Project No.: 0172.09.029.043 DISTRIBUTION 

Page _1_ of __2_

Project Name: Steam Electric Rulemaking 

TELEPHONE CALL RECORD 

 Outgoing Call 

Date: 4/21/2011 Time: 10:30 AM 

Company Name: United Conveyer Corporation (UCC) 

Contact Name: Kevin McDonough 

Phone No.: 847-473-5900 ext. 350 

Name: EPA and ERG (See Below) 

GENERAL SUBJECT : Conversion from Wet to Dry Ash Handling Systems – Fly and Bottom 

TOPICS DISCUSSED AND ACTION TAKEN 

On November 8, 2010, ERG sent an e-mail to Kevin McDonough (see DCN SE02018) requesting information 

on wet to dry fly/bottom ash handling conversions including equipment, operations, capital costs, and operation 

costs. Mr. McDonough responded to the e-mail request on April 13, 2011 (see the attached responses below, 

UCC Ash Handling Response). Based on the response, ERG, EPA, and UCC participated in a conference call to 

ask follow up questions on the information provided on April 21, 2011. A list of participants on the call is 

provided below: 

EPA

Ron Jordan 

Jezebele Alicea-Virella 

UCC

Kevin McDonough 

Mike Kipnis 

ERG

TJ Finseth 

Elizabeth Sabol 

Notes:

UCC stated with new generating units, the mechanical drag system (MDS) is more cost effective than the wet 

sluicing system. They explained that the majority of the new systems installed are MDS or completely dry 

mechanical systems. 

However, UCC mentioned that for existing unit, and existing infrastructure, these conversions can be difficult 

based on space constraints. UCC stated that plants are considering a remote MDS rather than installing a 

completely dry system, which requires the replacement of the wet hopper with a dry hopper. UCC also stated 

that these dry systems (particularly the pipelines from the boiler to dry bottom ash silos) are more expensive 

than the remote MDS alternative. 

UCC stated that the costs for the remote MDS are comparable to the MDS conversions, maybe slightly more 

expensive. UCC stated that there savings associated with remote MDS conversions at plants where there are 

multiple units. At these plants, one remote MDS is designed to handle bottom ash from multiple generating 
units (referred to as multiple unit synergies). UCC stated that there is an overwhelming response to these 

systems because it does not require any boiler work or extended outages. UCC confirmed that no plants were 

currently operating a remote MDS; however, a handful of plants were looking into the option. 

UCC explained that the size of the remote MDS is based on the existing sluice flow rate, ash generation, and 

pipeline size of the wet handling system. UCC stated that flow rate is generally a function of ash generation (in 

tph) and the distance the bottom ash is conveyed. 

Next, complete recycle systems, particularly chemical treatment for recycle systems, were discussed. UCC 

explained that the closed loop system consumes water (moisture content or removed bottom ash). UCC 

mentioned that chemical additional is not currently being utilized in any of their systems and pH control is only 

used in a minimal amount of systems to reduce scaling.

For fly ash, UCC estimates that 66 percent of the handling systems in the industry are already dry. Additionally, 

all new installations are mechanical exhausters (no hydrovacs for wet pneumatic systems). 

Finally, EPA, ERG, and UCC discussed the timing for the proposed rulemaking. UCC stated that it may take 

approximately six years to complete fly ash handling conversions to the remaining wet fly ash sluicing systems 

in the industry. UCC provided the estimate considering the outage time, time for piping and getting control 

systems up and running, and pre-outage time, which includes the set up of the filter separator and all other 

piping/silo equipment. 

UCC stated that completing bottom ash handling conversions for the entire industry would likely take longer 

(approximately seven years) because of the large number of bottom ash wet sluicing systems requiring 

conversion. UCC stated that it would be a challenging timeframe for completion. Additionally, UCC stated that 

because the remote MDS and complete recycle systems do not require any outages, so they may be more 

attractive conversion options for the industry. 

After the call, ERG delivered a request for more information, particularly cost data, for bottom and fly ash 

handling conversions. Please find the additional requests and UCC responses in the attachments provided 

below.

The attachments to this telecon include: 

1. Email from Kevin McDonough, UCC on April 13, 2011 delivering UCC’s response to EPA’s ash 

request November 8, 2010. 

2. PDF attachment to the email from Kevin McDonough on April 13, 2011 providing UCC’s responses to 

EPA’s ash request. 

3. Email from Kevin McDonough, UCC on May 10, 2011 delivering UCC’s response to follow up 

questions from the teleconference held April 13, 2011. 

4. Attachment to the email from Kevin McDonough on May 10, 2011 providing UCC’s responses to 

EPA’s follow up requests. 
From: Elizabeth Sabol [mailto:Elizabeth.Sabol@erg.com]

Sent: Wednesday, March 30, 2011 2:25 PM

To: McDonough, Kevin

Cc: Alicea.Jezebele@epa.gov; jordan.ronald@epa.gov; Deborah Bartram

Subject: RE: Ash Information for EPA Steam ELGs

Kevin,

As previously discussed, EPA is still requesting the ash handling cost information sent in November 2010. In an effort to move forward with our 

cost methodology, we've prepared a prioritized list of the information that is necessary for our analysis. Please provide information you have on 

the following subjects as soon as it is available, regardless if some of the other information isn't pulled together.

1. Fly ash conversion costs (capital and O&M) for dry vacuum systems based on conveyance distance and capacity (tons per hour (TPH) of fly 

ash);

2. Fly ash conversion costs (capital and O&M) for combination vacuum/pressure systems based on conveyance distance and capacity (TPH of fly 

ash);

3. Silo costs (capital and O&M) based on tons of fly ash;

4. Bottom ash conversion costs (capital and O&M) for mechanical drag systems based on TPH of bottom ash; and

5. Bottom ash conversion costs (capital and O&M) for a dry vacuum system based on TPH of bottom ash.

Please provide this information as quickly as possible.

Please call me directly if you have any questions (703 - 633 -1659).

Thanks,

Elizabeth

Elizabeth A. Sabol

Environmental Engineer

Eastern Research Group, Inc.

