MEMORANDUM

DATE: October 17, 2014

SUBJECT: Revised Technology Review for the Off-Site Waste and Recovery Operations 

Tanks

FROM: Lesley Stobert, EC/R Inc.

TO: Paula Hirtz, EPA/OAQPS/SPPD

The EPA proposed amendments to off-site waste and recovery operations (OSWRO) national 

emissions standards for hazardous air pollutants (NESHAP) on July 2, 2014, based on residual 

risk and technology reviews conducted for the source category. The purpose of this 

memorandum is to present a revised analysis related to the technology review for tanks at 

OSWRO facilities, considering comments submitted during the public comment period for the 

proposed OSWRO NESHAP amendments.

1.0 INTRODUCTION

On July 2, 2014 (79 FR 37850), the EPA proposed amendments to the OSWRO source category

following the results of a review required by section 112(d)(6) of the CAA, which directs the 

EPA to review previously issued NESHAP regulations and to revise them as necessary (taking 

into account developments in practices, processes and control technologies) no less frequently 

than every 8 years. Section 112(f)(2) of the CAA requires the EPA to assess, within 8 years of 

promulgation of the original NESHAP for major sources and area sources subject to MACT, the 

remaining risks due to emissions of HAP from these source categories and determine whether the 

emissions standards provide an ample margin of safety to protect public health. These reviews 

are collectively referred to as residual risk and technology reviews (RTRs).

For the July 2014 proposal, a technology review for tanks at OSWRO facilities was conducted. 

Under CAA section 112(d)(6), the EPA proposed to require more stringent emissions controls

for tanks of certain capacities storing materials above a specified vapor pressure. Following the 

July 2014 proposal, the EPA received comments from one industry trade association challenging 

some of the data and assumptions used in the analysis of emissions reduction and costs 

associated with the emissions controls for these tanks. We have considered these comments and 

revised certain aspects of our technology review analysis for OSWRO tanks. 
2

2.0 TANKS RE-ANALYSIS

2.1 Tanks at OSWRO Facilities

Tanks are used for many different applications at OSWRO facilities to accumulate, store or treat 

off-site materials. The amount of HAP emissions from tanks depends on the type of material in 

the tank, the type of tank (e.g., fixed roof tanks, internal floating roof tanks, external floating roof 

tanks), the methods used to fill and empty the tank, and the number of turnovers per year.

Emissions of HAP from fixed roof tanks and floating roof tanks are the result of working and 

breathing losses. Working losses occur when vapors are displaced by a rising level of liquid in

the tank. Breathing losses occur as a result of liquid level changes due to fluctuations in ambient 

temperature or pressure. The quantity of emissions from tanks depends greatly on the volatility

of the organic material in the tanks and whether the tanks are vented to the atmosphere, equipped 

with a pressure-vacuum relief valve, vented to an air emission control device, or fitted with a 

floating roof.

2.2 Summary of Existing MACT Level of Control

The current OSWRO MACT standards for tanks require either Level 1 or Level 2 controls, 

depending on the tank capacity and the vapor pressure of the materials in the tank. Tanks subject 

to Level 1 control requirements are required to be equipped with a fixed roof designed to form a 

continuous barrier over the entire surface area of the liquid in the tank, with no visible cracks, 

holes, gaps, etc., between roof section joints or where the roof and tank wall meet. Openings in 

the roof must be equipped with a closure device or connected to a closed vent system and routed 

to a control device. The fixed roof and its closure devices are subject to routine visual inspection 

and repair requirements.

For tanks subject to Level 2 control requirements, one of the following five control alternatives

must be used: (1) equip the fixed roof tank with an internal floating roof; (2) equip the fixed roof 

tank with an external floating roof; (3) equip the tank with a vapor-tight cover and vent to a 

control device that has a HAP removal or destruction efficiency of 95 percent; (4) use a pressure 

tank; and (5) locate the tank inside a permanent total enclosure (PTE) that is vented to a 

combustion control device that has a HAP destruction efficiency of 95 percent.

