# MEMORANDUM
To: Mike Pettis (Owens Corning) 

### From: Judy CoHora (Trinity Consultants) 

### Date: May 22, 2013 

### RE:

. Control Technology and Associated Economic Assessment
Trinity has completed the attached Control Technology**~nd** Associated Economic Assessment for the Owens Corning DM2 furnace located in Delmar, New York This assessmentwas performed for the DM2 furnace as it would requireadditional emission controls to meet U.S. EPA's chromium standard thatwas proposed on April 15, 2013, under40 CFR Part 63 Subpart NN. Ifyou need additional information, please contact me at (678) 441-9977.

## CONTROL TECHNOLOGY AND ASSOCIATED ECONOMIC ASSESSMENT FOR OWENS CORNING DM2 FURNACE IN REFERENCE TO PROPOSED AREA SOURCE RULE NN AFFECTING FIBERGLASS MANUFACTURING



## Contents 1.1. BACKGROUND .... .................................................................................................................. 2 

### 1.2. U.S. EPA ASSESSMENT

.........................................................................................................2 1.2.1. U.S. EPA Cost Esti mate for Caustic Scrubbi ng
.......................................................................4 1.2.2. Caustic Scrubber Train

.............................- ........................................................................... 6 

### 1.3. REVISED ASSESSMENT

......................................................................................................... 7 1.3.1. Data Sources

......................................................................................................................7 1.3.2. Cases for Cost Effectiveness

................................................................................................8 1.3.3. Identification of Potential Control Tecimologies (Step 1)

...................................................... 8 1.3.3.1. Proven Controls

...........................................................................................................8 1.3.3.2. Experimental Controls

..................................................................................................9 1.3.4. Elimination of Tecimically Infeasible Control Options (Step 2)

............................................... 9 1.3.5. Rank of Remaining Control Tecimologies (Step 3)

............................................................... 10 1.3.6. Evaluation of Most Stringent Controls (Step 4)

................................................................... 10 1.3.6.1. Economic Feasibility Calculation Process

..................................................................... 10 1.3.6.2: Experimental Dry/Physical Filtration

.............................................;.............................. 11 1.3.6.3. Experimental Wet Scrubbing

....................................**~** ................................................. 12 1.3.6.4. Proven Controls**~ith** Proper Maintenance and Operating Practices

............................. 12 1.3.7. Selection of Control Technology (Step 5)

........................................................................... 18

1

## 1.1. BACKGROUND To develop an emission limit under the maximum.achievable control technology (MACT) standard for major sources ofhazardous air pollutants (HAP) that is based on U.S. EPA's (the Agency's) 112(f) risk obligations and then justify a particular tec):mology under 112(d) is not an uncommon methodology. When the Agencyjustifies the emission limit based on the 'ample margin ofsafety' statute in 112(f), it is required to account for economic and technical feasibility. U.S. EPA based the proposed generally available control technology (GACT) standard for smaller (area) sources ofHAP on the above methodology. In the process, an unproven and cost prohibitive add-on emission control device was also proposed. It**app~ars** that U.S. EPA has not sufficiently researched the exhaust streams ofthe affected sources and, as a result, justified this inadequate control technology as economically feasible. In reality, it is neither technically nor economicallyjustified and documentation to this fact is included herein. It is clear that the only "generally available control technologies" are the particulate matter (PM) control devices already in operation on the furnaces, and that further consideration in setting the proposed chromium limit was warranted by U.S. EPA in the drafting ofthis rule. 

## 1.2. U.S. EPA ASSESSMENT U.S. EPA is indicating the use ofa single caustic scrubber on each furnace that does not meet the proposed chromium emission limit of 6.0E-05 lb/ton glass pull. However, U.S. EPA disregarded their own procedures on how to assess the true and reasonable cost ofinstalling and operating this control device even ifit were technically sound (which it is not). The U.S. EPA has developed a general procedure to determine the feasibility ofinstalling new controls, and it is routinely followed, for example, when applying for a major source permit. The Agency has followed this procedure in recent rulemakings for other area source GACT rules as means to determine what control technologies are economically feasible. However, it is apparent that this procedure was not applied equally in development ofthis GACT standard. U.S. EPA's evaluation ofsuitable control technologies are typically as follows: Step 1. Identify all possible control technologies (including technology transfer); Step 2. Eliminate technically infeasible options; Step 3. Rank the technically feasible control technologies based upon emission reduction potential; Step 4. Evaluate ranked controls based on energy, environmental, and/or economic considerations; and Step 5. Select control technology. Step 

## 1 was followed as dust collectors were identified as a viable technology that transfers from major sources to area sources. In fact, the proposal states that "major and area sources are equipped with technologiesthat effectively control chromium and metal hazardous air pollutant (HAP) emissions, including, but not limited to, ESPs and fabric filters."i U.S. EPA clearly states that an ESP is effective at removing chromium emissions. However, this statement is in direct contrast with the proposed emission limit, which is set too stringent for several area sources operating with an ESP to meet. To account for this difference, U.S. EPA claims.to have

1 Page 22383, Federal Register, Vol. 78, No. 72. ESPs is an acronym for Electrostatic Precipitators. ESPs includes Dry ESPs (DEPs), which is a term used interchangeably within the fiberglass manufacturing industry.

