ASARCO Hayden - revised visibility benefit from lower control efficiency, using scaling

A. Scale deciview benefit directly, in proportion to emission change

B. Scale deciview-implied extinction in proportion to emissions, account for background in computing deciviews

Natural background deciviews for best days from Guidance for Estimating Natural Visibility Conditions Under the Regional Ha

deciviews = dv = 10*ln(bext/10) (bext = extinction, proportional to emissions)

CALPUFF delta deciviews = ddv = dv(source + background) - dv(background) = dv(bs + bg) - dv(bg)

 ddv = 10*ln( (bs + bg)/10 ) - 10*ln(bg/10) = 10*ln(bs/bg + 1)

Invert this to get source extinction bs implied from ddv and natural background bg: bs = bg * ( expt(ddv/10) - 1 )

SO2 emissions, lb/day

Bag House 

(base)

Acid Plant 

(ctrl2)

Emission source 15% 99.81%

14,294 14,294

146,947 328

9,692 9,692

Total 170,933 24,314

Reduction rel. to base 146,619

Overall control efficiency rel. to base 85.8%

emissions ratio, ctrl2 rev. / ctrl2

reductions ratio, ctrl2 rev. / ctrl2

Stack parameters from ASARCO July 2013 (CALPUFF "base", "ctrl2")

EPA modeling results from NPR

Delta deciviews Deciviews

Class I Area

base: Base 

case, 

parms1

ctrl2: new 

acid plant, 

parms1

original 

benefit

A. revised 

benefit, 

direct 

scaling

benefit 

shrinkage

natural 

background

Chiricahua NM 1.049 0.155 0.894 0.880 1.5% 1.80

Chiricahua Wild. 1.012 0.145 0.867 0.854 1.5% 1.79

Galiuro Wild. 1.729 0.279 1.450 1.428 1.5% 1.76

Gila Wild. 0.692 0.093 0.599 0.590 1.5% 1.83

Mazatzal Wild. 0.877 0.128 0.749 0.737 1.5% 1.79

Mount Baldy Wild. 0.655 0.094 0.561 0.552 1.5% 1.83

Petrified Forest NP 0.702 0.097 0.605 0.596 1.5% 1.85

Pine Mountain Wild. 0.667 0.098 0.569 0.560 1.5% 1.80

Saguaro NP 1.382 0.201 1.181 1.163 1.5% 1.72

Sierra Ancha Wild. 1.087 0.153 0.934 0.920 1.5% 1.80

Superstition Wild. 1.736 0.268 1.468 1.445 1.5% 1.76

Sycamore Canyon Wild. 0.513 0.073 0.440 0.433 1.5% 1.84

Cumulative (sum) 12.10 1.78 10.32 10.16

Maximum 1.74 0.28 1.47 1.45

# CIAs >= 0.5 dv 12 0 11 11

Primary Hood/Acid Plant, Main stack - inner

Secondary Hood/Uncontrolled - annular stack

Converter Bldg Fugitives
Stack parameters from 2012 stack test (CALPUFF "baset", "ctrl2t")

