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HomeMy WebLinkAboutNC0005088_ Permit Application_20100202Mk Duke l Energy,. January 29, 2010 Mr. Charles H. Weaver, Jr. State of North Carolina Department of Environment and Natural Resources Division of Water Quality NPDES Unit 1617 Mail Service Center Raleigh, North Carolina 27699 -1617 CORPORATE EHS SERVICES Duke Energy Corporation 526 South Church St. Charlotte, NC 28202 Mailing Address: EC13K / PO Box 1006 Charlotte, NC 28201 -1006 Subject: Duke Energy Carolinas LLC — NPDES Permit Application Cliffside Steam Station - #NC0005088 Dear Mr. Weaver: Duke Energy Carolinas, LLC requests the subject permit be renewed and reissued. The above referenced permit expires July 31, 2010. As mandated by North Carolina Administrative Code 15A NCAC 2H.0105 (e), this permit application for renewal is being submitted at least 180 days prior to expiration of the current permit. Please find enclosed in triplicate, the renewal application, which includes the following items: EPA Form 1 EPA Form 2C EPA Form 2E EPA Form 2F Site Maps Water Flow Diagrams Supplemental Information Duke Energy Carolinas, LLC requests that the description of outfall 004 be revised to read "FGD Wastewater Treatment System Discharge ". Duke Energy Carolinas, LLC requests notification that this application is complete. www.duke-energy.com Thank you in, advance for your assistance on this matter. Should you have questions regarding this application, please contact'me at (704) 382 - 4309. Sincerely„ Allen Stowe Water Management Attachments cc wk, Mr Roger Edwards - NCDENR Asheville R O LL Ij '�` 'r +- ,� \. � � � 1 � :" r.. E.Q. •�'±O , I - 1`� . ii/7-}1 Seto ' ape T-7 IC 2A h r �� .� - - ' -r i I .'�^ - I �' su„r �•, r �f (f�wJ l\ \i 1!'L7 r �,Jl \-'-� / ,•. ., AVER -��,�• y' -- 1 �' BROAD. BROADER ... o Cliffside1 y .y Y:< =—♦ '' �cA Steam Station •irection \ f Flow 1 r�,. O���pY1?P� , �4I ♦ �'T� 1 i 1 - 'y'C'' i% n02 I \17i( ff /-•�`•y l' N'� R -.-.. � �4.' 004 �+ � - 4r. to / ; I :� i� ����Y 4 1 .s �r 'I �-• !iii', +(r' ;I�� `� %' it �\'. • �LTd \, 6 _�'I! i I - �' 1 .`9q. , � ,;� i% f '_'..till ✓,�'1 ll. `� ,•I ( f '�:'•' \ � , 0 r � l it ! _ ✓ � 1`' r r r � r ,���� ; r�1 j� 'iC _ tijFi._•.� Jam, � ....- - ` � � `�•o,.%yy ``_,`` \-\; _ i ! t Cli... Legend NPDES Outfall Location ~' •i\ ' 4 I M (1 j_ _ //• frr`," - '`,y j 00 NPDES Outfall Number f jy�� +�tf ( ` Duke Energy Property Boundary REFERENCE: BACKGROUND DATA: USGS TOPOGRAPHIC QUAD, WAS OBTAINED FROM NCDOT GEOGRAPHICAL 0 0.25 0.5 (� INFORMATION (GIS) WEBSITE. THE PROPERTY DATA WAS OBTAINED FROM THE CLEVELAND AND mommo== Kilometers RUTHERFORD COUNTY'S NORTH CAROLINA GIS DEPARTMENT, PLEASE NOTE THIS DATA IS FOR INFORMATIONAL PURPOSES ONLY. 0 0,25 0.55 Miles SCALE: AS SHOWN FIGURE Duke LOCATION MAP DUKE ENERGY No. DATE: 01 -14 -2010 CLIFFSIDE STEAM STATION DRAWN BY: NPDES # NC0005083 RDP PROJECT NO: Energy® CLEVELAND A DERUTH RFO DOCOUNTY 1411 -08 -140 NORTH CAROLINA J N I cp �� �0 NO 0 " � _ " v �3 r. CD 0 tea) .: 3 Y .°: ce m c N N �» D >Z r. cD o U n Cl) -n f D m w C = ^� n M m„3 N O (n c� o » 3 .. c m Cp d m a 3 - (D ,. m ID co o a o M 7 7 N N y , D 'n C X m 2) CD 0 lD m 0 0 O m a� N cD CA m v 3 0 Cliffside Steam Station, Rutherford County NPDES # NC0005098 Page 2 of 26 General Information Cliffside Steam Station (CSS) is, located on Duke Power Road, ,off NC State Road 1'002 dust south of Cliffside; North Carolina on the Broad River. CSS currently has five coal fired steam electric generating units in operation and one coal fired steam electric generating unit under construction. The five unit coal fired steam electric generating station has a combined rated capacity of 760 net MW. Units 1 - 4 have a combined capacity of 198 net MW and a once - through Condenser Cooling Water (CCW) maximum flow -rate of 11.81 rn /sec (417 cfs). Unit 5 has a capacity of 562 net MW and utilizes closed cycle, forced draft cooling towers for heat dissipation. Unit 5 cooling tower make -up water is withdrawn at a maximum rate of 0.39 m3 /sec (14 cfs) and the blowdown is discharged to the ash basin. Unit 6 is under construction and will have a capacity of approximately 825 net MW and will utilize a closed cycle, forced draft cooling towers for heat dissipation. Unit 6 cooling tower make up water is withdrawn at a maximum rate of 0.62 m3 /sec (22 cfs). Units 1 -4 will be decommissioned prior to first fire to provide steam to turn the Unit 6 turbine. Construction of a wet Flue Gas Desulfurization (FGD) control technology on Unit 5 is underway and will be operational in Fall of 2010. Unit 6 will have wet and dry FGD control technology. The Broad Rivet supplies the CCW and other service water systems from an intake located just upstream from the diversion dam off the Broad River. The service, water required by,units 1 - 4 is .drawn from ,the CCW tunnel Unit 5 can acquire intake water from either the unit 4 screen room (normal operation) or from the condenser cooling water discharge of units 3 and 4. Regardless=,of the intake, location, the intake water for unit 5 flows to a,storage tank before entering the unit. ' ,A new raw water pumping system ,is being installed to supply water for Unit 5' and Unit 6. The new pumps will have traveling screens for debris removal. The debris collected on the screens consists of twigs, leaves and other material indigenous to the river, and is therefore flushed back to the river The system will have control valves that will allow water to be recirculated to the suction side of the pumps instead of over flowing the, raw water storage tanks. A brief discussion of the individual, waste streams follows. Outfall 001 - Condenser Cooling Water (CCW) Units 1- 4 Units 1 - 4 utilize raw river water for once through- non - contact, condenser cooling water requirements, This water system removes heat from the condensers and other selected heat exchangers. No biocides or other additives are used in the condenser cooling water. There are two ,condenser circulating pumps per condenser /unit for units 1 - 4. Raw river water is pumped through the condensers for cooling. Annually, the condensers may be opened and cleaned by forcing plugs through the tubes. Approximately twice per year, the condenser tubes may need to be tested ,for leaks. This test is conducted using a tracer gas (i.e., sulfur hexaflouride, helium, etc.). The,levels of discharge will be well below any levels of aquatic biological toxicity concern. Any release to the environment will only occur during short intervals (approximately thirty seconds per'injection, normally less than six infections per condenser) as the tests are being conducted. The entire test period per unit is normally conducted in two or three hours. Cliffside Steam Station, Rutherford County NPDES, # NC0005088 Page,3 of 26 Units 1 - 4 CCW Pump Maximum Capacity Unit # 1 -Pump Operation 2 -Pump Op_ eration gpm gpm 1 19,800 39,600 2 19,800 39,600 3 28,125 r 56;250 4 28,125 56,250 Operational schedule for these pumps is dependent upon the intake water temperature and on the unit loads. Depending on the electrical' demand, pumps are operated to maximize CSS efficiency and to assure compliance with its permitted NPDES thermal limits. Flow recorded on the monthly Discharge Monitoring Reports is based on CCW pump run times Intake Screen Backwash The CSS 1 -4 intake screens are continuously backwashed during unit operation. The wash water required is taken from the service, water system (raw water). An average flow of 3000 gpm is utilized. The debris collected on the screens consists of twigs, leaves and other material indigenous to the river, and is therefore flushed back to the river Outfall 002 - Ash Basin Ash Sluicing CSS utilizes electrostatic precipitators to remove fly ash from stack gases. Both fly ash and bottom ash are sluiced to the basin A maximum of 5.9 _mgd is used for ash sluicing from units 1 - 5. Flyash from Unit 6 will'be a collected in a dry ash handling,system. Water will be mixed with the flyash to condition the flyash to 20% moisture for, compaction at the landfill. The bottom ash on Unit 6 will be removed' from the bottom of the boiler by a wet drag chain The ash will be dewatered on an incline, belt in the holding area,outside Unit 6: Unit 5 has an anhydrous ammonia and a sulfur trioxide flue gas conditioning system that 'injects anhydrous ammonia and sulfur trioxide into the hot air duct to make .the precipitator more efficient in collecting ash particles. Unit 5 (and ultimately Unit 6) also infects anhydrous ammonia in the exhaust ,gas of the boiler and prior to the Selective Catalytic Reduction (SCR)to initate a chemical reaction in the SCR to lower nitrogen oxides. Cooling Towers Unit 5 utilizes two cooling towers for its cooling water requirements. Unit 5 has four citculating, pumps. Each circulating condenser pump has 'a capacity of 62,500 gpm for, a combined total of 250,000 gpm. The circulating pumps on unit 5 operate continuously. Each tower,has a circulation rate of 125,000 gpm with a make -up rate of 2875 gpm per tower and a blowdown rate of approximately 2500 gpm. The cooling tower blowdown is pumped to the ash basin. Cooling tower water is chlorinated, to approximately 0 5 ppm, for one half hour, 3 times /week during the winter and approximately 1.0 ppm, for one hour, 5 times /week during the ,summer months. 