14555 Avion Parkway, Suite 200

Chantilly, VA 20151

elizabeth.sabol@erg.com<mailto:elizabeth.sabol@erg.com>

Phone:703-633-1659

From: "McDonough, Kevin" <KevinMcDonough@unitedconveyor.com>

To: Elizabeth Sabol <Elizabeth.Sabol@erg.com>

CC: "Alicea.Jezebele@epa.gov" <Alicea.Jezebele@epa.gov>, "jordan.ronald@epa.gov" <jordan.ronald@epa.gov>, Deborah 

Bartram <Deborah.Bartram@erg.com>, "Kipnis, Michael" <MichaelKipnis@unitedconveyor.com>, "Long, Gerald" 

<GeraldLong@unitedconveyor.com>

Date: 4/13/2011 1:07 PM

Subject: RE: Ash Information for EPA Steam ELGs

Attachments: EPA UCC_Ash Handling Attachment 041311.pdf

Elizabeth,

Draft attached. After you have had a chance to review, we are available for a conference call to discuss.

Kevin L. McDonough

Director, Sales - Americas

United Conveyor Corporation

2100 Norman Drive West

Waukegan, IL 60085-6753

Phone: 847-473-5900 ext.350

Fax: 847-473-5959

Email: kevinmcdonough@unitedconveyor.com<mailto:kevinmcdonough@unitedconveyorsupply.com>

Website: www.unitedconveyor.com<http://Website:%20www.unitedconveyor.com>

________________________________

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addressed and may contain information that is proprietary, privileged, confidential and/or exempt from disclosure under applicable law. If you are 

not the intended recipient, you are strictly prohibited from disclosing, copying, distributing or using any of this information. If you received this 

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Page 1 

Introduction

 EPA is currently developing a methodology to estimate the cost of conversions 

from wet to dry fly ash handling and the installation/conversion of bottom ash handling 

systems with systems that do not discharge sluice water. Below please find a brief 

overview of this methodology and a list of questions/cost requests that will assist EPA is 

further developing this methodology. 

Cost Methodology Background

Fly Ash Conversion 

EPA is developing a methodology that will estimate costs associated with the 

conversion from wet to dry fly ash handling at coal-fired power plants. The methodology 

will account for costs associated with the conveyance, intermediate storage, and 

transport/disposal portions of the fly ash handling system. This component-level 

approach to the ash handling system mirrors how EPA requested cost information in the 

questionnaire.

 The four dry fly ash handling systems that EPA is evaluating include:

Wet vacuum (pneumatic): System retrofit that utilizes the existing wet 

vacuum exhauster to pull vacuum for the dry system; 

Dry Vacuum: System that uses a mechanical exhauster to move air to 

entrain and convey dry fly ash particles (ideal for short distances); 

Pressure: Pressurized system that uses air produced by a positive 

displacement blower to convey ash to a certain destination (ideal for 

longer distances); and 

Combination vacuum/pressure: System that utilizes the vacuum 

equipment underneath the hoppers to transport fly ash by vacuum to a 

transfer station, where it is introduced to positive pressure and 

transported longer distances. 

The methodology will evaluate the existing ash handling system, as well as the 

conveyance distance and ash capacity associated with each plant to determine the most 

appropriate dry fly ash handling system to be installed. 

Bottom Ash Conversion/Installation 

EPA is developing a methodology that will estimate the costs for bottom ash 

handling system conversions and new installations. The bottom ash handling 

methodology will account for costs associated with the conveyance, intermediate storage, 

and transport/disposal portions of the bottom ash handling system. The three bottom ash 

handling systems that EPA is evaluating include: 
Page 2 

Complete Recycle System: Bottom ash system that utilizes dewatering 

bins and corresponding tanks to recycle all sluice water back to the 

system (Note: this system is a closed complete recycle system and 

does not include the use of ponds); 

Mechanical Drag System: Drag chain system that works on an incline 

to pull bottom ash from the quench water underneath the boiler to an 

intermediate or final storage destination; 

Pneumatic Handling Systems: Dry bottom ash handling system that 

grinds up bottom ash at the bottom of the hopper and transfers it 

pneumatically to an intermediate or final storage destination. 

Vibratory Handling Systems: Dry bottom ash handling system that 

grinds up bottom ash at the bottom of the hopper and transfers it by 

vibratory motion to an intermediate or final storage destination. 

Questions Regarding Fly and Bottom Ash System Operations and Costs

In order to properly develop the methodology to evaluate the installation and 

conversion costs for the industry, EPA would like to request system-level operating and 

cost information from you. Please respond to the following questions below to ensure that 

the cost model reflects appropriate information/costs. 

General Fly Ash System Design Characterization 

1. Please provide your estimate for the maximum capacity (tons/hour) and maximum 

distance that should be assumed for wet vacuum (pneumatic), dry vacuum, 

pressure, and combination vacuum/pressure systems. 

WetVacuum(Pneumatic)System:Awetvacuumsystemessentiallyhas

thesamecapacitycapabilitiesasadryvacuumsystemeventhoughthewet

vacuumsystemcouldtechnicallyoperateataslightlyhighervacuum.

WaterpoweredHydroveyorExhausterscangenerateslightlyhigher

vacuumlevelsthantypicaldryvacuumgenerators(e.g.Mechanical

Exhausters,VacuumPumps).Attheseelevatedvacuumlevels,the

increasedcapacityismarginal.

DryVacuumSystem:

o Upto90tons/hratadistanceof200300ft

o Approximately30to50tons/hratdistancesupto15001600ft

PressureSystem:

o Upto200tons/hratdistancesupto30004000ft.

o Pneumaticconveyingdistancescanreach50008000ft,butatreduced

conveyingcapacity.Page 3 

CombinationVacuum/PressureSystem:Sameasinformationnotedabove,

withproportionaladjustmenttodistancewithcombinationsystem.A

combinationVacuum/VacuumSystemisalsotechnicallypossible,but

wouldbelimitedincapacityanddistanceconsistentwiththemaximum

valuesabove.Seechartbelowforreference.

Figure1.FlyAshConveyingSystemPerformanceConsiderations

(Note:confidential/proprietaryinformationnotfordistribution)

2. When evaluating the conversion of an ash handling system from wet to dry, are 

there any circumstances that specifically require the installation of a pressure fly 

ash handling system (e.g., capacity requirement exceeds maximum capacity of 

vacuum or combination vacuum/pressure systems)? 