Tanks used to manage a waste stabilization process are subject to Level 2 requirements. Other 

tanks are subject to Level 1 or Level 2 controls as shown below in Table 1.

Table 1. Tank Control Levels for Tanks at Existing and New Facilities

Current OSWRO 

MACT Requirements

Applicability Threshold

Size Control Level

(m

3

)

Vapor Pressure 

(kPa)

Existing Sources Less than 75 < 76.6 1≥ 76.6 2*

75 ≤ capacity < 151 < 27.6 1
3

≥ 27.6 2

151 ≤ capacity

< 5.2 1

≥ 5.2 2

New Sources

Less than 38

< 76.6 1

≥ 76.6 2*

38 ≤ capacity < 151 < 13.1 1

≥ 13.1 2

151 ≤ capacity

< 0.7 1

≥ 0.7 2

* Except that fixed roof tanks equipped with an internal floating roof and tanks equipped with an external floating roof shall not 

be used

2.3 Proposed Standard for Tanks

At proposal, we identified two potential developments in existing practices and control 

techniques not currently required by the OSWRO MACT standards for tanks at existing sources. 

One option we evaluated (Option 1) was to revise the applicability of the OSWRO requirements 

to use the same thresholds for Level 2 control as the thresholds for control required by other 

MACT standards, specifically the Hazardous Organic NESHAP (HON). Based on information 

received from the industry as part of a CAA section 114 survey, which showed that the industry

primarily uses fixed roof tanks vented to control devices, under Option 2 we also considered the 

impacts of requiring a 98 percent emissions reduction for tanks required to use Level 2 control, 

rather than the currently required 95 percent emissions reduction, along with the revised capacity

and vapor pressure thresholds of Option 1. Based on the estimated control costs and emissions 

reductions, revisions to the standards for tanks at existing sources to require Option 1 were 

proposed. Table 2 presents a summary of the tank size and vapor pressure thresholds considered 

for existing sources under both options.

Table 2. Storage Tank Size Applicability Threshold Alternatives for Existing Sources

Regulatory 

Options

Applicability Threshold

Control 

Level

Option 1 

Requirements

Option 2 

If Size Requirements

(m

3

) is

And Vapor 

Pressure 

(kPa) is

Options 1 and 

2

Less than 75

< 76.5 1 Fixed roof 

≥ 76.5 2

a

95% controlb98% controlb

75 ≤ capacity 

< 151

< 13.1 1 Fixed roof

≥ 13.1 2 95% controlb98% controlb

151 ≤ 

capacity

< 5.2 1 Fixed roof

≥ 5.2 2 95% controlb

98% controlb

a Except that fixed roof tanks equipped with an internal floating roof and tanks equipped with an external floating 

roof shall not be used

b

Control efficiency would apply to tanks vented to a control device and tanks inside a permanent total enclosure 

(PTE) that are vented to a combustion control device; use of an internal or external floating roof or a pressure tank 

would still be available control options.
4

2.4 Revised Estimation of Tank Emissions

Based on comments regarding the proposed revised tank standards from the Cement Kiln 

Recycling Coalition (CKRC), an industry trade association, we have revised our analysis of tank 

emissions for tanks with capacities greater than or equal to 75 m3, but less than 151 m3, if the 

vapor pressure of the stored material is 13 kPa or greater. While we have not revised our estimate 

of the number of tanks in this size and vapor pressure range that would require controls under 

Option 1, we have revised some of the parameters used to estimate emissions potential from 

these tanks using the EPA’s TANKS 4.09d1program.

