# FINAL Engineering Site Visit Report for Georgia Power’s Plant Yates Newnan, GA

Prepared for:


## U.S. Environmental Protection Agency Engineering and Analysis Division Office of Water 1200 Pennsylvania Avenue Washington, DC 20004

Prepared by:



### Eastern Research Group, Inc. 14555 Avion Parkway Suite 200 Chantilly, VA 20151-1102

June 27, 2007

EPA Contract No. 68-C02-095 Work Assignment 4-22i TABLE OF CONTENTS

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1.0 S ITE V ISITED AND D ATE .......................................................................................... 1

2.0 A TTENDEES .............................................................................................................. 1

3.0 B ACKGROUND AND O BJECTIVES .............................................................................. 1

4.0 P LANT D ESCRIPTION ................................................................................................ 2

5.0 P LANT O PERATIONS ................................................................................................. 3 5.1 Coal Preparation.......................................................................................... 3 5.2 Biofouling Control...................................................................................... 4 5.3 Make-up Water ........................................................................................... 4 5.4 Nitrogen Oxide Controls............................................................................. 4 5.5 Particulate Control ...................................................................................... 5 5.6 FGD System................................................................................................ 5

6.0 W ASTEWATER M ANAGEMENT ................................................................................. 9 6.1 Flue Gas Desulfurizatio n Wastewater Treatment....................................... 9 6.2 Monitoring Data........................................................................................ 11

7.0 R EFERENCES .......................................................................................................... 12

Appendix A LIST OF ATTENDEES Appendix B PICTURES FROM SITE VISIT Appendix C MONITORING DATA PROVIDED BY PLANT YATESii LIST OF TABLES

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A-1 List of Attendees................................................................................................. A-1

C-1 Yates FGD Wastewater (JBR Sl urry Collected on 9/28/2005) ...........................C-1
C-2 TSS NPDES Monitoring Data .............................................................................C-2
C-3 2004 Ash Pond Blowdown Grab Sample ............................................................C-3
C-4 2005 Ash Pond Blowdown Grab Sample ............................................................C-4
C-5 2006 Ash Pond Blowdown Grab Sample ............................................................C-5iii LIST OF FIGURES

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5-1 Diagram of the Chiyoda Je t-Bubbling Reactor® FGD System...............................8
6-1 Wastewater Flow Diagram for the FGD System at Plant Yates............................10
B-1 Chiyoda Jet-Bubbling Reactor®..........................................................................B-1

B-2 FGD Stack............................................................................................................B-1
B-3 FGD Viewing Port ...............................................................................................B-2
B-5 Gypsum Ponds and Gypsum Stacking Area ........................................................B-3
B-6 Final Gypsum Pond at Plant Yates ......................................................................B-31 1.0 S ITE V ISITED AND D ATE

Georgia Power’s Plant Yates 708 Dyer Road Highway Alt 27 Newnan, GA 30263

December 11, 2006

2.0 A TTENDEES

Appendix A lists the attendees.

3.0 B ACKGROUND AND O BJECTIVES

Section 304(m) of the Clean Water Ac t (CWA) requires EPA to develop and publish a biennial plan that esta blishes a schedule for the annual review and revision of national effluent limitations guidelines and standards (E LGs) required by CWA section 304(b). During EPA’s 2005/2006 review of ELGs, EPA determined that the steam electric power generating point source category (40 CFR Part 423) is the second-largest discharger of toxic-weighted pollutants. EPA’s analyses indicated that the to xic-weighted loadings are predominantly driven by metals present in wastewater discharges, and that the wastestreams contributing the majority of the metals are associated with air pollution co ntrols. Other potential s ources of metals include coal pile runoff, metal/chemical cleaning wastes , coal washing, and certain low volume wastes.

In presenting the findings of the 2005/2006 study, EPA noted certain data limitations affect the Agency’s estimate of the potential hazard posed by discharges from this category and, therefore, EPA determined that fu rther review of these discharges during the 2007/2008 ELG planning cycle is warra nted. Due to the limited resources and time available for conducting this study, EPA is concentrating its efforts for the 2007/2008 study on better characterizing pollutant sources and available pollution control t echnologies/practices for the pollutants responsible for the majority of the toxic-weighted pollutant loadings from steam

electric facilities. This will focus the review on wastewater discharges from coal-fired power plants.2 EPA intends to review overall plant ope rations and better un derstand the various wastewater sources present at steam electric plants . This review is expected to largely focus on ash handling wastes, wet flue gas desulfurizati on (FGD) wastes, coal p ile runoff, and final

effluent.

