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NCS000546_Permit Application Complete_20140525
DUKE ENERGY, September 25, 2014 Mr. Bradley Bennett State of North Carolina Department of Environment and Natural Resources Division of Energy Mineral & Land Resources Stormwater Permitting Program 1612 Mail Service Center Raleigh, NC 27699-1612 Subject: NPDES Stormwater Permit Application Allen Steam Station Dear Mr. Bennett Environmental Seances Duke Energy 526 South Church Street Charlotte, NC 28202 Mailing Address Mail Code EC13K/ P.O Box 1006 Charlotte, NC 28201-1006 Duke Energy requests a stormwater discharge permit for the Allen Steam Station located in Gaston County. North Carolina Enclosed is a check from Duke Energy in the amount of $860.00 for the subject stormwater permitting fee; and three sets of the following documents related to this permit request: a EPA Form 1; b. EPA Form 2F; C. EPA Form 2F Supplemental Information, d. Available stormwater analytical data,. e. Site Location Map: f. Site Stormwater Plan Drawing Numerous stormwater outfalls are located at the Allen Steam Station. The accompanying analytical data was obtained from samples collected at stormwater outfalls SWO08 and SWO10 during a rainfall event on August 11, 2014 The remaining outfalls at the station will be sampled in due course as qualifying rainfall events occur at the site. Considering the number and spatial distribution of outfalls around the facility, more than one additional qualifying rainfall event will be necessary to obtain samples from all outfalls As described in the accompanying supplemental information, Duke Energy does not intend to collect samples from outfalls conveying stormwater runoff from non -industrial use areas of the site, nor from areas conveying runoff as sheet flow.. This includes Drainage Areas 5. 14 and 17 Should you have any questions regarding this submittal or require additional information, please contact Mark McGary at 980-373-7898 or email Mark.McGary@duke-energy.com. f ' DUKE ENERGY Environmental Services Duke Energy 526 South Church Street Charlotte. NC 28202 Mailing Address, Mail Code EC13K/ P O. Box 1006 Charlotte, NC 28201-1006 I certify, under penalty of law. that this doctmtent and all attachments were prepared tinder my direction or .supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information .submitted is, to the best of my knowledge and belief, true, accurate, and complete. 1 ant aware that there are significant penalties for submitting false information, including the possibility offtnes and imprisonment for /mowing violations Sincerely �A'e� &t:'. Eric Matthews - General Manager If Allen Steam Station Fossil Hydro Operations Carolinas West Attachments Check Date: Aui 29 2014 Venda, Number: 000007190 Name: STATE OF NOR H CAROLINA DEPARTMENT OF Check Number: t 0001225, t Invoice Number Invoice Date Voucher ID Gross Amount Discounts Taken Late Charge Paid Amount 082 148000ONC AH FN Au,: 25 2014 10668018 860.00 0.00 0.00 8(10 00 Check Number: Date Total Gross Amount Total Discounts Total Late Charges Total Paid Amount 1000122583 Aug 29 2014 5860.00 50.00 50.00 5860.00 Duke Energy Business Services 1000122583 DUKE 400 South Tryon Street JPMORGAN CHASE BANK, N.A. ENERGY. Charlotte, NC 28285 Syracuse, NY 50-937,213 Corporate Accounts Payable ST256 1 400 South Tryon Street Charlotte, NC 28285 Date 8/29/14 Pay Eight hundred sixty and xx / /00 Dollars $+*860,00 To The Order Of STATE OF NORTH CAROLINA DEPARTMENT OF ENVIROMENT AND NATURAL RESOURCES DIV OF ENERGY MINERAL AND LAND RESOURCES 1612 MAIL SERVICE CENTER Raleigh, NC 27699-1612 Authorized Signature FORM U.S. ENVIRONMENTAL PROTECTION AGENCY 1. EPA I.D. NUMBER 1 GENERAL INFORMATION S T/A C NC0004979 F Consolidated Permits Program D GENERAL (Read the "General Instructions" before starting.) 1 2 13 14 1s LABEL ITEMS GENERAL INSTRUCTIONS If a preprinted label has been provided, affix it in the I. EPA I.D. NUMBER designated space. Review the information carefully; if any of it is incorrect, cross through it and enter the 11. FACILITY NAME correct data in the appropriate fillwin area below. Also, if any of the preprinted data is absent (the area to the left of the label space lists the 111. FACILITY MAILING PLEASE PLACE LABEL IN THIS SPACE information that should appear), please provide it in ADDRESS the proper fill-in area(s) below. If the label is complete and correct, you need not complete Items I, III, V, and VI(except VI-8 which must be IV. FACILITY LOCATION completed regardless). Complete all items if no label has been proved. Refer to the instructions for detailed item descriptions and for the legal authorization under which this data is collected. 