Notes from Site Visit at JEA’s Northside Generating Station on April 8, 2014

EPA conducted a site visit at JEA’s Northside Generating Station (Northside) located in Jacksonville, FL on April 8th, 2014 to learn about the operations at the plant, specifically the dense slurry ash transport system. These notes describe the informatio n collected during the site visit. Table 2 identifies the site visit participants. P lant process flow diagram s , provided by JEA in preparation for the site visit, are included as Attachment 1 to these notes. Additionally, a material flow diagram of the d ense s lurry s ystem is included as Attachment 2 to these notes.

Plant Overview

 JEA Northside operates two circulating fluidized bed (CFB) boilers , Units 1 and 2. Units 1 and 2 are base load units that burn a mix ture of petroleum coke and coal and each ha ve a gross capacity of 310 megawatts (MW). JEA Northside operates one st and

- alone steam turbine generating unit , Unit 3. Unit 3 is a cycling unit that burns oil and gas and has a gross capacity of 540 MW. Table 1 contains some general information on the th ree steam electric generating units :

Table 1. Plant Summary

Unit Fuel Capacity (MW) Fly Ash Bottom Ash FGD NOx Control FGMC 1* Coal: Bituminous Petroleum Coke Gas: Natural gas and Landfill gas 310 Dry pneumatic transport to fly ash silo, transported by dense slurry system to landfill Dry mechanical

and pneumatic transport to bottom ash silo, transported by dense slurry system to landfill Spray

Dryer Absorber SNCR None

2* Coal: Bituminous Petroleum Coke Gas : Natural gas and Landfill gas 310 Dry pneumatic transport to fly ash silo, transported by dense slurry system to landfill Dry mechanical

and pneumatic transport to bottom ash silo, transported by dense slurry system to landfill Spray

Dryer Absorber SNCR None

3 Gas: Natural gas and Landfill gas Oil: No. 6 Fuel Oil 540 None None None Low NOx burner None

*CFB boilers.

 Unit 1 and Unit 2 were originally commissioned in 1966 and 1972 , respectfully

. Unit 3 was commissioned in 1978. I n 2002, JEA Northside repowered Units 1 and 2 with the Department of Energy’s (DOE) “clean coal” grant. The addition of the two CFB boilers doubled JEA Northside’s generation and reduced sulfur dioxide (SO 2 ) emissions by 10 percent.

 The JEA Northside plant covers approximately 88 acres and lies adjacent to JEA’s St. John’s River Power Park P lant (SJRPP)

. The two plants operate independently of eachPage 2

other ; however, they have a combined National Pollutant Discharge Elimination System

(NPDES) permit. As described in the NPDES permit, the only water that is shared between the two plants is the make

- up water for the SJRPP natural draft cooling towers. The make

- up water is withdrawn from the Northside discharge canal and the blowdown from the cooling towers is returned to the Northside discharge c anal just downstream of the SJRPP intake structure.

 At JEA Northside, the two by

- product storage areas account for approximately 21 acres of the JEA Northside property and the ponds account for approximately nine acres.

 Units 1 and 2 bur n a combination of petroleum coke (from Texas or Venezuela) and coal (from Col o mbia). JEA Northside burns approximately 1.4 million tons of petroleum coke and 200,000 tons of coal per year

. Currently, the fuel blend for one unit is 70 percent petroleum coke and 30 percent coal. The other unit burns a fuel blend that is 60 percent petroleum coke and 40 percent coal. Fuel blending for each unit can vary from 100% coal to 100% petcoke, and any mixture of percentages between those ranges. The fuel blending is based on the availability of petroleum coke and coal at the plant.

 There are two fuel domes which collectively store approximately 12 days worth of petroleum coke and coal . All fuel at JEA Northside is delivered by barge

.

 Units 1 and 2 run continuously. It takes ap proximately 16 hours to start up the units. Natural gas is the only fuel used for start up of Units 1 and 2. Gas is used to achieve a bed temperature of 900 o F to facilitate a s olid fuel permissive. At 1400 o F a solid fuel “latch” is achieved and gas is remo ved from the units

. Additionally, natural gas can be used for intermediate or peak operation schedules for Units 1 and 2

. The units can co

- fire up to 10 percent natural gas

.

 The internal circulating temperature within the CFB boilers at full load is approximately 1650 o F. The ideal temperature for the limestone reaction facilitating SO 2 capture is approximately 1600 o F. These units are termed “hotloop” boilers due to the material being blown in a loop within.

 JEA Northside adds limestone directly to th e boiler for SO 2 control. The plant injects approximately 450,000 tons of lime into the boilers each year. Additional SO 2 is removed downstream by the spray dry er absorber (SDA).