2"searched other industries for controls that would remove chromium and found that a sodium hydroxide (NaOH) scrubber is used in both high temperature metallurgical industries and the chrom ium electroplating industryfor removal of hexavalent chromium."z Based on our recent communications with multiple vendors of control technologies, aside from the existing, dry filtration controls (e.g., ESPs and fabric filters) none ofthe vendors were able to provide a proven chromium control technology that could be readilytransferred tothese furnaces. Furthermore, no vendor was prepared to guarantee an emission rate thatwould meettheproposed chromium limit. Even within the communications that U.S. EPA had in establishing a N aOH scrubber as technicallyand economically feasible,3 one vendor clearly statedthat "a wet or dry ESP is the recommended technology for glass furnace operations

...We also looked atthe technologies we do have available and

... we do not have a productthatwould address your earlier points below." Upon U.S. EPA's pressing ofthe matter, this point was reiterated bythe vendor who stated that "

..a pre-quenched gas streamto reduce the temperature, along with a wetpacked bed scrubberutilizing a recirculated solution ofcaustic is NOT capable of addressing removing sub-micron chromium

... " When we reviewed the referenced U.S. EPA communication with the vendor [Hansen Engineering] who proposed a NaOH scrubber as a viable solution, 4 it was clear the design was hopeful at best. The vendor caveated this proposed design with "We believe that a 90 to 95% Cr removal is [possible] maybe higher, but we can not give [a guarantee]. Itwould be from our standpoint, experimental." Upon subsequent communications, the vendor reiterated that "But again I [would] like to emphasize that a certain amount of experimenting for scrubbing out elements can not be avoided." Clearly, thisvendor's information was misconstrued by U.S. EPA, has been significantly updated from their original proposal, and is still considered experimental. There is also an unsubstantiated conclusion that since one furnace employs a PM control followed by a wet scrubber for sulfur dioxide (SOz) emissions control, itis "directly analogous to usinga NaOH wet scrubber downstream ofthe PM controls to achieve additional chromium removaL" The error is the assumption that a wet scrubber for SOz control can achieve any sort of chromium reduction downstream of a PM control device. Furthermore,while itis possible to add a NaOH scrubberto the exhaust of an ESP, U.S. EPA provided no explanation ofhow technically such a configuration can achieve compliance with the proposed chromium emission limit. If U.S. EPA were to have followed their own guidance on selecting controls, the next step would have beento eliminate any ofthe technicallyinfeasible options. Based on the conflicting data thatU.S. EPA did receive from vendors, it should have been clear thatthe only decision was to remove NaOH scrubbing from the list of technically feasible control technologies.**~aOH** scrubbersthat mightbe used in the metallurgical and chromium electroplating industries are treatinga much higher concentration of chromium witha significantly different particle size distribution.Application ofthis control technology to the alreadywell-controlled streams ofthese furnaces as itwas initiallyproposed to and evaluated by the U.S. EPA is technicallyinfeasible.

2 Page 22383, Federal Register, Vol. 78, No. 72. 3 htto:l!www.regulations.gov/#ldocketDetailjD=EPA-HO-OAR-2010-1042.Supporting&RelatedMaterial.11/25/2011. ID:EPA-HQ-OAR-2010-1042-0079 4 Docket ID: EPA-HQ-OAR-2010-1042-0079
3

### 1.2.1. U.S. EPA Cost Estimate for Caustic Scrubbing The cost of a N aOH (caustic) scrubber was assessed by U.S. EPA in thepreambleto theproposed rule. A cost-effectiveness of$7,600 per pound ofchromium removed was estimated byU.S. EPA based on the use ofa caustic scrubberatthreefurnaces requiringemissions reductionsto meettheproposed chromium limit. This estimateis apparentlybased on an initial capital cost of $250,000 thatresults in an annualized operatingcost of $100,000 peryear perscrubber. The annual cost was multiplied by three sources. Additionally, an$80,0

# ° 0 peryearper stacktest for eightsources, for a total of $3 B 0,0

# ° 0 peryearfor all sources was included. This cost was divided by a value of 50 poundsper year of chromium reduced from the three sources to provide a cost-effectiveness value of$7,600 per pound. The annualized operating cost of $100,000 for a system designed to achieve compliance with the proposed limit is thoughtto be an extremeunderestimate, even if the technology wheretransferrable to these systems. The initial capital outlayand ongoing operating costs

- based on our recent research as outlined laterin this document

- areunderestimated. Also, common practice is to split the costs evenly among all sources that will need control. In this case, the total expected emission reduction of 50 lb/yr of chromium is for three furnaces, but each one is emittingchromium atvery differentrates. Given this variation and such a small amountof overall reduction, to assumethe controls are cost feasible for each and everyone ofthese sources is unreasonable. Furthermore,there is no basis to the $100,000 peryear estimate ofcombined annualized cost. We have been unable to recreate this value usingthe U.S. EPA Office ofAir Quality Planning and Standards (OAQPS) guidance manual on estimatingcontrol technology costs. S We could not locate thebasis of this value in the docket following a review of data provided by industryvia Section 114 requests or by vendor quotes. When such data are not readilyavailable, then annualized costs should bederived from capital and operating costs, each one expressed as a function ofknown equipment and othercosts. Total purchased equipmentcost should**repres~nt** the delivered cost ofthe control equipment,auxiliary equipment, and instrumentation. Auxiliaryequipmentconsists ofall the structural,mechanical, and electrical components required for the efficient operation ofthe device. Auxiliary equipmentcosts are estimated as a straightpercentage ofthe equipmentcost. Direct installation costs consist ofthe direct expenditures for materials and labor for sitepreparation,foundations, structural steel, erection, piping, electrical, painting and facilities. Indirectinstallation costs include engineeringand supervision of contractors, construction and field expenses, construction fees, and contingencies. Other indirectcosts include equipmentstartup,performancetesting, working capital, and interestduringconstruction. None ofthese factors appearto have been considered in the cost estimateprovided in the proposed rule. Table 1 shows the OAQPS multipliers touse in estimatingthetotal capital investment (Tel) for a scrubberinstallation. Even taking thevendor's estimate of $210,000 for a "total package cost",6 keeping in mind that a vendor's estimate is typically for purchased equipmentonlyunless otherwise specified, the Tel should be 2.25 timesthetotal equipmentcost of $210,000; this results in a Tel of over $470,000. Instead, it appearsthat a vendor quote of$21O,OOOfor the equipmentalone plus an undocumented additional cost of $40,000 was used to derive U.S. EPA's total capital cost of$250,000. As such, it is clear the Tel was underestimated for the NaOH scrubber.

