1



### MEMORANDUM

TO: Amy Hambrick, U.S. EPA, Sector Policies and Programs D ivision/Natural

Resources and Commerce Group

FROM: Amber Allen and Danny Greene; Eastern Research Group, In c.

DATE: June 2010

SUBJECT: Secondary Impacts of Control Options for the Sewage Sludge Incineration Source

Category

1.0 INTRODUCTION

This memorandum presents the secondary impacts associa ted with control devices used to comply with the proposed standards for existing and new sewage sludge incineration (SSI) units. Secondary impacts result from the consumption o f fuel, water, and electricity and generation of solid wastes by control devices.

Section 2.0 presents the background for the proposed standar ds. Section 3.0 presents the secondary impact estimates associated with control devic es necessary for two scenarios: (1) all SSI units comply with proposed standards, and (2) only large entities comply with the proposed

standards and small entities divert their waste to land fills. This memorandum focuses only on secondary impacts associated with control devices. Additi onal air impacts resulting from small entities choosing to landfill are discussed in a separa te memorandum. 1 

### Section 4.0 summarizes the estimated secondary impacts that would result from t he compliance of new units expected to come online in the next five years. Section 5.0 summariz es the emissions resulting from increased fuel and electricity requirements for the cont rol options.

2.0 BACKGROUND

The U.S. Environmental Protection Agency (EPA), under sec tion 129 of the Clean Air Act (CAA), is required to regulate emissions of 9 polluta nts and opacity from existing sewage sludge incineration (SSI) units. The 9 pollutants are: hy drogen chloride (HCl), carbon monoxide (CO), lead (Pb), cadmium (Cd), mercury (Hg), part iculate matter (PM), dioxins/furans (CDD/CDF), nitrogen oxides (NO

x 

### ), and sulfur dioxide (SO 2 

### ). The CAA requires EPA to determine the maximum achievable control technology (MACT ) for each category or subcategory of sources. The SSI source category comprise s two subcategories: multiple hearth incineration units (MH) and fluidized bed incineration units ( FB). To determine the MACT for each subcategory, EPA must first determine the minimum stringency “floor” requirements. Development of the MACT floors for SSI units is descri bed in a separate memorandum. 2 

### An analysis of beyond-the-floor options was also conducte d, in which three different control options

were evaluated.2



### • Option 1 is the MACT floor level of control for the t wo subcategories developed for existing SSI units, MH units and FB units.

• Option 2 is the same as Option 1, with the addition of ac tivated carbon injection (ACI) for additional Hg and CDD/CDF emissions reduction from MH units.

• Option 3 is the same as Option 2, with the addition of an afterburner on all MH units

for additional control of CO.

3.0 SECONDARY IMPACT ESTIMATES FOR EXISTING UNITS

To comply with the control options, facilities may n eed to install the following types of

control devices on SSI units:

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

• Packed-bed scrubbers (PBS) to reduce HCl and SO 2 

### emissions,

• ACI systems to reduce CDD/CDF and Hg emissions, and

• Afterburners (AB) to reduce CO and organic compound emissions

.

Electricity is required to operate the pumps and fans ass ociated with FF and PBS systems. Also, water and subsequent wastewater disposal are required to operate PBS systems. Fabric filter and ACI systems require a method to dispo se of the dust produced from the systems. Additionally, ACI requires the use of activated carbon. Supplemental fuel (i.e., natural gas) is required to operate afterburners for MH SSI units.

Table 3-1 shows, for each of the control options, the estimated secondary impacts for the FB and MH subcategories for the case where all entitie s comply with the control option. Table 3- 2 shows, for each of the control options, the estima ted secondary impacts for the case where small entities landfill and large entities comply.

The algorithms used in the cost analysis provide annual cos t estimates for electricity, water, carbon requirements, and supplemental fuel as item ized components of the annual costs

for the control device. 1 

### These cost elements for the control devices antici pated to be installed to comply with the proposed standards were then summed up to pr ovide an estimate of the overall costs of electricity, water, activated carbon, and su pplemental fuel. To estimate the secondary impact components (e.g., electricity, water, dust), the itemized annual cost of each component was divided by the unit price of the component used by the al gorithm.3 

### Table 3-1. Secondary Impacts for Control Options: All Unit s Comply

Control Option

Subcategory Controls Required for Compliance Electricity

Required (MW

hr/yr) Water

Required (gal/yr) Activated

Carbon Required (ton/yr) Dust

Produced (ton/yr) Supplemental

Fuel (ft 3 natural gas/yr)