 For Units 1 and 2 , more bed (bottom) ash than fly ash is generated. Unit 1 and Unit 2 each produce approximately 700 tons of bed ash and 500 tons of fly ash per day. The plant generates approximately 500,000 tons of by

- product per year.

 The fly ash is conveyed dry by a vacuum system to the recycle bin, which feeds the

m ixing tank to make the spray slurry. When the upper level indicator on the recycle bin is satisfied, ash valves divert the fly ash and pneumatically convey the ash to the fly ash silos where it is either sold or transported to the by

- product storage area b y the densePage 3

slurry system (DSS). The bed ash is collected on a mechanical conveyor from underneath

the boiler . Then, it is blown by pressure to the bottom ash silos where it is either sold or transported to the by

- product storage by the DSS.

 JEA Northside either landfills the DSS by

- product offsite or markets it. The by

- product can be sold a s a binder for other landfill s , remediation sites, o r pond closures. The by

product can also be sold for interim cover or secondary road cover

. Spray Drye r Absorber (SDA)

 The fl ue gas (and entrained fly ash) from Units 1 and 2 exits the top of the CFB boilers and travels through the economizer and air heater ducting, where some fly ash falls out of flue gas stream and is collected into hoppers.

 The rest of the fly ash and flue gas enters the SDA and is sprayed with fly ash slurry (there is no lime directly added to the SDA) . The fly ash slurry is made up of some fly ash that was coll ected in the baghouse and reuse water. A mixing tank at the grou nd level continuously mix es the fly ash slurry used in the SDA. The fly ash slurry is pumped to a storage tank at each unit prior to being sprayed into the SDA

. T he high temperature of the flue gas dries the slurry (all water evaporates) and reacts with re maining sulfur compounds in the flue gas to produce gypsum. The SDA has a SO 2 removal efficiency of 99.9 percent

.

 Any solids that drop down in the bottom of the SDA are collected and recycled back to the process in the fly ash slurry.

 The only wastewater discharge s associated with the SDA are a result of cleaning operations

. The SDA cleaning operations include flushing out pumps twice a shift and high pressure water blasting the absorber on c e per ye a r

. General cleaning is conducted once daily to mitigate ash dust and control any ash accumulation. The water associated with the cleani ngs is sent to the baghouse sump

. The baghouse sump is flushed with approximately 100 gallons of re

- use water per day per un it when the pump cycles off. The water is then sent to a precip itation basin, followed by the chemical treatment system , before it is discharged to a percolation/evaporation pond or a publicly owned treatment works (POTW)

.

 Other cleaning operations include brushing the spray nozzles ( no wastewater is generated from this process) twice a day.

Fly and Bed Ash Handling

 After leaving the SDA, the fly ash is collected in fabric filter baghouses. Each fabric filter baghouse cons ists of 1,030 cages which are covered with filter bags to capture the fly ash. A pulse air system is used to clean baghouse filter bags . Fly ash is pulsed free from the filter bags and drops into one of eight hoppers under the baghouse

. T he fly ash isPage 4

pneumatically conveyed to the fly ash silos (Silo 1 and Silo 2) or to the SDA

. Silos 1 and

2 are both equipped with dry unloading spouts for marketing fly ash (road base/sub

- base and waste stabilization/solidification)

. The fly ash sent to the SDA building is recycled for use in the SDA.

 The bed ash flows out of the bottom of the CFB boilers into a s tripper / c ooler

, which removes bed ash material to maintain appropriate furnace bed level. The stripper/cooler

con tains piping at the top through which the fin e particles return to the boiler. The heavier particles are cooled with air to about 500°F and the bed ash is continuously removed from the s tripper / c ooler by a series of mechanical drag chains to a clinker grinder

. The clinker grinder breaks

- up any bed ash particles too large to pneumatically convey before the material drops into a surge hopper

. A pneumatic pressure system underneath the hopper conveys the remaining bed ash to storage silos (Silo 3 and Silo 4). Silos 3 and 4 are both equipped with dry unloading spouts for marketing bottom ash (road base/sub

- base and waste stabilization/ solidification)

.

 JEA Northside explained that a choke point of the fly and bed ash handling systems can be the valves from the hopper s to the silo. These valves are typically replaced once every
year

.

 JEA installed four silos at Northside to handle all of the ash from Units 1 and 2. The system was originally designed to have one fly ash and one bed ash silo for each unit. Because there are two silos for fly ash and two silos for bed ash there is redundancy within the system. F ly ash from either unit can be conveyed to Silos 1 or 2 and bed as h fr om either unit can be conveyed to Silos 3 or 4.

 The silos are emptied as frequently as poss ible. Both fly ash and bed ash material are typically slurried to the by

- product storage area when the height of fly ash material stored in the fly ash silo reaches 40 to 50 feet.

 From the silos, the fly ash and bed ash is either marketed (and transported offsite using rail or truck) or slurried to the by

- product storage area by the DSS . From the by

- product storage area, the ash mixture is either landfilled offsite or marketed.