5 U.S. EPA, OAQPS Control Cost Manual, 6th edition, EPA 452/B-02-001,Ju\y2002. http://www.epa.gov/ttn/catc/dirl/ollchs.pdf 6 Docket ID: EPA-HQ-OAR-2010-1042-0079

4Table 1. OAQPS Capital Cost Multipliers for Scrubbers7 Capital Cost OAQPSNotation 

### Purchased Equipment Costs Total Equipment Cost Instrumentation (e.g., PLC) Taxes/Tariffs Freight 

### Total Purchased Equipment Costs

Direct Installation Costs Foundations and Supports Handlingand Erection/Interconnection Electrical Piping/Ductwork Insulation Painting 

### Total Direct Installation Costs

Indirect Installation Costs Engineering Construction and Field Expense Contractor Fees Start-up Performance Test Contingencies 

### Total Indirect Installation Costs

Total Capital Investment 

### $ A O.10xA O.03xA O.05xA


### B= 1.18 

### xA

O.06xB O.40xB O.OlxB O.05xB O.03x B O.OlxB C =0.56 x B

O.10xB O.10xB O.10xB ·O.OlxB

O.OlxB O.03xB
D= 0.35 x B

TCI=B +C+D Annual costs should be comprised of direct and indirectoperating costs. Direct annual costs include labor, maintenance, replacementparts, rawmaterials, utilities, and waste disposal. Indirectoperating costs include plantoverhead,taxes, insurance, general administration, and capital charges. Replacement partcosts should be included, and raw material costs should be estimated based upon the unit cost and annual consumption. With the exception ofoverhead, indirect operating costs should be calculated as a percentageofthe total capital cost. The indirect capital costs should also be based on a capital recovery

7 U.S. EPA OAQPS, EPA Air Pollution Control Cost Manual (6th Edition), January2002,Section 6, Chapter 2,page2-48 (Table 2.8: Direct and Indirect Installation Costs for Venturi Scrubbers).While retrofit costs are excluded, "a retrofit multiplier of 1.3 to 1.5 can be applied to the total capital investmentto estimate these costs atthe studylevel" per the OAQPS Manual.

5factor (CRF). However, the $100,000 peryearoperating cost has no clear derivation from U.S. EPA's total capital cost of $250,000 and no references to these direct and indirect operatingfactors. Table 2 shows the OAQPS multipliers touse in estimating annual operatingcosts. Table 2. OAQPS Operating Cost Multipliers for Scrubbers8 Operating Cost OAQPSNotation 

### DirectAnnual Costs Operating Labor (2 hr, per8·hrshift) E SupervisoryLabor F 

## =0.15 x E Maintenance Labor (1 hr, per 8·hr shift) G Maintenance Materials H = 1.00 x G Water Quench & Other Consumption I FilterMedia Replacement Solid Waste Disposal 

### K Electricity L 

### Total DirectAnnual Costs DAC=E+ F+ G+ H+ 1+]+K+ L



### IndirectAnnual Costs Overhead M 

## = 0.60 x (E + F + G+ H) Administrative Charges N =0.02 x TCI PropertyTax 0= 0.01 x TCI Insurance P 

## =0.01 x TCI Capital Recovery 

### Q Total Indirect Annual Costs ID,AC 

## = M+

### N+ 

### 0 + 

### P +Q

Total Annual Cost 

### $ TAC 

## =(DAC + IDAC)



### 1.2.2. Caustic Scrubber Train Since Hansen Engineeringprovided theinitial design for a NaOH scrubber,theywere consulted again and providedwith more details on the process, additional data on the exhaustparameters, and the proposed limit. Based on discussions with this company, andthat most material collected from the existingPM control devices on thefurnaces is a yellowcolor, the chromium is likelyin the form of submicron sodium chromate, which unfortunatelyis not a suitable candidatefor the initiallyscoped scrubberthatHansen Engineering had suggested to U.S. EPA in earliercommunications. The initial Hansen proposal appearsto be a major part ofthe EPA's justification that NaOH scrubbertechnology was transferable for this application. This change in proposals is significant in that Hansen was the only vendor to initially suggest NaOH scrubbertechnology mightbe suitablefor the application. However,

B

### u.s. EPA OAQPS, EPA Air Pollution Control Cost Manual (6th Edition), January2002,Section 6, Chapter 2, page 2·51 (Table 2.9: Annual Cost Factors for Scrubbers).
6Hansen and othersproposed an alternateemission controls thatmightachieve the required reduction to the meet the proposed limit. Since these designs have not beenused inpractice, trials are needed to verify theirfeasibility. Inthe revised Hansen proposal the basic chemistrywould be to reactthe sodium chromate from the exhaustwithbarium nitrate via a series ofscrubbersto form a precipitate (barium chromate) and a salt (sodium nitrate). The design would include a venturi scrubber and a packed tower scrubber. The reaction requires a pH ofabout 12,which is a caustic environment. Ifthe removal of sodium dichromate is also needed, which is not known at this time, then one to two in-series packed tower scrubbers would be addedto the design. The additional scrubbers are required as removal of sodium dichromate requires moretime and exposure, and it maytake additional experimenting: For example,thelab test that Hansen Engineeringcompleted showed thatthree additional treatmentswere required to eliminate sodium dichromate as compared to sodium chromate. Again, the company offers no warranty on performance as the system is experimental. Whenusing the OAQPS multipliers shown in Table 2 and a more accurate purchased equipmentcost9 of $592,200 (the minimum Hansen proposal), we derive an annualized cost of approximately $495,000 for an experimental caustic scrubbersystem for the specific DM2 furnace as tested; details are provided at the end of this document. When this value is substituted for the $100,000 used in U.S. EPA's initial analysis, the cost effectiveness is greaterthan $29,700 perpound. As the system is experimental, it would need toungergo a trial period to determine whatlevel ofdesign would be requiredtomeet the proposed chromiumlimit. Ifthe second level of control is required perthe Hansen proposal the cost effectiveness is greaterthan $33,100 per pound. 

