From: Elizabeth Sabol

To: rong@deltaducon.com

CC: Alicea.Jezebele@epa.gov; Bartram, Deborah; Finseth, Thomas; Ventre, Adam; jordan.ronald@epa.gov

Date: 11/8/2010 2:50 PM Subject: Ash Handling Data Request

Attachments: Delta Ducon_Ash Handling Attachment_11.10.doc

Ron,

My name is Elizabeth Sabol, from Eastern Research Group, Inc. ERG is a contractor for the U.S. EPA ’ s Office of Water, and we are supporting EPA ’ s review and revision of effluent guidelines for the stea m electric power generation industry. Thank you for your assistance during our conference call in December 2009 in discussing the design and cost of ash handling systems. As you may recall, EPA was at that time preparing to distribute the Questionnaire for the Steam Electric Power Generating Effluent Guidelines. The questionnaire was distributed to the industry in June and the questionnaire is currently being received and reviewed by E PA. The questionnaire and other pertinent background information can be f ound online at: http://www.epa.gov/guide/steam.

In order to accurately revise the effluent guidelines, EPA is developing a methodology to estimate the costs associated with various technology options of interest to EPA. EPA is currently evaluating costs associated with the conversion of wet to dry fly ash handling and the conversion/installation of bottom ash handling systems that do not discharge bottom ash sluice water.

Attached, please find a document that summarizes some background on the cost app roach that EPA is developing and a list of questions for which we would appreciate your input. EPA is aware that system

- level cost data varies among different ash handling scenarios in the industry. We encourage you to provide cost data for scenarios that you consider typical in the industry. If you would like to discuss any assumptions that must be made to develop cost data for particular systems, please contact me with y our questions or times when you are available for a call (please find my information b elow).

EPA is requesting Clyde Bergemann/Delta Ducon's cost information by early December. We look forward to your answers and comments regarding costs associated with fly and bottom ash handling. We would appreciate your feedback and thank you in

advan ce for your time.

Thanks,

Elizabeth

Elizabeth A. Sabol Environmental Engineer Eastern Research Group, Inc. 14555 Avion Parkway, Suite 200 Chantilly, VA 20151 elizabeth.sabol@erg.com

Phone:703

- 633

- 1659Page 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 th is methodology and a list of questions /cost requests that will assist EPA is further developing this methodology

.

Cost Methodology Background

Fly Ash Conversion

EP A 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

- lev el 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 evaluatin g 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 displac ement 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 s ystem to be installed

.

Bottom Ash Conversion/Installation

EPA is developing a methodology that will estimate the costs for bottom ash handling system conversion s and new installations. The bottom ash handling methodology will account for costs associate d 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 f inal 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 (to ns/hour) and maximum

distance that should be assumed for wet vacuum (pneumatic) , dry vacuum, pressure, and combination vacuum / pressure systems.

2. When evaluating the conversion of an ash handling system from wet to dry, are there any circumstances that spec ifically require the installation of a pressure fly ash handling system (e. g., capacity requirement exceeds maximum capacity of

vacuum or combination vacuum/pressure systems)?

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)?

4. For each dry fly ash system, w hat is the typical length of outage required for the installation (or conversion to) the system? If kno wn, what is the typical outage

per year associated with scheduled and unscheduled maintenance of each type of dry fly ash system conversion? Can the conversion be implemented within normal scheduled maintenance outages, or must the maintenance outage be ex tended (and if so, for how long)?

5. Please describe how the design of the fly ash handling system would differ for a plant using petroleum coke instead of coal.

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

- fired boilers.

Please desc ribe how the design and operation differ from coal

- fired fly ash handling equipment.Page 3 Wet Vacuum ( P neumatic) Fly Ash Handling System Characterization

7. Please describe the prevalence of wet vacuum (pneumatic) fly ash handling systems in industry. What perce nt of new installations utilize wet vacuum systems? What percent of wet

- to

- dry conversions installed wet vacuum systems?

8. What equipment can typically be retained when converting from a wet fly ash handling (sluicing) to a wet vacuum (pneumatic) system? In addition to a wet

vacuum exhauster (vs. a mechanical exhauster) , what major equipment is required

for conversion?

9. What equipment is required for conversion from wet vacuum (pneumatic) fly ash handling systems to dry vacuum fly ash handling systems?

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?

Gener al Bottom Ash System Characterization

11. Please describe the prevalence of pneumatic bottom ash conveyance systems in industry. What percent of new installations and wet

- to

- dry conversions are pneumatic systems?

12. Are there certain boilers that are unable to be retrofitted with a pneumatic bottom ash conveyance system (e. g. , older boilers) ?

13. For each dry bottom ash system, what is the typical length of outage required for the installation (or conversion to) the system? If known, what is the typical

outage per year associated with scheduled and unscheduled maintenance of each type of dry bottom ash system conversion?

14. Please describe how the design of the bottom ash handling system would differ for a plant using petroleum coke instead of coal.

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.

Complete Recycle Systems

16. For a complete rec ycle bottom ash handling system , do you i nclude any costs associated with water treatment to prevent or eliminate the build up of dissolvedPage 4 solids? Please describe the type of treatment that is used to eliminate the build up

of dissolved solids.

17. What costs are included in the installation and operation of a complete recycle system? What water (make

- up, cooling water, re

- circ water) and power requirements are needed to operate the system?

Silo Configuration

18. Please describe the process for sizing a silo for intermediate ash storage. Specifical ly, is each silo individually designed for a specific plant, or are there several standard silo designs selected from based on amount of ash generat ed ?

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

sized to hold one u nit’s ash, or is a silo typically shared among multiple units that generate ash with similar characteristics?

20. What materials of construction are typically used for silos and how is the appropriate material of construction determined ? Provide range of cost s for typical materials of constructions for a typical silo.

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 w ould 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 c onfiguration , capacity, conveyance

distance , and number of units. For the purposes of providing cost data, please assume average industry operating condition s and no special circumstances (e. g. , headroom below the boiler). In order for us to properly evalu ate the cost data, please provide the list

of variables and assumptions used during the development.

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

, f or 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 syste m

.Page 5 Bottom A sh

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 syste m;

• Conversion from wet sluicing to pneumatic 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; and

• Install ation costs for pneumatic systems

.

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 us ed)

. Please assume that the silo has both wet and dry loading capabilities.

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 deve loping the cost curves (i.e., if outage time or maintenance time was factored in the price).

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 hand ling 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.

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.