WearenotawareofanycircumstancesthatwouldrequireaPositive

PressureFlyAshConveyingSysteminlieuofaCombination

Vacuum/PressureSystem.Theconveyingdistanceandcapacityprovided

byaCombinationVacuum/PressureSystemwillmatchthatofastraight

PressureSystem.However,ifaparticularinstallationrequiresthatthe

intermediateashstoragesilocannotbelocatedneartheboilerhouse

(largelyduetoavailablephysicalspaceneartheAQCequipment),orif

increasedcapacityisnecessarytoproperlyaccountforelevatedash

[REDACTED - Confidential Business Information] 
Page 4 

generation,thentheonlytechnicalalternativesarethePositivePressure

FlyAshConveyingSystemoraCombinationVacuum/PressureSystem.A

vacuumsystemalonecannotprovideforelevatedcapacitiesorextended

conveyingdistances.

3. Is there a type of dry ash handling system typically used to retrofit existing power 

plants? If yes, what about that particular system makes it preferable (e.g., ease of 

installation, capital, O&M)? 

Inmostcases,awetvacuumconveyingsystemisreplacedbydryvacuum

system.IftheplanthasavailablespaceneartheAQCequipment,an

intermediateashstoragesilocanbeaddedwithseparating/filtration

equipmentandconditioning/unloadingequipment.Inthisscenario,much

oftheexistingequipmentdirectlyunderneaththeAQCequipment(ash

intakes,piping,valves,supports,etc.)canremaininplacemakingitmore

economicalthanacompletesystemreplacement.Inaddition,O&Mcosts

foravacuumconveyingsystemaremoreeconomicalthantheother

technicalalternatives.

4. For each dry fly ash system, what is the typical length of outage required for the 

installation (or conversion to) the system? 

46weeksifallequipmentbeneaththeAQCequipmentcanberetained.If

thisequipmentisreplaced,theoutagecanextendto812weeks.

If known, what is the typical outage per year associated with scheduled and 

unscheduled maintenance of each type of dry fly ash system conversion? 

Normalashhandlingsystemmaintenancedoesnotrequirea”scheduled”

outage.Mostwearcomponentscanbereplacedwhiletheunitis

operating.UCCengineeringguidelinesprovideforconveyingcapacities

thatallowformaintenancewindows(e.g.approximately4hoursforevery

8hourshift).Inaddition,mostsystemdesignsincorporatesufficient

redundancythatprovidesforadditionalmaintenancewindowswhile

maintainingboileroperation.

Can the conversion be implemented within normal scheduled maintenance 

outages, or must the maintenance outage be extended (and if so, for how 

long)?

Conversiontypicallycanbedoneduringnormalscheduledmaintenance

outage.Page 5 

5. Please describe how the design of the fly ash handling system would differ for a 

plant using petroleum coke instead of coal. 

Petroleumcokehasareducedashcontentthantypicalcoals.However,the

typeofashproducedhassomeofthecharacteristicsofashproducedwhen

firingwithoil(seebelow).Thepipediameterswouldtypicallybesmaller

forapetcokefiredplantthanacoalfiredplantduetoreducedash

quantities.Smalldensephaseconveyinglinescanbeusedinlieuofthe

traditionalvacuumsystems.

6. Please describe the type of fly ash handling equipment used for oil-fired boilers. 

Please describe how the design and operation differ from coal-fired fly ash 

handling equipment. 

Currently,therearevacuumtypeandpressuretypesystemsinservicefor

oilash.Thebestsystemforoilashapplicationisdensephasepressure

system.Themaindifferencebetweenflyashsystemsandoilashsystemsis

thatoilashsystemairmustbeheatedandsystemcomponents(pipe,

airlocks,silos,etc.)mustbeheattracedandinsulated.Inaddition,the

systemmustberuncontinuously.Wehaveasayingsummarizingoilash

system:“Keepithotandkeepitmoving”.

Wet Vacuum (Pneumatic) Fly Ash Handling System Characterization 

7. Please describe the prevalence of wet vacuum (pneumatic) fly ash handling 

systems in industry. 

Historically,thevastmajorityofflyashconveyingsystemswerewet

vacuum.Overthelast1525years,approximately2/3oftheU.S.fleetnow

utilizesdryconveyingtechnologies.Theprimaryfactorsforwettodry

conversionswereasfollows:

o PRBFuelSwitchingInitiatives

o DryScrubberAdditions

o WaterAvailability/WastewaterTreatment

o AshPondCapacity/IntegrityLimitations

o AshMarketability/Beneficiation

Someinstallationsstillusewaterpoweredvacuumgenerators(Hydroveyor

Exhausters)butseparatetheashpriortomixingwiththewater.

What percent of new installations utilize wet vacuum systems?
Page 6 

Nearlyallnewinstallationsinthelast1020yearshaveutilizeddry

conveyingtechnologies.

8. What equipment can typically be retained when converting from a wet fly ash 

handling (sluicing) to a wet vacuum (pneumatic) system? 

Hopperisolationvalves,flyashintakes,branchlineconveyorpiping

(assumingflyashsilosorvacuumpressuretransferstationscanbe

locatedreasonablyclosetotheAQCequipment),andlineisolation

valvescanallberetained.Inaddition,theexistingwetvacuum

exhausterscanberetainedasavacuumgeneratoraslongasthenew

equipmentincludesfiltration/separationequipmentupstreamofthe

wetexhausters.

What major equipment is required for conversion?

FlyAshSilos

AshConditioning/UnloadingEquipmentatsilo

Venting/FiltrationEquipmentatsilo

AshFluidizingBlowersatsilo

Filter/Separators(ontopofashsilos),or;

Filter/SeparatorTransferStations(vacuum/pressuretransfersystem)

PressureBlowers/Compressors(vacuum/pressuretransfersystem)

Powerdistributionfornewequipment

Controlsfornewequipment

9. What equipment is required for conversion from wet vacuum (pneumatic) fly ash 

handling systems to dry vacuum fly ash handling systems? 

Hopperisolationvalves,flyashintakes,branchlineconveyorpiping

(assumingflyashsilosorvacuumpressuretransferstationscanbe

locatedreasonablyclosetotheAQCequipment),andlineisolation

valvescanallberetained.Newequipmentincludesthefollowing.

FlyAshSilos

AshConditioning/UnloadingEquipmentatsilo

Venting/FiltrationEquipmentatsilo

AshFluidizingBlowersatsilo

Filter/Separators(ontopofashsilos),or;

Filter/SeparatorTransferStations(vacuum/pressuretransfersystem)

MechanicalExhausters/VacuumPumps(fulldryconversion)

PressureBlowers/Compressors(vacuum/pressuretransfersystem)

PowerdistributionfornewequipmentPage 7 

Controlsfornewequipment

10. Do wet vacuum (pneumatic) fly ash handling systems generate a waste stream? If 

yes, how much wastewater is typically generated? What is the wastewaters usual 

destination? What percent of fly ash becomes entrained in the water used to create 

the vacuum? 