50 gallons of Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 4 of 26 the microbiocide Bulab 6002 are added approximately every 6 months to each tower. The towers are sprayed with the microbiocide Bulab 6009 once yearly. Mechanical means are employed for additional cleaning. Currently chlorine gas is used to chlorinate cooling tower water and water treatment. A project is under review to convert the chlorine gas to a sodium hypochlorite system for Unit 5. This project will not eliminate chlorine gas injection into the filtered water system. The CCW tunnels and cooling towers are unwatered during outages for inspections and maintenance. The water is pumped to the yard drains and pumped to the ash basin. Sawdust may be added to the CCW system if a condenser leak is detected. Depending on the size of the leak the sawdust will stop the leak until repairs can be made. Unit 6 Cooling Tower Unit 6 will utilize one cooling tower for its cooling water requirements. Unit 6 has two circulating pumps. Each circulating condenser pump has a capacity of 196,000 gpm for a combined total of 392,000 gpm. The circulating pumps on unit 6 will operate continuously. The maximum make -up rate of 9774 gpm and a blowdown rate of approximately 3258 gpm. The cooling tower blowdown is pumped to the ash basin. The cooling tower will be chlorinated with a 12% sodium hypochlorite solution. A unspecified corrosion inhibitor and an unspecified non - oxidizing microbiocide will be used as well. Sanitary Wastes The sanitary wastes from Units 1 -4 are treated by a 2500 gpd capacity septic tank. The Unit 5 sanitary wastes are treated by an activated sludge unit with a 3000 gpd capacity. An average of fifty people contribute to the loading on the two systems. The effluent from both systems is pumped to the Yard Drainage Basin and then to the ash basin. During construction of Unit 6, sanitary waste is being collected in portable tanks and hauled to a local waste water treatment plant. A package plant for treatment of sanitary wastewater was sized for 60 employees with a flow of 1550 gpd and will be installed at the end of construction. The discharge from the package plant will be sent to the Yard Drainage Basin and then it is pumped to the ash basin. Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 5 of 26 Boiler Cleaning Boilers #1 and #2 at CSS are no longer cleaned. Boilers #3, #4, and #5 are cleaned as needed. The wastes produced from a boiler cleaning are pumped to ,the ash basin The chemicals and approximate amounts for each cleaning are listed below. Chemicals Unit 3 or 4 Unit 5 Sodium bromate - -- 550 lbs Ammonium carbonate - -- 100,0 lbs Ammonium hydroxide, 26° Be - -- 1000 gal Hydrochloric acid, 20° Be 3300 gal 9000 gal Thiourea 1000 lbs 2900 lbs Ammonium biflouride 1000 lbs, 2700 lbs Proprietary Inhibitor 24 gal _ 130 gal Citric acid 200 lbs 600 lbs Soda Ash 2000 lbs 5600 lbs Sodium, sulfite - -- 100 lbs Iodine 213 24 gal 130 ,gal Approximately 220,000 gals of wash water are required for cleaning boilers, #3 or #4. Boiler #5 requires 950,000 gals of wash water per cleaning. Immediately prior to the beginning of a boiler chemical cleaning procedure, additional stop logs are added to the ash, basin discharge structure. This action ensures longer retention time of the chemical wastes for proper treatment through dilution, neutralization, precipitation and'ion- exchange. Alternately, the boiler may be cleaned using ethylenediaminetetraacetic acid (EDTA). If EDTA is used for cleaning, no waste water will be discharged to the ash basin. Unit 6 Boiler Information and Initial Start -up Equipment Wash Preheaters are back washed with raw water approximately two times per year to remove ash and corrosion products. The back wash water are routed to drains that are pumped to the ash basin. Precipitators are cleaned by mechanically vibrating the, wires and rapping the plates inside the precipitator. The inside of the precipitators are, washed prior to maintenance activities. The rinse water drains in to drains that are pumped to the ash basin. Effluent from a vehicle rinse station is directed to a drain that is pumped to the ash basin The vehicle rinse water contains no soaps or additives. Drinking Water CSS obtains all of its drinking water from the Grassy Pond Mur icipal'water system. Floor Drains CSS floor drains contain boiler blowdown, leakage from seals„ equipment cooling water, condensates, regeneration wastes, miscellaneous plant wastes and area washdown water. Effluents from these drains Chffside Steam Station, Rutherford County NPDES # NC0005088 Pages6 of 26 are flushed to the plant sumps and then to the Yard Drainage Basin and are then pumped to the ash basin. Ash Basin Toe, Drains In order to assure the integrity of the ash basin's dike structure, the dikes are designed with a system that allows for the water to be drained from the dike. This drainage system prevents the dikes from becoming.,overly saturated with water. This water is discharged out of the dikes, via toe drains. The volume of water is normally at a nominal seeping rate. It discharges to the ground, is dispersed by rip - rap, and is ultimately routed to the Broad River, and Suck Creek Water Treatment System Unit 5_ The CSS make -up water treatment system (non- potable) is comprised of (a) a clarifier, (b) chlorination system, (c) three gravity filters (d) two activated carbon filters, (e) reverse osmosis, (f) two mixed bed demineralizers and (g) polisher. Make -up water 'is supplied to the boilers to generate steam to turn the turbines. On occasion a vendor may be used with a mobile water treatment unit to augment the facility water treatment capacity,. Any vendor will use, ,traditional water treatment methods, chemicals, and disposal methods generally described below. The water treatment wastes consist of (a) flocculation and sedimentation, (b) filter backwash, (c) Reverse Osmosis (RO) wastes, and (d) demineralizer regeneration wastes. Clarifier The clarifier currently utilizes a continuous feed of cationic water treatment' polymer and clay (Nalco 8105 and Calgon 'CA -25 respectively or similar products) to remove ,suspended solids and colloidal material. The floccule and sedimentation collected by the clarifier consists of solids that were suspended in the service water. Approximately 1000 gpd of sedimentation wastes are pumped to the Yard Drainage Basin and then to the ash basin. Chlorine is added to the clarifier. The station may alter this.process to supply site clarified water by other traditional water treatment methods and,using traditional chemicals other than those listed above. 'In May of 2010, the chemical treatment system for ,the clarrifier will be upgraded to include sodium hypoclorite (12.5 %), ferric sulfate (60 %), polymer for coagulaton, and sodium hydroxide for pH adjustment. The sodium hypoclorite will be stored in a 6,000 gallon tank. The ferric sulfate will be stored in a 5,000 gallon tank. The sodium hydroxide will' be stored in a 5,000 gallon tank. Gravity Filters There are three gravity filters composed of anthracite (coal) which follow the clarifier in the water treatment process Each of these filters has a capacity of 360,000 gpd. One of these filters is backwashed once per week with the backwash water going to the ash basin The gravity filters are changed out on anus- needed basis with, the spent filter medium going to the ash basin. Activated Carbon Filters There are two activated carbon filters. These filters are backwashed once per week. The wash water is pumped to the ash basin., The activated carbon filters are changed out approximately once every 6 months with approximately 147 ft3 of activated carbon being pumped to the ash basin. Cliffside Steam Station, Rutherford County NPDES # NC0005098 Page 7 of 26 Demineralizers Demineralized 'water is, used to supply the plant with its make -up water requirements. Each deminerahzer consist of anion and cation mixed bed cells. Only one demineralizer is in operation at a time. A demineralizer is regenerated on average after '30 days of operation. A regeneration requires 79 gallons of 66013e sulfuric acid and 300 gallons of 50% sodium hydroxide. Approximately 10,000 gal of rinse water is used per regeneration. The dilute acid and caustic are discharged to the floor drains simultaneously through the ,same header for neutralization purposes. The demineralizer resin is changed out