 JEA Northside determines if the ash will be marketed or slurri ed to the landfill based on market conditions and production. The silos have the dry unloading capabilities for rail cars and trucks.

Dense Slurry System

 JEA Northside installed the DSS to transport fly ash and bed ash to a by

- product storage

area in 200 2

. It took the plant approximately three t o five years to get the DSS running efficiently. The DSS was designed to have enough capacity to handle all fly and bed ash produced from Units 1 and 2 . JEA installed the DSS because trucking the dry ash material w as not feasible due to traffic concerns and the volume of trucks requ ired. JEAPage 5

also stated that a tradition al

, lean wet sluicing system was not feasible because the

amount of limestone in the ash would result in scaling and they did not want to build new ponds to store ash.

 United Conveyor Corporation (UCC) designed and delivered the equipment for the DSS. The diaphragm (GEHO) pumps were procured from a European

- based company.

 As shown in Attachment 2, pre

- mix and mixing tanks are located under neath t he fly ash and bed ash storage silos. Fly ash is first combined with makeup water

, from the POTW

, underneath the fly storage silo in the pre

- mix and mixing tanks

. T he resulting fly ash slurry is then pumped to one of two bed ash mixing tank s located undern eath the bed ash silos. I t is mixed with bed ash and additional makeup water to produce the dense slurry transferred to the by

- product storage area

. The dense slurry is approximately 60 percent solids by weight and pumped by one of two high pressure piston diaphragm pumps to the by

- product storage area through four inch diameter slurry pipes . The by

- product storage area is approximately one m ile away.

 The system is capable of mixing 220

- 250 tons of ash per minute. JEA Northside only conveys ash from one f

ly ash silo and one bed ash silo to the by

- product storage area at a time.

 The ratio of fly ash, bed ash, and water used in the preparation of the slurry depends on the blend of fuel burned and the market for dry fly and bed ash.

 The preparation of the slurry is a highly exothermic reaction that raises the slurry temperature to 190  ̊ F. According to plant personnel, the small amount of free water left after pumping the dense slurry to the landfill evaporates within a few days in the form of steam, resulti ng in a stable landfill placement of the wet by

- product s. The material takes approximately 48 hours to cure. The resulting by

- product material mostly consists of limestone, giving it a chalk

- like consistency.

 During the DSS start up, JEA Northside had to add dry bed ash to the slurry to meet the desired composition in the landfill

. T hat procedure is no longer needed because they have adjusted boiler input and the ratio of fly ash, bed ash, and water to have a quick drying slurry product. The dried by

- produ ct is excavated before being milled and deposited into large mounds on the far side of the storage area.

 The dried, milled dense slurry product is tested to ensure it meets minimum strength and waste stabilization benchmarks before being marketed and transported off

- site via trucks. Common uses for this material include

, but are not limited to

, waste stabilization at landfills, r emediation sites

, and pond closure s and road sub

- base

.

 When JEA slurries ash to the by

- product storage area, the DSS runs continuously for three to four days (usually once a week) . To prevent and manage the build

- up of finePage 6

particles in the dense slurry pipe, the system is flushed with water recycled from other

plant processes after each run . The water generated during the fl ush process stays on the by

- product storage area and is absorbed into the ash material . The slurry discharge can be recirculated within the mixing tanks while flushing the downstream dense slurry line and GEHO pumps if necessary

.

 JEA Northside explained t hat a choke point of the DSS is the valves in the DSS. Regular maintenance on the system includes rebuilding valves once a year during scheduled outages, cleaning the mix tanks after every run (the flushing process), and performing maintenance in the silos as necessary when they are empty. A plant operator walks the dense slurry transport lines from the mixing tanks to the by

- product storage area every two hours to ensure there are no maintenance issues.

 JEA Northside did not mention any climate or geographical limitations for operating the DSS.

By

- Product Storage Areas/Landfills

 The dense slurry is pumped to one of two by

- product storage areas. One storage area is the onsite landfill (the upper by

- prod uct storage area) for the dense slurry by

- product

, which was brought online in 2002. The landfill stores the product of the dense slurry system ( a mixture of bed ash, fly ash, and water ) . The 21

- acre landfill is double

- lined with an HDPE liner and a two foot drainage layer.

 The upper by

- product storage area w as designed to be operational for a five year period

. However, the plant has sustained use of the landfill for over 10 years by d redging the by

product material and disposing of it offsite

. The by

- product is either marketed or trucked to an offsite landfill. JEA Northside sends the slurry by

- product to offsite landfills because they did not want to permit another landfill area. Initially, the plant had a cell fill plan for the upper by

- produ ct storage area , but no longer follow s it.