Wetvacuumsystems,withfiltration/separationequipmentupstream

ofthewetvacuumgenerator,donotgenerateanappreciablewaste

stream.Thedesignefficiencyoftheashfiltration/separation

equipmentremovesthemajorityoftheash(>99.9%)priortocoming

intocontactwithwater.However,shouldaleakinthefiltermedia

occur,anyashleakingthroughwouldcomeintocontactwithwater.

Typically,wastewaterisdischargedintoandwater/ashstoragepond.

Theoretically,thewatercouldbecollectedinatemporarystoragetank

andrecycledinaclosedloopsystem.Thishasbeenattemptedinthe

pastwithunsuccessfulresultsduetoheatbalanceissues,thoughitis

stillatechnicalpossibility.However,mostinstallationshaveelectedto

convertwetvacuumgeneratorstodryvacuumgeneratorsifdischarge

toastoragepondisnolongeranoption.Lessthan0.1%oftheash

becomesentrainedinthewaterusedtocreatethevacuum.Page 8 

General Bottom Ash System Characterization 

11. Please describe the prevalence of pneumatic and vibratory bottom ash conveyance 

systems in industry. What percent of new installations utilize each? What percent 

of wet-to-dry conversions are pneumatic versus vibratory systems? 

Inthelast25years,therehavebeennonewU.S.utilityplantswithPC

boilersbuiltwitheitherpneumaticorvibratorytechnology.UCChas

onlyrecentlyintroducedthevibratorytechnology.Inthatsametime,

therehasonlybeen(1)newU.S.plantcontractedtoinstalla100%dry

bottomashsystem(mechanicalstainlesssteelbelttypeconveyor)and

itisnotyetoperational.AllothernewPCboilerinstallationsarebased

onthesubmergeddragchaintechnology.ThreeutilityPCUnitshave

beenconvertedfromwetconveyingsystemstodrypneumatic

conveyance.Manyoftheolder,industrialunitsutilizedrypneumatic

conveyance.Theoverwhelmingmajority(>90%)stillutilizewet

conveyancetoashstoragepondsordewateringsystem.

12. Are there certain boilers that are unable to be retrofitted with a pneumatic bottom 

ash conveyance system (e.g., older boilers)? 

Inmostcases,existingbottomashsystemscanberetrofittedwitha

pneumaticsystem.However,thistypeofconversionrequiresremoving

theexistingbottomashhopperwithanewtypeofdryhopper.Dueto

theuniquecharacteristicsofthedryhopperdesign(steeperminimum

hopperangles),someinstallationsmaynotpossesssufficientvertical

headroomtoallowfortheconversion.Inaddition,thistechnology

doeshavesomelimitationsoncapacityandconveyingdistance.Asa

result,theplantmusthavephysicalspaceneartheboilerhouse(within

200300ofthebottomashhopper)tolocateabottomashsiloor

intermediateseparatingstation.

13. For each dry bottom ash system, what is the typical length of outage required for 

the installation (or conversion to) the system? 

Therearetwotypesofclosedrecirculationsystemsusedinthepower

industry.Thetraditionalsystemusesmultiplereceivingandstorage

vessels(DewateringBins)andthenSettlingandSurgeTanksinflow

sequencetoclarifyandstorethewaterforreuse.Thenewerdesign

systemusesaremotelylocatedSubmergedFlightConveyorthat

providesallthreefunctions(dewatering,settlingandsurge)intoa

singleunit.Bothsystemscanbeconstructedwiththeboileronlineand

canbetiedintothesystemwithoutamandatoryoutage.Some

customerswillplantomaketheconversionduringaplannedoutageifPage 9 

changestothewatersupplypipingarenecessitatedbyconversiontoa

closedlooprecirculationdesign(Higheroperatingpressure,

constructionofanewdrainsystemintheplanttocollectoverflow

wateranddrains,etc.).Thisoutageworkwouldnotnormallyrequire

morethanafewdaysandcanfitwithinthetypical2weekshort

outage.

AretrofittoanSFCwouldtypicallyrequire48weeks.

Drypneumaticandmechanicalbottomashsystemswouldtypically

requireaminimumof6weeksandtypicallycloserto8weeksfora

retrofitconversion.Areducedschedulecanbeaccomplishedby

incorporatingmultipleshiftsandovertimelaborbuthigherinstallation

costswillbeincurred.

TypeofConversion ApproximateOutage

Requirement

ClosedLoopDewateringSystems(Remote

SFC’sorDewateringBins)02weeks

SubmergedFlightConveyor68weeks

PneumaticAshExtractor(PAX)68weeks

VibratoryAshExtractor(VAX)68weeks

If known, what is the typical outage per year associated with scheduled and 

unscheduled maintenance of each type of dry bottom ash system conversion? 

Noneofthesystemsinthemselveswillrequireanoutageforservice.

Provisionsforonlinemaintenanceandstandbyequipmentare

incorporatedintothesystemdesignsthatallowanyinternal

maintenancetobeperformedduringthenormallyscheduledboiler

outages.

14. Please describe how the design of the bottom ash handling system would differ 

for a plant using petroleum coke instead of coal. 
Page 10 

Petroleumcokehasaverylowashcontentsoifthereisabottomash

hopper,itcanbesignificantlysmaller.Thetransportconveyorcanalso

bedesignedatalowercapacityifoneisused.Seeresponsetoquestion

15below.

15. Please describe the type of bottom ash handling equipment used for oil-fired 

boilers. Please describe how the design and operation differ from coal-fired 

bottom ash handling equipment. 

Oilfiredboilersmaynothavebottomashhandlingsystems.Thereis

usuallyarectangularboxplacedbelowtheboilerandperiodically

(every23months),theunitisshutdownandtheashescollectedare

removedviaamobilevacuumtruck.

Complete Recycle Systems 

16. For a complete recycle bottom ash handling system, do you include any costs 

associated with water treatment to prevent or eliminate the build up of dissolved 

solids? Please describe the type of treatment that is used to eliminate the build up 

of dissolved solids. 