EPA modeling results from NPR

Deciviews Deciviews

Class I Area

baset: Base 

case, 

parms2

ctrl2t: new 

acid plant, 

parms2

original 

benefit

A. revised 

benefit, 

direct 

scaling

benefit 

shrinkage

natural 

background

Chiricahua NM 1.122 0.172 0.950 0.935 1.5% 1.80

Chiricahua Wild. 1.084 0.167 0.917 0.903 1.5% 1.79

Galiuro Wild. 2.049 0.350 1.699 1.673 1.5% 1.76

Gila Wild. 0.702 0.104 0.598 0.589 1.5% 1.83

Mazatzal Wild. 1.054 0.157 0.897 0.883 1.5% 1.79

Mount Baldy Wild. 0.698 0.104 0.594 0.585 1.5% 1.83

Petrified Forest NP 0.673 0.107 0.566 0.557 1.5% 1.85

Pine Mountain Wild. 0.730 0.119 0.611 0.602 1.5% 1.80

Saguaro NP 1.637 0.240 1.397 1.375 1.5% 1.72

Sierra Ancha Wild. 1.268 0.192 1.076 1.059 1.5% 1.80

Superstition Wild. 2.109 0.369 1.740 1.713 1.5% 1.76

Sycamore Canyon Wild. 0.536 0.082 0.454 0.447 1.5% 1.84

Cumulative (sum) 13.66 2.16 11.50 11.32

Maximum 2.11 0.37 1.74 1.71

# CIAs >= 0.5 dv 12 0 11 11
sjb 2014-06-05

s Under the Regional Haze Program, EPA-454/B-03-005. September 2003, Appendix B.

ddv/10) - 1 )

Amine 

scrubber 

(ctrl2 rev.)

98.50% 98.69%

14,294 Base case emissions are from original "ASARCO model emissions" spreadsheet

2593

9,692

26,579

144,354

84.5% 98.46%

1.0931 for scaling extinction or impact

0.9846 for scaling benefit

Extinction Source Extinction Scaled Delta deciviews

natural 

background

base, 

implied

ctrl2, 

implied ctrl2 rev.

ctrl2 (as 

check) ctrl2 rev.

B. revised 

benefit, 

using ddv

benefit 

shrinkage Difference from direct scaling

11.972 1.324 0.187 0.204 0.155 0.169 0.880 -0.001

11.960 1.274 0.175 0.191 0.145 0.158 0.854 0.000

11.924 2.251 0.337 0.369 0.279 0.305 1.424 -0.003

12.008 0.860 0.112 0.123 0.093 0.102 0.590 0.001

11.960 1.096 0.154 0.168 0.128 0.140 0.737 0.000

12.008 0.813 0.113 0.124 0.094 0.103 0.552 0.000

12.032 0.875 0.117 0.128 0.097 0.106 0.596 0.000

11.972 0.826 0.118 0.129 0.098 0.107 0.560 0.000

11.877 1.760 0.241 0.264 0.201 0.220 1.162 0.000

11.972 1.375 0.185 0.202 0.153 0.167 0.920 0.000

11.924 2.261 0.324 0.354 0.268 0.293 1.443 -0.002

12.020 0.633 0.088 0.096 0.073 0.080 0.433 0.000

1.78 1.95 10.15

0.28 0.30 1.44

0 0 11
Extinction Source Extinction Scaled Delta deciviews

natural 

background

baset, 

implied

ctrl2t, 

implied ctrl2t rev.

ctrl2t (as 

check) ctrl2t rev.

B. revised 

benefit, 

using ddv Difference from direct scaling

11.972 1.422 0.208 0.227 0.172 0.188 0.934 -0.001

11.960 1.369 0.201 0.220 0.167 0.182 0.902 -0.001

11.924 2.712 0.425 0.464 0.350 0.382 1.667 -0.006

12.008 0.873 0.126 0.137 0.104 0.114 0.588 0.000

11.960 1.329 0.189 0.207 0.157 0.171 0.883 -0.001

12.008 0.868 0.126 0.137 0.104 0.114 0.584 0.000

12.032 0.838 0.129 0.141 0.107 0.117 0.556 -0.001

11.972 0.907 0.143 0.157 0.119 0.130 0.600 -0.002

11.877 2.112 0.288 0.315 0.240 0.262 1.375 0.000

11.972 1.619 0.232 0.254 0.192 0.210 1.058 -0.001

11.924 2.800 0.448 0.490 0.369 0.403 1.706 -0.007

12.020 0.662 0.099 0.108 0.082 0.090 0.446 -0.001

2.16 2.36 11.30

0.37 0.40 1.71

0 0 11
missions" spreadsheet

Difference from direct scaling
Difference from direct scaling