approximately every ten years with the waste resin being pumped to the ash basin. All regeneration wastes are pumped to the ash basin. Polisher A 60 cubic foot pplisher (30 cubic feet cation, 30 cubic feet anion resin) is used, to polish demineralizer effluent. The polisher minimizes silica and. sodium leakage. The resin will be replaced annually with spent resin being pumped to the ash basin Reverse Osmosis System There is a three stage Reverse ,Osmosis (RO) system which processes approximately 400 gallons per minute of filtered water. Approximately 300 gpm of permeate water is producted and flows to the permeate water storage tank- Approximately 100 gpm of concentrate water is produced which flow to the yard drain and is pumped to the ash basin. Water from the permeate tank is pumped to the demineralizers as supply water The RO system is cleaned' approximately twice a year using a dilute low pH cleaner sulfamic f acid (AD -20), biocide (Trisep Tristat 110), and a high pH cleaner (sodium hydroxide /sodium lauryl suffate). Temporary Mobile Water Treatment A vendor may be used with a mobile water ,treatment unit to augment the facility water treatment capacity. All vendors will use tradional water treatment methods, chemicals, and disposal methods generally described above. This waste water will drain to a system that is pumped to the, ash basin. Water' Treatment System Unit 6 The water treatment at Unit 6 will take clarified water (from existing clarifier) and pump it to an ultra filtration (UF) unit that will provide 330 gpm. The OF will routinely use 12% sodium,hypochlorite as a cleaning solution. The effluent from the OF will then be. pumped through a two pass reverse osmosis (RO) The RO will use the same cleaning chemicals as the U5 RO: After the RO, the water will be treated further through a gas transfer membrane to remove dissolved gases. After sodium bisulfate injection for chlorine removal, the water will enter final treatment through,mixed bed demineralizers at a rate of 250 gpm. Demineralizers will be regenerated offsite. Unit 6 Condensate Polishers U6 will use full condensate flow mixed ion exchange 'resin (deep bed) condensate polishers. Ion exchange resin will be regenerated on.site with 93% sulfuric acid and 50% sodium hydroxide. Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 8 of 26 Boiler Blowdown Boilers 1 - 4 each blowdown at a,rate of approximately 500 lbs. of steam/hour. Most of the blowdown is vented to the atmosphere with a minimal amount going to the boiler room floor drains. The blowdown from unit 5 is vented to a blowdown tank with a minimal flow of condensate being pumped to the ash basin. Hydrazine is maintained at a concentration of <30 ppb in the feedwater train for deoxygenation. Ammonium hydroxide is used for pH control in the units. A minute amount of hydrazine ( <10 ppb) may be present in the steam jet air ejector waste condensate flow to ,the floor drains which is pumped to the ash basin. Recirculating Cooling Water S Ystem The recirculating cooling water system provides cooling for the air conditioning system and other plant equipment cooling. `These systems are closed -loop systems, however, they may be drained on occasion for maintenance activities This water is pumped to the ash basin. The microbiocide Calgon H -550 (or similar product) is added monthly. Calgon CS corrosion inhibitor is added once per month to maintain 2500 ppm nitrites within the system Unit 5 and Unit 6 Generator Stator Cooler Cooling water for the unit generator stator cooler goes through an additional deminerali-zen The, demineralizer resin is changed out approximately every 18 months and pumped to the ash basin. Uiiit 5 ID 'Vii iable Speed Water from fhe clarifier is used to cool the heat exchanger for the Unit 5 Variable Speed Drive house. The internal electrical breakers of the U5 ID Variable Speed are cooled by a closed loop of propylene glycol system that, is routed to the heat exchanger The cooling water from the heat exchanger is discharged into the drains that are pumped to the ash basin. When the closed loop of propylene glycol is drained it will be drummed and sent off site to be reconditioned. FGD Stormwater Sump Stormwater collected at FGD site including: the dry ash handling facility, gypsum pile, WWTS area (not process water), stack, absorbers, switchgear building, �dewatering building, reagent. prep building, and the control room area is routed to the- Yard Drainage Basin prior to being, pumped to the ash basin Landfill Leachate collection discharge An Industrial Solid'Waste Landfill is being constructed to accept coal combustion byproducts (fly ash, bottom ash, gypsum, WWT,S filter press sludge cake) This landfill consists of a.double liner with leachate collection system. Collected leachate will be pumped to Yard Drainage Basin and then to the ash basin. Limestone Unloading /Storage Area Sump Limestone sump collects stormwater and rinse water from limestone unloading and storage area.and routes to Yard Drainage Basin. Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 9 of 26 Flue Gas Desulfurization (FGD) A Wet Flue Gas Desulfurization (FGD) system will be installed at Cltffside Station, for the reduction of S '02 from the stack gas. The following provides a description of the FGD system at CSS. In a Wet Scrubber system, the S02 component of the flue gas produced from the coal combustion process is removed by reaction with limestone -water slurry. The particular system used at CSS collects the flue gas after it passes through the electrostatic precipitator and, routes the gas into the absorber tank As the gas rises through the tank to the, outlet at the top, the, gas passes through 'a spray header: A islurry of water and limestone droplets 'is continually sprayed through this header into the stream of flue gas. The S02 in the flue ,gas reacts with the calcium in the limestone and produces S03. The S03 slurry falls to the bottom of the tank where a stream of air is injected to oxidize the slurry to form gypsum (CaSO4 2H2O)'. The gypsum slurry is drawn off the absorber tank and subsequently pumped to a vacuum belt filter. Part of the process water from the FGD, system is blown down in order to maintain the FGD water chemistry within the FGD system specifications. This water is, treated in a wastewater treatmen stem that discharges to the Yard Drainage Basin via internal Outfall 004 and then pumped, to the ash basin. The FGD system has a material handling system that supplies limestone to the scrubber and a gypsum storage area for the gypsum removed from the process. The limestone comes onto the site by rail and is then transferred to the FGD site via a covered conveyor. Runoff from the storage area is routed to the ash basin. The gypsum is,routed from the FGD tank to a:dewatering belt and then to a covered conveyor 'belt that will carry it to a storage pile., The runoff from this area is also routed to the ash basin. The FGD system also requires a gypsum landfill when the by product is not suitable for beneficial use as wallboard Landfill operation is, slated for late 2010. Fly ash, FGD gypsum, clarifier WWTS sludge and other similiar material will be disposed in this landfill Landfill runoff from the active cell and leachate will, be routed to the Yard Drainage Basin and pumped to the ash basin ,for treatment. Internal Outfall 004 — Treated FGD Wet Scrubber Wastewater The wastewater from ,the FGD system is conveyed to the Wastewater Treatment System (WWTS) solids removal system. The initial, part of the wastewater treatment system is the equalization tank. The equalization tank also receives flows from the WWTS Filtrate Sump and if needed recycled flow from the WWTS Effluent Pump. The wastewater streams that are mixed in the equalization tank are conveyed to the WWTS,Reaction Tank. In the WWTS Reaction'Tanks chemicals are added to form a dense floc. Overflow from the WWTS Reaction Tank goes to the WWTS Flocculating Clarifier which is utilized as the liquid/solids separation device. Polymer, may be injected to aid in the settling process. Clarified effluent is conveyed to the WWTS Continuous Backwash Gravity Filters for fine particulate removal. Effluent from the filters is gravity, feed to the WWTS Effluent Tank then to outfall 004. This outfall discharges to Yard Drainage Basin which is pumped to the ash basins. Settled solids are removed from the clarifier by the operating sludge transfer pump and conveyed to the WWTS Sludge Holding Tanks and dewatered by the filter presses. Dewatered cake from the filter presses is ultimately landfilled Filtrate from the dewatering process and back wash from the gravity filter are conveyed to the WWTS Sump and transferred to the WWTS Equalization Tank for reprocessing, Cliffside Steam Station, Rutherford,County NPDES # NC0005088 Page 10 of 26 Stormwater Run -Off The ash basin at CSS collects /receives