### 1.3. REVISED ASSESSMENT We are providing a revised assessment ofpotentiallyfeasible chromium emission controls. This approach follows U.S. EPA's traditional methodology used in settingGACT standards of first selecting technicallyfeasible controls and then determiningthe cost effectiveness ofsuch controls. This assessmentfocuses on one ofthreefurnaces thatwould requireadditional controls to meetthe proposed chromium emission limit: Owens Corning's furnace DM210cated in Delmar, NewYork 

### 1.3.1. 

### DataSol.lrces The following data sources wereused: 

## > Section 114 stacktest report (2012) for the Owens Corning Delmar furnace, which contains the tested chromium emissions from furnace DM2 with DEP 

### > Actual cost ofDEP installation on the Delmar furnace 

### > Communications (emails and call logs) with Monroe Environmental for site-specific application of a chrome emission control technology on the Delmar furnace 

## > Communications (emails and call logs) with Met-Pro for site-specificapplication of a chrome emission control technology on the Delmar furnace 

## > Communications (emails and call logs) with Hansen Engineering for site-specific application of a chrome emission control technology on the Delmar furnace

9 Upon detailed communications with Hansen Engineering in April and May 2013, it was determined that more equipmentwill be required and that such a design is still experimental in nature. Hansen Engineeringprovided an estimate for equipment costs in therange of $592,200-$787,700 fortreatmentofa 15,000 acfm flowrate.
7

## > Prior communications (emails and call logs) between u.s. EPA and multiple vendors of environmental control equipmentfor general information on chrome emission control technologies 

## > u.s. EPA publishedinformation such as the OAQPS cost manual for assumptions on capital costs excluded from vendor estimates and operatingcosts 

## > Consumerprice indexfor adjustingOAQPS cost calculations



### 1.3.2. Cases for Cost Effectiveness Once the cost effectiveness was determined for Delmar, separatecalculationswere performedto determinethe cost effectiveness (order of magnitude) for the remaining furnaces. While the same annualized cost is used, the range in cost effectiveness reflects thevariation in emissions from each of thethree furnaces thatwould require additional controls to meettheproposed limit. Specifically, Owens Corningdeveloped cost effectiveness estimatesfor the following cases: 

## > Case A - Delmar furnace 

## > Case B Example case for an Owens Corning furnace that might require the most control 

### > Case C - Example case for an Owens Corning furnace that might require the least control 

## > CasEl D - Revised case for an average reductionof 16.67Ib/yrfor each of thethree furnaces that require control (50 lb/yr divided by 3 sources) 

### 1.3.3. Identification of Potential Control Technologies (Step 1) Potentially applicable emission control technologies were identified for the reduction ofchromium emissions byresearchingthe U.S. EPA control technology database,technical literature,control equipmentvendor information, and by usingprocess knowledge and engineeringexperience. The ReasonablyAvailable Control Technology (RACT)/Best Available Control Technology (BACT)/Lowest Achievable Emission Rate (LAER) Clearinghouse (RBLC), a database made available to thepublic throughthe u.S. EPA's Technology Transfer Network (TTN), lists technologies and corresponding emission limitsthathave been approvedby regulatoryagencies in permitactions. A search ofthe RBLC databasein April 2013 was performed to identifythe emission control technologies and emission limits thatwere imposed by permittingauthoritieswithinthe pasttenyears for all sources of chromium emissions. The following category was searched: 

## > Chromium/ Chromium Compounds,-3 &-6 (CAS No. 7440-47-3) The RBLC search results contained mostlycombustion devices. However, one candidatecontrol option was identified from a manufacturingprocesswhich employsthe same type ofchromium emission controls as those presentlyin place for the furnaces: dry filtration (i.e., traditional dustcollection devices). In addition to the RBLC, the existing controls for fiberglass manufacturingfurnaces wereassessed. These controls are similarto thatidentified in the RBLC database (Le., traditional dustcollection devices). 1.3.3.1. Proven Controls Dust collectors, baghouses, ESPs, and similar devices are a form of dry/physical filtration and are used in this field extensively. Each such technology has a meansby which to collect or trap the chromium, which

8is in particulate form. Emissions from the existing furnaces in this source category are already being reduced using these proven controls. 

### 1.3.3.2. Experimental Controls All ofthe designs that we have analyzed, and which are listed below, are completely experimental in nature, and have never been applied to any source in the United States. As such, any selected technology would require a trial period and such costs are not included in the evaluation.


## > 3-Stage filter consisting ofa quench tower, coalescing pad and fiber bed filters. This custom design has the option ofutilizing a water system to clean the filter media; otherwise, the filter media would need replacement on a more frequent basis. 

## > Series ofin line high efficiency particulate air (HEPA) filters with water quench. This custom design would require changeouts at an unknown frequency. 

## > Venturi scrubber train (custom design) with water quench, sub-cooling (required to create water droplets in the gas stream onto which the fine particulates might collide), a series ofventuri scrubbers (each designed for a minimum pressure drop of50" water column), and a final mist eliminator vessel (to capture the fine liquid mists generated in the venturi). Ancillary equipment would include heat exchange, cooling water, cooling tower, liquid filters, and specially designed high pressure fans. 