Completerecycle(closedloop)systemscanhaveachemicaldeposition

ofcalciumcarbonateifthefuelsourceishighincalcium.Some

customersaddressthisduringtheirnormaloutagesandsomemay

injectacidtohelpadjustthepHofthewatertoreducematerial

deposition.Wearenotawareofanyothermeasurestoaddress

dissolvedsolidsinclosedlooprecirculationsystems.

What costs are included in the installation and operation of a complete recycle 

system? 

Additionalequipmentrequiredforcompleterecycle(closedloop)

system:

RemotelylocatedSubmergedFlight(dragchain)Conveyors,or;

RemotelylocatedDewateringBins/Settling&SurgeTanks

ReturnWaterPumps

PipingandValves

Powerdistributionfornewequipment

ControlsfornewequipmentPage 11 

What water (make-up, cooling water, re-circ water) and power requirements are 

needed to operate the system?

Thereisminimalmakeupwaterrequirement(2040gpm/system)and

typicallynoneedforadditionalcoolingwater.Theoperatingpower

requirementsvarywiththedistancetherecirculationequipmentis

placedfromthebottomashhopper.Itiscommontoneedconveying

pumpsproducing300350psigwatersupplytotheventurieducator

pumpsforatraditionalrecirculationsystemand250–300psigforaSFC

recirculationsystem.Atraditionalrecirculationsystemhas1015HP

sludgereturnpumpsatboththesettlingandsurgetanks(noneneeded

forSFC.

Silo Configuration 

17. Please describe the process for sizing a silo for intermediate ash storage. 

Specifically, is each silo individually designed for a specific plant, or are there 

several standard silo designs selected from based on amount of ash generated? 

Silosizingisbasedonashgenerationratesandcustomerspecification

fordesireddurationofashstorage.Silosaretypicallydesignedfora

minimumof72hoursofstorage,whichaccommodatesanextended

weekend(3days)ofashstoragepriortounloadingandtransport,butis

itnotuncommontosizethestoragesilosfora4daystorageperiodor

longer.

18. What factors drive the number of silos installed at a facility? Are silos typically 

sized to hold one unit’s ash, or is a silo typically shared among multiple units that 

generate ash with similar characteristics? 

Itisgoodengineeringpracticetouseapairofsilosformultipleunits.

However,numerousplantshavehadasinglesiloservingmultipleunits.

Customersnowrealizethatserviceonasiloservingmultipleunitsis

almostimpossibleasitwouldrequirethatallunitsbesimultaneously

shutdowntodoanysilomaintenance.Anotherfactorfordetermining

thenumberofsilosisbasedontheashgenerationandnumberofdays

ofstorage.Extremelylargesiloscanbemorecostlythan(2)smaller

silos.

19. What materials of construction are typically used for silos and how is the 

appropriate material of construction determined? Provide range of costs for 

typical materials of constructions for a typical silo.
Page 12 

Smallersilos(2030ftindiameter)aremostcommonlymadeofsteel

andareofweldedconstruction.Largersilos(>30ftindiameter)are

typicallyofweldedsteelconstructionormadeofconcrete.Boltedsilos

arealsoutilizedbutarelesscommon.Theinstalledcostofconcrete

silosaretypicallylowerby30%to75%thansteelweldedsilos.The

pricedifferencedependsonsilosize;thelargerthesilo,themore

favorablethepricedifferenceinfavorofconcrete.Typically,thecost

ofboltedsilosarelessthaneitherweldedsteelorconcretesilosbut

requiresubstantiallymoremaintenanceandhavesomedesign

limitations.

Costs for Fly and Bottom Ash Handling Systems 

EPA is seeking system-level cost information for wet to dry fly ash handling 

conversions and bottom ash handling conversions/installations. EPA would like to obtain 

these costs broken out for the conveyance portion of the system (e.g., from the hopper to 

intermediate storage) and the intermediate storage portion of the system (e.g., silo). EPA 

is aware that cost varies greatly depending on boiler configuration, capacity, conveyance 

distance, and number of units. For the purposes of providing cost data, please assume 

average industry operating conditions and no special circumstances (e.g., headroom 

below the boiler). In order for us to properly evaluate the cost data, please provide the list 

of variables and assumptions used during the development. 

UCChasprovidedapproximatecostdatabelowbasedonrecentprojectand

proposalactivity.Severalkeyvariablescanalsogreatlyimpacttotalproject

cost:

o #ofUnits

o AvailableSpaceforNewEquipmentandConstructionAccess

o DistanceofConveyingSystem/Equipment(silolocation/dewatering

equipmentlocation/etc.)

o PowerAvailability

o Geotechnical/FoundationIssues

o PondClosureand/orLandfillDevelopmentCosts(notincludedbelow)Page 13 

Fly Ash 

Please provide capital and O&M cost curves for fly ash conveyance (please do 

not include silo costs), based on tons per hour (tph) of fly ash, for the following 

conversion types: 

Conversion from wet sluicing to wet vacuum system; 

Conversion from wet sluicing to dry vacuum system; 

Conversion from wet sluicing to pressure system; and 

Conversion from wet sluicing to combination vacuum pressure system. 

TypeofConversion

(assumes1unit@600MW)

Approx.

EquipmentCost

Approx.

InstallationCost

WetSluicingtoWetVacuumSystem

(assumeswaterwillbeclosedloop) $4M$812M

WetSluicingtoDryVacuumSystem$4M$812M

WetSluicingtoPressureSystemN/AN/A

WetSluicingtoCombinationVacuum

PressureSystem

(installedcostaccountsformultiple(2)unitsynergies)

$1015M$15$30M

FlyAshO&MCosts:

Wearestillcompilingthisdata.Oneofthecomplicatingfactorsisthatmany

wettodryflyashconversionswerenotsimpleconversions(remove

hydroveyors/addlocalsilos,filter/separators&exhausters,etc).Manywent

toVacuum/PressureTransferSystemsthataddedasecondconveyingsystem

tomoveashfromtheboilerareatoremotesilos,whichaddmorecomponents

andhorsepower.Moretimewillberequiredtocompileandpresenttruly

accuratedata.

KeyVariables:

RemoveHighPressureWaterSupplyPumps(approx.200HP)forHydoveyor

Exhausters

AddMechanicalExhaustersforVacuumGeneration(approx.75150HP)

AddFilter/Separators,TransferValves,Line&BinIsolationValves,VentValves,

Etc.

