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MEMORANDUM

TO: Toni Jones, U.S. Environmental Protection Agency

FROM: Eastern Research Group, Inc.

DATE: November 21, 2011

SUBJECT: Summary of the Secondary Impacts of Control Options for CISWI Standards for 

Reconsideration Proposal

1.0 PURPOSE

This memorandum summarizes the secondary impacts associated with control devices used to 

comply with the proposed emission standards for Commercial and Industrial Solid Waste 

Incineration (CISWI) units. Secondary impacts result from the consumption of fuel, water, and 

electricity and generation of solid wastes by control devices. Section 2.0 provides a background 

for the standards, Section 3.0 presents the secondary impact estimates associated with control 

devices necessary for all units to comply with the standards, and Section 4.0 presents the air 

emission estimates associated with the secondary impacts. 

2.0 BACKGROUND

The U.S. Environmental Protection Agency, under section 129 of the Clean Air Act (CAA), is 

required to regulate emissions of the following nine pollutants from CISWI units: hydrogen 

chloride (HCl), carbon monoxide (CO), lead (Pb), cadmium (Cd), mercury (Hg), particulate 

matter (PM), dioxins/furans (PCDD/PCDF), nitrogen oxides (NOx), and sulfur dioxide (SO2). 

On December 1, 2000, the EPA established new source performance standards (NSPS) and 

emission guidelines (EG) for CISWI units under Sections 111 and 129 of the CAA. In 2001, 

EPA was granted a petition for reconsideration regarding the definitions of “commercial and 

industrial waste” and “commercial and industrial solid waste incineration unit.” Also in 2001, 

the United States Court of Appeals for the District of Columbia Circuit granted the EPA’s 

voluntary remand, without vacatur, of the 2000 rule. In 2005, the EPA proposed and finalized 

the CISWI definition rule which revised the definitions of “solid waste,” “commercial and 

industrial waste,” and “commercial and industrial waste incineration unit.” In 2007, the United 

States Court of Appeals for the District of Columbia Circuit vacated and remanded the 2005 

commercial and industrial solid waste incineration definition rule.

On March 21, 2011, the EPA promulgated revised NSPS and EG as its response to the voluntary

remand that was granted in 2001 and the vacatur and remand of the commercial and industrial 

solid waste incineration definition rule in 2007. In addition, the standards re-development 

included the 5-year technology review of the new source performance standards and emission 

guidelines required under Section 129. Following that action, the Administrator received 

petition[s] for reconsideration and identified some issues that warranted further opportunity for 

public comment. In addition, data were received that enabled the EPA to revise the CISWI
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inventory of waste-burning kilns and energy recovery units to more accurately reflect the 

definition of non-hazardous secondary materials.

The EPA has developed maximum achievable control technology (MACT) floors and emission 

limits in the development of the proposed standards. The development of the proposed emission 

limits used to determine these options is discussed in more detail in a separate memorandum.1 

3.0 SUMMARY OF SECONDARY IMPACT ESTIMATES 

To comply with the final standards, facilities may need to install the following types of controls 

on CISWI units:

 Wet scrubbers (WS) to reduce HCl and SO2 emissions, 

 Fabric filters (FF) to reduce Cd, Pb, and PM emissions,

 Duct sorbent injection/fabric filter (DIFF) systems to reduce HCl and SO2 emissions,

 Regenerative Thermal Oxidizers (RTO) to reduce CO emissions,

 Selective non-catalytic reduction (SNCR) to reduce NOx emissions,

 Activated carbon injection (ACI) systems to reduce PCDD/PCDF and Hg emissions, and

 Afterburner retrofits, tune-ups, or oxidation catalysts to reduce CO emissions.

Additional electricity is required to operate the pumps and fans associated with wet scrubbers, 

FF, DIFF, and SNCR systems. Also, water and subsequent wastewater disposal are required to 

operate wet scrubbers, DIFF and SNCR systems. Activated carbon injection systems require 

activated carbon as well as a method to dispose of the dust produced from the ACI system. 

RTOs require natural gas to oxidize the carbon monoxide in the flue gas. Although afterburners 

require natural gas to operate, these are primarily replacing existing afterburners, so the change 

in natural gas consumption may be minimal, and we do not have the data to be able to estimate 

this change.

The algorithms used in the cost analysis provide annual cost estimates for electricity, water, and 

carbon requirements as itemized components of the annual costs for the control device.2 These 

cost elements for the control devices anticipated to be installed to comply with the final 

standards were then summed up to provide an estimate of the overall costs of electricity, water 

and activated carbon. To estimate the secondary impact components (e.g., electricity, water, and 

dust from carbon), the itemized annual cost of each component was divided by the unit price of 

the component utilized by the algorithm. To estimate the additional annual fuel requirements for 

each combustion unit operating an RTO the annual operating hours were multiplied by the 

natural gas fuel requirement.