11. POLLUTANT CHARACTERISTICS INSTRUCTIONS: Complete A through J to determine whether you need to submit any permit application forms to the EPA. If you answer yes' to any questions, you must submit this form and the supplemental from listed in the parenthesis following the Mark 'X' in the box in the third column If the form is If 'no' question. supplemental attached. you answer to each question, you need not submit any of these fomes. You may answer *no" if your activity is excluded from permit requirements; see Section C of the instructions. See also, Section D of the instructions for definitions of bold-faced terms. SPECIFIC QUESTIONS MARK "X SPECIFIC QUESTIONS MARK 'X FORM FORM YES NO ATTACHED YES NO ATTACHED A. Is this facility a publicly owned treatment S. Does or will this facility (either existing or works which results in a discharge to waters of1:1 ® ❑ proposed) include a concentrated animal 1:1 ® 1:1the U.S.? (FORM 2A) feeding operation or aquatic animal production facility which results in a discharge to waters of the U.S.? (FORM 2B) 16 17 18 19 20 21 C. Is this facility which currently results in® ❑ ® D. is this proposal facility (other than those ❑ ® ❑ discharges to waters of the U.S. other than described in A or B above) which will result in a those described in A or B above? (FORM 2C) discharge to waters of the U.S.? (FORM 2D) 22 23 24 25 26 27 E. Does or will this facility treat, store, or dispose of F. Do you or will you inject at this facility industrial or hazardous wastes? (FORM 3) ❑ ® ❑ municipal effluent below the lowermost stratum ❑ ® ❑ containing, within one quarter mile of the well bore, underground sources of drinking water? (FORM 4) 28 29 30 31 32 33 G. Do you or will you inject at this facility any produced H. Do you or will you inject at this facility fluids for water other fluids which are brought to the surface in connection with conventional oil or natural gas 1:11:1® special processes such as mining of sulfer by the Frasch process, solution mining of minerals, in 1:1® ❑ production, inject fluids used for enhanced recovery situ combustion of fossil fuel, or recovery of of oil or natural gas, or inject fluids for storage of geothermal energy? (FORM 4) liquid hydrocarbons? (FORM 4) 34 35 36 37 1 38 1 39 I. Is this facility a proposed stationary source J. Is this facility a proposed stationary source which is one of the 28 industrial categories listed in the instructions which is NOT one of the 28 industrial categories 1:1® 1:1listed 1:1 ® 1:1 and which will potentially emit in the instructions and which will potentially 100 tons per year of any air pollutant regulated emit 250 tons per year of any air pollutant under the Clean Air Act and may affect or be regulated under the Clean Air Act and may affect located in an attainment area? FORM 5 40 41 42 or be located in an attainment are? FORM 5 43 44 45 111. NAME OF FACILITY c SKIP Allen Steam Station 1 15 1 16-29 30 69 IV. FACILITY CONTACT A. NAME & TITLE last, first, & title B. PHONE area code & no. CMcGary, Mark / Lead Engineer 980 373 7898 15 1 16 45 1 46 48 1 49 51 1 52 55 V. FACILITY MAILING ADDRESS A. STREET OR P.O. BOX P.O. Box 1006, Mail Code EC3K s1 15 1 16 45 B. CITY OR TOWN C. STATE D. ZIP CODE C Charlotte NC 28201 15 1 16 "4041 42 47 S1 VI. FACILITY LOCATION IIIIIII A. STREET, ROUTE NO. OR OTHER SPECIFIC IDENTIFIER • 6 C 253 Plant Allen Road ro 15 1 16 45 B. COUNTY NAME Gaston 46 70 C. CITY OR TOWN D. STATE E. ZIP F. COUNTY CODE CODE s Belmont NC 28012 15 1 16 40 41 42 47 51 52 54 EPA FOR1113510-1 (5-90) CONTINUED ON REVERSE CONTINUED FROM THE FRONT VII. SIC CODES (4 -digit, in order ofpriority) A. FIRST B. SECOND CJ 4911 (sPeCY) � (specify) Electric Services 15 16 1% 15 18 19 C. THIRD D. FOURTH C(specify) 7 (specify) 7 1515 1 16 19 Vlll. OPERATOR INFORMATION A. NAME I B. Is the name listed in Item c:: Duke Energy Carolinas, LLC (Attention: Mark McGary) VIII -A also the owner? 