EPA and its contractor, Eastern Resear ch Group, Inc. (ERG), conducted a site visit to Georgia Power’s Plan t Yates on December 11, 2006. The pur pose of the visit was to: 1) gather information about the operation of wet flue gas desulfurization (FGD) systems, the wastewater discharges from thes e FGD systems, and the wastewater management practices used to control the discharges from these systems; a nd 2) evaluate the feasib ility of collecting and analyzing wastewater samples to char acterize certain waste streams.

4.0 P LANT D ESCRIPTION

Georgia Power’s Plant Yates began opera tion in Newnan, Georgia in September, 1950, when Unit 1 came on line. Unit 2 began comm ercial operation shortly after Unit 1 in November, 1950. From 1952 to 1958, the plant incr eased its capacity by installing Units 3, 4,

and 5. Units 6 and 7 were the last units to be installed at the plant in 1974. Today, Plant Yates operates these seven generating units, with a total capacity of 1,250 megawatts (MW). On a yearly average, the plant generates approximately 50 percent of its available capacity. The plant is located on approximately 2,400 acres of land in Newnan, GA alongside the Chattahoochee River. The plant employs approximately 300 people.

Units 1-5 were initially built with on ce-through cooling systems; however, in 2004, the plant retrofitted each unit with a recircul ating cooling system. The plant changed the cooling system operation due to a fish kill down stream on the Chattahoochee River that was attributed to the plant. The cooling tower st ructure for Units 1-5 is now the United States’ largest single-structure cooling tower. Units 6 an d 7 were originally installed with recirculating cooling systems; therefore, they di d not require a retrofit in 2004.

In 1992, Plant Yates retrofitted Unit 1 with an advanced FGD system. The retrofit was a joint project conducted by the Department of Energy (DOE), Electric Power3 Research Institute (EPRI), and Southern Compa ny, the largest investor-owned utility in the United States and Georgia Power’s parent company. The plant installed the Chiyoda Corporation’s Thoroughbred-121 advanced FGD pr ocess for the entire flue gas generated by Unit 1, which is a 110-MW pulverized coal-fired bo iler. The system incl udes the Jet-Bubbling Reactor® scrubber system (described in Section 5.6). This project was the first Chiyoda JetBubbling Reactor® demonstration completed in the United States. Due to the relatively small scale of the FGD system at Plant Yates, the sc rubber has since been used for many projects, including several mercury control pr ojects sponsored by DOE and EPRI.

5.0 P LANT O PERATIONS

The Plant Yates site visit focused on the FGD system on Unit 1 and the wastewaters associated with the system. EPA and ERG did not observe the other plant operations or their wastewater di scharges. Plant Yates personnel did discuss several of the other process operations with EPA and ERG and these are presented in the site visit report; however, the majority of this site visit report focuses on the Unit 1 FGD system. According to the plant, most of the process operations at Plant Yates ar e similar to the operati ons at Georgia Power’s Plant Wansley (see the Plant Wansley site visi t report for more details). For a general description of the steam el ectric power generation pro cess, see Section 3.2.1 of the Interim Detailed Study Report for the Steam Electri c Power Generating Point Source Category

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5.1 Coal Preparation

All seven generating units at Plant Yates ha ve coal-fired boilers. Plant Yates uses

eastern bituminous coal that has a one-percent sulfur cont ent. Trains deliver coal to the plant, each carrying approximately 10,000 tons of coal fr om Kentucky. The plant unloads the coal and transports it to the storage coal pile via conveyor belts. The coal pile contains between a 25- and 30-day supply of coal. From the coal pile, the plant transfers the coal to a series of bunkers, which contain a one-day supply of coal for each unit. The plant then feeds the coal to the pulverizers where the coal is crushed into a fine flammable powder and blown into the boilers. The plant uses approximately 5,500 tons of coal per day for the seven units.4 5.2 Biofouling Control

Plant Yates uses chlorine for biofouling control of each of the seven cooling water condensers. The closed-loop cooling tower system is dosed year round. When the plant adds chlorine to the cooling water for biofouling cont rol, the plant also isolates (shuts down) its cooling system blowdown. After closing the co oling tower blowdown valv es, chlorine gas is injected to reach a concentration of 0.2 to 0.5 mg/L. The plant typically waits about 12 hours after the chlorine has been applied until the tota l residual chlorine (TRC) concentration is less

than the method detection level of 0.01 mg/L, which is verified by the plant before reopening the valves and discharging the cooling water blowdown from the system. Each of the cooling water condensers receives chlorine biofouling control approximately every other day.