FB units FF, PB, ACI 13,750 31,983,667 1,711 1,762 -

MH units FF, PB, ACI 20,088 314,409,712 35 347 - Option 1

Total FF, PB, ACI 33,839 346,393,379 1745 2109 -

FB FF, PB, ACI 13,750 31,983,667 1,711 1,762 -

MH FF, PB, ACI 20,088 314,409,712 9,725 10,037 - Option 2

Total FF, PB, ACI 33,839 346,393,379 11,436 11,799 -

FB FF, PB, ACI 13,750 31,983,667 1,711 1,762 -

MH FF, PB, ACI,

AB 20,088 314,409,712 9,725 10,037 1,686,090,925 Option 3

Total FF, PB, ACI,

AB 33,839 346,393,379 11,436 11,799 1,686,090,925



### Table 3-2. Secondary Impacts for Control Options: Small Ent ities Landfill

Control Option

Subcategory Controls Required for Compliance Electricity

Required (MW

hr/yr) Water

Required (gal/yr) Activated

Carbon Required (ton/yr) Dust

Produced (ton/yr) Supplemental

Fuel (ft 3 natural gas/yr)

FB units FF, PB, ACI 10,662 21,432,013 1,381 1,421 -

MH units FF, PB, ACI 18,548 297,979,345 35 319 - Option 1

Total FF, PB, ACI 29210 319,411,358 1,416 1,740 -

FB FF, PB, ACI 10,662 21,432,013 1,381 1,421 -

MH FF, PB, ACI 18,548 297,979,345 8,674 8,958 - Option 2

Total FF, PB, ACI 29210 319,411,358 10,055 10,379 -

FB FF, PB, ACI 10,662 21,432,013 1,381 1,421 -

MH FF, PB, ACI,

AB 18,548 297,979,345 8,674 8,958 1,550,033,242 Option 3

Total FF, PB, ACI,

AB 29210 319,411,358 10,055 10,379 1,550,033,2424



### 4.0 SECONDARY IMPACT ESTIMATES FOR NEW UNITS As discussed in the new source analysis memorandum, E PA expects that two new FB units would come online in the next five years 4 

### . Estimations of the secondary impacts resulting from the pollution controls implemented for these units were calculated using the same methodology described for existing units in Section 3.0.

Table 4-1 shows the estimated values for secondary impact s for the two new FB units.

Table 4-1. Secondary Impacts: New Units

Subcategory Controls

Required for Compliance Electricity

Required (MW

hr/yr) Water

Required (gal/yr) Activated

Carbon Required (ton/yr) Dust

Produced (ton/yr) Supplemental

Fuel (mmcf natural gas/yr)

New Units FF, PBS,

ACI, AB 1,348 18,267,411 97 100 25



### 5.0 SECONDARY AIR POLLUTANT IMPACTS

Emission factors from EPA’s Egrid 5 

### database were used to calculate emissions resulting from the electricity required for additional control de vices, and emission factors from EPA’s AP42 emission factor document 6 

### were used to calculate emissions resulting from the com bustion of

additional fuel for afterburners. Increased electrical use from the control options will require additional fuel to be burned in power plants, resulting in em issions of CO 2 

### and criteria pollutants,

such as SO 2 

### , NO

x 

### , and CO. Emissions of these pollutants (caused by increas e in electricity) were estimated using EPA’s Egrid database. 5 

### The Egrid database summarizes emissions of criteria pollutants on a per electrical usage basis (lb emitted pe r MW-hr), on a national average or state average basis. For this analysis the national average was used. Option 3 also requires afterburners to be applied to all MH units, resulting in supp lemental fuel requirements, such as natural gas, to run the afterburner. The afterburner algo rithm indicates the amount of fuel needed by each unit. To estimate emissions from combu stion of natural gas, emission factors