To estimate the number of tanks existing in the OSWRO source category with a capacity range 

of 75 m3to 151 m3and with a vapor pressure of stored material between 13.1 kPa and 27.6 kPa 

(i.e., those tanks with a stored material vapor pressure of 2.76 kPa are already regulated under 

the current NESHAP), OSWRO CAA section 114 survey data was used and then scaled up to 

nationwide values based on the number of known OSWRO facilities. Table 3 shows the 

estimated number of tanks in this size and vapor pressure range and how this estimate was 

calculated. Although CKRC commented that they believe there are more tanks in this size and 

vapor pressure range than the estimate used at proposal, we received no data to support this 

assertion, and many of the CKRC member companies submitted data through the CAA section 

114 survey, which was used in developing this estimate of tanks in this size and vapor pressure 

range in the source category.

Table 3. Estimated OSWRO Tank Population Based on CAA 114 Survey Responses

Tank Size/Vapor 

Pressure 

Estimated 

Number of 

Tanks in the 

OSWRO 

Source 

Category

Estimated 

Number of Tanks 

in the OSWRO 

Source Category

that Would 

Require Level 2 

Controls

Explanation

75 - 151 m3and 13.1 

≤ kPa < 27.6 21 tanks 14 tanks

One of 15 facilities responding to the 

survey has tanks with this size and 

vapor pressure. Total number of tanks 

for this facility is 7. Scaling up to 49

facilities in the source category, 1/15 x 

49 = 3 facilities have 7 tanks or 21 total 

tanks. 

The one facility reporting tanks of this 

size and vapor pressure already uses 

Level 2 emissions controls for these 

tanks. It is assumed that the tanks of this 

size and vapor pressure at other 

facilities are not already controlled with 

Level 2 controls. 

 

1

http://www.epa.gov/ttnchie1/software/tanks/
5

We estimated the emission potential from a model tank in the capacity range of 75 m3to 151 m3

and vapor pressure between 13.1 kPa and 27.6 kPa using the EPA’s TANKS 4.09d program, 

which is a software tool that calculates HAP emissions from fixed and floating roof tanks. The 

parameters shown in Table 4 were used as inputs to the TANKS program and were based on 

information reported in the OSWRO CAA section 114 survey responses and on comments from 

CKRC. The specific changes incorporated since proposal include:

 Tank conservation vent pressure setting of 0.5 psi rather than 0.03 psi to reflect probable 

vent settings currently in place under control Level 1; 

 Tank location of Concordia, KS, rather than Houston, TX. Concordia, KS is the closest 

city to the geographic center of the continental U.S. included in the TANKS program and 

is more representative of national average temperatures;

 Revised mix of tank constituents to include non-HAP contents, with an overall HAP 

content revised to 60 percent from 100 percent to more accurately reflect typical 

OSWRO tank contents. 

We note that although CKRC commented that they believe the estimated throughput is too high, 

we have not changed our estimate. The commenter did not provide detailed information to 

support the use of a different value. Our estimate of 4,996,918 gal/yr was developed from data 

reported in the supporting documentation for the proposed storage tank uniform standards,

2

and 

data from the one facility reporting tanks in this size and vapor pressure range is similar to this

estimate.

The revised estimated emission potential for tanks with capacities greater than or equal to 75 m3, 

but less than 151 m3, if the vapor pressure of the stored material is between 13.1 kPa and 27.6 

kPa is shown in Table 4. See the Appendix to this document for more information on the inputs 

used and outputs obtained from the TANKS 4.09d program.

 

2 Memorandum from Randall, D., RTI International, to Parsons, N., EPA/OAQPS. Survey of Control Technology 

for Storage Vessels and Analysis of Impacts for Storage Vessel Control Options. January 20, 2012. EPA Docket No. 