## > Caustic scrubber train (custom design) using a venturi scrubber with caustic, a collection tank, and a finishing scrubber jwash tower. This design would introduce a reactant to precipitate outthe chromium, which would be collected and sent to a filter press to reduce the water content before disposal. These experimental control technologies fall into one oftwo types ofcontrol systems: dry jphysical filtration or wet scrubbing. Dryjphysical filtratLon is in the form ofdust collectors, ESPs, HEPA filters, candle filters, and other similar materials used to trap the chromium. It should be noted that the size of the chromium being collected is submicron since the exhaust stream is already treated for particulate reduction. Also, the material on which the residual chromium and non-chromium particulate is deposited must either be cleaned continuously with a water system or replaced frequently. Wet scrubbing uses a series ofeither very high pressure drop venturi scrubbers to trap the,material in the water or caustic scrubbers to chemically react and precipitate out chromium. In most cases, there must be an initial step to quench the exhaust. That is, the temperature ofthe exhaust must be lowered for any ofthese controls to be effective. 

### 1.3.4. Elimination of Technically Infeasible Control Options (Step 2) After the identification of control options, the second step in the assessment is to eliminate any technically infeasible options. A control option is eliminated from consideration ifthere are processspecific conditions that would prohibitthe implementation ofthe control or ifthe highest control efficiency ofthe option would result in an emission level that is higher than any applicable regulatory limits. The existing furnace PM controls are achieving chromium reductions ofgreater than 97%. This amount ofreduction is proven in the field and is likely the highest control efficiency ofall proven and experimental options. As such, in a typical analysis, the existing PM controls would have already been considered the highest ranking. Since the Agency proceeded with an evaluation ofthe less effective, experimental controls to determine ifadditional controls were feasible, we have continued the analysis ofthe following controls using U.S. EPA's own guidance to provide more accurate results:

9

## > 3-Stage filter 

### > HEPA filters 

## > 3-Stage filter with water cleaning 

## > Venturiscrubbertrain 

## > Caustic scrubbertrain (updated from U.S. EPA proposal) Based on discussions with vendors,it will be difficult, if not impossible, to design and operate a system for the Delmar furnace thatwould meettheproposed limit. While some level ofreduction can be predicted, thefact thatthe furnace exhauststream is alreadybeingtreated with a particulate control device (i.e., a DEP) means thatthe majority of chromium emissions from thefurnace (in some cases, over 99.97%) are already controlled. Confirming this assertion is the fact that a DEP is the type of

. control device thatU.S. EPA has accepted as MACT and GACTfor otherfurnaces. Additional control of a

streamwith such low concentrations of chromium is above and beyond what should be required for any source of HAP

- major or area. Aside from the fact thatexisting PM controls shouldbe considered as GACT for these furnaces, there is anotherfactor thatU.S. EPA did not consider in their control analysis. The particulate is in submicron form, which is difficultto remove with wet scrubbing. Thus, U.S. EPA's proposed method of a scrubberis technicallyinfeasible. Even ifthe cost ofthe scrubberwas feasible, and even ifcausticwere added to a wet scrubber, this system alone would not be sufficient to meet U.S. EPA's proposed chromium emission limit. As such, a stand-alone caustic scrubber shouldbe removed from further consideration. Becausenone ofthesetechnologies havebeen demonstrated in practiee, it is optimisticallyassumed that each option would achieve U.S. EPA's proposed emission limitfor chromium emissions, andthuseach is given equalweightinginthisregard. However, thevendors do not guarantee a specific level of control efficiency thatmeets theproposed limit for any ofthese systems atthis time. Followinga period oftrial and error, some vendors may be ableto provide a better defined system and estimatea removal efficiency for chromium compounds. 

### 1.3.5. Rank of Remaining Control Technologies (Step 3) The third ofthefive steps in the top-down assessmentprocedure is to rank technically feasible control technologies by control effectiveness. The existingPM controls have thehighestcontrol reductions.All experimental options are presumedto have the same reduction efficiency though none have been shown to meet such a requirementin practice. 

### 1.3.6. Evaluation of Most Stringent Controls (Step 4) The fourth ofthe five stepsin the top-down assessmentprocedure is to evaluatethe most effective control and documentthe results. This step has been performed for an control technologies on the basis ofeconomic, energy, and environmental considerations, and is described herein. 1.3.6.1. Economic Feasibility Calculation Process Economic analyses are performedto compare total costs (capital and annual) per ton ofpollutant removed for various potential control technologies thathave been deemed technicallyfeasible. In these analyses, however, the cost perpound ofremoval was assessed. 10 Capital costs includethe initial costof

10 A cost perpound basis was used for consistency with US EPA's cost analYSiS, as provided in the preambleto the proposed rule.


### 10the components intrinsicto the complete control system. Annual operating costs include the financial requirementsto operatethe control system on an annual basis including overhead, maintenance, outages, raw materials, and utilities. The capital cost estimationtechnique used is based on a factored method of determining direct and indirectinstallation costs. That is, installation costs are expressed as a function of known equipment costs. This method is consistentwith U.S. EPA's control cost manual. Total purchased equipment cost represents the delivered cost ofthe control equipment, auxiliary equipment, and instrumentation. Auxiliary equipment consists ofall the structural, mechanical, and electrical components required'for the efficient operation ofthe device. Auxiliary equipment costs are estimated as a straight percentage ofthe equipmentcost. Direct installation costs consist ofthe direct expendituresfor materials and labor for site preparation, foundations, structural steel, erection, piping, electrical, painting and facilities. Indirectinstallation costs include engineering and supervision of contractors, construction and field expenses, construction fees, and contingencies. Other indirect costs

- include equipmentstartup, performance testing, working capital, and interestduring construction. Annual costs are comprised of direct and indirect operating costs. Direct annual costs includelabor, maintenance, replacement parts, raw materials, utilities, and waste disposal. Indirect operating costs include plant overhead, taxes, insurance, general administration, and capital charges. Replacement part costs were included where applicable, while rawmaterial costs were estimated based upon the unit cost and annual consumption. With the exception of overhead, indirect operating costs were calculated as a percentage ofthe total capital costs. The indirectcapital costs werebased on the CRF, defined as: i(l+ 

# on CRF 

## = (1 

### + 

# on - 1 where i is the annual interestrate and 

### nis the equipmentlife in years. The equipmentlife is based on the normal life ofthe control equipment and was set to 15 years. The same interest rate was applied to all control equipment cost calculations. For this analysis, a conservative interest rate of4% was used, which is lower thanthe 7% thatis provided in the OAQPS Control Cost Manual. ll Note that all calCulations presented herein arebased on March 2013 dollars. Detailed calculations for the economic analyses are provided in Tables 3,4, and 5. 

