1

MEMORANDUM

TO: Anne Pope, EPA

FROM: Susan Fairchild, Project Lead

DATE: September 1 6 , 2011

SUBJECT: Emissions Data Used in Residual Risk Modeling for Wool Fiberglass Production

The purpose of this memorandum is to document the technical approach and rationale used to assign process information and hazardous air pol lutant (HAP) emissions data for wool fiberglass manufacturing facilities . This work is being performed as part of the residual risk assessment for

facilities that are subject t o the National Emission Standards for Hazardous Air Pollutants for Wool Fiberglass Manufacturing (40 CFR 63, S ubpart NNN ).

I. Information Collection Request (ICR)

A voluntary ICR was sent out in March 2010 to the 29 wool fiberglass facilitie s currently oper ating

in the U S. ICR responses from all the facilities were compiled in the project database and included

information on facility process es , equipment, control devices , costs, and HAP emissions

. Facility

specific p roduction rate information was also included and was claimed as confidential business information (CBI), which resulted in much of the project database being treated as CBI.

II. Emissions Testing

Emissions test data provided by the w ool fiberglass industry varied widely by facility. Companies
were allowed to, in lieu of new testing, submit existing and well documented test data that was representative of current operations and used the recommended test methods. A number of f acilities

submitted existing test reports on one or more of the follow ing emission sources : glass melting furnaces, curing ovens, forming, and collection operations. In order to fill data gaps in existing data, new test data was also required. Companies were , however, allowed to test a subset of facility operations

, if the facilit ies were able to demonstrate that the tested subset was representative of the

untested subset. Test results were typically presented as three test runs and provided in units of mass of pollutant per mass of production (e.g., lbs of HAP/ton of glass pulled ).

III. Source

- Specific Emissions

A combination of new and existing test data was used to populate the wool fiberglass r esidual risk modeling file. The following sources and pollutants were included in the risk modeling.

Glass

- Me lting Furnaces2 o Pollutants: Carbonyl Sulfide ( COS ) , Antimony, Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Lead, Manganese, Nickel, Selenium, Chromium VI, Hydrogen Chloride (HCl), Hydrogen Flouride (HF), and Mercury (Hg).

Bonded Lines:

o Curing Ovens: Formaldehyde, Phen ol, Methanol

o Forming Operations: Formaldehyde, Phenol, Methanol

o Collection Operations: Formaldehyde, Phenol, Methanol

Several types of furnaces are found in wool fiberglass manufacturing facilities. The furnace types included: oxy

- fuel, air gas, cold top electric, and electric steel shell furnaces. The furnaces were also equipped with several different control devices, including: electrostatic precipitators, baghouses,

a nd batch wetting.

Forming, curing, collection, and cooling operations vary facility to facility. Some facilities do not operate a collection process and most facilities route a combination of these operations into one or more stacks. It is common industry practice for these operations to share control devices, including: air filters, inci nerators, scrubbers, ESPs or a combination of these.

Using the glass pull rates (generally given in tons of glass pulled/day) that each facility provided in their ICR response and the source emission rates (lb/ton) from emission testing , annual emissions (tpy) were calculated for each pollutant and emission source . A sample calculation for annual formaldehyde emissions from a curing oven is provided as follows

.

Sample Calculation for Annual Formaldehyde Emissions from Curing Oven A (tpy):

( Average of all Formaldehyde test runs for c uring oven A

, lb HCHO/ton) x ( Production rate of

line A

, ton/day) x ( 365 days/yr) ÷ ( 2000 lb/ton)

These calculations were completed for each source and each pollutant listed above. For sources that

were not tested for a giv en pollutant

, an average emission rate (lb/ton melt) for each missing pollutant was calculated from similar sources at other facilities (or at the same facility if available) and then multiplied by the production rate the facility listed in their ICR response for the untested

source . If a source was tested for only one binder HAP pollutant (i.e., a curing oven was tested for formaldehyde but not phenol or methanol) the ratio o f the binder HAP emission rates (lb/ton) at a similar source was applied to the binder HAP tested

, in order to estimate the emission rates of the missing pollutants. This approach was also taken if a facility tested a furnace for total chromium (Cr) , but n ot for hexavalent chromium (Cr+6) . The ratio of total Cr to Cr+6 emission rate for a

similar source was applied to the Cr results in order to calculate the lb/ton emission rate of Cr+6

. An example scenario where HAP ratios were used follows:

Scenario 1: T he furnaces at facility A and facility B are similar and have comparable control

devices and the facilities provided the following results:

Facility A Furn a ce Results:

C r = 1.2E

- 4 lbs Cr/ t on of glass pulled3 Cr+6 = 1.05E

- 4 lbs Cr+6 /Ton of glass pulled

Facility B Furnace Results:

C r = 8.5E

- 5 lbs Cr/ t on of glass pulled

Cr+6 = No results provided.