EPA-HQ-OAR-2010-0871-

0027.
6

Table 4. Estimation of Tank HAP Emission Potential

Size and Vapor 

Pressure Range

Capacity1

(gal/m

3

)

Height1

(Ft)

Diameter1

(ft)

Throughput

2

(gal)

Tank 

Contents 

Vapor 

Pressure3

(kPa)

Location4 Tank Contents5

Speciated and Total 

Emission Potential6

(lb/yr)

Tank

≥75 to < 151 m3

and 

13.1<kPa<27.6

25,000 gal

(94.6 m3)

28.4 12.3 4,996,918 14.86 Concordia, 

KS

10% methanol* 361

20% methylene chloride* 2,863

10% tetrachloroethylene* 52

10% toluene* 83

10% trichloroethane (1,1,1)* 417

20% acetone 1,482

6.66% cyclohexene 204

6.67% isopropyl alcohol 79

6.67% methyl ethyl ketone 182

Total Emissions 5,722

Total HAP Emissions 3,776

1 Capacity, height and diameter based on average of CAA section 114 survey response data for tanks meeting these thresholds.

2 Due to insufficient OSWRO survey response data (data not reported or units not reported), throughput estimated via linear interpolation from data reported in the 

supporting documentation for the proposed storage tank uniform standards (Memorandum from Randall, D., RTI International, to Parsons, N., EPA/OAQPS. Survey of 

Control Technology for Storage Vessels and Analysis of Impacts for Storage Vessel Control Options. January 20, 2012. EPA Docket No. EPA-HQ-OAR-2010-0871-

0027). This value is similar to the value obtained from the average of the 7 tanks at the one facility reporting tanks in this size and vapor pressure range, which reported an 

average of 19.161 tons of annual throughput. Based on the tank emissions reported by this facility, the average weight per gallon of stored material is 8 lbs/gal, resulting 

in an average throughput of 4,790,143 gal. 

3 Vapor pressure was determined with TANKS4.0.9d based on the tank contents.

4 Location assumed as Concordia, KS, the closest city to the geographic center of the continental U.S. to be representative of a national average.

5 Chemicals included are based on comments from CKRC. The relative amount of each chemical varied to give more weight to chemicals with higher vapor pressures to 

make the overall vapor pressure of the tank be above the 13.1 kPa threshold for regulation. * Denotes chemicals that are HAP.

6 Uncontrolled emissions from TANKS 4.0.9d.
7

To determine the nationwide emissions reduction that would be achieved under Option 1, we first 

determined the nationwide HAP emissions from the additional tanks that would require Level 2 control

under Option 1. This was calculated using the estimated tank population shown in Table 3, the Level 1 

HAP emissions per tank for this size and vapor pressure type shown in Table 4, and the estimated number 

of uncontrolled tanks within the estimated tank population shown in Table 3. This calculation is shown 

below:

Baseline HAP Emissions:    ..  =

14 tanks × 3,776 lb

yr

2,000 lb

ton

= 26.4 tpy

The Option 1 emissions reduction requirement is 95 percent. Application of a 95 percent emissions 

reduction to the uncontrolled emissions calculated above results in a reduction of 26.4 tons per year

(tpy). 

2.5 Revised Estimate of Option 1 Costs

Based on comments from CKRC, we have revised our analysis of tank control costs under Option 1. As 

described above, Option 1 considers lowering the vapor pressure threshold to apply to more storage 

tanks, which requires additional storage tanks to control emissions with Level 2 controls. To estimate 

the costs for requiring these additional storage tanks to use Level 2 controls, it was assumed that the 

emissions from these tanks would be routed to an existing control device at the facility already used to 

control emissions from other tanks. We previously assumed that the only additional costs associated 

with Option 1 would be for ductwork for the estimated 21 additional tanks that would be captured under 

the new vapor pressure threshold. 