### 1.3.6.2. Experimental Dry/Physical Filtration Costs for installation and operation ofthe following dry/physical filtration de signs were developed: 

## > 3-Stage filter (Option A) 

### > HEPA filters (Option B) 

### > 3-Stage filter with water cleaning (Option C) Even ifthe use of any ofthese devices was technically feasible on a furnace, the cost of using such a device exceeds thebenefit of the chromium reduction it offers. For the site-specific application at the Owens Corning Delmar furnace (Case A), the cost of controlling chromium with additional dry filtration is estimated atbetween $49,100

- $63,900,per pound of chromium removed, depending on the device

11 

### u.s. EPA, OAQPS Control Cost Manual, 6 th edition, Section 2,Chapter 1, page 1-52. http://www.epa.govIttn/catc/dir1/c allchs.pdf

11selected. The cost effectiveness for Case B for a furnace thatwould require the most control to meetthe proposed limitwas estimated in the range of$lS,500

- $24,100 perpound. The cost effectiveness for Case Cfor a furnace thatwould requirethe least control to meetthe proposed limit was estimated in the range of $235,000

- $306,000 per pound. Finally, the cost effectiveness for Case D, which is based on an average reduction of 16.67 pounds peryear for each ofthethree furnaces thatrequire control (as noted in U.S. EPA's proposal), was estimated in the range of $24,100-$31,400perpound. These high costs are largelydue to the initial capital cost of not only the control device but also the related infrastructure and installation cost. The ongoing cost of cleaningthe filters and the cost to dispose of a newhazardous waste stream are significant. There would alsobe associated energyand environmental impacts resultantfrom use of the electricityto operate the system, as well as thetransfer ofthis compound into either a wastewaterstream or a solid waste stream. The detailed cost calculations are provided as Attachment 1 ofthis document. 1

..3.6.3. Experimental Wet Scrubbing Costs for installation and operation ofthe following wet scrubbing designs weredeveloped:


### > Venturi scrubbertrain (Option D) 

## > Caustic scrubbertrain

- revised U.S. EPA estimate (Option E) Again, even iftheuse of any ofthese devices was technicallyfeasible on a furnace, the cost ofusing such a device exceedsthebenefitof the chromium reductionit offers. For the site-specific application atthe Owens Corning Delmar furnace (Case A), the cost of controlling chromium withwet scrubbingis estimated atbetween $60,500

- $S4,900 per pound 

### of chromium removed, dependingon the device selected. The cost effectiveness for Case B, for a furnace thatwould requirethe most control to meetthe proposed limit, was estimatedinthe range of$22,SOO

- $32,000 perpound. The cost effectiveness for Case C, for a furnace that would requirethe least control to meetthe proposed limit,was estimated in therange of$289,000

- $405,000 perpound. Finally, the cost effectiveness for Case D, which is based on an average reduction of 16.67 pounds peryear for each ofthethree furnaces thatrequire control (as noted in U.S. EPA's proposal), was estimated in the range of $29,700-$41,700 perpound. These high costs are largelydue to the initial capital cost of not only the control device but also the related infrastructure andinstallation cost. In additionto similar requirements as dry filtration, a new hazardous waste stream is generatedthatmustbetreated and disposed of (Le., wastewater). Unlike particulate collected from the DEP at Delmar, the wet material collected from this system will be treated with chemicals and will be unsuitablefor reuse in the furnace. There would also be significantlyhigher energyand environmental impacts resultantfrom the use ofthese systems. The detailed cost calculations are provided as Attachment 1 ofthis document. 1.3.6.4. Proven Controls with Proper Maintenance and Operating Practices The only remainingtechnology to consider is proper maintenanceand operating practices ofthe furnaces and therr associated PM control devices, a logical option since a properlymaintainedand operated furnace with PM control can effectivelyreduce chromium emissions. This control option should be considered acceptable for thefurnaces. A baseline scenariofor the Owens Corning Delmar DEP is presented in the attached cost calculations, which has a cost effectiveness of$1,350 per pound of chromium removed.The material collected from the DEP is returnedtothe process and therefore does not generate a hazardouswaste stream.



### 12

# ATTACHMENT ATable 4. Cost Analysis for Technically Feasible Controls

,



### - Capital Cost1 Current**Controf~**

DEP Potential Add-On Chrome Removal OptionA3 OptionB4 Option C 5 Option D6 Option Causti Scrubb 3-Stage Train Filterwith Venturi (REVISI 3-Stage "EPA Water Scrubber EPA

Filter Filters Cleaning Train Estimal PUrGhased Equipment Costs Total Equipment Cost Instrumentation (e.g., PLC) Taxes/Tariffs Freight Total Purchased Equipment Costs 300,000 225,000 tOOO,OOO 592,200**592,~** 30,000 22,500 100,000 59,220**59,~**

9,000 6,750 30,000 17,766**17,~** 15,000 11,250 50,000 29,610 29,t 354,000 265,500 1,180,000 698,796 698,1 DirectInstallation Costs 8 Foundations and Supports 21,240 15,930 41,928**41,~** Handling and Erection/Interconnection 141,600 106,200 279,518**279,~** Electrical 3,540 2,655 6,988**6,~** Piping/Ductwork 17,700 13,275 34,940**34,~** Insulation 10,620 7,965 20,964**20,~** Painting 3,540 2,655 6,988**6,~** Total DirectInstallation Costs 198,240 148,680 391,326 391,5 Indirect Installation Costs 8 Engineering 35,400 26,550 69,880**69,~** Construction and Field Expense 35,400 26,550 69,880 69J Contractor Fees 35,400 26,550 69,880**69,~** Start-up 3,540 2,655 6,988 6/ Performance Test 3,540 2,655 11,800 6,988**6,~** Contingencies 10,620 7,965 35,400 20,964**20,~** Total IndirectInstallation Costs 123,900 92,925 47,200 244,579 244,:' Total Capitallnvestmcnt $ 1,962,500 676,140 507,105 1,227,200 1,334,700 1,334,1

