Final Notes from Site Visit at South Carolina Electric & Gas Co mpany ’s Wateree Station on January 24, 2013

EPA conducted a site visit at South Carolina Electric & Gas Co mpany ’s ( SC E & G ) Wateree Station (Wateree) located in Eastover, S outh C arolina on January 24, 2013

, to learn about the operations at the plant, specifically the bottom ash handling retrof it from wet sluicing to using a remote submerged flight conveyor (SFC). These notes de scribe the information collected during the site visit. Table 2 , located at the end of these notes, identifies the site visit participants. The summary and block diagram of the remote SFC that the SCE&G personnel gave during the site visits are provided as Attachment 1 to these notes.

Plant Overview

**•** Wateree operates two identical coal

- fired generating units

, Units 1 and 2, which began operation in 1970 and 1971, respectively. Each unit has a gross generating capacity of 372 megawatts (MW). Both generating units are categorized as base load units. Table 1 below contains some general information for the two generating units.

Table 1. Plant Summary

SE Unit Installation Date Gross Capacity (MW) Particulate Control NOx Control

1 1970 372 Reverse Gas Baghouse SCR, Low NOx burner

2 1971 372 Reverse Gas Baghouse SCR, Low NOx burner

**•** The Wateree plant is loca ted on 1

, 300 acres of land adjacent to the Wateree River. Wateree employs approximately 99 employees on site. The plant draws raw intake water from the Wateree River.

**•** At full load, Wateree burns 6,000 tons of coal per day. The ash content of the coal is approximately 10 percent

. T he following is a non

- comprehensive list of suppliers that provide b ituminous coal to Wateree :

o Alpha Natural Resources;

o Arch Coal Sales Company Inc.;

o B&W Resources Inc.;

o Blackhawk Mining LLC.;

o Cargill Incorporated;

o Coalsales LLC.;

o Consol Energy Sales Company;

o Cumberland River Energies Inc.;

o Delta Coals LLC.;

o EDF Trading North America LLC.;

o ICG LLC.;

o J A D Coal Company Inc.;

o James River Coal Company;Page 2

o JP Morgan Ventures Energy Corporation;

o Kopper GLO Fuel Inc.;

o Louis Dreyfus Energy Services LP;

o Massey Coal Sales Company Inc.;

o Patriot Coal Services LLC;

o Pea body Coaltrade International Limited;

o TECO Coal Corporation;

o Trinity Coal Marketing LLC;

o Virginia Power Energy Marketing Inc.;

o Vitol Inc.; and

o Xinergy Corp.

**•** Wateree stated th at the fly ash/ bottom ash split is approximately 90/10

, which is roughly 22.5 tons per hour (tph) of fly ash and 2.5 tph of bottom ash. In total, Wateree generates 150,000 tons of ash per year.

**•** Wateree initiated the retrofit of the wet sluicing bottom ash handling system on both units in 201 1

. Wateree insta ll ed two remote SFCs that dewater the bottom ash sluice and re cycle the overflow back to the boiler to be reused as quench

water ( in the bottom of the boiler ) and sluice water. Wateree completed t he retrofit on both units in October 2012

.

**•** Wateree operates reverse gas bag houses to control fly ash and particulate emissions from the plant and pneumatically conveys the collected fly ash to two silos (one specific to each unit)

. Wateree has the capability to handle the collected fly ash both wet and dry , but aims to transition to completely dry fly ash handling by 201 8 and close the primary ash settling pond (Ash Pond 1) by 2021

.

**•** Currently, Wateree operates two ash pond s (Ash Pond 1 and Ash Pond 2) in series that settle fly ash and bottom ash from the wet sluicing operations. Ash Pond 1 is where the majority of the settling occurs, while Ash Pond 2 acts as a polishing pond prior to discharge. Both the fly ash and bottom ash handling systems have the ability to direct wet sluice to the ash ponds , even after the bottom ash conversion to the remote SFC . Wateree is currently planning to close Ash Pond 1 by 202 1

. As part of the closure, Wateree’s goal is to eliminate the use of the fly ash wet sluicing system and operate the re mote SFCs as a complete recycle system.