AddFluidizingBlowers(approx.5075HP)

AddAshConditioners/Unloaders(approx.4060HP)Page 14 

Bottom Ash 

Please provide capital and O&M cost curves for bottom ash conveyance (please 

do not include silo costs), based on tph of bottom ash, for the following installations or 

conversion types: 

Conversion from wet sluicing to mechanical drag system; 

Conversion from wet sluicing to pneumatic system; 

Conversion from wet sluicing to vibratory system; 

Conversion from wet sluicing to a dewatering bin system with 

complete recycle (including dewatering bin, surge tank, and settling 

tanks costs); 

Installation costs for mechanical drag systems; 

Installation costs for pneumatic systems; and 

Installation costs for vibratory systems. 

TypeofConversion

(assumes1unit@600MW)

Approx.Equipment

Cost

Approx.Installation

Cost

Approx.O&M

Costs

WetSluicingtoMechanicalDrag

System$23M$57M$250/MWYR

WetSluicingtoPneumaticSystem$45M$810MTBD

WetSluicingtoVibratorySystem$56M$1012MTBD

WetSluicingtoDewateringBin

System

(canaccommodatemultipleunits)

$67M$1012M$9501,100/

MWYR

WetSluicingtoRemoteSFCSystem

(canaccommodatemultipleunits)$34M$48M$800950/MWYR

KeyConsiderations:

WetSluicingtoMechanicalDragSystem:Sensitivetoboileraccessand

configurationandamountofdemolition.Requiredoutagetimeisalsoa

significantfactor.

WetSluicingtoPneumaticSystem:SensitivetofinallocationofBottomAsh

StorageSilo(s)andMultipleUnitSynergies.Requiredoutagetimeisalsoa

significantfactor.

WetSluicingtoVibratorySystem:SensitivetofinallocationofBottomAsh

StorageSilo(s)andboileraccess.Requiredoutagetimeisalsoasignificant

factor.Page 15 

WetSluicingtoDewateringBinSystem:Sensitivetoavailablespacenearboiler

houseandlengthofclosedloopsluiceconveyingsystem.Outage

considerationsmakethisveryfavorable.

WetSluicingtoRemoteSFCSystem:Sensitivetoavailablespacenearboiler

houseandlengthofclosedloopsluiceconveyingsystem.Outage

considerationsmakethisveryfavorable

Intermediate Storage 

Please provide the following data for silos: 

Silo cost curves (capital and O&M) as a function of capacity (please 

provide separate silo capital cost curves for typical materials of 

constructions used). Please assume that the silo has both wet and dry 

loading capabilities. 

TypeofConversion

(assumes1unit@600MWandConcrete/SteelWeldedSilos)

Approx.SiloInstalled

Cost

WetSluicingtoWetVacuumSystem$23M

WetSluicingtoDryVacuumSystem$23M

WetSluicingtoPressureSystemN/A

WetSluicingtoCombinationVacuumPressure

System$56M

Please include a detailed list of components included for each system level cost 

curve provided. Also, please provide an explanation of any underlying assumptions made 

while developing the cost curves (i.e., if outage time or maintenance time was factored in 

the price). 

Informationnotpresentlyavailable.Page 16 

Petroleum Coke-Fired Fly Ash and Bottom Ash Costs 

Please provide capital and O&M cost curves for fly ash and bottom ash handling 

systems associated with the handling of ash from petroleum coke-fired units, if different 

than coal-fired units. Please provide cost curves with the same details that are included in 

the request above.

Informationnotpresentlyavailable.

Oil-Fired Fly Ash and Bottom Ash Costs 

Please provide capital and O&M cost curves for fly ash and bottom ash handling 

systems associated with the handling of ash from oil-fired units. Please provide cost 

curves with the same details that are included in the request above. 

Informationnotpresentlyavailable.From: Alicea.Jezebele@epamail.epa.gov [

mailto:Alicea.Jezebele@epamail.epa.gov]

Sent: Monday, April 25, 2011 4:22 PM

To: McDonough, Kevin

Subject: Action Items-EPA Call with UCC

Importance: High

Kevin,

Thank you again for helping put together the conference call last

Thursday, April 21, 2011, to discuss the costs associated with ash

handling technologies. It was a very helpful meeting for us to better

understand how these systems work and to give context to the

information that you provided previously.

Based on the call, a list of action items that we discussed during the

meeting is included in the document attached. Please note that these

action items are listed in priority order.

We would appreciate if you could provide us the information from the

action items no later than Monday, May 9th, 2011, which is two weeks

from today. However, feel free to send us the information piecemeal if

you are able to put some of it together before May 9th.

Please let me know if you have any questions.

I look forward to hearing from you.

Sincerely,

Jezebele Alicea-Virella

From: McDonough, Kevin

Sent: Thursday, April 28, 2011 8:42 AM

To: Kipnis, Michael

Subject: FW: Action Items-EPA Call with UCC

Importance: High

Mike,

Please review the attached document. I’d like you to lead this effort.

Kevin L. McDonough

Director, Sales - Americas

United Conveyor Corporation

2100 Norman Drive West

Waukegan, IL 60085-6753

Phone: 847-473-5900 ext.350

Fax: 847-473-5959

Email: kevinmcdonough@unitedconveyor.com

Website: www.unitedconveyor.com

-----"Kipnis, Michael" <MichaelKipnis@unitedconveyor.com> wrote: -----

To: Jezebele Alicea/DC/USEPA/US@EPA

From: "Kipnis, Michael" <MichaelKipnis@unitedconveyor.com>

Date: 05/06/2011 10:11AM

Subject: RE: Action Items-EPA Call with UCC

Jezebele,

I want to make sure that you really want the price information on

steel silos? If you recall we originally suggested to use concrete

silos as most economical option specially for larger silo sizes.

Michael Kipnis

1 847 473 5900 ext. 430
From: Alicea.Jezebele@epamail.epa.gov [

mailto:Alicea.Jezebele@epamail.epa.gov]

Sent: Monday, May 09, 2011 9:05 AM

To: Kipnis, Michael

Subject: RE: Action Items-EPA Call with UCC

Importance: High

Yes, we are interested on price information on steel silos. You can

include information about concrete silos too if this won't delay the

delivery date of the information requested by us.

Also, I take the opportunity to check the status on delivering the

information requested. Your prompt response will be highly appreciated,

as you may know our contractor are in great need of this information to

keep moving forward with the cost estimate for ash handling without

delaying our schedule.