 The dense slurry is directed into one of two 25

- 3 0 foot deep pits at the upper by

- product storage area

. The dense slurry pump line discharge is not fixed and can be moved to alter the location of the dense slurry discharge at the by

- product storage area. The slurry is only pumped into one pit at a time, filled until approximately four feet of headroom is lef t , and then the slurry line is directed into the other pit. While one pit is receiving slurry, the dried material from the other pit is dredged a nd prepared for the next slurry

. The dredged by

- product is stacked until it is loaded in trucks for final dispo sal.

 At the upper by

- product storage area, JEA Northside established a low

- permeability membrane at start

- up by laying down thin layers of slurry and letting dry. T he permeability of the by

- product ranges between 10

- 3 and 10

- 5 cm/sec.Page 7

 The upper by

- product storage area is in compliance with its 62

- 701 permit (Florida Department of Environmental Protection) solid waste management facility requirements. The permit cycle for the landfill is five years. The base of the upper by

- product stora ge area is at an elevation of 15 feet and the maximum permitted elevation is 100 feet . The landfill is currently at an elevation of 70 feet.

 JEA Northside is required to survey the landfill annually and perform semi

- annual ground water monitoring reports . There are over 30 compliance wells and 10 to 15 detection wells around the upper by

- product storage area . Currently

, the plant is dealing with one issue at a well where vanadium was detected . JEA Northside suspects that this is a result of storm water runoff associated with truck traffic at the landfill . As a result, the plant is planning to build a truck washing facility that should be completed in October 2014.

 The other, smaller by

- product storage area ( the lower by

- product storage area /EZ Base Fac ility) was constructed after the upper by

- product storage area . The storage area is self

declared for beneficial reuse and , as such, does not require a liner. The platform for the area is seven feet of compacted slurry by

- product. Additionally, the storage area has berms that were built using the slurry by

- product.

 Plant operators are working on at least one of the by

- product storage areas every day. The operators are responsible for dredging and stacking the by

- product for final disposal and the next slu rry event . Additionally, t hey build up the edges of the active slurry pits with dry by

- product

.

 No transport water is recirculated back to the plant for reuse . All the water used to convey the ash is absorbed by the material through a hydration reaction, or is evaporated. Leachate for the upper storage area and runoff from rainfall are collected and treated in the plant waste water treatment system (see next section)

.

Leachate Collection

 Around the perimeter of the upper by

- product storage area there is a perimeter ditch to capture runoff

. Additionally, there are four sumps that collect the leachate from the upper by

- product storage area. The four sumps and the perimeter ditch drain to four double

lined collection ponds.

 The collection ponds have an est imated capacity of 12 million gallons and cover approximately 11 acres.

 The water from the collection ponds is not recycled back to the plant process; however, it is sent to the plant’s chemical waste treatment system. The chemical waste treatment system includes flocculation and the addition of acid for pH control. The effluent from the treatment system is sent to percolation/evaporation ponds or to a POTW. Other wastewaters combined in the treatment system include oth er water from other plantPage 8

sumps, once through cooling water, low volume waste, metal cleaning waste, and ion

exchange wastewater.

 JEA Northside s amples wastewater effluent at t he combi ned discharge from the chemical waste treatment system . Analytes inclu de metals, conductivity, pH, oil and grease, and total suspended solids ( TSS )

.Page 9

Table 2. List of Attendees

Name Organization (Representing) Telephone E

- mail

Matt McClure JEA 904

- 665

- 6253 mcclmr@jea.com

Ed Cordova JEA 904

- 665

- 7840 corded@jea.com

Steve McInall JEA 904

- 665

- 4309 mcinsg@jea.com

C. Shay Hill JEA HillCs2@jea.com

Katie Bizub JEA bizukj@jea.com

Jaclyn Taricska JEA tarijm@jea.com

Farid Zahir JEA 904

- 665

- 6576 zahimf@jea.com

James Stancia JEA stanjm@jea.com

Scotty Bichsel JEA bichks@jea.com

John Wiseman JEA wiseje@jea.com

Michael D’Avico JEA davimt@jea.com

Kristen Sealey Golder Associates 352

- 336

- 5600 ksealey@golder.com

Ron Jordan EPA 202

- 566

- 1003 jordan.ronald@epa.gov

Jezebele Alicea

- Virella EPA 202

- 566

- 1755 alicea.jezebele@epa.govPage 10

Table 2. List of Attendees

Name Organization (Representing) Telephone E

- mail
Phillip Flanders EPA 202

- 566

- 8323 f landers

. p hillip @epa.gov

Deborah Bartram ERG 703

- 633

- 1669 d eborah

. b artram@erg.com

Elizabeth Sabol ERG 610

- 344

- 0829 e lizabeth

. s abol @erg.com

Ryan Novak ERG 703

- 633

- 1668 r yan. n ovak @erg.com