**•** Wateree installed selective catalytic reduction (SCR) systems on both units to control nitrogen oxide (NOx) emissions from the plant , and these systems operate
year

- round. Additionally, e ach unit utilizes low

- NOx bu rners

. The NOx burners were installed in June 1998 (modified November 1998) for Unit 1 and October 1998 for Unit 2. The SCR ’s were install ed in 2003 and 2004 for Unit s 1 and 2

, respectively.

**•** Wateree operates one wet flue gas desulfurization ( FGD ) system which services both units. This system is a limestone forced oxidation system that achieves aPage 3

90% sulfur dioxide (SO 2 ) removal efficiency. The plant uses i ntak e water from the Wateree River a s FGD reagent preparation water, absorber make

- up water, and mist eliminator wash water

. FGD make

- up water is also a source of make

- up water to the remote SFC

.

**•** Wateree sells its fly ash and bottom ash to cement and concrete pipe manufacturers. The plant also sells a mix of fly ash and bottom ash that is dredged from Ash Pond 1, fly ash product from the carbon burnout (CBO) process, and dewatered bottom ash from the remote SFC. Wateree stores any fly ash and bottom ash that cannot be sold in a lined, onsite landfill.

Bottom Ash Handling

**•** In 2012, Wateree converted their bottom ash handling system to a remote SFC designe d by United Conveyor Corp oration (UCC). Wateree started planning the bottom ash handling system conversion in 2010 for both units. Construction for the remote SFC system started in 2011, simultaneously for both units, in a n area of the plant that was not occupied by any equipment or buildings at the time. T he following is a list of key points in the timeline of the retrofit, starting from when the project went out t o bid to end of construction :

o August 2010 to November 2010

– Project Bid Phase ;

o November 2010 to January 2011

– Bid Evaluation and Award Phase ;

o January 2011 to June 2011

– Preliminary Engineering, Scope and Budget Development ;

o August 2011

– Mobilization Construction to Site ;

o Fall 2011

– Piping Installation and Modifications to Unit 2 ;

o Spring 2011

– Piping Installation and Modifications to Unit 1 ;

o Feb ruary 2012 to August 2012

– Installation of remote SFC equipment and piping from Units 1 an d 2 to remote SFC ;

o August 2012 to October 2012

– Start

- up and Commissioning ; and

o November 2012

– Final Project Completion.

**•** The remote SFC retrofits were completed by the end of October 2012. The units were operational at that time, but the plant is continuing to work through minor start up issues

. Wateree expects to resolve these minor issues by June 2013 . The startup issues include working on flow regulation and sorting out the controls,

sensors , pumps and valves. In total, t he bottom ash convers ion took approximately two and one

- half years from inception to completion.

**•** Prior to the conversion, Wateree wet sluiced bottom ash to the ash pond s. From the ash ponds

, Wateree adjusts the p H of the water prior to discharge to the Wateree River via Outfa ll 03A.

**•** Wateree started looking into bottom ash handling retrofit options after determining that wet sluicing bottom ash to Ash Pond 1 was not a sustainable

, long

- term solution. Additionally, Wateree has identified groundwater monitoringPage 4

issues associated with Ash Pond 1. Wateree stated that they were trying to anticipate what could result from the revisions to the Steam Electric ELGs. Furthermore, Wateree aimed to cease bott om ash sluicing by June 1, 2015

, and close A sh P ond 1 by 202 1

.

**•** As stated previously , t he bottom ash technology evaluation began in 2010. Wateree evaluated the following systems for the conversion:

o Mechanical drag system (MDS);

o Dr y drag conveyer system /vibratory conveyor system;

o Pneumatic handling systems (vacuum/pressure);

o Complete recycle system with dewatering bins; and

o Remote SFC (operated in complete recycle).

**•** Wateree did not install the MDS, dry drag conveyor system, or the vibratory conveyor system because these dry ash h andling systems require more space in the boiler basement than Wateree had available . Additionally, Wateree d oes not have a direct path out of the boiler room required for these types of conveyor systems . Accommodating t hese systems would have required boi ler a nd hopper modifications, and relocation of equipment and piping beneath the boiler such as the boiler feed booster pump and the coal mill process piping. Additionally, there was not enough vertical space below the boilers, so installing any of these o ptions would have required excavation.

