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Updated MSW Landfill Emission Factors for RTR Risk Modeling

In order to conduct modeling required for the residual risk and technology review (RTR) of the Municipal Solid Waste (MSW) Landfills National Emission Standards for Hazardous Air Pollutants (NESHAP), the EPA has developed MSW landfill emission factors specifically for the RTR. These factors are based on the data originally used in the 2008 Draft AP-42 for this source category in addition to the data submitted in response to the 2008 Draft AP-42. Overall, including the original data and additional data submissions, test reports were available for landfills in 37 different states. All non-detect data was removed then to remove outliers, data that was two standard deviations above or below the mean of each HAP was removed. Each HAP’s data was then averaged to develop the emission factor.

             Municipal Solid Waste Landfill Emission Factors for the Residual Risk and Technology Review of Subpart AAAA (Corrected for Air Infiltration)

Compound

CAS Number

Number of Test Reports

Mean (ppm)

1,1,2,2-Tetrachloroethane

79345

17

3.65E-01

1,1,2-Trichloroethane

79005

4

1.19E-01

1,2,4-Trichlorobenzene

120821

8

3.02E-02

1,3-Butadiene

106990

6

1.77E-01

1,3-Dichloropropene

542756

10

5.73E-03

1,4-Dichlorobenzene

106467

116

9.30E-01

2,2,4-Trimethylpentane

540841

11

7.03E-01

Acetaldehyde

75070

5

7.74E-02

Acetonitrile

75058

16

3.85E-01

Acrylonitrile

107131

2

6.29E-02

Allyl Chloride

107051

1

4.08E-03

Benzene

71432

131

1.70E+00

Benzyl Chloride

100447

4

1.16E-02

Bromoform

75252

5

1.02E-02

Carbon Disulfide

75150

88

1.72E-01

Carbon Tetrachloride

56235

6

1.28E-02

Carbonyl Sulfide

463581

86

2.31E-01

Chlorobenzene

108907

93

1.82E-01

Chloroform

67663

18

3.27E-01

Cumene

98828

7

4.51E-01

Ethyl Benzene

100414

55

4.12E+00

Ethyl Chloride

75003

33

1.66E+00

Ethylene Dibromide

106934

4

8.20E-03

Ethylene Dichloride

107062

77

2.09E-01

Ethylidene Dichloride (1,1-Dichloroethane)

75343

99

1.11E+00

Formaldehyde

50000

5

1.17E-02

Hexachlorobutadiene

87683

3

4.71E-03

Hexane

110543

48

1.64E+01

Methanol

67561

6

1.64E+01

Methyl Bromide

74839

7

1.28E-02

Methyl Chloride

74873

15

1.46E-01

Methyl Chloroform

71556

62

1.69E-01

Methyl Isobutyl Ketone

108101

27

9.22E-01

Methyl Tert-Butyl Ether

1634044

14

6.68E-01

Methylene Chloride

75092

121

5.05E+00

m-Xylene

108383

19

1.47E+01

Naphthalene

91203

4

1.07E-01

o-Xylene

95476

110

3.14E+00

p-Dioxane

123911

2

5.73E-02

Propylene Dichloride

78875

7

5.70E-03

Styrene

100425

31

4.23E-01

Tetrachloroethylene

127184

88

1.42E+00

Toluene

108883

134

2.61E+01

Trichloroethylene

79016

128

7.71E-01

Vinyl Acetate

108054

7

8.08E-02

Vinyl Bromide

593602

1

3.06E-03

Vinyl Chloride

75014

124

1.21E+00

Vinylidene Chloride

75354

67

1.08E-01

Xylenes (Mixture of o, m, and p Isomers)

1330207

139

1.07E+01