Thanks in advance for your help and time. Looking forward to hear from

you.

Sincerely,

Jezebele Alicea

From: Kipnis, Michael

Sent: Monday, May 09, 2011 4:04 PM

To: 'Alicea.Jezebele@epamail.epa.gov'

Cc: McDonough, Kevin

Subject: RE: Action Items-EPA Call with UCC

Jezebele,

Sorry for delay, but it may take us extra day or two to complete.

Michael Kipnis

From:"Kipnis, Michael" <MichaelKipnis@unitedconveyor.com>

To:Jezebele Alicea/DC/USEPA/US@EPA

Cc:"Long, Gerald" <GeraldLong@unitedconveyor.com>, "McDonough,

 Kevin" <KevinMcDonough@unitedconveyor.com>

Date:05/10/2011 12:34 PM

Subject:Action Items-EPA Call with UCC

Jezebele,

Please refer to the attached document addressing your questions.

Give me a call if you need further clarifications.

Regards,

Michael Kipnis

Manager, North American Sales

1 847 473 5900, ext 430

>>> <Alicea.Jezebele@epamail.epa.gov> 5/10/2011 3:03 PM >>>

Hi,

Please let me know if you have any questions or concerns that need to be

addressed back to Kevin. Thanks!

(See attached file: EPA.docx)

(Embedded image moved to file: pic05035.jpg)

----- Forwarded by Jezebele Alicea/DC/USEPA/US on 05/10/2011 03:01 PM
This electronic mail message and any attached files contain information

intended for the exclusive use of the individual or entity to whom it

is addressed and may contain information that is proprietary,

privileged, confidential and/or exempt from disclosure under applicable

law. If you are not the intended recipient, you are strictly prohibited

from disclosing, copying, distributing or using any of this

information. If you received this communication in error, please

contact the sender immediately and destroy the material in its

entirety.

This electronic mail message and any attached files contain information

intended for the exclusive use of the individual or entity to whom it is

addressed and may contain information that is proprietary, privileged,

confidential and/or exempt from disclosure under applicable law. If you

are not the intended recipient, you are strictly prohibited from

disclosing, copying, distributing or using any of this information. If

you received this communication in error, please contact the sender

immediately and destroy the material in its entirety.
Please note that these action items are listed in priority order.

Bottom Ash

1. Please provide capital costs (equipment and installation), O&M, and a detailed list of any 

assumptions and pieces of equipment included in the costs for the following conversions:

a) Conversion from Wet Sluicing to Submerged Flight Conveyor (SFC) based on 

bottom ash generation rate in tons per hour (tph) for one generating unit; and

b) Conversion from Wet Sluicing to Remote SFC based on wet sluicing flowrates in 

gallons per minute (gpm).

Assumptions:

 -system type: remote SFC w/ closed loop recirculation system 

 -bottom ash generation rate: up to 8tph (most of the power plants)

 -location of remote SFC: up to 700-800ft

List of major equipment:

 -(1) remote SFC including Hydraulic Power Unit (HPU)

 -(2) Pumps supplying water for Jetpulsion Pumps

 -(2) Pumps supplying water to Bottom Ash Hopper

 -(2) Pumps for overflow from Bottom Ash Hopper

 -(2) sump pumps 

 -(1) overflow tank

 -10” conveying pipe, water pipe, pipe supports, valves, etc.

 -instruments, controls, MCC 

System and assumptions as described above shall cover vast majority of the utility size units. 

Approximate price for above system/scope is $2,500,000-$3,500,000

Approximate price for installation and BOP scope: $5,000,000-$7,000,000. BOP design and 

supply scope includes civil/foundation, buildings, pipe racks, power cables, field wire, trays,

etc.)

“Deviations” from above assumptions will result in the following cost impact:

-conveying line diameter increase from 10” to 12” which will result in larger SFC, pumps, 

motors, etc. Price adder for equipment scope is approx. $300,000. Price adder for 

installation/BOP scope is approx. $300,000

-conveying distance increase beyond 700-800ft. This would require a set of additional High 

Pressure Pumps so that two pumps will operate in series to produce required head. Price adder 
for pumps, motors, MCC, etc. is approx. $300,000 Price adder for installation/BOP scope is 

$500,000

2. Please also provide the frequency and cost for the drag chain replacement. Please 

provide the cost as a function of ash generation rate.

The service life of the chain in general depends on the following factors( and not only a 

function of ash generation rate):

 -ash characteristics: abrasive ash (eastern) vs less abrasive (PRB). Depending on the 

ash characteristics the service life of chain may fluctuate from 2-3 years up 4-6 years

 -ash generation rate: in general the higher the ash generation rate the higher chain 

speed and the chain wear/service life is the function of the chain speed

 -mode of operation continuous vs intermittent 

The cost of replacing chain and some worn out components (L&M) is $150,000-$200,000

Fly Ash

Please provide capital costs (equipment and installation), O&M, and a detailed list of any 

assumptions and pieces of equipment included in the costs for the following conversions:

a) Conversion from Wet Sluicing to Dry Vacuum based on fly ash generation rates in 

tph (please note any assumptions made to calculate fly ash conveyance rate based on 

fly ash generation rate); and

Assumptions:

 -conveying distance: 300-400ft

 -ash generation rate: 20-25tph

 -conveying capacity: 40-50tph 

 -silo storage capacity: 72hrs of ash generation 

 -silo construction: concrete (refer to info below regarding steel vs concrete silos)

List of Major Equipment:

 -(2)vacuum blower/motor(100-150HP/each) packages (1oper and 1 spare), 

 -(2) Filter/Separators, bin vent filter, etc.

 - conveying pipe, air pipe, pipe supports, valves, etc.

 - (1) concrete silo

 - Silo fluidizing system (fluidizing elements, 2 blowers/motors (50-75HP/each), (1) air 

heaters (50-75KW), valves, etc.

 -silo unloading equipment (2 wet unloaders w/ 50HP motor) 1 dry spout) 

 -instruments, controls, MCC 
Capital and Maintenance Cost

Approximate price for above system/material scope is approx. $4,000,000.

Estimated system maintenance cost: $150,000/year

Approximate price for installation and BOP scope: $10,000,000. 