Operating Cost1 DirectAnnual Costs Operating Labor (2 hr, per 8-hr shift)9 Supervisory Labor9 Maintenance Labor (1 hr, per 8-hr shift)9 Maintenance Materials9 Water Quench & Other Consumption 1O DEP
56,673

8,501 28,336 28,336 0 3-Stage Filter

56,673

8,501 28,336 28,336

1,088 Potential Add-On Chrome Removal Causti Scrubb 3-Stage Train Filterwith Venturi (REVISI "EPA Water Scrubber EPA Filters Cleaning Train Estimal

56,673 56,673 56,673 56,t

8,501 8,501 8,501**8,~** 28,33,6 28,336 28,336**28,~** 28,336 28,336 28,336**28,~** ,1,088 1,133 2,246**2,~**Notes to Table 4; 1, Capital and Operating Costs based on a combination ofVendor estimates and U.S. EPA OAQPS, EPA AirPollution Control Cost Manual (6th Edition) , Jan

OAQPS percentages for scrubbers are specified in the OAQPS Manual, Section 6, Chapter 2, page 2-48 (Table 2.8; DirectandIndirect Instollation CostsJ (Table 2.9:Annual Cost Factors for Scrubbers). The scrubber OAQPS multipliers were selected, as they are the same or less than those provided for sir Filters, Gas Adsorbers and Electrostatic Precipitators) and thus provide a more conservative estimate ofthe total cost. See, for example, Section 6, Ch, Factors for Fabric Filter. While retrofitcosts are excluded, "a retrofit multiplier of 1.3 to 1.5 can be applied to the total capital investment to estimate I the OAQPS Manual. 2 Actual cost ofDEP installation on wood fiberglass manufacturing Oxy-fuel furnace. Comprised of$1,600,000 forDEP equipment and installation + $n

batch handling (25% * $1,150,000) for DEP dust portion ofhandling. Costs are in 1999 $. 3 Budgetary cost estimate of$300,000 was provided (November 2012) for a Monroe Three Stage Filter composed ofQuench Tower, Coalescing Pad anc

16,000 ACFM at 420°F, 223' ASL, 10% moisture. Excludes equipment for the cleaning system. Exclusions in quote, which have been estimated using f" include the following: Installation, Offloading services, External piping, Taxes/Tariffs, Insulation, Ductwork, PLC/ HMI, Freight, Interconnecting ductw in quote, which have notbeen estimated and ifrequired will increase the estimated costs are as follows; Special packaging, Chemicals, Chemical stora VFD's or Dampers, Freeze Protection, Fume hoods, Pumps, and Explosion Proofmotors. 4 The cost for a'HEPA filter system was assumed to be similar to the Three-Stage Filter, butwith less parts. As such, an estimate of75% ofThree-Stage :

analysis. 5 Order ofMagnitude estimate (-0%/+50%) for Three Stage Filter with Cleaning System per email communication within Owens Corning dated 12/14/

costs for the water supply, drains, containment/handling for the collection ofa hazardous substance, engineering, foundations, installation, startup c( existing exhaust to the filter and bypass system for servicing the filter. The scope also includes a membrane filter system to clean the water for reuse hazardous sludge. Under this design, the expectation is thatthe 3rd stage filter candles, which are similar to HEPA filters, should last longer ifthey arE ability to clean these filters has never been demonstrated. Assuming that all direct installation costs are included. 6 Proposed system by Met-Pro (March 2013) would include the following steps (italics as provided by Met-Pro): The gas would be quenched to the wet bulb temperature. The gas would need to be sub-cooled below its wet bulb temperature. Sub-cooling the gas will create water droplets in the gas stream for thefine partia • The gas then wouldgo through a couple of venturi scrubbers that are each designed for pressure drop of 50" w.c. ormore. The gas stream will then go through a final mist eliminatorvessel to capture thefine liqUid mistsgenerated in the venturi.

- The system will require significantancillary equipmentas well such as heat exchange, cooling water; cooling tower, liquid filters, and specially designed I Since the cost for this Venturi Scrubber Train is notknown, it was set equal to the Caustic ScrubbingTrain. However, purchased equipmentcostmay I additional required process components. 7 A costestimate for a single caustic scrubber was provided by Hansen Engineering to US EPA on 07/10/2011 as Total Package Cost of$210,000.lnthe

flowrate was specified and an exhaust fan was not specified for this system, which is now known to be needed. Upon more detailed discussions betwe Engineering in April and May 2013, it was determined that more equipment will be required, and that such a design is experimental in nature and not the US. Hansen Engineering provided an equipment cost on 05/17/2013 in the range of$592,200-$787,700 for treatment ofa 15,000 acfm flowrate. a venturi scrubber, a collection tank, and a final scrubber. Ifneeded, one to two in-series scrubbers would be added to the design, which represents th means to treat and dispose ofthe chrome-laden wastewater (i.e., precipitation and filter presses) was not included in the cost, and as such has been e! provided in the proposed rule [i.e., a $250,000 capital cost, $100,000 total annualized costs, plus $10,000 peryear for stack tests ($380,000/yr /3 sOl on page 22384, Federal Register, Vol. 78, No. 72] were revised. The following changes were made: since a Total Capital Investment of$250,000 equat! ofless than $115,000 when the OAQPS Cost Manual factors are applied, this amount was revised to reflect the lowest purchased equipmentcost of$5 Engineering. Also, as the basis ofthe $100,000/yr operating costs was not provided, these costs were revised usingthe methods defined in EPA's OA( 8 Where no value is shown, the cost is included in the Total Equipment Cost. 9 Values based on minimum requirements specified in OAQPS Manual, Section 6, Chapter 2, page 2-51, and Section 6, Chapter 2, page 2-55. Maintenanc(