Two control scenarios were considered for the proposed standards: 

 Compliance by additional control only, and

 Compliance or choose another method of disposal, depending on which cost was lowest.

These scenarios are described in sections 3.1 and 3.2, respectively. 
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3.1 Compliance by Additional Control Only

In the first scenario, each CISWI unit in all subcategories complies with the proposed MACT 

floor standards by installing the anticipated control devices and associated monitoring 

equipment. 

Table 3-1 shows the estimated values for secondary impacts, by subcategory, for the “All units 

comply” scenario.

TABLE 3-1. Secondary Impacts for MACT Compliance 

All units comply

Subcategory

Electricity 

Required 

(MWh/yr)

Water Required 

(gal/yr)

Activated 

Carbon 

Required 

(ton/yr)

Dust 

Produced 

(ton/yr)

Supplemental 

Fuel 

Requirements 

(MMft3/yr)

ERU - Liquid/Gas 5,637 21,303,000 0 308 -

ERU - Solids 187,499 90,042,168,599 4,424 16,721 -

Incinerators 7,725 102,581,104 235 335 -

Small, remote 140 0 5 10 -

Kilns 48,624 424,226,569 5,328 5,450 1,288

Totals 249,626 90,590,279,272 9,993 22,824 1,288

3.2 Compliance or Alternative Method of Disposal

The second scenario entails a situation where facilities considered alternative disposal options 

and, where the alternative disposal methods are less expensive than adding control devices to 

comply with the standards, would instead cease burning waste and use alternative disposal 

methods. In addition to the electricity, water, and activated carbon requirements for those 

facilities that choose to add control devices to comply with the standards, secondary impacts also 

occur when alternative waste-handling methods are used. For the majority of incinerators, it 

would be less expensive to send waste to a landfill than to comply with the proposed emission 

limits (i.e., facilities would choose to shut down CISWI units). According to our estimates based 

on unit capacities and annual operating hours, this would result in approximately 110,417 tons 

per year of additional waste being sent to landfills. This would also result in subsequent landfill 

gas emissions from decomposition of this waste, which would likely be sent to a landfill gas 

flare. This gas flaring would result in emissions of NOx and CO, with some SO2, PM, and small 

amounts of mercury also being emitted. Further details on landfill emissions can be found in a 

separate memorandum.3 For small, remote units, it was determined that it is generally less 

expensive for facilities to segregate their waste and divert the nonferrous metal and chlorinated plastic to 

a landfill than to landfill all of their waste. In this case, the landfilled material is considered nondigestable and will not contribute significantly to landfill emissions. While not quantified in our 

analysis, there are also likely to be secondary emissions associated with the transport of the 

waste to a landfill site. These emissions would be site-specific and depend primarily on the 

number of trips, type of vehicle, and distance traveled necessary to transport the waste to the 

landfill. 
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Table 3-2 shows the estimated values for secondary impacts resulting from each facility

choosing the lowest-cost option for its units. Details regarding the unit-specific, lowest-cost 

options can be found in the compliance cost memorandum.2

TABLE 3-2. Secondary Impacts for MACT Compliance for Lowest Cost Options

Lowest Cost Option

Subcategory

Electricity 

Required 

(MWh/yr)

Water 

Required 

(gal/yr)

Activated 

Carbon 

Required 

(ton/yr)

Dust 

Produced 

(ton/yr)

Supplemental 

Fuel 

Requirements 

(ft3/yr)

Annual Waste 

Diverted to 

Landfill 

(ton/yr)

ERU - Liquid/Gas 5,637 21,303,000 0 308 -

ERU - Solids 187,499 90,042,168,599 4,424 16,721 -

Incinerators 494 8,178 67 68 - 110,417

Small, remote 29 0 1 3 -

Kilns 48,624 424,226,569 5,328 5,450 1,288

Totals 242,283 90,487,706,345 9,820 22,549 1,288 110,417

4.0 SUMMARY OF SECONDARY IMPACT EMISSION ESTIMATES

Emission factors from EPA’s eGRID4database were used to calculate emissions resulting from 

the electricity required for additional control devices, and emission factors from EPA’s AP-42 

emission factor document5 were used to calculate emissions resulting from the combustion of 

additional fuel for RTOs. Increased electrical use from the control options will require 

additional fuel to be burned in power plants, resulting in emissions of CO2 and criteria pollutants, 

such as SO2, NOx, and CO. Emissions of these pollutants (caused by increase in electricity) were 