flows from the Yard Drainage Basin, ash removal lines and rainfall run -off from the basin watershed,area. The average rainfall run -off flows are based on 49 inches of rain per year with 100 % run -off from the pond surfaces and 50% run -off from other areas. The average rainfall run -off for the ash basin watershed area is 0.8 MGD. The coal yard drainage at Cliffside Steam Station drains to the Yard Drainage Basin and is then pumped to the ash basin. The coal yard has a average run -off of approximately 0.03 MGD. The area ofthe coal yard may be expanded at a future date. There are some storm drains located on the CSS site that flow directly to the Broad River. These storm drains contain stormwater runoff only and do -not contain any process wastewater discharges. On the main entrance road to the site, a natural spring /creek flows continuously in the road ditch. The water enters the ,storm drainage system and flows directly to the Broad River. Oil Storage Run -Off CSS, has above: ground oil storage tanks and one underground gas tank (1,000 gal). The total aboveground storage capacity-is 125,300 gal. All above ground tanks are surrounded by concrete dikes. Any spills not contained by•the dikes would be pumped to the ash basin. The underground gas tank is of double - walled fiberglass construction. All ,oil storage facilities and oil- filled equipment are presently covered ,under Spill Prevention Control and Countermeasure'Plans (SPCC). See Cliffside's SPCC plan for additional information. Miscellaneous Waste Streams Acid Drip System: Due to occasional high pH levels in the basin, CSS installed .a 93 % sulfuric acid drip system at, the ash basin discharge tower. The system consists of a 5000 gallon tank with a variable feed PUMP. Caustic Drip System: Due to occasional low pH levels in the basin, ,CSS installed a sodium hydroxide drip system at the ash basin discharge tower. The, system consists of a 5000 ,gallon double lined tank of 25% sodium hydroxide with a variable feed pump. Unit 5 Ash Sluice Line Pretreatment To assist, in controlling Total Suspended Solids, a pretreatment of ash sluice water can be conducted, prior to the sluice water being discharged into the ash basin. Surfuric acid can be injected into the ash sluice line to lower the pH. Ferric Sulfate and other polymers can be added to the sluice line to precipitate solids from, the sluice water when it is discharged into the ash basin. Dredging: The intake from the Broad River at CSS is dredged on an as needed basis. Dredging takes place approximately 3 -4 times a year. The ,frequency and duration 'of the dredging is dependent upon river levels, unit load and the amount of material deposited at the intake. Cliffside Steam Station, Rutherford County NPDES,# NC0005088 Page 1 "l of 26 Cliffside has a mining permit to dredge, sand from the Broad River. The dredging ,operation and outfall is across the Broad River from Units, Since the area that needs to be dredged is on the plant side of the Broad River, CSS would prefer the capability to route the dredge material to to the Yard Drainage Basin and then pump the water to the ash basin. Laboratory Wastes The ,chemistry lab on site performs a variety of water analyses and routine sample collections. 'Therefore, several chemicals /reagents are used in the lab yin small quantities for sample" preservation, equipment calibration, analytical analyses, etc. The wastes are poured down the sink, flushed to the activated sludge unit and then pumped to the ash basin. Borosonic Rotor Testing Approximately once per year, one turbine is tested for cracks in the generator shaft using an ultrasonic nondestructive test During the process a maximum, of '400 gal of demur_ eralized water mixed with 4 gal of corrosion inhibiior,is used and is pumped to the, ash basin. Condenser Leakage Testing Occasionally, the condensers are tested for inleakage. This involves filling the steam side of the condenser with demineralized water and using a disodium fluorescing dye. The maximum yearly usage of the dye would be 6 lbs of dye in 90,000 gal of water. All wastes are pumped to the ash basin Photographic Waste During large outages a portable x -ray film developing machine will be onsite to develop x -rays of welds. 'The developing process has a rinse cycle that has been sampled and determined non hazardous. The rinse water is routed to the yard drains and pumped to the ash basin. The developer and fixer chemicals are drummed and not sent to the yard drains. Limestone Silo Rinse Spray Unit 5 limestone silo uses water to rinse the belt and to wash the concrete floor. The rinse water goes, to the yard drain and is pumped to the ash basin. Outfall 002A — Emergency Yard Drainage Basin Over Flow An existing overflow discharge pipe from the Yard Drainage Basin is used as an emergency. outfall to prevent submergence and damage of the pump motors that pump the water to the ash basin. The Yard Drainage Basin contains all the plant waste water from Units 1 -6, FGD Waste Water Treatment and Landfill Leachate, and the ,storm drains around the units. The Yard Drainage Basin temporarily holds the waste water before pumping the water to� the ash basin. Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 12 of 26 Hazardous and Toxic Substances Table 2c -3 At Cliffside, the potential the for toxic and hazardous substances being discharged is very low In reference to Item V -D, Form 2 =C, the substances identified under Table 2c -3 that may be in the discharge are as follows• Cliffside Steam Station Hazardous and Toxic Substances Acetaldehyde Formaldehyde Naphthenic Acidalene Vinyl Acetate Asbestos - from floor drains Furfural Pyrethrrns Xylene (Mixed'Isomers) —plant Cyclohexane Methyl Methacryl'ate Styrene Epichloroh dnn Monoeth lamine Vanadium Pentoxide During the course of the year products such as commercial cleaners and laboratory�reagents may be purchased that can contain,very'low levels of- a;substance found in Table 2C -3. It,is not anticipated that these products will impact the ash basin's capacity to comply with toxicity limits, since their concentrations are extremely low. Cliffside Steam Station, Rutherford County NPDES #, NC0005088 Page, 13 of 26 4:0 CFR 117 and CERCLA, Hazardous Substances The below table identifies `hazardous substances located, on -site that may be released to ,the ash basin during a spill in quanti'tie"s equal to or greater than the Reportable Quantity (RQ) levels as referenced, in 40, CFR 117, 302 and 355. This list is being provided in order- to qualify for the spill reportability exemption provided in 40 CFR 117 and the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). These values ,Below represent the maximum quantities, on -site ihat could be released at one tune, and sent° to the ash basin. They do not effect quantities that are discharged ,through typical use. List,of Hazardous'Substances Cliffsid'e Steam Station iHazardous, Substances in Excess �of RQ SUBSTANCE GZ ANTITY Ibs, SOURCE Ammonia 443,606 Anh..drous Ammonia Tanks Benzene 21,,231 Gasoline and Diesel Fuel Tanks Benzene,,;Dimethyl 1,09,1 Z2 G'a"sohneand Diesel Fuel Tanks; Paints, Oils Chlorine 2,400 1500',Pound ,& 150, Pound Cylinders Fe- rric,Sulfate 1,1;,11`9 Tote Bin_ - _ Heaxane 30,899, Gasoline and Diesel Fuel-Tanks, Spray Adhesives 'Hydrazine, 298 PowerhouseNVarehouse Methyl Tert=B_ut ,I Ether 1'65',305 Gasoline, and Diesel, Fuel Tanks Naphthalene' 75,211 Gasoline and Diesel Tanks, Oils Phosphorus, 207 Oil - Power,Hduse Sodium_ Hydroxide 41,617 Powerhouse, 'Storage Tank Sodium H "ochl'onte 1,072 Clarnfier Sulfuric acid 85,087 - Powerhouse Batteries, °Stoarge Tank Toluene 63;081 _ Gasoline and'Di6t6[ Fuel`Ti nks„ Paint X lene Mixed I`sotri&s 1,234 11 Gasoline Tanks, Cliffside Steam Station, Rutherford County NPDES #'NC0005088 Page 1.4 of 26 STORM WATER DESCRIPTION Site Description Cliffside Steam Station is a fossil - fueled, electric generation plant located approximately six miles southwest of Boiling Springs, North Carolina on the, Broad River in,Rutherford and'Cleveland Counties Units 1 and 2 began operation in 1 -940, and Units 3 and 4 began operation in 1948. Units 1=4 have a total generating capacity of approximately 198 net MW. Unit 5 began operation-in 1972, and it has a generating capacity of approximately 562 net, MW: Cliffside Steam Station is currently undergoing,a modernization project that is expected to be completed in.2012. The project will retire Units 1 -4, and build a new 825 net MW, highly efficient Unit 6 that will feature advanced clean-coal technology and emission controls. Also, a wet Flue Gas Desulfurization,(FGD) and a wastewater treatment system will be added'to treat FGD waste from Unit 5. Cliffside Steam Station is also constructing the following: dry ash handling facility, Coal Combustion, Products (CCP) landfill, limestone unloading area, and _ gypsum storage