We have made several revisions to our prior cost estimate. First we have revised the analysis to include 

costs for only the assumed 14 tanks without Level 2 emissions controls. CKRC commented that the EPA 

should have included a flame arrestor for each tank to prevent back-flash to the tanks. We have revised 

the estimated costs to include costs for flame arrestors. However, since one flame arrestor typically is 

installed in the piping system that serves several tanks, we have assumed that two arrestors per facility

(i.e., two arrestors to serve the 7 tanks at each facility) would be installed. In addition, we have added 

costs associated with adding a carbon adsorption system. While some air pollution control devices may 

have sufficient capacity to control additional tanks, it is possible that the facilities with these tanks may 

not have excess capacity to control emissions from these tanks. In this case, depending on the control 

device(s) already in place, an additional carbon adsorption unit may be needed or could be used for these 

tanks rather than other control devices already at the facility. Based on the relatively low flow rate 

expected for these tanks and the costs of the different types of carbon adsorption systems, we assumed 

carbon canisters would be used for these tanks. We did not add, as the commenter suggested, costs for a 

nitrogen blanketing system, as these systems are not required and could already be in place on these 

tanks.

Based on information contained in the EPA Air Pollution Control Cost Manual3, the revised nationwide 

capital costs associated with the Tank Option 1, including ductwork, flame arrestors, and carbon 

 

3 Data used were from 'OAQPS Control Cost Manual', 5th edition. See the Appendix to this memo for more specific 

information regarding the specific values and calculations used in this estimate.
8

adsorption canisters, were estimated to be $139,000 with nationwide annual costs of $192,000. See the 

Appendix to this document for more information about how these costs were determined. The revised 

annual HAP emissions reduction estimate for Option 1 is 26.4 tpy, and the revised estimate of the annual 

cost per ton of HAP removed is $7,000. These cost estimates are summarized in Table 5.

Table 5. Revised Nationwide Costs and Emission Reductions of Regulatory Option 1 Tanks

Regulatory 

Alternative

HAP 

Emissions

Reduction 

(tpy)

Capital 

Cost ($)

Annual 

Costs 

($/yr)

Cost 

Effectiveness 

($/ton HAP)

Incremental 

Cost 

Effectiveness 

($/ton HAP)

Option 1: (HON 

TS/VP thresholds, 95% 

control)1

26.4 $139,497 $191,886 $7,268 -----

1 The costs associated with this option are for ductwork, flame arrestors and a carbon adsorption system (canisters).
Appendix
A-1

Baseline Average Pollutant Heat Content Calculations

OSWRO

Component

Emissions 

(lb/hr)*

Molecular

Weight (lb/lbmole) lb-moles

Volumetric

Flow Rate 

(scf/min)

-ΔHc

(KJ/mole)

Heat of

Combustion 

(Btu/lb)

Heat of 

Combustion 

(Btu/scf)

Volume 

Fraction of 

Component in 

Exhaust Gas

Vent Heat 

Content 

(Btu/scf) Mole Fraction Freundlich K Freundlich M Reference

VOC 1.55582 61.27 0.025395 0.163075 2220 15,591 2,479 3.92E-01 971.54997 0.391890366 0.412 0.389 1

Methane 16.04 0.000000 890.4 23,884 994 0.00E+00 0.00000

Ethane 30.07 0.000000 1559.9 22,321 1,742 0.00E+00 0.00000

Other HAP 44.09 0.000000 2220 21,665 2,479 0.00E+00 0.00000

Hexanes 86.17 0.000000 4194.8 20,946 4,684 0.00E+00 0.00000

Benzene 78.11 0.000000 3301.5 18,187 3,687 0.00E+00 0.00000

Methylene Chloride 2.28779 84.94 0.026934 0.172962 605 3,065 676 4.16E-01 280.82144 0.415649541 7.175 0.469 2

Toluene 0.06632 92.13 0.000720 0.004623 3947.9 18,438 4,409 1.11E-02 48.97889 0.011109518 0.551 0.11 3

Ethylbenzene 106.16 0.000000 4607.1 18,673 5,145 0.00E+00 0.00000

Xylenes 106.16 0.000000 4595.2 18,625 5,132 0.00E+00 0.00000

Methanol 0.28847 32.04 0.009003 0.057817 764 10,260 853 1.39E-01 118.54244 0.138941796 0.22 0.383 4

Tetrachloroethylene 0.04155 165.83 0.000251 0.001609 830 2,154 927 3.87E-03 3.58413 0.00386686 0.436 1.47 5