estimated using EPA’s eGRID database.4 The eGRID database summarizes emissions of criteria 

pollutants on a per electrical usage basis (lb emitted per MW-hr), on a national average or state 

average basis. For this analysis the national average was used. To estimate emissions from 

combustion of natural gas, emission factors from EPA’s AP-42 emission factor document were 

used.5 

Tables 4-1 summarizes the resulting emissions of CO2, CO, NOx, and SO2 from combustion of 

natural gas supplemental fuel and increase electricity usage for the control options analyzed for 

existing sources. Table 4-2 shows the resulting emissions of CO2, CO, NOx, and SO2 from 

combustion of natural gas supplemental fuel and increase electricity usage for the lowest cost 

options analyzed for existing sources.

The Appendix to the secondary impacts analysis contains the spreadsheets supporting these 

summaries. 
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TABLE 4-1. Secondary Emission Impacts for MACT Compliance

Subcategory

Electricity Requirements and 

Emissions (tons/yr)

Supplemental Fuel Requirements and 

Emissions (tons/yr) Total Secondary Emissions (tons/yr)

Mwhr/yrCO2

Emitted

NOx 

Emitted

SO2

Emitted

Million 

ft3

Natural 

Gas/ yr

CO2

Emitted

CO 

Emitted

NOx 

Emitted

CO2

Emitted

CO 

Emitted

NOx 

Emitted

SO2

Emitted

ERU - Liquid/Gas 5,637 3,747 5.46 14.82 - - - - 3,747 - 5.46 14.82

ERU - Solids 187,499 124,626 181.56 493.02 - - - -

124,626

- 181.56 493.02

Incinerators 7,725 5,135 7.48 20.31 - - - - 5,135 - 7.48 20.31

Small, remote 140 93 0.14 0.37 - - - - 93 - 0.14 0.37

Kilns 48,624 32,319 47.08 127.85 1,288 77,287 54.1 64.4 109,606 54.1 111.49 127.85

Totals 249,626 165,920 242 656 1,288 77,287 54.1 64.4 243,207 54.1 306 656

a. National emission factors from Egrid4for EGUs.

b. Natural gas emission factors from AP-42.5

TABLE 4-2. Secondary Emission Impacts for Lowest Cost Option

Subcategory

Electricity Requirements and 

Emissions (tons/yr)

Supplemental Fuel Requirements and 

Emissions (tons/yr) Total Secondary Emissions (tons/yr)

Mwhr/yrCO2

Emitted

NOx 

Emitted

SO2

Emitted

Million 

ft3

Natural 

Gas/ yr

CO2

Emitted

CO 

Emitted

NOx 

Emitted

CO2

Emitted

CO 

Emitted

NOx 

Emitted

SO2

Emitted

ERU - Liquid/Gas 5,637 3,747 5.46 14.82 - - - - 3,747 - 5.46 14.82

ERU - Solids 187,499 124,626 181.56 493.02 - - - - 124,626 - 181.56 493.02

Incinerators 494 328 0.48 1.30 - - - - 328 - 0.48 1.30

Small, remote 29 19 0.03 0.08 - - - - 19 - 0.03 0.08

Kilns 48,624 32,319 47.08 127.85 1,288 77,287 54.1 64.4 109,606 54.1 111.49 127.85

Totals 242,283 161,039 235 637 1,288 77,287 54.1 64.4 238,327 54.1 299 637

a. National emission factors from Egrid4for EGUs.

b. Natural gas emission factors from AP-42.5
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REFERENCES

1. “CISWI Emission Limit Calculations for Existing and New Sources for 

Reconsideration Proposal” Memorandum from Eastern Research Group, Inc. to Toni 

Jones, U.S. Environmental Protection Agency. November 3, 2011.

2. “Reconsideration Proposal Compliance Cost Analyses for CISWI Units” 

Memorandum from Eastern Research Group, Inc. to Toni Jones, U.S. Environmental 

Protection Agency. November 20, 2011.

3. “Reconsideration Proposal Baseline Emissions and Emissions Reductions Estimates 

for Existing CISWI Units” Memorandum from Eastern Research Group, Inc. to Toni 

Jones, U.S. Environmental Protection Agency. November 20, 2011.

4. EPA eGRID database eGRID2007 Version 1.1. Year 2005 summary tables located at 

www.epa.gov/cleanenergy/documents/egridzips/eGRID2007V1_1_year05_SummaryTab

les.pdf

5. U.S. Environmental Protection Agency, 1995. Compilation of Air Pollutant Emission 

Factors (AP-42), Fifth Edition, Volume 1: Stationary and Point Sources, Chapter 1: 

External Combustion Sources.