from EPA’s AP-42 emission factor document were used. 6 

### Tables 5-1 summarizes the resulting

emissions of CO 2 

### , CO, NO

x 

### , and SO 2 

### from combustion of natural gas supplemental fuel and increase electricity usage for the three control option s analyzed for existing sources. Table 5-2 shows the results for new sources, and table 5-3 shows re sults for combined existing and new sources. Table 5-4 shows the Egrid and AP-42 emission facto rs used for the calculations.5Table 5-1. Secondary Air Pollutant Impacts: Existing UnitsAll Units ComplyElectricity Requirements and Emissions(tons/yr)*Supplemental Fuel Requirements and Emissions(tons/yr)*Total Secondary Emissions(tons/yr)OptionMWhper yrCO2EmittedNOxEmittedSO2Emittedft3Natural Gasper yrCO2EmittedCOEmittedNOxEmittedCO2EmittedCOEmittedNOxEmittedSO2Emitted1 33,83922,500 32.8 89.0- - - -22,500- 32.8 89.02 33,83922,500 32.8 89.0- - - -22,500- 32.8 89.03 33,83922,500 32.8 89.01,686,000,000 101,200 70.8 84.3 123,700 70.8 117.1 89.0Small Units LandfillElectricity Requirements and Emissions(tons/yr)*Supplemental Fuel Requirements and Emissions(tons/yr)*Total Secondary Emissions (tons/yr)OptionMWhper yrCO2EmittedNOxEmittedSO2Emittedft3Natural Gasper yrCO2EmittedCOEmittedNOxEmittedCO2EmittedCOEmittedNOxEmittedSO2Emitted1 29,210 19,400 28.3 76.8 - - - - 19,400 - 28.3 76.82 29,210 19,400 28.3 76.8 - - - - 19,400 - 28.3 76.83 29,210 19,400 28.3 76.8 1,550,000,000 93,000 65.1 77.5 112,400 65.1 105.8 76.8*Emissions estimated based on emission factors listed inTable 5-4.6Table 5-2. Secondary Air Pollutant Impacts: New UnitsElectricity Requirements and Emissions(tons/yr)*Supplemental Fuel Requirements and Emissions(tons/yr)*Total Secondary Emissions (tons/yr)MWh per yrCO2EmittedNOxEmittedSO2Emittedft3Natural Gasper yrCO2EmittedCOEmittedNOxEmittedCO2EmittedCOEmittedNOxEmittedSO2Emitted1,348 896 1.31 3.54 24,514,485 1,470 1.03 1.23 2,370 1.03 2.53 3.54*Emissions estimated based on emission factors listed inTable 5-4.Table 5-3. Secondary Air Pollutant Impacts: Combined Existing and New UnitsTotal Secondary Emissions (tons/yr)All Units ComplySmall Units LandfillOptionCO2EmittedCOEmittedNOxEmittedSO2EmittedCO2EmittedCOEmittedNOxEmittedSO2Emitted1 24,9001.03 35.3 92.521,7821.03 30.8 80.32 24,9001.03 35.3 92.521,7821.03 30.8 80.33 126,00071.8 119.6 92.5114,78466.1 108.3 80.3Table 5-4. Emission FactorsElectricityaNatural GasbPollutant(lb/MWh)(lb/106scf)(lb/ft3)(ton/ft3)CO2 1,329 120,000 0.12 0.00006CO - 84 8E-05 4.2E-08NOX1.9366 100 0.0001 5E-08SO2 5.2589 - - -a. National emission factors from Egrid5for EGUs.b. Natural gas emission factors from AP-42.67



### REFERENCES

1. Cost and Emission Reduction of the MACT Floor Level of Control. Memorandum from Amber Allen and Roy Oommen, Eastern Research Group, Inc. to Amy Hambrick, U.S. Environmental Protection Agency. June 2010.

2. MACT Floor Analysis for the Sewage Sludge Incinerator Source Category. Memorandum from Roy Oommen, Eastern Research Group, In c. to Amy Hambrick, U.S. Environmental Protection Agency. June 2010.

3. Analysis of Beyond the Maximum Achievable Control Techn ology (MACT) Floor Controls for Existing SSI Units. Memorandum from Roy O ommen, Eastern Research Group, Inc. to Amy Hambrick, U.S. Environmental Protect ion Agency. August 2010.

4. Estimation of Impacts for New Units Constructed Within Five Years After Promulgation of the SSI NSPS. Memorandum from Roy Oommen, Easter n Research Group, Inc. to Amy Hambrick, U.S. Environmental Protection Agency. June 2010.

5. EPA eGRID database eGRID2007 Version 1.1. Year 2005 summary tables located at www.epa.gov/cleanenergy/documents/egridzips/eGRID2007V1_1_year05_S ummaryTab les.pdf

6. U.S. Environmental Protection Agency, 1995. Compilation o f Air Pollutant Emission Factors (AP-42), Fifth Edition, Volume 1: Stationary a nd Point Sources, Chapter 1:

External Combustion Sources.