Trichloroethane (1,1,1)0.33322 133.42 0.002498 0.016038 1442 4,650 1,610 3.85E-02 62.06492 0.038541919 1.06 0.161 3

Air 0 0 0 0.00E+00 0.00000

Total 4.57317 70.57 0.06480 0.416 1.00E+00 1485.5418 3.22 0.414

* Emissions are based on model tank of 25,000 gal and kPa 14.86

References

1

 Based on values for acetone, EPA Control Cost Manual Table 1.1: Parameters for Selected Adsorption Isotherms

2

 K and M (1/n) values obtained from Tsai, W.-T. and Chang, C.-Y. (1994), Adsorption of methylene chloride vapor on activated carbons. J. Chem. Technol. Biotechnol., 61: 145–151. 

3

 EPA Control Cost Manual Table 1.1: Parameters for Selected Adsorption Isotherms

4

 K and M values were obtained from Agarwal M, Dave M, Upadhayaya S. Adsorption of Formaldehyde on Treated Activated Carbon and Activated Alumina. Curr World Environ 2011:6(1);53-59.

5

 K and M values were obtained from Erto A., Andreozzi R., Di Natale F., Lancia A., Musmarra D., 2009, Experimental and isotherm-models analysis on TCE and PCE adsorption onto activated carbon, 
A-2

TOTAL ANNUAL COST SPREADSHEET PROGRAM--STRAIGHT DUCTWORK [1]

COST BASE DATE: CEPCI 1993 [2] 359.2

COST ESCALATION: CEPCI 2013 [3] 567.3

INPUT PARAMETERS

 Inlet stream flowrate (acfm):[4] 729

 Duct velocity (ft/min): [5] 3840

 Duct length (ft): [6] 150

 Material of construction: [7] 304 SS Sheet

 Insulation thickness (in.): (text input) [8] 0

 Duct design: [9] Circ.-spiral

 Cost equation parameters: [10]

 a: 1.56

 b: 1

 Cost equation form: [11] 1

 Control system installation factor: [12] 1.5

 (if no system, enter '0')

 Fan-motor combined efficiency (fraction): 0.6

DESIGN PARAMETERS

 Duct diameter (in.): 5.89777904

 Pressure drop (in. w.c.): [13] 5.314321378

CAPITAL COSTS

Equipment Cost ($)--base: $1,380

 ' ' ' --escalated: $2,180

Purchased Equipment Cost ($): $2,354

Total Capital Investment ($): [14] $3,531

====================================================================

ANNUAL COST INPUTS

 Operating factor (hours/year): 8760

 Electricity price ($/kWhr): [15] 0.067

 Annual interest rate (fractional): 0.07

 Ductwork economic life (years): 15

 Capital recovery factor (system): 0.109794625

 Taxes, insurance, admin. factor: 0.04

ANNUAL COSTS

Cost ($/yr) Wt.Fact.

Electricity $445 0.457075677

Taxes, insurance, administrative $141 0.144978319

Capital recovery $388 0.397946003

------------------------------------------------------------------------------------------------------------------------

Total Annual Cost $974 1
A-3

Notes:

[1] Data used to develop this program were taken from 'OAQPS Control Cost Manual', 5th edition, Chapter 

10. Prices are for CIRCULAR straight ductwork, only.

[2] Base ductwork costs reflect this date.

[3] PPI = Producer Price Index PCU 3444#1 ('Air-conditioning ducts and stove pipe') for year and quarter 

shown. Ductwork equipment cost has been escalated to this date via this PPI.

[4] Median flow rate of tanks controlled by thermal oxidizers in OSWRO CAA section 114 survey

[5] See 'Manual,' pp. 10-30 to 10-33.

[6] Duct length is a site-specific parameter that can vary from < 10 to > 1000 ft.