5.3 Make-up Water

Plant Yates uses fresh river water from the Chattahoochee River as make-up for some of the plant’s operations, such as the limest one slurry preparation, quenching the flue gas, and make-up water for the FGD system. Plant Yates treats the river water prior to using it within the process. This treatment c onsists of a physical separation process (i.e., clarification and filtration). The filter backwash water is combined with other low-volume wastewaters and pumped to the ash pond.

5.4 Nitrogen Oxide Controls

Plant Yates is located in Atlanta’s oz one non-attainment area, which requires the plant to meet strict nitrogen oxi de emission limits during the ozone season. To meet these strict limits, Plant Yates installed low-NO x burners and over-fire air system s on units 4, 5, 6, and 7. In addition to these technologies, in 1999, Plant Yates retrofitted all seven un its with the capability to burn natural gas; th erefore, during the ozone season, Ma y through September, the units burn natural gas in conjunction with co al to reduce the formation of NO x .5 5.5 Particulate Control

Plant Yates Unit 1 operates an electrostatic precipitator (ESP), which removes fly ash and other particulates from the flue gas prior to the FGD scrubber. The ESP uses high voltage to generate an electric charge on the part icles contained in the flue gas. The charged particles then collect on a metal plate with an oppos ite electric charge. As the particles begin to layer on the metal plates, the plates are tapped/rapped to loosen th e particles, which fall into a collection hopper.

There is no wastewater generated from the operation of the ESP; however, the plant uses a wet fly ash handling system. The fly ash that is collected from the ESP is continuously sluiced from the collection hopper. The ash sluice water is drawn from the ash pond and is recycled continuously from the pond to the hoppers and back. There are no particular water quality require ments for the ash sluice water.

5.6 FGD System

Plant Yates Unit 1 operates a Jet-Bubbli ng Reactor® FGD system, manufactured by Chiyoda Corporation. The FGD system uses a limestone-in-water slurry as the sorbent used to scrub sulfur dioxide from the flue gas. This system is different from traditional scrubbers (e.g., counter-current flow columns using trays or p acking) in that the flue gas is sparged into a reservoir bath of the absorbent liquid, forming a jet-bubbling layer in a shallow upper region of

the absorbent bath. Air is also introduced in a lower region of the absorbent bath to provide a stream of fine oxygen-containi ng gas bubbles throughout the vessel. For a description of the FGD process and the chemical r eactions involved, see Section 3.2.1.6 Interim Detailed Study Report for the Steam Electric Power Generating Point Source Category . Figures B-1 and B-2, in Appendix B, present pictures of the scrubber and the FGD stack, respectively.

Prior to entering the scrubber, the plant quenches the flue gas with ash pond sluice water in a gas cooling section of the system, whic h cools the gas and prevents a wet-dry interface from occurring between the absorbent liquid and the flue gas. After the flue gas is quenched, the plant saturates it with an amount of absorbent liquid from the scrubber.6 From the gas cooling section, the flue ga s enters the scrubber chamber formed by an upper deck plate and a lower deck plate. Fi gure 5-1 presents a diag ram of the Chiyoda JetBubbling Reactor® used at Plant Yates. Sparger tubes are contained in the lower deck plate and protrude downward into a reservoi r of the absorbent liquid. As th e flue gas enters the scrubber, it is forced to enter the sparger tubes and injected directly into the absorbent liquid. Because the flue gas is sparged into the absorbent liquid, it ensures good gas-liquid contact. The high flow of the flue gas causes a turbulent bubb ling in the scrubber. Figure B-3, in Appendix B, presents a picture of the FGD viewing port which allows one to view the bubbling in the reactor. In addition, the plant feeds air to the scrubber to force oxidation of the sulfite product into gypsum, a more useful by-product. The fl ue gas bubbles out of the absorb ent liquid and exits the top of the scrubber through gas riser t ubes that bypass the entering scrubbe r chamber. The cleaned flue gas then passes through a mist eliminator pr ior to being released out of the stack.