**•** Wa teree did not install any pneumatic bottom ash handling systems due to vertical space underneat h the boiler and experience with the performance of the systems at the SCE&G ’s McMeekin Station . Wateree noted the fol lowing issues with a pneumatic bottom ash handling system based on its experience with the McMeekin Station :

o Total length of piping required for the system and likelihood that it would plug (characteristics of bottom ash) ;

o N ew air compressor required to m ove ash;

o Modification required to the bottom of the furnace to replace the wet boiler seal;

o Limited space for any e xcavation underneath the boiler; and

o Employee safety concerns working with the system

.

**•** Wateree personnel explained that after the initial evaluation, t he remote SFC and dew atering bin complete recycle systems had equal benefits. Wateree evaluated the following items to select the system for the conversion :

o Confidence in the technology;

o Capital inst allation costs;

o Life cycle costs;

o Equipment/footprint/layout required for the system;

o Industry and SCE&G experience; and

o Schedule for installation.Page 5

**•** Wateree ultim ately selected the remote SFC system because it was determined to be more cost effective (on p aper, not based on direct numbers because this is the first system of its kind)

, the foot print of the remote SFC wa s more flexible

, and the installation schedule matched their needs

. Wateree determined that the cost of the substantial foundations required for the dewatering and settling bins were too high. Based on available data about the system , Wateree determined that the remote SFC was a more robust system. A dditionally, Wateree stated that because the remote SFC is at ground level versus the taller dewatering bin set up, the equipment is more accessible and O&M of the remote SFC system is more convenient.

**•** Wateree installed two remote SFC systems to handle the bottom ash from both units. T he bottom ash handling system retrofit was completed within t he planned outages in October 2012 . The majority of the construction (which lasted approximately 18 months) was completed while the units were still online , and work during the outage was related to piping tie

- ins

. The planned unit outage was

two weeks in duration, but t he actual time required for the tie

- in of the remote SFC s was less than one week. The cost for the two remote SFC system retrofit was approximately $22.5 million. Wateree could not provide a further break down of because t he system has not been in service with sufficient operating time to estimate the frequency of replacement for equipment components

, including the pump seals.

**•** Both remote SFC s are located behind the U nit 2 fly ash baghouse . Each remote SFC was designed large enough to serv e as a combined dewatering tank, settling tank and surge tank for the total volume of bottom ash sluice from both units

. The front of each remote SFC (i.e.

, the ramp) perform s the separating and dewatering

, and the middle and rear of each remote SFC acts a s a settling tank

.

**•** Although there are two remote SFCs, under normal operating conditions

, Wateree directs the bottom ash sluice from both units (sequentially) to one remote SFC at a time , while the other remote SFC acts as a surge (overflow) tank. The plant alternates between which remote SFC receives bottom ash sluice and which remote SFC act s as the surge tank every other week so that solids accumulating in the remote SFC receiving the overflow can be removed. Wateree stated that UCC design ed the system to have redundancies (i.e., each individual remote SFC has the capacity to service bottom ash sluice from both units without overflowing to the other remote SFC ) . In order to operate one remote SFC alone ( i.e., without the other remote SFC as a surge tank) , Wat eree would need to change the sequence of operation and timing of pulling bottom ash

. Wateree stated that this is not a typical or expected mode of operation. As a backup, each remote SFC has an emergency flow line located near the front of the SFC that directs water to the remote SFC sump

. The remote SFC sump is an area where emergency overflow and water from the bottom ash pile are directed. This water is immediately recycled back into the remote SFCs using slurry pumps.Page 6

**•** Wateree did not make any changes to the bottom of the boiler /hoppers, clinker grinders, or hydroveyor for the retrofit. Wateree installed additional piping and a “Y” joint , approximately 100 feet away from the bottom of the boiler . The forks of th e “Y” represent the split in the piping where the plant can direct the bottom ash sluice to Ash Pond 1 or the remote SFCs

. Additional piping around the boiler was installed to return overflow water from the remote SFCs to the hopper ( i.e., makeup quench wa ter). Wateree also altered the bottom ash sluice piping to bring the recycled overflow water from the remote SFCs back to the hydroveyor (the vacuum supplying the power to wet sluice the bottom ash).

