INTERNAL DRAFT DELIBERATIVE: DO NOT QUOTE OR C ITE

Page 1 of 4 Notes from Meeting with GEA EGI Contracting/Engineering Co., Ltd

. March 31, 2014

On Monday, March 31, 2014, EPA and ERG participated in a meeting with GEA EGI Contracting/Engineering Co., Ltd. (GEA EGI) at EPA Headquarters in Washington, D.C. to discuss GEA EGI’s Circumix ® Dense Slurry System (DSS) technology. Participants in the meeting included representatives from EPA, ERG, and GEA EG I , as listed in Table 1.



### Table 1. List of Participants

Name Organization Istvàn Kovacsics GEA EGI
Ron Jordan EPA Phillip Flanders EPA Jezebele Alicea EPA Deb Bartram ERG (contractor to EPA) Elizabeth Gentile ERG (contractor to EPA)

Mr. Kovacsics visited EPA to give a presentation on their DSS ash handling technology. The presentation, company brochures

, and other supporting documents provided by Mr. Kovacsics following the meeting are included as attachments to these notes and listed in Table 2 below. Mr. Kovacsics also provided copies of the public commen ts submitted on this rule and the CCR rule ( EPA

- HQ

- RCRA

- 2013

- 0209 ), which are available in the dockets.



### Table 2. List of Attachments

DCN Title
SE059 36 A1 GEA Circumix® Dense Slurry Technology Brochure
SE059 36 A2 NAES Circumix® Dense Slurry System (DSS) for Ash and Waste Water Management

and How it Addresses Proposed ELG and CCR Rule Change
SE059 36 A3 NAES Corporation DSS Presentation
SE059 36 A4 NAES Statement of Qualifications
SE059 36 A5 NAES Corporation Brochure
SE059 36 A6 Year Two Follow

- Up Investigati on Report: Soil and Water Quality Evaluation St.

Mary’s Shoals Park Roadway Improvements
SE059 36 A7 GEA EGI DSS Technology Photos

Mr. Kovacsics started with an introduction of the DSS technology, stating that mixing water with fly ash will result in a product that hardens up naturally (due to the compounds and mineral structures that are formed). However, this reaction requires calcium oxide and optimal operating conditions including the quantity of water, particles size of the ash, and chemical composi tion. For each installation, GEA EGI evaluates a diverse set of inputs to determine if the DSS technology is an applicable ash handling technology for a specific plant

. GEA EGI has been experiencing a high level of interest in the system from the industry.INTERNAL DRAFT DELIBERATIVE: DO NOT QUOTE OR C ITE

Page 2 of 4 The system is designed for coal

- or petroleum coke

- fired generating units; however, it is not an available technology for oil

- fired generating units (mainly due to the small amount of ash generated)

. Mr. Kovacsics stated that pulverized coal boilers are preferred for the DSS technology because of the high temperature and low concentration of potassium oxides. Fly ash and bottom ash from circulating fluidized bed boilers are also good candidates for the system because plants often add lime to the
fluidize d bed, resulting in high calcium oxide content, and the bottom ash is very reactive (like the JEA Northside (Jacksonville, FL) installation)

.

In order for the system to function efficiently, it is important to identify the optimal level of
water. If the slurry is too thick, pumping costs can be too high. If the slurry is too thin, large particles can settle in the pipelines and won’t be carried to the final destination. The solids to water ratio in a traditional wet sluicing system ranges from 1:10 to 1:1 5. In a DSS, the solids to water ratio is 1:1

.

Typically, fly ash is only considered in the calculations for the design of the DSS. Bottom ash is usually too big to affect the viscosity of the slurry . When designing the system, GEA EGI focuses on the extremes of different fuel types or coal blends that are used at the plant to calculate the solids to water
ratio for the slurry . The plant can make adjustments to this ratio when mixing the slurry if necessary. Typically, a plant does not need to adjust t he solids to water ratio day to day unless a very different type of coal is being burned.

The mixer developed for the system makes the mixing of the dense slurry more efficient. Previously, the design called for a pugmill; however, this resulted in high maintenance costs because components of the pugmill were eroding. It also resulted in poor mixing and dead zones that could not be reached by the pugmill pedals. The mixer results in a homogenous mixture.