The inlet flue gas sulfur dioxide co ncentration to the FGD system varies depending on the fuel content; therefore, it is di fficult for the plant to operate the FGD system to

control the sulfur dioxide concentration at the ou tlet. Instead, the plant operates the FGD system to maintain a constant removal efficiency. Plant Yates’ FGD system achieves a 98 percent removal of sulfur dioxide from the flue gas. The plant controls the removal efficiency by varying the gas side pressure drop across the scrubber, which is controlled by changing the volume of absorbent liquid within the scrubber. A higher absorb ent liquid level in the scrubber increases the gas-liquid surface area, which incr eases the sulfur dioxide removal. The plant continuously measures the flue ga s sulfur dioxide concentration at the inlet to the FGD system.

These measurements are used to determine the limestone-in-water slurry requirements for the system. The plant recalibrates thes e requirements every two days.

The rate at which the limestone slurry is introduced into the sc rubber is also used to control the operating pH of the system, which impacts the sulfur dioxide removal efficiency. An increase in the limestone slurry feed rate in creases the pH of the system. A higher pH in the system results in a higher sulfur dioxide removal efficiency because the higher alkalinity results in a more rapid neutralization of the absorbed sulfur dioxide.7 To control the primary operating parame ters of the scrubber system (i.e., the volume of the absorbent liquid, the chlorides concentration, an d the solids concentration), gypsum slurry is intermittently withdrawn from the bottom of the scrubber and sent to the gypsum slurry transfer tank. From the gypsum sl urry transfer tank, the plant pumps the gypsum slurry to the gypsum ponds. A lthough the gypsum slurry is only intermittently withdrawn from the scrubber, it is cont inuously pumped to the gypsum ponds to avoid settling in the transfer lines. For this reason, the pl ant continuously recycles the gypsum pond water to the gypsum slurry transfer tank.

The Chiyoda scrubber used at Plant Yates is constructed with a fiberglass frame, which is ideal for recirculating the gypsum pond wa ter back to the scrubber since it can tolerate relatively high chloride concentrations (up to 20, 000 ppm). The plant uses a mixture of fresh and recycled gypsum pond water as the scrubber make- up water. The scrubber make-up water must

meet the follow criteria to be used in the scrubber:

y <300 ppm hardness;

y <100 ppm TSS;

y <100 ppm chlorides;

y <10 ppm COD; and

y <5 ppm BOD.

The chloride concentration in the scrubber n eeds to be maintained to less than 20,000 ppm; however, it is usually below this level because the coal used has a low chlorine content. In addition, the absorbent liquid within the scr ubber is maintained at a 30-percent solids

concentration.8Flue GasCleanFlue GasLimestoneSlurryGypsumSlurryAirUpper Deck PlateLower Deck PlateAbsorbent LiquidLevelFigure 5-1. Diagram of the Chiyoda Jet-Bubbling Reactor® FGD System9 6.0 W ASTEWATER M ANAGEMENT

EPA and ERG observed the discharges fr om the FGD scrubber and the treatment of these wastewater discharges. As discusse d in Section 5.0, EPA and ERG did not observe all of the plant operations, nor did EPA and ERG observe all of the wastewater sources and discharges. This section desc ribes FGD wastewater treatment operations at Plant Yates.

6.1 Flue Gas Desulfurization Wastewater Treatment

Figure 6-1 presents a wastewater flow di agram for the wastewater associated with the FGD system at Plant Yates. The gypsum slurry from the transfer tank is transferred to the gypsum ponds. Gypsum is a by-product of the FGD process, and is contai ned in the wastewater discharged from the FGD process. For a descri ption of the chemical reactions involved in the FGD process, see Section 3.2.1.6 Interim Detailed Study Report for the Steam Electric Power Generating Point Source Category

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The gypsum ponds at Plant Yates are lined with high-density pol yethylene. Plant Yates uses a technique known as “gypsum stacki ng” to dewater the gypsum. Within the gypsum ponds, the gypsum in the slurry settles to the bottom of the pond. As gypsum begins to fill the ponds, the plant excavates the gypsum out of th e pond with a backhoe and stacks it in an area around the pond, which increases the height of the pond embankment. Figure B-4, in Appendix B, presents a picture of the first gypsum pond at Plant Yates. The gypsum in these stacks is dewatered through gravity as the water flows do wn into the pond and through evaporation as the sun dries the gypsum piles. The gypsum is also washed by rainfall during the process.