area. The site -will also add more railroads, roads, and parking areas. The site covers approximately 1,600 acres. The railway and. road system have changed due to modernization of the site. Currently, there' are three to four miles of'rail access, and two to three miles of paved roadways on -site. The plant yard, Units 1 -4 powerhouse, and switchyard for Units 1 -4 cover about 7'/2 acres adjacent to the Broad River. The coal pile covers 15 acres between the Units 1 -4 powerhouse and' the Unit 5 powerhouse. The Unit 5 powerhouse, plant yard, and cooling towers cover 12 acres. The Unit 5 switchyard is located on 5 acres across the river. The Unit 6 area covers approximately 66.5 acres and includes the FGD system, Unit 6 powerhouse, turbine building, boiler, cooling towers, and plant yard The Unit 6 switch yard is under construction across the river. There i's a Yard Drainage Basin that is approximately 3`'/z acres. An old settling pond that was about 1'/4 acres has been filled in and the corresponding stormwater outfall has been abandoned. Water in the Yardbrainage Basin is pumped to the ash settling basin. The ash settling basin has a natural drainage area ,of 288 acres including the surface area of about 75 acres. Drainage from an additional 80 acres, at the plantYyards goes to the ash settling basin Discharge from the ash settling basin is an NPDES permitted outflow Across the river from the station; there is a staging area and settling pond for a sand dredge project. Discharge from the dredge settling pond is addressed by an NPDES general permit for sand dredge wastewater. Soils at Cliffside Steam Station are typical of the region. Soils are primarily micaceous sandy silts and silty sands with some clayey sands in flatter areas. The site topography i's generally flat in developed areas with rol'l'ing hills in outlying, undeveloped areas. In developed areas, runoff flows overland to ditches and catch basins which are connected ,to a buried network of corrugated metal pipes (CMP). Stormwater from areas with significant materials or activities is routed through treatment systems prior to discharge. Rainfall runoff from the plant yards, coal handling areas, coal pile, Unit 6, and the FGD ,site goes to the Yard Drainage Basin; effluent from the holding basin is pumped to the ash basin. Rainfall runoff from the switchyards that contain oil cooled transformers is routed through oil trap tanks. Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 15 of 26 There are twelve active stormwater outfalls and one abandoned storm water outfall The stormwater outfalls are described in Section 2.3. There are four outfalls for the discharge of treated wastewater from station operations that are permitted by the NPDES permit NC0005088. The NPDES permitted outfalls for permit NC0005088 are described below There is also a general permit (NCG520000,) for the sand dredging operation which is described below. • NPDES Outfall 001 - Condenser Cooling Water This discharge contains once through non - contact cooling water from the plant condensers for units 1 -4. This outfall also has an exteriors yard drain that drains into the CCW outlet piping. See Stormwater Outfall 13 • NPDES Outfall 002 - Ash Settling Basin This discharge contains treated wastewater from the 75 acre ash settling basin. The treated wastewater contains low volume wastes, coal pile runoff, metal cleaning wastes, treated domestic Wastewater, chemical, metal cleaning wastes, effluent from the wastewater treatment system, ash transport water, CCP landfill leachate (landfill contains fly and bottom ash, and gypsum from FGD system), cooling, towers blow down, runoff from limestone stacking area and gypsum stacking area. • NPDES Outfall 002a- Emergency overflow/ SW Outfall 7 This is an emergency Yard Drainage Basin overflow. Discharge from this outfall is not .a normal occurrence. See Stormwater Outfall 7 in section 2.3 formore information. • Abandoned NPDES Outfall 003- Transformer Cooling Water This outfall was permitted for transformer cooling- water from switchgear equipment in the Units 1 -4 switchyard. Those transformets have been replaced with air cooled equipment, so the NPDES discharge no longer exists, but the outfall does. This outfall also conveys yard drainage and is, dually listed as Stormwater Outfall-4. • NPDES, I"nternal Outfall 004- Wastewater Treatment System WWTS) The wastewater treatment system for the Flue Gas Desulfurization (FGD) blowdown will discharge to the ash settling basin through NPDES Internal Outfa11004. NPDES In- Stream_Sand Mining/ SW Outfall 8 This consists of in- stream sand mining wastewater, associated stormwater, and similar wastewaters under a NPDES general permit number NCG520000. See Stormwater Outfall 8 `in section 2.3 for more information. Facility Drainage and Inventory of Significant Materials and Controls Based on pipe networks and site topography, the Cliffside site was divided into individual stormwater drainage basins as shown on attached the site. drawing. This section details the drainage basin characteristics of the site's twelve stormwater outfalls to the Broad, River. To provide a complete description of the stormwater drainage system, the Yard Drainage Basin and sump system is also characterized. A description of the drainage area, significant materials, and material control measures is presented for each drainage basin: Since Cliffside is undergoing construction, there are erosion control plans and structures that are so general that they might not be mentioned for each drainage area (e.g silt fences). In addition to the significant materials particular to each drainage basin, herbicides are applied annually to selected, areas throughout the Cliffside site to eliminate undesirable vegetation along railways, ash Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 16 of 26 pipelines, and perimeter fencing and around the buildings, cooling towers, light posts, and fire hydrants. Herbicides are spot applied where required and are applied in such areas as parking areas, switchyards, laydown areas, and along walkways. Herbicides, are also sprayed on the riprap around the intake structure, on the bank beneath the Units 1 -4 precipitators, at ,the boat ramp, at the septic lift station, the ash basin 'dikes, and the clubhouse. All herbicides used at Cliffside Steam Station are approved by the company as environmentally safe and are applied in an environmentally safe manner, quantity and in compliance with label instructions. Records are retained at the site which document information such as: the, areas treated, the'herbicide used andihe amounts of,herbicide used. Stormwater Outfall Drainage Areas Characteristics for the stormwater outfalls are presented. Stormwater Outfall 1 Discharge Structure: 24 inch ( ") diameter CMP Location: Broad River at Unit 5 Switchyard Control Structure: 30,000 gallon oil trap tank Drainage Area. 3.5 acres Area Description This drainage area includes the Unit 5 115 kV switchyard and the relay house The switchyard is fenced and coveted with gravel., The switchyard is relatively flat and elevated slightly above the surrounding ground A curb surrounds the southern and western perimeters, and ditches divert upland runoff around the switchyard. There is approximately ,2 acres of gravel area and 1 acre of paved roadways and within this drainage basin. Approximately 40 percent of this drainage basin is paved or roofed. Significant Materials/ Controls Oi1:Switchgear equipment in the Unit 5 115 kV switchyard contains a total of 47,891 gallons of mineral' oil. The AT -1 transformer contains 15,906 gallons of mineral oil, and the AT -2 transformer contains 20,764 gallons of mineral oil. The 17 oil circuit breakers contain a total of 11,221 gallons of mineral, oil Stormwater from this area is processed through a 3,0,000 gallon oil trap tank. Stormwater Outfall 2 Discharge Structure: 18" CMP Location: Broad River at Unit 5 Switchyard Drainage Area: 4.4 acres Area Description This drainage area includes the Unit 5 230 kV switchyard. The switchyard is covered with gravel. The switchyard is relatively flat and elevated, slightly above the surrounding ground: A curb surrounds the southern and eastern perimeters, and ditches divert upland runoff around the switchyard. 