Mr. Jordan asked if bottom ash that is current ly wet sluiced could be transported by the DSS. Mr. Kovacsics stated that because bottom ash is inert, it must be kept in suspension. He stated that unlike bottom ash, gypsum helps with the viscosity of the dense slurry because it is a fine powder. In
orde r to transport bottom ash, the particle size must first be reduced prior to mixing with the slurry. Mr. Kovacsics reiterated that all of these systems are custom built. Additionally, he stated that some systems are designed to service all generating units at the plant and some are designed to have one mixer per generating unit.

In order to pump the slurry to the final destination, GEA EGI prefers to use centrifugal pumps or piston diaphragm pumps (PDP) because they require less maintenance. Mr. Kovacsics stated that the maximum conveying distance for the DSS ranges from 15 to 20 kilometers, although that distance can be influenced by elevation differences.

Mr. Kovacsics explained that in the conversion of a traditional fly ash wet sluicing system to a

D SS , the plant can install any type of dry fly ash handling system and that some silos can be utilized in
the DSS. In addition, the plant will need to install mixers, pumps, and piping to the landfill. Mr. KovacsicsINTERNAL DRAFT DELIBERATIVE: DO NOT QUOTE OR C ITE

Page 3 of 4 stated that these systems can range from anywhere to $5 million to $60 million dollars, excluding the
costs of the landfill.

The main maintenance associated with the system is the pumps; however, they are easy to replace. If the pumps are running 24 hours, they need to be replaced every [PLACEH OLDER] years. Additionally, an operator must inspect the length of pipe at least once a day for any leaks. Normally, the system is designed with a high level of redundancy. For example, there is typically a dedicated mixer per boiler and 2 pumps are inc luded per train / pipeline for each mixer

. Within the system, each mixer is connected to a dedicated pump site, including crossover valves. Therefore, any mixer can supply slurry to any pipeline in the system.

The silos for the system are designed for 8

- 24 hours of capacity. Mr. Kovacsics stated that this is enough capacity because any maintenance issue should be able to be resolved with in 8 hours provided the plant has the parts required for the maintenance.

Makeup water for the system is required; howev er, it can come from other wastewaters at the plant (e.g., bottom ash transport water). Plants can also use FGD wastewater; GEA EGI does not expect chlorides in the FGD wastewater to be an issue in the system. GEA EGI confirmed that there is one plant
in R om ania using FGD wastewater as makeup water for the DSS . Flushing water is also required when the system is stopped to flush the slurry pipelines, preventing solidification of the slurry.

The resulting ash by

- product is a solid that dries in the landfil l. The by

- product is solid; however, if dropped it will break. The ash by

- product does not generate any dust. The cure time for the by

product is associated with the hydraulic conductivity of the slurry. The resulting by

- product would not typically be mark eted.

At the disposal site, plants typically scrape the surface into cells. Using this approach, plants can sluice the dense slurry into one cell, let another cell dry, and work on the remaining surface of the disposal site. Because of the composition of the material, the landfill can be built vertically in tiers

. Mr.
Kovacsics stated that water does not need to be added to the landfill to scrape or spread the ash by

product. Two operators are required at the landfill to prepare cells and move the slurry p ipelines.

The slurry is a 1:1 ash

- water mixture. Approximately 5 to 10 percent of the water is excess water that becomes a thin film on top of the ash by

- product at the landfill. This wa ter either evaporates or slowly seeps and is collected by a leachate collection system. This water and any precipitation that is captured is either sent back to the system or discharged. GEA EGI confirmed that any leachate associated with the system that can be collected and reused as makeup water to achieve zero discharge

. The dikes built around the landfill are typically 3 meters tall and are typically built using ash by

- product. Mr. Kovacsics stated that there aren’t any run

- on issues and that there can be excess water from precipitation. Commented [E1]: Note to GEA EGI: Can you provide the this maintenance information on the system pumps?INTERNAL DRAFT DELIBERATIVE: DO NOT QUOTE OR C ITE

Page 4 of 4 The DSS may not be ideal in g eographic locations that have cold climates (10

- 15 ̊F) for extended periods of time (e.g., Russia). If the slurry freezes it will not harden and set. However, this process is an exothermic reaction; therefore, it may be OK in locations that have short perio d s of freezing weather.
Plant s could also put slurry pumps underground to avoid the freezing of flush water or install trace heating.