[7] Choices available are: carbon steel sheet (galv. CS sh.), stainless steel sheet (304 SS sh.), coated carbon 

steel plate (coat. CS pl.), 304 stainless steel plate (304 SS pl.), polyvinyl chloride (PVC), and fiber-reinforced 

plastic (FRP)

[8] Choices are: 0, 1, and 3.

[9] Choices are: circular spiral (circ.-spiral) and circular longitudinal (circ.-long.)

[10] Equation type and parameters depend on duct material of construction. Parameters reflect 2nd 

quarter 1993 costs. See 'Manual,' pp. 10-44 to 10-49.

[11] Choices are: power function (1) and exponential (2).

[12] Installation factor depends on control device ductwork is supporting. This factor, when multiplied by 

Purchased Equipment Cost, yields Total Capital Investment (TCI). If ductwork is installed alone, factor is 

1.25 to 1.50. (Default = 1.50.) See 'Manual'.

[13] Pressure drop applies ONLY to circular, spiral-wound galvanized duct with 10 joints per 100 feet. For 

pressure drop data for other duct types, see 'Manual,' Chapter 10.

[14] Product of installation factor and Purchased Equipment Cost. Costs are presented both in terms of 

2nd quarter '93 and above escalation date. Latter costs are based on Producer Price Index PCU 3444#1 

('Air-conditioning ducts and stove pipe')

[15] 2012 Table 5.3. Average Retail Price of Electricity to Ultimate Customers: Industrial 

http://www.eia.gov/electricity/monthly/epm_table_grapher.cfm?t=epmt_5_3
A-4

TOTAL ANNUAL COST --DETONATION ARRESTOR

CAPITAL COSTS

Equipment Cost ($):1$10,000

Sales Tax and Freight (fractional): 0.08

Purchased equipment cost: $10,800.00

Direct and indirect installation costs (fractional):20.5

Direct installation costs ($): $5,000.00

Total Capital Investment ($): [14] $15,800

====================================================================

ANNUAL COST INPUTS

 Operating factor (hours/year): 8760

 Annual interest rate (fractional): 0.07

 Economic life (years): 15

 Capital recovery factor (system): 0.109794625

 Taxes, insurance, admin. factor: 0.04

 Maintenance labor rate ($/hr):3

54.117

 Maintenance labor factor (hr/year): 4

ANNUAL COSTS

Cost ($/yr) Wt.Fact.

Taxes, insurance, administrative $632 0.244655604

Capital recovery $1,735 0.671546755

Maintenance labor $216

------------------------------------------------------------------------------------------------------------------------

Total Annual Cost $2,583 0.916202359

Notes:

1

Based on equipment price stated by commenter CKRC, docket ID EPA-HQ-OAR-2012-0360-

0066

2

Based on 'OAQPS Control Cost Manual', 5th edition, Section 2, Chapter 1, page 1-50 for 

equipment that would have similar installation costs (hoods and ducts)

3 May 2013 National Industry-Specific Occupational Employment and Wage Estimates NAICS 325000 -

Mean of Installation, Maintenance and Repair Occupations 

http://www.bls.gov/oes/current/naics3_325000.htm plus 110% overhead
A-5

Carbon Working Capacity Calculation

INPUT PARAMETERS:

 Inlet stream flowrate (acfm):18.90

 Inlet stream temperature (oF):278

 Inlet stream pressure (atm):31

 Inlet VOC flowrate (lb/hr):44.573

 VOC molecular weight (lb/lb-mole):470.57

 VOC inlet volume fraction: 4.767688E-02

 VOC inlet partial pressure (psia): 0.7007

 Freundlich isotherm equation constants for VOC (see Table 1 below):

 VOC number (enter Table 1 # or zero, if no data):

 K:53.223

 M:50.414

DESIGN PARAMETERS:

 Carbon equilibrium capacity--Freundlich (lb VOC/lb carb): 2.7819

 Carbon working capacity (lb VOC/lb carbon): 1.3909

1

Flow rate calculated using 219.6 turnovers/yr and 22754.81 gal for working loss and breathing loss emission rate 

(0.0266 lb/hr) and vapor density (0.0274 lb/ft3) for 7 tanks

2

Assumed ambient temperature

3

Assumed ambient pressure

4

Based on model tank emissions

5

The K and M constants were calculated using a mole fraction weighting of the emission components (see "Heat 

content - mid tanks").