**•** Bottom a sh falls from the boiler into the hopper where it is quenched in water

. The source o f the quench water is primarily overflow recycle from the remote SFC ; however, Wateree uses raw intake water as makeup water for bottom ash handling when necessary (i.e., losses due to evaporation)

.

**•** Wateree hol ds the b ottom ash in the hopper s until the o perator s determine it is time to convey bottom ash to the remote SFCs

. The plant usually sluices bottom ash from each unit on e time during first and second shift s ( totaling two times per day for each unit). Wet s luicing the bottom ash takes approximately 20 minutes f

o r each unit. From the bottom ash hopper

, the bottom ash sluice is conveyed by hydroveyors to the remote SFC system s or Ash Pond 1 . The bottom ash sluice is conveyed approximately 400 feet to 500 feet from the unit to the remote SFC. Any overflow from the hoppers is directed to an overflow tank prior to being transferred directly to the remote SFC s through different piping than the bottom ash sluice

.

**•** The sluice pipes transport the bottom ash sluice to the remote SFC, dropping it directly over the center of the open remote SFC

, and the bottom ash is discharge d over a splash plate. The splash plate prevent s bottom ash solids from accumulating directl y below the inlet to the remote SFC and evenly distri butes the bottom ash in the remote SFC. As the bottom ash settles, the drag chain collects it from the bottom of the tank and drag s the bottom ash from th e rear of the system to the front and up the ramp of the remote SFC. The drag chain consists of two lo ng parallel chains that run the length of the remote SFC. The chains are connected with conveyor blades that run horizontally which are the mechanisms that grab the settled bottom ash and move it up the incline.

**•** At the front of the remote SFC, the conveyo r moves bottom a sh out of the water and up the incline, wh ich dewaters the bottom ash

. The drag chain is operated on a timer, determined during system testing, for optimal bottom ash removal. At the top of the incline, the dewatered bottom ash falls over t he edge and in to a concrete bunker

. The moisture content of the dewatered bottom ash on the drag chain is approximately 23

- 25 %

, but the ash continues to dewater to approximately 20 % moisture as it sits in the concrete bunker

. The water from this additional dewatering is collected in the remote SFC sump and then sent back to the remote SFC.Page 7

**•** Wateree personnel stated that they are not concerned about residual solids in the sump because slurry pumps send any water collected back into the remote SFC system for dewatering

. UCC stated that removing solid s from the sumps should not be necessary; therefore, Wateree is not planning any solids removal at this time. Trucks come to retrieve the bottom ash out of the concrete bunkers periodically. Wateree sells the b ottom ash to concrete and block/ pipe fabrication companies or store s it in the onsite landfill , located approximately one mile from the remote SFC systems

. In the last month , Wateree sold a lmost 100 percent of its bottom ash. Currently due to market demand, trucks transport bottom ash on a daily basis Monday through Friday.

**•** The remote SFC dewatering the bottom ash sluice is receiving bottom ash sluice periodically, makeup water (raw

- intake water) as necessary , water from the remote SFC sumps, hydroveyor water (constantly running), and hopper overflow water (quench water). Make

- up water is sent to the remote SFC system to maintain water level in the system due to evaporation and drainage associated with miscellaneous maintenance and operating ac tivities

. As the remote SFC fills with water, the solids s ettle to the bottom and the overflow flows over weirs at the rear of the SFC

. The top of the weir is approximately 24 feet above the base of the remote SFCs. The overflow is directed to the main com partment of the second

remote SFC acting as the surge tank

. The empty weight of each remote S F C is 250,000 pounds, the weight filled with water and ash for the design storage time is 1,100,000 pounds for each remote S F C. Water from the overflow of the remote SFC is returned to the boilers constantly by low pressure pumps to supply the hydroveyor with water and keep the water seal on the bottom of the boilers intact

.