'There are aboui 2.7 acres of gravel surface and one acre of paved roadways within this drainage basin. Approximately 40 percent of°this drainage basin is paved. Significant Materials/ Controls Oil-Two components in the 230 kV switchyard contain a total of 342 gallons of mineral oil. All other components in the 230 kV switchyard are air /,gas cooled. I Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page f7 of 26 Stormwater Outfall 3 Discharge Structure: 36" CMP Location: Broad River beside Bridge to Unit 5 Switchyard Drainage Area: 38.0 acres Area Description This drainage basin includes. the yard area west of the Unit 5 powerhouse, cooling towers, 'Unit 5 warehouse, fire water tank and diesel fire areas, areas in front of #5 maintenance shop and #5 administrative building. Also in this drainage area is the Shaw Office Complex on hill just south of FGD site which contains the Shaw Office Complex, Maintenance Shop, satellite Hazmat storage facility, and 253 parking spaces. Two rock dams (RD -1 and RD -2) receive. most of the stormwater runoff from `the Shaw Office Complex area. There are two laydown areas with miscellaneous supplies, one near, cooling tower B and the other behind the warehouse. The open area between the warehouse and cooling `tower B ,is being used as a temporary staging area to ,support the modernization project of Units 5 and 6. There is approximately a mile of paved roadways and about '1/2 mile of railways crossing through this drainage basin. Parking areas cover about 2 acres. About 50 percent of the drainage area is paved or roofed. There are two natural springs in this drainage area, one adjacent to the station, access road and the other behind cooling tower B. SignificantMaterials/ Controls The 30 X 35 foot wash station and' hazmat storage facility drains are conveyed to the P -5 Yard Drainage Basin, so they due to pose a threat to stormwater runoff in Outfall 3. The significant materials for these facilities are listing in,section 2.4. Laydown Areas: Spare equipment, parts, steel, cable, and miscellaneous supplies are stored in laydown areas throughout the site. The equipment and supplies generally do not contain liquids. Parking: There are several'paved and gravel parking areas within this drainage basin. Ash- Flyash is transported by covered trucks on the station access road for use in off -site structural fill projects Oil: The cooling tower fans contain a total of 400 gallons of lube oil. Stormwater Outfall 4 Discharge Structure. 24" CMP Location: Broad River'at Units 1 -4 Switchyard Control Structure, Drainage Area: 20,000 gallon oil trap tank 2.9 acres Area Description This drainage basin is comprised mostly of the Units 1 -4 switchyard. The switchyard is covered with gravel. It is slightly elevated from the surrounding grade and surrounded by concrete curbing, except on the northwest end. Less than five percent of this drainage area is paved. 'Significant Materials /, Controls Oil:Switchgear equipment in this drainage basin contains 73,616 gallons of mineral oil. Stormwater runoff from this drainage area is processed through a 20,000 gallon oil trap tank. Waste: 1 -4 septic tank and associated piping is located in this area. Cliffside Steam,Station, Rutherford County NPDES # NC0005088 Page T8 of 26 Stormwater ,Outfall5 Discharge Structure: Open, Grated Concrete Trenches Location: From the Intake Screen Wash boxes to the, Discharge Canal Drainage Area- 2.0 acres Area Description ,These trenches are used to return river water used to wash debris from the intake screens. Roof drainage from the Uriits 1 -4 turbine room roofs is discharged into these trenches via a French drain system. The turbine room roofs cover ,about '/2 acre. The trenches are open and covered with grating so runoff from the adjacent ,areas can enter them. The trenches run from -the intake room to the discharge canal. The area surrounding them is relativel y flat and covered with grass and gravel. Significant Materials/ Controls Parking: The ,gravel area in back of the powerhouse can be used for parking. Oil- There is a pump room that contains less than 100 gallons of oil that operates inside the motors of the pumps. Waste. 1 -4 septic lift station piping is underground in this area. Abandoned Stormwater Outfall 6 Discharge Structure: 36" CMP Location: Discharge Canal Area Description This outfall has been abandoned, and the drainage basin is routed to the Yard Drainage Basin. Stormwater Outfall 7/ NPDES 602A Discharge Structure. 36" CMP from Old Units 1 -4 Ash Basin Discharge Tower Location: East of Yard Drainage Basin Drainage Area: 14 acres Area Description This is an emergency overflow drainage area for the Yard Drainage Basin. Discharge from this outfall is not a normal occurrence, and would only occur if the Yard Drainage Basin overflows in the event of a significant rainfall event. This area is covered with vegetation and is bermed on all sides, and functions as a dry detention pond. This dry detention pond covers approximately 4.5 acres. The drainage feature in the dry detention pond is the discharge tower for the old, abandoned ash basin for Units 1 -4. The dry detention pond would have to fill at least up to four feet high, in order to spill over into the discharge structure. Significant Materials/ Controls ,See section 2.4 Yard Drainage Basin to see a list of potential overflow materials. Stormwater Outfall 8/ NPDES In- Stream Sand Mining Discharge Structure. 15" MP Location: Northeast of Units 1=4, across the Broad River Drainage Area: 4.5 acres Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 19 of 26 Area Description This is the discharge area that discharges in- stream sand mining wastewater, associated stormwater, and similar wastewaters under a NPDES general permit number NCG520000. The solid debris from the sand mining operation is collected and deposited in a `location away from the river bank. The water collects into a detention basin, and an overflow dry detention basin collects stormwater overflow from the road and surrounding area. In the event of extreme rain event, runoff would overflow into the river. Significant Materials/ Controls Significant materials are not stored in this drainage basin: Stormwater Outfall 9 Discharge Structure: 42" concrete, pipe „rock channel to river Location: West,of FGD site Drainage Area: 1,50 acres Area Description 'This drainage area covers approximately 100 acres west of 'the powerhouse and includes the old ash basin for Unit 5. Stormwater runoff from the area is collected into sedimentation basins and overflow is conveyed through Channel S`2, Channel S' =3, or a riprap ditch In the case of heavy rains, overflow runoff from this area would end Lip in Sedimentation Basin # 3 (SB -3). Overflow is conveyed from a 42” concrete pipe into a rock channel, and then into the Broad River. SB -3 contains a sedimentary basin skimmer. The following is a list of laydown or work areas and the corresponding erosion control measures taken for that area: The FGD Project Spoil Dirt Area is located in this drainage area. Stormwater runoff from the area is collected into SB -3 which contains a sedimentation basin skimmer. Concrete is mixed in this drainage area by three concrete batch plants. Laydown area #I A (12.6 acres) has a small detention pond. Overflow would be conveyed into Channel S -3 that runs to an existing pond (P -2), but overflow is not a normal occurrence. Laydown area # 1 A, # 1 B (6.9 acres), and # 1 C (14.2 acres) share a sedimentation basin (SB -4) that is equipped with a skimmer. Water is routed into riprap channels. Laydown area #3 (5.3 acres) and #2A (2 acres) are located by the clubhouse and helicopter pad Runoff from this area flows through a riprap channel to SB-3. Significant Materials/ Controls Laydown Area: Spare equipment, parts, steel, iron, cable, and miscellaneous supplies are stored in a flat, concrete laydown yard adjacent to the warehouse. The, equipment and supplies generally do not contain liquids. Chemicals: Concrete plant chemicals and Ershings chemicals are located in this stormwater outfall drainage area. Stormwater Outfall 10 Discharge Structure: 36" CMP Location- Broad River Drainage Area: 8 5 acres Cliffside'Steam Station, Rutherford County NPDES # NC0005088 Page 20 of 26 Area Description ° This drainage, area conveys water -from a perennial stream that starts from adjoining property. The stream enters a 36" CMP pipe on the West side of the switchard and continues under the switchyard. The outfall ends into ,a channel between the Broad River and the switchyard and flows into the Broad River. Significant Materials/ Controls No significant materials are located in this drainage area. Stormwater , Outfall 11 Discharge Structure: 30" CMP Location: Suck Creek Drainage Area: 43 acres Area Description This drainage area conveys runoff from Laydown area #4 ,and #5, as well as, the construction parking area into a large sedimentation basin (SB -1) (approximately 80,000 square feet). Overflow is conveyed into a pipe and empties near Suck Creek. Laydown area #4 (14 acres) is the duct yard; and has 38,500 square feet of 'gravel parking. Construction parking (360,000 square feet) is gravel and runoff is conveyed to a large sedimentation basin (approximately 140,000 square feet)., Laydown area #5 (1.3 acres) is the laydown area for Alstom, and runoff from this area is also conveyed to the basin Significant Materials/ Controls Laydown Areas: Spdre equipment, parts, steel, cable, and