Facility B Cr+6 Emission Rate (lb Cr +6 /ton of glass pulled) =

Where:

Facility B Cr+6 Emission Rate (lb Cr +6 /ton of glass pulled) =

The ratio approach to estimate emissions was only used in instances where testing for similar sources existed and a facility provided emission data for only one of the three bind er HAP (formaldehyde, phenol, and methanol) for a bonded emission source or to find Cr+6 emission rates when a facility only provided testing for Cr

.

If a furnace was not tested for any pollutant, the emission rate (lb/ton) from a similar furnace with

sim ilar controls was used. If there were several furnaces that were similar to the furnace that was not tested, the average emission rates and testing parameters of all the similar furnaces (for each pollutant) were used.

For each source, s tack heights, dia meters, an d coordinates were compiled from ICR responses and then sent to each facility for confirmation. Once, a facility confirmed the stack parameters and

coordinates were correct

, they were used as inputs in the modeling file. Testing parameters ( veloc ity, temperature, and flow rates ) were based on data from emission tests. If a source did not provide emission test data

, the velocity and temperature fro m the emission test used to estimate the

emission rate for the untested source was used and the flow r ate was calculated based on the stack diameter and the velocity. Stack configuration and control devices were taken into account when substitute emission rates were used for sources that did not have emissions testing or when binder

HAP ratios were used on sources that only tested for one pollutant.

IV. Chromium and Mercury Speciation

Consistent with the HAP list in the Clean Air Act, metals such as chromium and mercury may be reported in the ICR under different names, including chromium, chromium compounds, mercury, and mercury compounds. Facilities that submitted chromium data reported it as total chromium

and /or hexavalent chromium emissions. Hexavalent chromium emissions were not speciated further and were modeled as chromium VI. Total chromium was specia ted to Chromium III by subtracting4

chromium VI emissions from total chromium

. In some cases chromium VI emissions were larger

than total chromium. For these circumstances it was assumed that all chromium emissions were

hexavalent chromium and chromium III emissions were “ 0 ” . Facilities that submitted mercury data provided it as total mercury ; the following t able summarizes the speciation factors that were applied to mercury emissions.

POLLUTANT_CODE POLLUTANT_DESCRIPTION HAP_CATEGORY_NAME % of total

200 Elemental Gaseous Mercury Mercury Compounds 80%

202 Particulate Divalent Mercury Mercury Compounds 10%

201 Gaseous Divalent Mercury Mercury Compounds 10%

V. Emission Process Group Assignment

In order to assign risk results to specific operations within wool fiberglass facilities, Emission Process Groups are assigned to SCCs. For furnaces, the emission group assigned was based on furnace type , which included; oxy

- fuel, electric steel shell, col d

- top electric, air

- gas, and pot and
marble, The other emission groups modeled consisted of forming, collection, curing, and cooling processes. Combinations of these processes were used as emission process groups when one or more of these processes share d a common stack.

VI. QA/QC

Companies were sent aerial views of each plant and asked to label and provide coordinates for each

stack. They were also asked to review their stack configurations for each emission unit. All wool fiberglass facilities answered the request and provided labeled aerial views along with coordinates.

EPA also conducted an extensive review of the locational coordinates for all facilities in the wool fiberglass source category. Locations were vis ually reviewed using Google Earth or ArcExplorer. Adjustments were made for coordinates based on these visual evaluations.

Emissions data, stack parameters, and facility information was also reviewed for each unit and pollutant at a given plant. Producti on rates for each unit were checked with the responses provided

in the ICR. After risk modeling was conducted, one change was made to the stack height of the K2 furnace at the CertainTeed Kansas City facility due to an error in the stack parameter data the y provided in their ICR response. This stack was adjusted and remodeled once the facility confirmed the correct stack height.

VII. Allowable Emissions

The analysis of allowable emissions for the Wool Fiberglass Manufacturing source category was largely focus ed on emissions of chromium compounds and formaldehyde, which we considered the most important HAP emitted from this source category.

To estimate emissions at the MACT

- allowable level from process stacks, we averaged actual formaldehyde emission rates of manufacturing lines and compared those values to the max imum level allowed by the existing MACT standard (i.e., 1.2 or 0.8 pounds per ton of glass pulled for5

formaldehyde). Based on this analysis, the average wool fiberglass manufacturing facilit y is

emit ting formaldehyde at a level approximately 3 times lower than allowable. Therefore, to develop

the MACT

- allowable emissions the actual stack emissions were multiplied by 3 for formaldehyde, phenol and methanol.

MACT

- allowable emissions for hexavalent chr omium in the Wool Fiberglass Manufacturing category are equal to actual emissions because there is currently no emission limit for hexavalent

chromium.