“Deviations” from above assumptions will result in the following cost impact: 

Price adder to supply 60-80tph system (instead of 40-50tph) is $1,000,000

Price adder to install 60-80tph system (instead of 40-50tph) is $1,500,000

Price deduct to supply 20-35tph system (instead of 40-50tph) is $1,000,000

Price deduct to install 20-35tph system (instead of 40-50tph) is $1,500,000

b) Conversion from Wet Sluicing to Combination Vacuum/Pressure based on fly ash 

generation rates in tph.

Assumptions:

 -vacuum system conveying distance: 300ft 

 -pressure system conveying distance: 3000ft

 -conveying capacity: 40-50tph 

 -Filter/Separator Transfer stations to be utilized (not a surge bins)

 -silo storage capacity: 72hrs of ash generation 

 -silo construction: concrete (refer to info below regarding steel vs concrete silos)

List of Major Equipment:

 -(2)vacuum blower/motor(100-150HP) packages 

 -(2) Filter/Separators Transfer Stations including Nuvafeeder Vessels

 - conveying pipe, air pipe, pipe supports, valves, etc.

 -(2) pressure blowers or air compressors/motor (500-600HP) packages

 - (1) concrete silo

 - Silo fluidizing system (fluidizing elements, 2 blowers/motors (50-75H)), 1 air heaters 

(50-75KW, ) valves, etc.)

 -silo unloading equipment (2 wet unloaders w/ 50HP motor, 1 dry spout) 

 -instruments, controls, MCC 

Capital and Maintenance Cost

Approximate price for above vacuum/pressure system/scope is approx. $12,000,000.
Approximate price for installation and BOP scope: $24,000,000. 

Estimated system maintenance cost: $200,000/year

“Deviations” from above assumptions will result in the following cost impact: 

Price adder to supply 60-80tph system (instead of 40-50tph) is $3,000,000

Price adder to install 60-80tph system (instead of 40-50tph) is $5,000,000

Price deduct to supply 10-20tph system (instead of 40-50tph) is $2,000,000

Price deduct to install 10-20tph system (instead of 40-50tph) is $4,000,000

Price adder to supply 4000ft long pressure system (instead of 3000ft) is $1,500,000

Price adder to install 4000ft long pressure system (instead of 3000ft) is $3,000,000 

Price deduct to supply 2000ft long pressure system (instead of 3000ft) is $1,500,000

Price deduct to install 2000ft long pressure system (instead of 3000ft) is $3,000,000 

3. Please also provide capital (equipment and installation) costs and O&M costs as a 

function of the distance from the hoppers to the silo for both of the conversions identified 

above. 

Please refer to the answers above. 

Silo

Please provide capital costs (equipment and installation), O&M, and a detailed list of any 

assumptions and pieces of equipment included in the costs for the installation of a basic steel 

silo. Please include information used to size the silo (i.e., three days storage time, density).

The price of the concrete silo and related equipment was included in total ash handling system 

cost described above. Below is approximate break out price for the silo and silo fluidizing and 

unloading equipment.

Key assumptions for silo sizing:

Storage capacity: 72hr of ash generation

Ash density for silo sizing: 45-50lb/ft3

Ash density for structural design: 90-120lb/ft3
Ash

Generation

72hr Silo 

Storage 

Capacity,

Silo 

Diameter,

ft Steel Silo, $$$ mil

Steel silo 

Installed 

Cost,

$$$, Mil 

Concrete 

Silo, 

Installed,

$$$ mil 

Unloading 

and 

fluidizing 

equipment

Design and 

Material, Installation

Installed

Cost $$$, mil

10-17 720-1224 25-30

0.6-1.0 0.4-0.7 1.0-1.5 0.9-1.5 0.8

20-25 1440-1800 30-38 

1.1-1.3 0.8-1.0 1.9-2.3 1.4-1.8 1.0

30-40 2160-2880 38-45 2.4-1.8 1.3-1.7 2.7-3.5 2.0-2.6 1.3

For maintaining silo unloading and fluidizing equipment assume $20,000 cost/year for either silo 

size.

Additional Topics

4. Summary/factors of multiple unit synergies and corresponding plant savings for the 

remote SFC and the combination vacuum/pressure system.

Multiple unit synergies examples, Remote SFC

-single unit plant as a minimum should have (1) remote SFC. But it could be possible to 

design three or even four unit plant with two or three remote SFC potentially reducing 

system cost by 30% to 50%.

Multiple unit synergies examples, Combination Vacuum/Pressure System

-single unit plant as a minimum should have (1) Combination Vacuum/Pressure System

But it could be possible to design two unit plant with two vacuum system but only with 

one pressure system (common for both units) potentially reducing system cost by 15% to 

25%.

5. Please provide information on “typical” fly ash conveying times versus fly ash 

generation. B times.

 Typical fly ash system is designed to convey at a rate equal to two (2) times of ash 

generation rate. 

6. Please provide information on “typical” bottom ash conveying times versus bottom ash 

generation times.
Typical bottom ash system utilizing jetpumps to convey ash from water impounded hopper is 

designed to operate 1-2hr per 8hr shift. In the beginning of the ash conveying cycle when

hopper is full of ash conveying capacity could be in range of 50tph to 100tph. As ash quantity in 

the hopper is rapidly reduced so the ash conveying capacity.

The remote SFC is designed to receive ash from the existing jetpump system at the above 

mentioned rate of 50tph to 100tph. But since remote SFC has “surge capacity” it is typically 

designed to convey/dewater ash at a rate of 2tph to 20tph

7. Summary of the types (i.e., operating engineer, engineering technician) and number of 

workers required to operate and maintain each type of system.

With the new Emerson systems, usually the unit operator is in the control room and runs the ash 

system as well as all the other equipment. If there is a local PLC then the AUO(axillary unit 

operator) will run the system. Besides the unit operator there is always an AUO assigned to the 

system should they need to go check something since the unit operator can’t leave the control 

room. Sometimes the AUO won’t be needed for weeks at a time and times when hoppers need 

to be poked or limit switches, or pressure switches are a problem they may be needed several 

hours a day. 

Most of the bottom ash systems are not automated so the unit operator turns on the booster 

pumps for the JP then the AUO pulls the bottom ash hopper(usually not longer than an hour) at 

the hopper locally. 

Most maintenance like bags, crushers and valves are replaced during outage unless it is an 

emergency. When maintenance like valve, fittings , pipe or jetpumps need to be replaced on 

line it usually takes a team of 3 about 3-4 hours. 

Typically the replacement of limit switches and solenoids are done by one electrician and takes 

less than one hour.