MEMORANDUM 

Date: June 25, 2015 

To: Docket EPA-HQ-OAR-2010-1042 

From: Susan Fairchild 

OAQPS/SPPD/NRG (D243-02) 

U.S. Environmental Protection Agency 

Research Triangle Park, NC 27711 

Subject: Control Cost Evaluation for Glass-Melting Furnaces and 

Manufacturing Lines - Final Wool Fiberglass Manufacturing NESHAP 

Residual Risk and Technology Review Amendments 

1.0 Introduction

This memorandum presents the control cost analysis for the final Risk and Technology Review 

(RTR) amendments to the Wool Fiberglass Manufacturing NESHAP. Section 2 presents the 

control cost analysis for glass-melting furnaces and Section 3 discusses the cost analysis for 

flame attenuation (FA) and rotary spin (RS) manufacturing lines. 

2.0 Glass-Melting Furnaces 

2.1 Particulate Matter Control 

The EPA is finalizing the emission limits (0.33 lb/ton of glass pulled) for particulate matter 

(PM), as proposed in the November 13, 2014 supplemental notice, for all existing, reconstructed, 

and new glass-melting furnaces located at wool fiberglass manufacturing facilities that are major 

sources. As noted in the November 2014 proposal (79 FR 68026), and as shown in the graph 

below, data indicate that all sources currently meet the final PM limit and no additional controls 

will be needed. Therefore, the EPA did not conduct a control cost analysis for reducing PM 

emissions. Figure 1 shows the available furnace PM emissions data. 
Figure 1. Furnace PM Emission Rate Data

2.2 Chromium Compound Control 

As discussed in the November 13, 2014 supplemental proposal (79 FR 68020-68022), we 

evaluated the cost of the following options identified by industry representatives as potential 

compliance approaches to meet the proposed emission limit for chromium compounds from 

existing, reconstructed, and new gas-fired glass-melting furnaces located at wool fiberglass 

facilities that are major sources: 

• Furnace rebuild, when chromium emissions approach the limit. 

• Raw material substitution (reduced use of glass cullet in the raw material furnace charge). 

• Installation of high efficiency particulate air (HEPA) filters at the outlet of the dry 

electrostatic precipitator (DESP). 

• Installation of a venturi scrubber at the outlet of the DESP. 

• Installation of a 3-stage filter at the outlet of the DESP. 

• Installation of a 3-stage filter with water cleaning at the outlet of the DESP. 

• Installation of a membrane baghouse at the outlet of the DESP. 

• Installation of a caustic scrubber at the outlet of the DESP. 

The control options analysis developed for the November 2014 supplemental proposal is 

presented in the memorandum, “Control Cost Evaluation for Glass-Melting Furnaces” (docket 

EPA-HQ-OAR-2010-1042-0329). As noted in the 2014 supplemental proposal (79 FR 68021), 

we used the furnace rebuild as the cost basis for the chromium standards. 

In response to the 2014 proposal, we received comments stating that the EPA’s use of the Net 

Present Value (NPV) approach to estimate the cost of rebuilding a gas-fired glass-melting 

furnace before its useful service life to reduce emissions of chromium compounds was 

inappropriate. We agreed with the commenter’s findings that the NPV approach was not 

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

PM (lb/ton)

Furnace PM

Emission Rates (lb/ton glass pulled) 

 PM

Baghouses and Fabric 

Filters

Batch

Wetting

Baghouse

+ Secondary 

Control

ESP
appropriate for estimating the costs of rebuilding the furnace. Consequently, the EPA revised the 

costing methodology from the NPV to the replacement costing approach described in section 

2.5.5.6 of the EPA Air Pollution Control Cost Manual. We also revised the capital cost estimate 

for rebuilding a furnace to include the cost ($700,000) of transferring production to another 

facility while the furnace is being rebuilt, based on information provided by the commenter.1

Based on the revised cost-estimating procedure and capital cost ($10.7 million), we estimated the 

total annualized cost for rebuilding a furnace to be $462,000. 