The final gypsum product is approximate ly 90 percent solids. In 1996, the state of Georgia issued Plant Yates a Pl ant Food Permit that allows the pl ant the unrestricted sale of its ash-free gypsum for agricultural use (e.g., soil amendment). The plant does not wash the gypsum prior to selling it off site. Plant pers onnel noted that, in the future, Georgia Power’s plants that plan to produce marketable gypsum will most likely combine gypsum wash water

with other FGD wastewater and gypsum sluice water, and use this combined wastewater as make-up scrubber water.10Flue GasLimestoneSlurryCleanFlue GasAirFGDScrubberGasCoolerESPRecycle GypsumPond WaterGypsumSlurryGypsumSlurryTransferTankGypsumPond 3GypsumPond 1GypsumPond 2Emergency Overflowto Ash PondFigure 6-1. Wastewater Flow Diagramfor the FGD System at Plant Yates11 The gypsum slurry wastewater flows through three gypsum ponds, each one fed to the next by gravity. Figure B-5, in Appendi x B, presents a picture of the FGD gypsum ponds and the gypsum stacking area. Fi gure B-6, in Appendix B, presen ts a picture of the third and final gypsum pond. The wastewater from the final gypsum pond is reused throughout the process with the exclusion of high-temperature op erations (e.g., use as bo iler water), due to the dissolved solids that are present in the pond water. The dissolved solids in the pond water would scale and form deposits on the equipment at hi gh temperatures. Some of the recycled gypsum pond water is used as make-up to the FGD scrubbe r system, dilution water to the gypsum slurry transfer tank, and a water supply for lime stone grinding and slurry preparation.

The plant typically recycles all of the wastewater from the gypsum ponds back to the plant’s operations, but they also have the ca pability to transfer the gypsum pond effluent to the ash ponds to prevent the overf low of the gypsum ponds during excessive rainfall events. To ensure the pumps are working properly, the plant tests the pumps that transfer the gypsum pond wastewater to the ash ponds once per month. Due to evaporation lo ss and the typical levels of rainfall, the plant does not typically need to transfer the gypsum pond effluent to the ash ponds; therefore, every month, there is on ly a small amount of wastewater that is sent to the ash ponds and ultimately discharged. Plant Yates disc harges approximately 60,000 gallons of gypsum pond water to the ash ponds every month during th e testing of the emergency overflow pumps. The plant does not monitor the gypsum slurry or the recycled gypsum pon d water; therefore,

EPA cannot characterize the FGD wastewat ers from this plant at this time.

6.2 Monitoring Data

Plant Yates provided EPA with monitori ng data for a few of the wastewaters generated by the plant. Table C-1, in Appendix C, presents monitoring data for the FGD slurry from the JBR collected on September 28, 2005. Table C-2, in Appendix C, presents total suspended solids (TSS) monitoring data for th e ash pond blowdown and the ash pond emergency overflow from January 2004 through February 20 07. Tables C-5 through C-7, in Appendix C, present metals monitoring data for the ash pond blowdown for three separate grab samples.12 7.0 R EFERENCES

1. Burford, David P. 1997. Southern Company Services, Inc. Chiyoda Thoroughbred CT-121 Clean Coal Project at Georgia Power’s Plant Yates: Phase II Results . Birmingham, AL. Available online at: http://www.netl.doe.gov/publications/p roceedings/97/97cct/cct_pdf/97CCT3_3.P DF

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2. Georgia Power. Plant Yates . GP9901571. Available online at: http://www.southerncompany.com/gapow er/about/pdf/Plant%20Yates%20brochu re%20FINAL.pdf

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3. Southern Company R&EA. 2006. FGD a nd SCR – An Overview. December 11.

4. Southern Company Services, Inc. 1997. Demonstration of Innovative Applications of Technology for the CT -121 FGD Process at Georgia Power’s Plant Yates: Final Report, Volume 1 . SCS C-90-00284. Birmingham, AL. January. Available online at: http://www.netl.doe.gov/techno logies/coalpower/cctc/cct dp/bibliography/demonst ration/pdfs/ct121/CT121_vol1_1997.pdf

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5. U.S. EPA. 2006. Interim Detailed Study Report for the Steam Electric Power Generating Point Source Category . EPA-821-R-01-015. Washington, DC. November. DCN 03401.Appendix A