**•** The plant has kept the option of sending the bottom ash sluice to Ash Pond 1 if needed. The operator controls w hich pipeline the sluice travels down by opening and closing valves at the “Y” junction point

. During the first few months of

remote SFC operation

, Wateree sent some bottom ash sluice to the ash pond s due to startup issues. M oving forward, Wateree does not plan to send any bottom ash sluice to Ash Pond 1 after 2015 and plans to close Ash Pon d 1 by 202 1

. Wateree stated that the bottom ash sluice flow from the unit to the remote SFC is similar to the sluice amount previously sen t to the pond. Wateree does not have a way to monitor the flows from their sluice systems, but t he SFC operation is expected to reduce the total sluice flow and discharge flow at Outfall 03A.

**•** The new piping f or the system is ceramic, fiber glass pipe. This type of pipe is corrosion resistant

. SCE&G plants have had good experiences with this type of piping for sluicing systems

. The length of pipe from where the new system ties in to the old sluice pipes and the return from the remote SFCs to boiler is all new piping . Wateree installed metal piping to transfer makeup water to the remote SFC system s and boiler

.

**•** The remote SFC systems are open

- top tanks. Wateree stated that rainfall does not alter the water balance of the system unless ther e is a n uncharacteristically high rainfall

. In anticipation of unusually high rainfall, Wateree attempt s to adjust thePage 8

water usage rate to accommodate , but i f the rainfall is too great and the available water in the bottom ash sump exceeds the water balanc e for the system, then water is discharge d from the Bottom Ash Sump to Ash Pond 1 until the system water balance is restored.

**•** Wateree stated that the drag chain in the system should last approximately three to five years prior to requiring replacem ent. Sp ecific plates within the chain cannot be replaced because the chains can stretch and become uneven, making the replacement of a single pla t e difficult. Wateree also stated that they complete tests on the equipment to replace these chains prior to breaking, as preventative maintenance. After the drag chain, the pumps seals will likely need replacing.

**•** The plant stated that the a nnual operati on and maintenance cost will ra nge from approximately $800,000 to $1.5 million, which is a hypothetical cost for replacement of a drag chain

. As previously noted, t he system has not been in service with sufficient operating time to estimate the frequency of replacement for equipment components including the pump seals. The O&M cost for equipment repair and replacement does not necessarily include all possible costs.

**•** Wateree does not monitor the concentration of total suspended solids ( TSS ) recycled from the remote SFC s to the boiler

. UCC complete d some testing on TSS concentrations between operating both remote SFCs compared to operating just one without an overflow tank. TSS testing was performed during initial system start

- up and commissioning. The system is still undergoing design modifications based on boiler hopper overflow items discovered during operation

. Representative TSS results will not be available until completion of system modifications and a subsequent reasonable duration for system operation. Wateree also stated that they do not mon itor the pH of the recycle stream and that UCC did

not recommend any chemical addition to the recycle stream

.
Fly Ash Handling

**•** Wateree collects fly ash using fabric filter baghouses

. Electrostatic precipitators were originally installed on each unit and replaced with reverse gas fabric filters in 2001 and 2002 for Units 1 and 2, respectively.

**•** Wateree can convey fly ash using a wet sluicing system or a wet vacuum pneumatic system. Wet fly ash is sluiced directly to Ash Pond 1

. Dry fly ash from Unit 1 is c onveyed to Silo 1. Dry fly ash from Unit 2 is conveyed to Silo 2. Unit 1 silo ha s a capacity of 1

, 000 tons.

**•** F rom Silo 1, the dry fly ash can be pneumaticall y conveyed to the onsite carbon burnout ( CBO ) system

. The CBO system is a self

- sustained fluid bed boiler , and it re

- burns the fly ash to achieve a lower loss on ignition (LOI)

. Wateree sends fly ash to the CBO system with LOI ’s that range from 8

- 25 percent
, and the CB O system produces a 1

- 3 percent LOI product. The plant stores the fly ash product in

a storage dome on site. If the fly ash feed does not meet 8

- 25 percent LOI, thenPage 9

Wateree either supplements the feed with fly ash from outside sources ( e.g., McMeekin) or moisture conditions the fly ash for disposal in the onsite landfill. Actual LOI ra nges vary considerably with the process of combustion , which may slow

- down or speed up the process.