1 1e 19 ® YES ❑ NO C. STATUS OF OPERATOR Enter the appropriate letter into the answer box; if "Other,"s ci D. PHONE area code & no. F = FEDERAL M = PUBLIC (other than federal or state) P I (specify) c 9$Q 373 7898 A S = STATE O = OTHER (specify) Electric Utilit y 56 16 19 r-19-2-1-1 22 25 P = PRIVATE 15 E. STREET OR PO BOX P.O. Box 1006, Mail Code EC13K 26 5s F. CITY OR TOWN G. STATE H. ZIP CODE IX. INDIAN LAND c Charlotte NC 28201 Is the facility located on Indian lands? B DYES NO 15 16 40 42 42 47 51 X. EXISTING ENVIRONMENTAL PERMITS A. NPDES (Discharges to Surface Water D. PSD Air Emissions from Proposed Sources 9 N' NC0004979 c T e 9 1 P 15 16 17 18 30 15 16 1 17 1 16 30 B. UIC (Underground Injection of Fluids E. OTHER (specify) (Specify) 9 u I T 8 03757T39 Air permit 9 15 1 16 17 18 30 15 16 1 17 1 18 30 C. RCRA Hazardous Wastes E. OTHER s ci (Specify) s R ' NCD043678937 s T ° W00000452 / 36-12 Distr. of residual solids 15 1 16 1 17 1 18 30 1 15 1 16 1 17 1 16 30 permit / Ind. landfill permit XI. MAP Attach to this application a topographic map of the area extending to at least one mile beyond property boundaries. The map must show the outline of the facility, the location of each of its existing and proposed intake and discharge structures, each of its hazardous waste treatment, storage, or disposal facilities, and each well where it injects fluids underground. Include all springs, rivers and other surface water bodies in the map area. See instructions for precise requirements. X11. NATURE OF BUSINESS(provide a brief descri tion Coal-fired electric generation XIII. CERTIFICATION see instructions I certify under penalty of law that / have personally examined and am familiar with the information submitted in this application and all attachments and that, based on my inquiry of those persons immediately responsible for obtaining the information contained in the application, I believe that the information is true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment. A. NAME & OFFICIAL TITLE (type or print) B. SIGgTURE 2" C. DATE SIGNED Eric Matthews - General Manager II 6ecu- .J/ZS 114 COMMENTS FOR OFFICIAL USE ONLY c C 15 1s ss EPA FORN13510-1 (8-90) EPA ID Number (copy from Item 1 of Form 1) Please orint or tune in the unshaded areas gni NCO 0 04 979 Form Approved OMB No. 2040-0066 FORM 2F NPDES Approval expires 5-31-92 U.S. Environmental Protection Agency Oto E PA pp Washington DC 20460 A lication for Permit to Discharge Storm Water Discharges Associated with Industrial Activity Paperwork Reduction Act Notice Pubfic reporting burden for this application is estimated to average 26.6 hours per application, including time for reviewing instructions, searching existing data sources gathering and maintaining the data needed, and completing and reviewing the collection of information Send comments regarding the burden estimate, any other aspect of this collection of information, or suggestions for improving this form, including suggestions which may increase or reduce this burden to: Chief Information Policy Branch, PM -223, U.S Environmental Protection Agency, 1200 Pennsylvania Avenue, NW, Washington, DC 20460, or Director, Office of Information and Regulatory Affairs, Office of Management and Budget, Washington, DC 20503 (.Outfall Location For each outfall, list the latitude and longitude of its location to the nearest 15 seconds and the name of the receiving water A. Outfall Number D Receiving Water (list) B Latitude C. Longitude (name) See attached supplemental information II. Improvements A Are you now required by any Federal, State, or local authority to meet any implementation schedule for the construction, upgrading or operation of wastewater tr-atment equipment or practces or any other environmental programs which may affect the discharges described in this application? This includes, but is not limited to permet conditions, administrative or enforcement orders, enforcement compliance schedule letters, stipulations, court orders, and grant or loan conditions. 2. Affected Outfalls 4 Final 1. Identification of Conditions Compliance Date Agreements Etc number source of discharge 3. Brief Description of Project a. req b prof B You may attach additional sheets describing any additional water pollution (or other environmental projects which may affect your discharges) you now have under way or which you plan. Indicate whether each program is now under way or planned, and indicate your actual or planned schedules for construction. III. Site Drainage Map Attach a site map showing topography (or indicating the outline of drainage areas served by the outfalls(s) covered in the application if a topographic map is unavailable) depicting the facility including: each of its intake and discharge