LIST OF ATTENDEESA-1Table A-1. List of AttendeesNameOrganization (Representing)TelephoneE-mailDonna Hill Southern Company (205) 257 5234 dbhill@southernco.comNick Irvin Southern CompanyRussel Noble Southern CompanyBill Evans Georgia PowerDavid ParksGeorgia PowerMike Knowles Georgia Power – Plant YatesLindy Johnson Tennessee Valley Authority (423) 751 3361 lpjohnson@tva.govPaul Chu Electric Power Research Institute (650) 855-2812 PCHU@epri.comLiz AldridgeHunton & Williams(804) 788 8549 ealdridge@hunton.comKristy Bulleit Hunton & Williams (202) 955 1547 kbulleit@hunton.comJosh Hall EPA/Office of Water (202) 566 1002 hall.josh@epa.govRon Jordan EPA/Office of Water(202) 566 1003 jordan.ronald@epa.govKarrie-Jo Robinson-Shell EPA/Region 4(404) 562 9308 shell.karrie-jo@epa.govLeslie Churilla ERG (Contractor to EPA) (404) 634 0038 leslie.churilla@erg.comT.J. Finseth ERG (Contractor to EPA) (703) 633 1698 thomas.finseth@erg.comAppendix B

PICTURES FROM SITE VISITB-1 Figure B-1. Chiyoda Jet-Bubbling Reactor®

Figure B-2. FGD StackB-2 Figure B-3. FGD Viewing Port

Figure B-4. Gypsum Pond at Plant YatesB-3 Figure B-5. Gypsum Ponds and Gypsum Stacking Area

Figure B-6. Final Gypsum Pond at Plant YatesAppendix C

MONITORING DATA PROVIDED BY PLANT YATESC-1 Table C-1. Yates FGD Wastewater (JBR Slurry Collected on 9/28/2005)

Constituent Units Concentration MDL Group A BOD Not analyzed Chemical Oxygen Demand Not analyzed Total Organic Carbon mg/L 0.593 0.30 TSS mg/L 4 1.0 Flow gpm 2,000 Ammonia (as N) mg/L 0.55 0.01 Temperature (Field) ° C 34.4 pH SU 4.49 Group B Bromide mg/L 7.42 0.02 Chlorine, Total Residual Not analyzed Color PCU 8 Fecal Coliform Not analyzed Fluoride, Total mg/L 62.3 0.01 Nitrate-Nitrite (as N) mg/L 0.01 0.01 Oil and Grease Not analyzed Ortho-Phosphorus (as P) Total mg/L 0.24 0.01 Sulfate (as SO4) mg/L 1549.5 1.0 Sulfide (as S) Not analyzed Sulfite (as SO3) Not analyzed Surfactants Not analyzed Aluminum, Total mg/L 15.8 0.018 Barium, Total mg/L 0.271 0.002 Boron, Total mg/L 30.1 0.003 Cobalt, Total mg/L 0.037 0.004 Iron, Total mg/L 1.88 0.003 Magnesium, Total mg/L 276 0.026 Molybdenum, Total mg/L 0.031 0.01 Manganese, Total mg/L 1.81 0.004 Tin, Total mg/L 0.014 0.002 Titanium, Total mg/L 0.107 0.003 Group B – Section 1 Antimony, Total mg/L 0.032 0.012 Arsenic, Total mg/L 0.013 0.005 Beryllium, Total mg/L 0.003 0.001 Cadmium, Total mg/L 0.033 0.002 Chromium, Total mg/L 0.076 0.001 Copper, Total mg/L 0.143 0.005 Lead, Total mg/L 0.004 0.004 Mercury, Total mg/L 0.021 0.0002 Nickel, Total mg/L 0.124 0.004 Selenium, Total mg/L 0.551 0.005 Silver, Total mg/L <0.006 0.006 Thallium, Total mg/L 0.013 0.007 Zinc, Total mg/L 1.70 0.004 Cyanide, Total Not analyzed Phenols, Total Not analyzedC-2 Table C-2. TSS NPDES Monitoring Data

NPDES Operations Monitoring Report data excerpts 1/1/04 through 2/28/07

Outfall 01 Outfall 01 Outfall 02 (continued) Date TSS (mg/L) Date TSS (mg/L) Date TSS (mg/L) 1/5/2004 2 7/5/2005 4 9/17/2004 6 1/20/2004 1 7/18/2005 8

