCD

Control efficiency

HF 95% 95%

HCl 30% 30%

Cl2 42% 42%

Non-Hg HAP metals 20% 20%

PM 20% 20%

SO2 12% 12%

Parameters

Fan hp 60 90

Total hp for other motors 10 40

Waste, lb/hr 83.8 117.3

Emissions reductions, tpy

HF 14.4 33.0

HCl 0.620 1.42

Cl2 0.0371 0.0850

Non-Hg HAP metals 0.0182 0.0417

PM 1.65 3.79

SO2 9.90 22.7

Energy impacts, MMBtu/yr 3,741 7,424

Secondary air impacts, tpy

Particulate matter 0.0276 0.0548

PM2.5 0.00925 0.0184

Carbon monoxide 0.0465 0.0923

Nitrogen oxides 0.370 0.734

Sulfur dioxide 1.08 2.14

Solid waste impacts, tpy 306 457
Appendix F

Retrofit/Replacement Model Impacts
F-2

Table F-1. Model Impacts of Retrofitting ACI System to Existing Control Device

Parameters

MACT Floor Beyond the Floor

SCD LCD SCD LCD

Parameters

Injection blower fan power, hp 5.2 8.7 5.2 8.7

Carbon feed rate, lb/hr 2.8 4.6 4.2 7.0

Mercury emissions reduction, tpy 0.00136 0.00311 0.00152 0.00347

Energy impacts, MMBtu/yr 309 553 309 553

Secondary air impacts, tpy

Particulate matter 0.00228 0.00408 0.00228 0.00408

PM2.5 0.000765 0.00137 0.000765 0.00137

Carbon monoxide 0.00385 0.00688 0.00385 0.00688

Nitrogen oxides 0.0306 0.0547 0.0306 0.0547

Sulfur dioxide 0.0891 0.159 0.0891 0.159

Solid waste impacts, tpy 10.2 17.9 15.3 27.3
F-3

Table F-2. Model Impacts of Replacing Dry Limestone Adsorber with New DIFF

Parameters

SCD LCD

DLA DIFF Increm. DLA DIFF Increm.

Control efficiency

HF 95% 99.5% 95% 99.5%

HCl 30% 83.3% 30% 83.3%

Cl2 42% 89.3% 42% 89.3%

Non-Hg HAP metals 20% 94% 20% 94%

PM 20% 94% 20% 94%

SO2 12% 48.7% 12% 48.7%

Parameters

Fan hp 60 150 90 190

Total hp for other motors 10 30 40 30

Waste, lb/hr 83.8 102.1 117.3 154.9

Emissions reductions, tpy

HF 14.4 15.1 0.683 33.0 34.6 1.56

HCl 0.620 1.72 1.10 1.42 3.94 2.52

Cl2 0.0371 0.0789 0.0418 0.0850 0.181 0.0958

Non-Hg HAP metals 0.0182 0.0855 0.0673 0.0417 0.196 0.154

PM 1.65 7.78 6.12 3.79 17.8 14.0

SO2 9.90 40.2 30.3 22.7 92.1 69.4

Energy impacts, MMBtu/yr 3,741 9,620 5,879 7,424 12,563 5,139

Secondary air impacts, tpy

Particulate matter 0.0276 0.0710 0.0434 0.0548 0.0927 0.0379

PM2.5 0.00925 0.0238 0.0145 0.0184 0.0311 0.0127

Carbon monoxide 0.0465 0.120 0.0731 0.0923 0.156 0.0639

Nitrogen oxides 0.370 0.951 0.581 0.734 1.242 0.508

Sulfur dioxide 1.08 2.77 1.69 2.14 3.62 1.48

Solid waste impacts, tpy 306 372 66.8 457 604 147
F-4

Table F-3. Model Impacts of Replacing Spray Dryer/ESP with New DIFF

Parameters

SCD LCD

SD/ESP1 DIFF Increm.2 SD/ESP1 DIFF Increm.

2

Parameters

Fan hp 125 250

Total hp for other motors 200 400

Water usage, gpd 6.25 12.5

Emissions reductions, tpy

HF -2.36 15.1 17.5 -2.72 34.6 37.3

HCl -2.21 1.72 3.93 -4.41 3.94 8.35

Cl2 -0.455 0.0789 0.534 -0.958 0.181 1.14

Non-Hg HAP metals 0.0855 0.0855 0.00 0.196 0.196 0.00

PM 7.78 7.78 0.00 17.8 17.8 0.00

SO2 39.6 40.2 0.606 90.7 92.1 1.39

Energy impacts, MMBtu/yr 17,369 9,620 -7,749 37,118 12,563 -24,555

Secondary air impacts, tpy

Particulate matter 0.128 0.0710 -0.0572 0.274 0.0927 -0.181

PM2.5 0.0430 0.0238 -0.0192 0.0918 0.0311 -0.0607

Carbon monoxide 0.216 0.120 -0.0964 0.462 0.156 -0.305

Nitrogen oxides 1.72 0.951 -0.766 3.67 1.242 -2.43

Sulfur dioxide 5.00 2.77 -2.23 10.7 3.62 -7.07

Solid waste impacts, tpy 365 372 7.22 591 604 12.9

Wastewater impacts, gpy 1,901 0 -1,901 4,063 0 -4,063

1 The negative emission reduction estimates for the SD/ESP are a result of the small dataset for kilns with this type of 

control and the lack of control efficiency information for SD/ESP. 2 A negative increase in impacts would be equivalent to a reduction in impacts.
F-5

Table F-4. Model Impacts of Replacing Existing DIFF with New, More Efficient DIFF

Parameters

SCD LCD

Existing 

DIFF

New 

DIFF Increm.

Existing

DIFF

New 

DIFF Increm.

Control efficiency

HF 98% 99.5% 98% 99.5%

HCl 82% 83.3% 82% 83.3%

Cl2 88% 89.3% 88% 89.3%

Non-Hg HAP metals 72% 94% 72% 94%

PM 72% 94% 72% 94%

SO2 48% 48.7% 48% 48.7%

Parameters

Fan hp 150 150 190 190

Total hp for other motors 30 30 30 30

Waste, lb/hr 100.1 102.1 151.6 154.9

Emissions reductions, tpy

HF 14.9 15.1 0.228 34.0 34.6 0.521

HCl 1.69 1.72 0.0259 3.88 3.94 0.0594

Cl2 0.0778 0.0789 0.00119 0.178 0.181 0.00272

Non-Hg HAP metals 0.0655 0.0855 0.0200 0.150 0.196 0.0458

PM 5.96 7.78 1.82 13.6 17.8 4.17

SO2 39.6 40.2 0.606 90.7 92.1 1.39

Energy impacts, MMBtu/yr 9,620 9,620 0 12,563 12,563 0

Secondary air impacts, tpy

Particulate matter 0.0710 0.0710 0 0.0927 0.0927 0

PM2.5 0.0238 0.0238 0 0.0311 0.0311 0

Carbon monoxide 0.120 0.120 0 0.156 0.156 0

Nitrogen oxides 0.951 0.951 0 1.242 1.242 0

Sulfur dioxide 2.77 2.77 0 3.62 3.62 0

Solid waste impacts, tpy 365 372 7.22 591 604 12.9