Table 1. Freundlich Constants for Selected Compounds. 

These constants fit the following equation: Q = K(P)^M where: Q = equilibrium adsorption capacity (lb/lb carbon), P = 

VOC partial pressure (psia at 1 atm & listed temperature)

Correlation Range 

(psia)

VOC name VOC 

number

K M Temperatur

e (F)

Minimum Maximum

Benzene 1001 0.597 0.176 77 0.0001 0.05

Chlorobenzene 1002 1.05 0.188 77 0.0001 0.01

Cyclohexane 1003 0.508 0.210 100 0.0001 0.05

Dichloroethane 1004 0.976 0.281 77 0.0001 0.04

Phenol 1005 0.855 0.153 104 0.0001 0.03

Trichloroethane 1006 1.06 0.161 77 0.0001 0.04

Vinyl chloride 1007 0.200 0.477 100 0.0001 0.05

m-Xylene (low-pressure range) 1008 0.708 0.113 77 0.0001 0.001

m-Xylene (high-pressure range) 1009 0.527 0.0703 77 0.001 0.05

Acrylonitrile 1010 0.935 0.424 100 0.0001 0.015

Acetone 1011 0.412 0.389 100 0.0001 0.05

Toluene 1012 0.551 0.110 77 0.0001 0.05

Note: This program has been based on data and procedures in Chapter 4 of the OAQPS CONTROL COST MANUAL (5th 

edition).
A-6

Carbon Adsorption Canister System (1,000 lb Canister System)

COST BASE DATE: CEPCI 1999 390.6

COST ESCALATION: CEPCI 2013 567.3

Capital Costs

-- Carbon canister equipment cost (1,000 lb carbon): ($1999)a$5,600

-- Carbon canister installation cost (1,000 lb carbon): ($1999)a$3,200

-- Carbon canister equipment cost (1,000 lb carbon): ($2013) $8,133

-- Carbon canister installation cost (1,000 lb carbon): ($2013) $4,648

Purchased Equipment Cost ($): ($2013) $8,784

Total Capital Investment ($): ($2013)b$13,432

-- Carbon canister, total (lb) 1000

-- Inlet VOC flowrate (lb/hr) 4.573

-- Carbon working capacity (lb VOC/lb carbon)c2.0864

-- Days per canister (days/canister) 19.01

-- Number of canister exchanges per year 19.2

Annual Costs

Cost of carbon replacement ($/lb)($1999)d2.00

Cost of carbon replacement ($/lb)($2013) 2.90

Annual cost of carbon replacement $81,005

Annual maintenancee$940

Capital recovery

f

$1,475

Taxes, insurance, administrativeg$537

Total Annual Cost (without credits) $83,957

a

 Cost from Section 1.3.2 of Carbon Adsorbers from the EPA Control Cost Manual

b

 Includes vessel, instrumentation, sales tax, and freight

c

 Assumes 75% of the equilibrium capacity

d

 Average carbon cost from Section 1.3.2 of Carbon Adsorbers from the EPA Control Cost Manual

e

 Assumes 7% of installed capital cost

f

 Assumes 15 year equipment life and 7% interest

g

 Assumes 4% of installed capital cost
A-7

Total Tank Control Costs

Total Capital Investment ($): ($2013)

1,000 lb canister system $13,432

ducts $24,717

flame arrestor $31,600

$69,749 per facility

$139,497 per source category

Total Annual Cost (with credits)

1,000 lb canister system $83,957

ducts $6,819

flame arrestor $5,166

$95,943 per facility

$191,886 per source category