miscellaneous supplies are stored in laydown areas throughout the site. The equipment and supplies generally do not contain liquids. Stormwater Outfall 12 Discharge Structure: 30" CMP Location: Suck Creek Drainage Area: 10 acres Area Description This drainage area covers a small portion of the FGD site. A portion of the new cooling tower and any runoff from construction activities is conveyed into SB -2 Significant Materials/ Controls No significant materials are stored in this drainage area. Stormwater Outfall 14 Discharge Structure: 36" CMP Catch containment Location: Broad River Drainage Area: <0.5 acres Cliffside Steam Station, Rutherford County NPDES # NC0005088 Page 21 of 26 Area Description This drainage area conveys water' on the downriver side of 1 -4 building There is one yard drain that is tied into Condenser Cooling Water Discharge (NPDES 001). This drains,the water from the area around the east side of the plant and Raw River Water Pumps and the road by the CCW discharge structure Significant Materials/ Controls No significant materials are stored in this drainage area. Yard Drainage Basin The Yard ,Drainage Basin i's located east of the ,coal pile and, the Broad River. .Effluent from the, Yard Drainage Basin is pumped to the station's 75 acre ash settling basin. Area Description The Yard Drainage Basin is approximately 2.8 acres. The drainage area for the Yard Drainage Basin covers approximately 1,50 acres and is largely °under construction at this time. The drainage area covers: "Industrial" wastewater from the powerhouses: includes effluent from the turbine room .sumps, boiler room sumps, ash sumps, and cooling tower dewatering sumps Effluent from the septic system. Area that formerly was drained by Stormwater Outfall 6: includes the coal unloading area, raw water storage tanks, and the clarifier. There is a large storage building and two laydown areas. The anhydrous ammonia tanks for the SCR project are located adjacent to the clarifier. Stormwater runoff from most of the plant yards, powerhouse roofs, and from the coal pile drains to the yard sump. Roofed areas at the powerhouses, the warehouses, the tractor shed, coal sampling and crusher, houses, and various outbuildings account for,about 4 acres. Floor drains from the tractor shed, hazmat storage area, andvash station flow to the Yard Drainage Basin. The ash lines, ash silos and ash handling activities are in this drainage basin. There are several equipment and material laydown areas and temporary staging areas. About 50 percent of this drainage basin is paved or roofed. Significant Materials/ Controls Oil :There are several fuel oil tanks in the plant yards. Unit 5, has two fuel oil tanks with a capacity of 50,000 and 35;000 gallons. Units 1 -4 have two fuel.oil tanks that have a capacity of 12,000 and 15,000 gallons. There is a 6,000 gallon diesel fuel oil tank and dispenser at the tractor shed for fueling bulldozers. There is a diesel fuel dispenser and a 3,000 gallon steel storage tank between the storage building and the railroad. Concrete dikes surround all of these tanks. Stormwater that collects within the dikes is inspected for the presence of oil prior to being released by unlocking and opening the release valve. The tanks are filled from an 8,000 gallon tanker truck DOT regulations are followed Oil clean- up supplies are available nearby in the event of spill's. Shaw has 3 gas and diesel fuel tanks that are within a secondary containment area. Powerhouse equipment contains -a total of about 25,586 gallons of oil. There is a gasoline dispenser northwest of the tractor shed. The gasoline is stored in a 1,000 gallon, double walled underground tank. The tank is filled by a 1,500 gallon tanker truck. An earthen berm runs behind the dispenser to ensure spills and runoff flow toward catch'basins thatdrain to the holding basin, . `Cliffiside Steam Station, Rutherford County NPDES # NC0005088 Page 22 of 26 There is a 4,000 gallon used oil storage tank adjacent to the Unit 5 new oil storage house. The tank is surrounded by a concrete dike. Stormwater that collects within the dikes is' inspected for the presence of oil prior to being released by unlocking and opening the release valve. Used oil drums and oily waste products are stored on a concrete pad adjacent to the waste oil tank. New 55- gallon drums of petroleum products are, stored inside the new oil house. The quantity of drums varies, but generally, the total amount stored in the new oil house could, be approximated ,as 2,750 gallons. An earthen berm runs behind the entire, area to ensure spills and runoff flow toward catch basins that drain to the Yard Drainage Basin. Oil clean-up supplies are stored adjacent,to the used oil tank. There is a 300 gallon used oil tank located in a shed at the north end of the tractor shed. Used oil drums and oily waste products ,are stored, in an adjacent shed About 220 gallons of motor oil and hydraulic fluid are stored in drums inside the tractor shed The Unit 5 main transformers are located on the northwest side of the powerhouse, and the start-up transformers are located around the- corner on the northeast side of the powerhouse. The transformers are surrounded by a short concrete curb The transformers contain a total of 45,237 gallons of mineral oil. Oil content for individual components are: 5UT: ,13,3801gal. 5AT: 4,047 gal.5CTA &,5CTB: ,27,8,10 gal. Two new transformers have been installed to supply power to the FGD. They are located on the northwest' of unit 5 and .are tied, to the '23'0kv aux lines. The transformers contain a total of 16,264 gallons of mineral oil The Unit 5 precipitators are located on, overhead supports adjacent to the powerhouse, on the southeast side. There are 12 transformers for the Unit 5 ,precipitators, and they contain a total of 2,344 ,gallons of mineral oil. The Units 1 -4 precipita`tors'are southwest of the powerhouse There are 14 transformers for the Units 1-4 precipitators, and they contain a total of 2,4`14 gallons of mineral oil. A transformer for the pumps at,the Yard Drainage Basin has 270 gallons of mineral oil. Chemicals: A 6,000 - gallon tank of 93% sulfuric acid and a 6,000 gallon tank of 50% sodium hydroxide are located on the northeast side of the Unit 5 powerhouse. The ,tanks, are surrounded by a concrete dike. Stormwater that collects within the dike can be released by unlocking and opening the release valve. There is an eyewash station adjacent to the tanks. There is a 5,000 gallon tank of sulfuric acid and a 5,000 gallon tank of ferric sulfate at the pretreatment of Unit 5. These tanks are double walled. The old variable speed ID Fan drives contam about 300 gallons of glycol, and the FD variable speed house contains 200 gallons of propylene glycol. There is an anhydrous ammonia tank near unit 5 CEMS building that contains less than 2000 gallons. If this tank were to rupture, some product would spill and then evaporate. There are two 45,000 gallon anhydrous, ammonia tanks with secondary containment for the SCR adjacent to the clarifier. Two 60,0,00 gallon anhydrous ammonia tanks with secondary containment will be installed for Unit 6. Coal: Runoff from the coal pile goes to �the� holding basin. Coal dust is present along the railroad tracks, coal handling areas, and the plant yard. Ash: Wet ash is sluiced through this basin to the ash settling basin. The, ash pipelines are both aboveground and in concrete trenches. Dry flyash is transferred from the plant to the ash silos, through above grade pipelines. The dry flyash is transferred'Trom the ash silos to trucks for transport to off -site projects where it is used as a concrete additive. Dry ash may also be landfilled on -site. Cliffside Steam Station, Rutherford County NPDES #'NC0005088 Page23 of 26 Hazardous Waste: Hazardous wastes are accumulated and stored on a temporary basis under cover in hazardous waste areas adjacent to the Unit 5 new oil house, inside the tractor shed, and on the hill near the Shaw Office Complex_. All spills will be contained and managed per the applicable state and federal hazardous waste regulations. Laydown Areas and` Temporary Staging Areas: Spare equipment, parts, steel, cable, and miscellaneous supplies are stored in laydown areas throughout the site. The equipment and supplies generally do not contain liquids. Parking: There are several areas used for parking within this drainage basin. Wastewater. Plant wastewater from equipment discharges, floor drains, sumps, FGD wastewater treatment plant, and the wash station is routed to the plant yard drainage sump. This wastewater may include oil, chemical, and hazardous waste spills. Known Future Significant Materials/ Controls Gypsum & Limestone Other Drainage Areas This section covers drainage areas that are `not in the sump system and either do not have an outfall, or have an outfall that is far away from the creek/ river,and/ or temporary. Railroad, Drainage Area Location: West of FGD site Drainage Area: 110 acres Area Description Stormwater runoff from the approximately ,5000 feet of railroad tracks is conveyed into a riprap channel and into Suck Creek. This drainage area also receives runoff from approximately 100, square feet of Duke Power Road near where the bridge passes over, Suck Creek. Significant Materials/ Controls Limestone/ Coal/ Anhydrous Ammonia:, Potential for a spill or leak from railroad activities. Laydown #1 Location: Drainage Area: Suck Creek 44 acres Area Description Laydown area #1 (44 acres) has two large sedimentation basins referred to as ,SB -5 and SB -6. Also, two rock damns -(RD -4 and RD -5) are located in this area. Overflow from S8-5 and SB -6 is conveyed through a pipe into a corresponding riprap area RD -4 and RD -5 have riprap spill ways designed for overflow. Overflow is not a normal occurrence. The roadways are at least 30 feet ,in width, and are composed of gravel 6 to 8 inches thick with fabric for heavily travelled areas. The southeastern edge of this area will be the site of a future ash/gypsum landfill haul road and utility corridor. Existing and future rail are located near- Suck Creek. Significant Materials/ Controls s Cliffside Steam Stahon,,Rutherford County NPDES # NC0005088 Page 24 of 26 Laydown Areas. Spare equipment, parts, steel, cable, and mi'scell'aneous supplies are stored in laydown areas throughout the site. The equipment and supplies generally do not contain liquids. Laydown #2 Location: Drainage.Area: West of FGD site 10 8 acres Area Description Stormwater runoff from this area is collected-'in a sedimentation basin (SB -7). This basin has a skimmer to improve sedimentation. Overflow for SB -7 is conveyed to a nearby stream that feeds into the Broad River. Significant Materials/ Controls Laydown.Area: Spare equipment, parts, steel, iron, cable, and miscellaneous supplies are stored in a flat, concrete laydown yard adjacent to the warehouse. The equipment and supplies generally do not contain liquids. Drainage Area 13 Location: Drainage Area: South of FGD site 6 3 acres Area Description This area encompasses part of Duke Power Road and the largely vegetated,area east of the entrance to the plant. Stormwater runoff from the area travels via sheet flow to a drainage ditch that conveys the water to. the Suck Creek. Significant Materials/ ,Controls No significant materials are stored in this drainage area. Future Unit 6 Switchyard Area Location: Across river, North of plant, off of McCombs Rd. Area Description The Unit 6 switchyard will tie into the 500 kV switchyard. Stormwater runoff from this future construction site will run into two sedimentation basins. Significant Materials/ Controls No significant materials are, located.in this drainage area, at present. Identification of Past Leaks and Spills Within the past three years, there have not been any significant spills of hazardous substances in excess of reportable quantities set forth by Section 311 of the Clean Water- Act or Section 102 of `CERCLA. All significant spill incidents shall be logged by the Environmental Coordinator, and the necessary updates shall be made to the various related plans, and procedures. All environmental 'incidences at Cliffside Steam Station are stored for review in the station's,Environmental Incident Database. Cliffside Steam Station, Rutherford County NPDES 9'NC0005088 Page 25 of 26 Identification of Non - Stormwater Discharges Non - stormwater discharge is conveyed through Stormwater Outfalls 3, 5, 6, 8 and 9 The non - ,stormwater discharge of Stormwater Outfall 3 is groundwater flow from springs. The non - stormwater discharge at Stormwater Outfall 5 is intake screen backwash water. Stormwater Outfall 8 is dually listed as NPDES In- Stream Mining and consists of in- stream sand mining wastewater during operation. The non - stormwater low flow discharge at Stormwater Outfall 9 is from a,perennial stream. Monitoring and Sampling Data There are thirteen stormwater, outfalls at Cliffside Steam Station Monitoring all of those outfalls is not necessary since many of the outfalls convey stormwater from areas of substantially identical activities and materials. There are seven,land use categories: roof drainage, switchyards, plant yard, open grass or undeveloped areas, laydown areas, parking, and other. Some drainage areas have more than one land use. O.utfalls 3 and 4 are recommended for sampling. Samples from these outfall's should be characteristic of all the land uses, ,significant materials, and activities. e Cliffside Steam Station, Rutherford County NPDES # NC000508& ,Page 26 of 26 Cliffside Steam Station (CSS) 316 Determination Cliffside Steam Station 316(a) determination Duke's operation experience during the past five years under the thermal limitations imposed in NPDES Permit No 'NC0005088 substantiates the above conclusion and further supports that the operating characteristics of the station have a minimal effect of the aquatic environment of the Broad 'River. Surveys of the aquatic community in the Broad River in the vicinity of"CSS demonstrate that a Balanced Indigenous Population exists. Accordingly, Duke Energy requests a 316(a) variance and further requests that the thermal limitations imposed in the permit be continued. Retirement of CSS units 1-41s planned before first fire to produce steam for turbine roll of Unit 6. This,retirement will significantly reduce the thermal discharge. Cliffside Steam Station 316(b) Determination In conjunction with the rulemaking process for the new Phase II 3.16(b) rule pertaining to fish impingement and entrainment, historical data and permitting records were reviewed. Initial 316(a) and 316(b) studies associated with enactment of the Clean Water Act concluded that the location, construction capacity, and design of the cooling water intake of CSS and other Duke Energy steam stations were not detrimental to the aquatic ecosystem ,and minimize adverse environmental impacts. Both North Carolina and EPA regulators concurred in 1976 that 3,16(b) fish impingement and entrainment studies were no longer needed at that time. Since the new Phase II 316(b) rule for existing facilities has been remanded and retirement of CSS units 1 -4 is planned in 2012, no changes to the existing cooling -water intake system should be- required. Ash Basin Capacity Part'II'I B (1) of the existing NPDES permit for Cliffside requires the permiee to provide and maintain at all times a minimum free water volume (between the top of the sediment level and the maximum water elevation within the basin). The sum of the maximum 24 hour plant- discharges plus all direct rainfall and ,all runoff flows to the pond resulting from a 10 year, 24 hour rainfall event, when using a runoff coefficient of 1.0 equals 213.1 acre -feet. The ash basin was last surveyed for its level of ,sediment in January 2009. The amount of sediment to accumulate in the ash -basin since January 2009 is based on coal consumption and ash content of the coal. It is estimated that from January 2009 through 12/31/2015 the volume of solids to the ash basin will be 287.0 acre -feet. The required storage volume equals the summation of 287 and 213 or 500 acre -feet. The available 'storage capacity based on the January'2009 basin survey is 1,703:1 acre-feet and an ash basin cleanout was completed in December of 2009 resulting in an additional 111.6 acre -feet. The total available storage capacity as of December 2009 is 1,814.7 acre -feet Ash `Basin Cauacit Part III B (1) of the existing NPDES permit for Cliffside requires the permittee to provide and maintain at all times a minimum free water volume (between the top of the sediment level and the maximum water elevation within the basin). The sum of the maximum 24 hour plant discharges plus all direct rainfall and all runoff flows to the pond resulting from a 1`0 year, 24 hour rainfall event, when using a runoff coefficient of 1.0 equals 213 1 acre -feet. The ash basin was last surveyed for its level of sediment in January 2010. The amount of sediment to accumulate in the ash basin since Januay 2010 and through December 2015 is based on projections of coal consumption, and ash content of the coal. It is estimated that from January 2010 through 12/31/2015 the volume of solids to the ash basin will be 350 acre -feet The required storage volume equals the summation of 350 and 213 or 563 acre -feet. The available storage capacity based on the January 2010 basin survey is 1,399.0 acre - feet. Based on these calculations, there'is sufficient capacity in'the ash basin to provide the retention volume specified in the permit through the year 2015. Allen Stowe /csssoutfallO01_11092011 be Dayna Herrick Steve Hodges Cliffside Steam Station Rick Roper Cliffside Steam Station Penny Stafford John Velte File Number 8 -6 Record Number 248464 UPS.