materials, not filter media. 10 The water quench step is needed in all scenarios. The water quench is essentially a set ofwater spray nozzles located in the ductworkprior to each c( reduce the temperature ofthe DEP exhaust gas. In addition to water use from the quenching step, a small amount ofwater is needed for the 3-Stage F ongoing cleaning ofthe filter media to extend life). Significant water usage is needed for designs involving water scrubbers. The cost ofwateruse for t equal to that estimated for the Venturi ScrubberTrain. 11 Frequency of6 months for changeouts with no cleaning or 1 year for changeouts with cleaning. Unlike typical applications, where the filter bags have years (OAQPS Manual, page 1-46 ofSection 6, Chapter 1), application ofthis technology to a wool fiberglass furnace, even post-PM control device, is e: to 2 times peryear or more. Since this technology has never been applied to the proposed process, it is unknown how frequent the,changeouts will Q( need to bypass this system during changeouts to continue to operate. 12 Estimated based on the weight ofPM collected on the filter media and frequency offilter changeouts. For option with water cleaning system, sludge is of, in addition to the spent filter media. Set DEP cost equal to 3-stage filter cost. 13 The electricity requirement provided for the basic 3-stage scrubber system was used for all filter media devices and for the caustic scrubbertrain. Set cost. 14 In place ofthe cost manual methodology, which is (0.1098 

### * TCI), a lower multiplierwas used to calculate these factors. As the DEP was installed in l' assessed for 14years. However, the ongoing budget to maintain and repairthe DEP will require a similar, annualized cost afterthe originallyestimat. 15 Values taken from Table 1. CostAnalysis Supporting Information Technically Feasible Controls. 16 Current Surrogate PM removal rate (ton/yr) [(2Ib/hr maximum, additional PM control) 

### * (8760 hr/yr) * 1 ton PM/2000 lb]/ (100%

- 97% DEP Rell 17 Add-On System Surrogate PM removed (ton/yr) (2Ib/hr maximum, additional PM control) 

### * (8760 hr/yr) * 1 ton PM/2000 Ib 18 Cost per lb ofChromium Removed ($/lb) = (Total Annual Cost, $) / (Pollutant Removed, lb/yr). 19 Cost per ton ofSurrogate PM Removed ($/ton) 

### = (Total Annual Cost, $) / [(Pollutant Removed, Ib/yr) 

### * (2000 lb/ton)]Table 5. Cost Comparisons for Alternate Scenarios

Parameters Chromium Emission Inputs (lb/yr) Current, Future, Incremental Controlled Proposed Chromium Emissions Emissions Removed 3-Stage Filter Cost Effectiveness ($/lb removed)1 3-Stage Filter Venturi

with Water Scrubber HEPA Filters Cleaning Train CaseA2 CaseB3 CaseC CaseD5 11.48 3.29 8.19 25 3.29 21.72

5 3.29 1.72

- 

### - 16.67 51,845 19,555 247,602

25,478 49,163 63,980 84,91: 18,544 24,132 32,02: 234,795 305,558 405,52:

24,160 31,442 41,72' Notes to Table 5: 1 Annual cost divided by incremental chromium removed. Annual Cost ($/yr) taken from Table 2 for Case A. Costs are assumed to be the same Order of $ 424,638 3-Stage Filter $ 402,673 HEPA Filters $ 524,031 3-Stage Filter with Water Cleaning $ 695,481 Venturi Scrubber Train $ 495,826 Caustic Scrubber Train (REVISED EPA Estimate) 2 Case Ais based on reducing the Owens Corning, Delmar furnace to the proposed US .EPA limit of6.0E-05Ib/ton glass pull, converted to a mass emissi(

glass pull rate and 8760 hrs/yr operation. 3 Case Bis a 'best case' for Owens Corning when reducing the highest expected emission rate that would requite controls to meetthe proposed US EPA

glass pull, converted to a mass emission rate using a 6.25 ton/hr glass pull rate and 8760 hrs/yr operation. 4 Case Cis 'worst case' for Owens Corning when reducing the lowest expected emission rate that would require controls to meet the proposed US EPA I

glass pull, converted to a mass emission rate using a 6.25 ton/hr glass pull rate and 8760 hrs/yr operation. 5 Case Dis based on reducing the emissions presented in the proposed rule, page 22384, Federal Register, Vol. 78, No. 72 [i.e., SO lb/yr /3 sources'" 16

to a level thatwould meet the proposed US EPA limit of6.0E·05Ib/ton glass pull, converted to a mass emission rate using a 6.25 ton/hr glass pull ratE



### 17

### 1.3.7. Selection of Control Technology (Step 5) Based on steps 1 through 4 ofthis analysis, it has been determinedthatpropermaintenance andgood operatingpractices for the existing particulate control devices arethe only controls thatare truly feasible for these furnaces. All otherpotential control technologies should be eliminated for the reasons outlined in this assessment. This is especiallytrue considering that none ofthe removal costs include the unknown cost of developing these technologies for production operations and the potential to have removal efficiencies that do not meetthe proposed emission rateeven withthese additions. Without an adjustment ofthe proposed emission rates for chrome the DMZ furnace, which is three and a halftimes the proposed limit, will have to install experimental technologycosting at least $50,000 per lb ofchrome removed. All this to remove 8.19 pounds of chrome annually, which hasbeen shown not to pose a riskto the community. This is well above the costs referenced bythe U.S. EPA asnot viable in the proposed rules. For furnaces thatonly marginallyexceed theproposed limitsthe costs can easilyexceed $ZSO,OOO perpound of chrome removal.



### 18