**•** When Wateree cannot send fly ash to the CBO system
, the plant moisture conditions the fly ash to approximately 20 percent using pug mill mixers and transpo rts the fly ash via trucks to the onsite landfill. Silo 1 has the capability to send ash to the CBO system and moisture condition the ash for unloading into trucks.

**•** From Unit 2 , Wateree can pneumatically convey the dry fly ash to Silo 1, wet sluice the ash to Ash Pond 1 , or store the fly ash in Silos 2A and 2B

. Silo s 2 A and 2B have the ability to send fly ash to the CBO system but do not have the capability to unload the fly ash onto trucks

.

**•** Currently

, the priority for handling fly ash at the Wateree p lant is to re

- burn the fly ash at the CBO system and market the ash , store it in the onsite landfill, and as a last resort, wet sluice the fly ash to Ash Pond 1

.

**•** Wateree originally designed t he fly ash handling system to be a dual wet and dry system
, but the system does not have any redundancies built in. Because of this

, Wateree need s to wet sluice their f ly ash to the ash pond s if the dry handling system is down for maintenance

. Wateree is working on solutions to handle their fly ash completely dry by 2 018 and to close A sh P ond 1 by 2021

.

Flue G as Desulfurization System

**•** Wateree operates one wet FGD system that services both units. This system is a limestone forced oxidation system that achieves approximately 90 percent removal of sulfur dioxide. The plant uses i ntake wate r from the Wateree River for FGD reagent preparation water, absorber make

- up water, and mist eliminator wash water.

**•** Wateree maintains their chlorides concentration in the scrubber at 2 ,000 to 3,000

ppm , though the design chlorides level is 15,000 ppm

. Plant staff stated that this low chlorides level is due to the quality of their coal and not due to any special effort on the plant’s part to keep chloride level s low

.

**•** The plant blows down from the FGD scrubber twice a day. The scrubber blow down flow rate varies with unit load and coal sulfur content. The blowdown is sent to primary hydrocyclones

. T he overflow from the primary hydrocyclones is transferred back to the FGD scrubber or sent to the secondary hydro cy clones . The under flow from the primary hydrocyclones is sent to the f ilter feed tank and vacuum drum filters.Page 10

**•** O verflow from the secondary hydrocyclone s (i.e., FGD scrubber purge) is sent to the FGD ponds

. The underflow from the secondary hydrocyclones is sent to Wateree’s WFGD Reclaim Water Tank and returned to the FGD scrubber

. Filtrate is also transferred to the WFGD Reclaim Water Tank and returned to the FGD scrubber

. Wateree stores the dewatered g y ps um in the onsite landfill.

**•** The FGD ponds consist of two conc rete fore bays operated in parallel

. FGD scrubber purge is discharged into one forebay at a time. While one forebay is filling, the other is being dredged and the solids are sent to the onsite landfill. The

two forebays overflow into a combined pond, and th en into a polishing pond. From the polishing pond, the treated FGD water discharges into the back end of Ash Pond 1 (i.e., near the overflow weir)

, prior to overflowing into Ash Pond 2. The FGD wastewater is ultimately discharged to the Wateree River after pH adjustment in Ash Pond 2

. During EPA’s site visit, a filter press was observed at the FGD ponds. Plant personnel stated that this was rental equipment from a

c ontractor dredging the FGD ponds

. SCE&G does not own a filter press or oth er equipment used at the FGD ponds.

**•** Wateree is currently in the process of installing further t reatment for the FGD scrubber purge. As part of the addition al treatment

, Wateree is considering adding equalization tanks (immediately after the hydrocyclones) and a Lamella clarifier with polymer addition prior to send ing the FGD wastewater to the FGD ponds

. Wateree w ould also add a filter press for solids remov al. Wateree w ould either landfill or potentially sell the solids from the filter press. The filtrate would likely be discharged to the FGD ponds. Because this waste stream is the FGD blowdown, used to maintain the chloride levels in the absorber, the filtrate cannot be recycled back to the absorber due to high chloride levels.