2/2/2004 2 10/3/2005 9 3/28/2005 21 2/16/2004 4 10/17/2005 0 3/29/2005 10

3/1/2004 2 11/7/2005 8 4/1/2005 **562 3/15/2004 2 11/21/2005 5 4/2/2005 25

4/5/2004 0 12/5/2005 8 7/11/2005 18 4/19/2004 3 12/19/2005 8 7/12/2005 40

5/3/2004 5 5/17/2004 2 1/3/2006 1

6/7/2004 6 2/6/2006 5 6/21/2004 12 2/20/2006 12 Outfall 01 – Final Plant Discharge (Ash Pond Blowdown) 7/6/2004 7 3/6/2006 8 7/26/2004 1 3/20/2006 2

8/2/2004 11 4/3/2006 4 Outfall 02 – Ash Pond Emergency Overflow 8/16/2004 6 4/17/2006 3

9/7/2004 6 5/1/2006 3 9/20/2004 13 5/15/2006 1 Total Suspended Solids 10/4/2004 3 6/5/2006 4 EPA Method 160.2 10/18/2004 1 6/20/2006 1 Reporting limit = 1 mg/l

11/1/2004 3 7/5/2006 6 11/15/2004 5 7/17/2006 8 Permit Limits: Avg. 30 mg/l

12/6/2004 5 8/7/2006 6 Max 100 mg/l 12/20/2004 6 8/21/2006 4 9/5/2006 6 1/3/2005 4 9/18/2006 10 1/17/2005 12 10/2/2006 13 1/18/2005 3 10/16/2006 10 ** Emergency overflow due to large storm event

2/7/2005 2 11/6/2006 21 2/21/2005 2 11/16/2006 12

3/2/2005 4 12/4/2006 6 3/21/2005 2 12/18/2006 5

4/4/2005 12 4/18/2005 11 1/2/2007 6

5/2/2005 4 1/16/2007 8 5/16/2005 2 2/5/2007 4

6/6/2005 6 2/19/2007 6 6/20/2005 2C-3 Table C-3. 2004 Ash Pond Blowdown Grab Sample

November 15, 2004

Ash Pond Blowdown Discharge

Chemical Intake Concentration Form 2C, 2/22/02 (mg/L) Discharge Concentration (mg/L) Discharge Flow (MGY) Antimony <0.05 <0.05 Arsenic <0.03 0.071 7906 Barium 0.02 0.093 Beryllium <0.01 <0.01 Chromium <0.01 0.0050 Cobalt <0.04 0.0031 Copper <0.02 0.022 Lead <0.025 <0.025 Manganese 0.10 0.17 Mercury <0.0005 <0.0005 Nickel <0.02 0.0076 Selenium <0.04 <0.04 Silver <0.01 0.0022 Thallium <0.05 <0.05 Vanadium N/A 0.030 Zinc 0.02 0.0099C-4 Table C-4. 2005 Ash Pond Blowdown Grab Sample

December 5, 2005

Ash Pond Blowdown Discharge

Chemical Intake Concentration Form 2C, 2/22/02 (mg/L) Discharge Concentration (mg/L) Discharge Flow (MGY) Ammonia 0.2 0.4 Antimony <0.05 0.017 7884 Arsenic <0.03 0.32 Barium 0.02 0.19 Beryllium <0.01 0.0011 Cadmium <0.01 <0.0010 Chromium <0.01 0.0071 Cobalt <0.04 0.0052 Copper <0.02 0.043 Lead <0.025 <0.0070 Manganese 0.10 0.21 Mercury <0.0005 <0.000064 Nickel <0.02 0.013 Selenium <0.04 0.032 Silver <0.01 <0.0030 Thallium <0.05 0.005 Vanadium N/A 0.022 Zinc 0.02 0.046C-5 Table C-5. 2006 Ash Pond Blowdown Grab Sample

December 4, 2006

Ash Pond Blowdown Discharge

Chemical Intake Concentration Form 2C, 2/22/02 (mg/L) Discharge Concentration (mg/L) Discharge Flow (MGY) Ammonia 0.2 0.3940 Antimony <0.05 0.0088 7884 Arsenic <0.03 0.0490 Barium 0.02 0.1800 Beryllium <0.01 0.0005 Cadmium <0.01 0.0005 Chromium <0.01 0.0028 Cobalt <0.04 0.0023 Copper <0.02 0.0260 Lead <0.025 0.0015 Manganese 0.10 0.1800 Mercury <0.0005 0.000026 Nickel <0.02 0.0120 Selenium <0.04 0.0590 Silver <0.01 0.0030 Thallium <0.05 0.0030 Vanadium N/A 0.0520 Zinc 0.02 0.0250