For this cost analysis, the replacement cost method uses the following assumptions: 

• Furnace rebuild cost = $10.7 million; 

• Furnace life cycle = 10 years; 

• Furnace life cycle for compliance = 7 years; and 

• Interest rate = 7%.2 

The replacement cost method determines the incremental capital recovery cost as the difference 

between the annualized capital recovery cost (CRC) of rebuilding the furnace in 7 years versus 

10 years. The CRC is calculated by multiplying the total capital cost ($10.7 million) by the 

capital recovery factor (CRF): 

CRC = Total Capital Cost x CRF 

Where CRF is defined according to the formula: 

( )

( ) 















+ −

+

=

1 1

1

n

n

i

i i

CRF

Using the 10- and 7-year furnace campaign lengths and a 7% interest (discount) rate, the CRF 

values3 are 0.1424 (for 10 years) and 0.1856 (for 7 years). The table below shows the 

calculations used to determine the incremental capital recovery cost. 

Description

Furnace Rebuild

10 Years 7 Years 

Furnace rebuild cost (total capital 

cost) $10,700,000 $10,700,000 

Furnace life with rebuild (yr) 10 7 

Interest rate 0.07 0.07 

Capital recovery factor 0.1424 0.1856 

Annualized capital recovery cost 

of furnace rebuild $1,523,680 $1,985,920 

Incremental capital recovery costs $462,240 

 

1 Comment submitted by Angus E. Crane, Executive Vice President, General Counsel and Christopher C. Martin, 

Assistant Legal Counsel, North American Insulation Manufacturers Association (NAIMA). Appendix 2. EPA-HQOAR-2010-1042-0348.

2

 7% interest rate is in accordance with OMB guidance under Circular A-4. 

3

 Table A-2: Capital Recovery Factors (from EPA Air Pollution Cost Manual, EPA/452/B-02-001, January 2002). 
(CRC7yr – CRC10yr) 

Total annual cost for furnace 

rebuild ($/yr) $462,240 

Because the wool fiberglass companies operate more than one furnace at each facility, and 

operate several facilities in the U.S., and numerous facilities worldwide, industry practice is to 

move production from a furnace rebuild to other operating furnaces, in order to avoid loss of 

production. Therefore, this calculation includes the cost of moving production of wool fiberglass 

products to other facilities, a cost that was explained and accounted for by industry comments. 

Note that the calculation using the replacement cost method does not include any improvements 

in productivity and energy efficiency, among other factors, resulting from rebuilding a furnace, 

factors that would typically come into play when a wool fiberglass company assesses the need 

for a furnace rebuild using this approach. 

3.0 Manufacturing Lines 

3.1 FA Lines 

The EPA is finalizing the emission limits for formaldehyde, methanol, and phenol, as proposed 

in the November 13, 2014 supplemental notice, for existing, reconstructed, and new FA lines 

located at wool fiberglass manufacturing facilities that are major sources. As noted in the 

preamble to the November 2014 proposal (79 FR 68025-68026), none of the existing FA lines 

will require additional controls to comply with the final emission limits. Therefore, the EPA did 

not conduct a control cost analysis for reducing emissions of formaldehyde, methanol, and 

phenol from FA lines. 

3.2 RS Lines 

As discussed in Section V.H of the promulgation preamble of the RTR amendments for wool 

fiberglass manufacturing, the EPA has issued an Information Collection Request (ICR) under 

Clean Air Act (CAA) section 112(d)(6) to obtain updated emissions and process information for 

RS lines because we do not believe that the data currently available to the EPA are representative 

of the current operation in the industry. The EPA will analyze the ICR data and evaluate RTR 

limits for RS lines at wool fiberglass manufacturing facilities at a future date. Consequently, we 

did not conduct a control cost analysis for RS lines.