**•** Wateree is considering this addition because the FGD treatment ponds are filling up with solids , which are difficult to dewater naturally.

Landfills/Ponds

**•** Wateree currently operates two unlined ponds in series

– a primary ash settling pond (Ash Pond 1) and a polishing pond (Ash P ond 2)

. Ash Pond 1 receives bottom ash sluice (when the system is not achieving complete recycle) , fly ash sluice (when not handling dry)

, low volume wastes ( LVW ), coal pile runoff (CPR)

, general runoff, filter backwash, ion exchange wastewater, and boiler leakage

. These wastewaters enter Ash Pond 1 at the front end of the pond

. Ash Pond 1 also receives treated FGD wastewater combined with ash landfill runoff/leachate , which enters the ash pond near the overflow weir in the pond

. Ash Pond 1 is approximately 80 acres and is currently 80% full. Ash Pond 1 drains into the Ash Pond 2 (polishing pond) prior to discharge.

**•** Wateree intends to close Ash Pond 1 by 2021

. Since the installation of the remote SFC, Wateree is confident that they should never need to send bottom ash sluice

to Ash Pond 1 again . Wateree still wet sluices fly ash to Ash Pond 1 when the dryPage 11

fly ash handling system is down for maintenance. For the other wastewaters, Wateree plans to install a lined pond adjacent to or within the existing ash pond. The new pond will be operated as a wastewater pond and will receive landfill leachate, CPR, LVW, treated FGD wastewater , etc. , prior to draining into Ash Pond 2

. Wateree adjusts the pH of the wastewater with 93% sulfuric acid at the end of Ash Pond 2 prior to discharge in to Wateree River.

**•** At this time, there are no plans to replace or close Ash Pond 2.

**•** Ash Pond 1 is currently being excavated i n two areas

. The plant is excavating ash near the inlet of the pond where the larger particles of ash have settled and is moving the ash to the landfill. In addition, c ompanies who want to purchase the mixed bottom and fly ash solids are excavating further out in the ash pond where the finer particles have settled out (more marketable combined ash)

. As part of the Ash Pond 1 closure and installation of a new pond , Wateree first set s the dredged solids on the side of the pond to dewater prior to trucking them away

. Wateree plans to finish dredg ing Ash Pon d 1 and m oving the solids offsite by 2021

.

**•** Wateree personnel stated that they have found issues related to Ash Pond 1 in groundwater monitoring results. Wateree personnel stated that Ash Pond 1 has not had any impacts on surface water.

**•** Wateree began operating its onsite l andfill four years ago , and it was designed for

a 30

- 35 year life. The landfill is approximately 140 acres and stores boiler slag, bottom ash, fly ash, and calcium sulfate (gypsum ). The la ndfill is lined

, and the leachate collected is transferred to Ash Pond 1 (which ultimately discharges to Ash Pond 2)

. The landfill was designed to provide 17.6 M cubic yards of disposal capacity, with the life span of the landfill dependent on CCR recycling efforts.Page 12

Table 2 . Site Visit Attendees

Name Organization (Representing) Telephone E

- mail

Tom Effinger SCANA 803

- 217

- 9367 teffinger@scana.com

Mike Summer SCE&G 803

- 217

- 9155 msummer@scana.com

Jack Robinson SCE&G 803

- 217

- 6324 jrobinson @scana.com

Jim Landreth SCE&G 803

- 217

- 7224 jlandreth @scana.com

Mark Ferguson SCANA 803

- 217

- 8103 mferguson1@scana.com

John Durkee E 2 S 843

- 214

- 0663 e2sciences@bellsouth.net

Donna Hill Southern Company 205

- 257

- 5234 dbhill@southernco.com

April Kelly SCE&G 803

- 217

- 4020 apkelly@scana.com

Ron Jordan EPA 202

- 566

- 1003 jordan.ronald@epa.gov

Jezebele Alicea EPA 202

- 566

- 1755 alicea.jezebele@epa.gov

Daisy Wang ERG 703

- 633

- 1692 daisy.wang@erg.com

Elizabeth Sabol ERG 610

- 344

- 0829 elizabeth.sabol @erg.com