structures the drainage area of each storm water outfall; paved areas and buildings within the drainage area of each stone water outfall, each known past or present areas used for outdoor storage.6f disposal of significant materials, each existing structural control measure to reduce pollutants in storm water runoff, materials loading and access areas, areas wher pesticides, herbicides soil conditioners and fertilizers are applied; each of its hazardous waste treatment, storage or disposal units (including each area not required 10 have a RCRA permit which is used for accumulating hazardous waste under 40 CFR 262.34); each well where fluids from the facility are injected underground, springs and other surface water bodies which received stone water discharges from the facility " ^ ' —'. ate' "-4r t' -'Z) Page 1 of 3 Continue on Page 2 Continued from the Front IV. Narrative Description of Pollutant Sources A. For each outfall, provide an estimate of the area (include units) of imperious surfaces (including paved areas and building roofs) drained to the outfall, and an estimate of the total surface area drained by the outfall Outfall Number Area of Impervious Surface (provide units) Total Area Drained (provide units) Outfall Number Area of Impervious Surface (provide units) Total Area Drained (provide units) See attached supplemental information B. Provide a narrative description of significant materials that are currently or in the past three years have been treated, stored or disposed in a manner to allow exposure I to storm water; method of treatment, storage, or disposal; past and present materials management practices employed to minimize contact by these materials with storm water runoff; materials loading and access areas, and the location, manner, and frequency in which pesticides, herbicides, soil conditioners and fertilizers are applied. attached supplemental information C. For each outfall, provide the location and a description of existing structural and nonstructural control measures to reduce pollutants in storm water runoff; and a description of the treatment the storm water receives, including the schedule and type of maintenance for control and treatment measures and the ultimate disposal of any solid or fluid wastes other than by discharge. Outfall I List Codes from Number Treatment Table 2F 1 See attached supplemental information Nonstormwater Discha A. I certify under penalty of law hat the outfall(s) covered by this application have been tested or evaluated for the presence of nonstormwater discharges, and that all nonstormwater discharged from these outfall(s) are identified in either an accompanying Form 2C or From 2E application for the outfall. Name and Official Title (type or print) Signature/ Q.44=" Date Signed Eric Matthews - General Manager II 1I/l -r 9/ZsllA/ B. Provide a description of the method used, the date of any testing, and the onsite drainage points that were directly observed during a test. sual inspection was performed on August 28, 2014. Stormwater outfalls were inspected following a period of dry weather of at eat 72 hours duration. NPDES discharges of process water were excluded. Non-stormwater discharge flows were observed only at 014 and at one 10 inch diameter CMP within the outfall group for Drainage Area 13. The flow source at both of these outfalls believed to be groundwater. Leaks or S Provide existing information regarding the history of significant leaks or spills of toxic or hazardous pollutants at the facility in the last three years, including the approximate date and location of the spill or leak, and the type and amount of material released. n the past three years there have been no significant spills or leaks of hazardous substances ities set forth by Section 311 of the Clean Water Act or Section 102 of CERCLA. excess of reportable EPA Forth 3510-2F (1-92) Page 2 of 3 Continue on Page 3 Continued from Paae 2 1 EPA ID Number (copy from Item 1 of Form 1) II. Discharge Information A, B, C &D See instructions before proceeding. Complete one set of tables for each outfall. Annotate the outfall number in the space provided. Table VII -A VII•H, VII -C are included on separate sheets numbers VII -1 and VII -2. E Potential discharges not covered by analysis — is any toxic pollutant listed in table 2F-2, 2F-3, or 2F-4, a substance or a component of a substance which you currently use or manufacture as an intermediate or final product or byproduct? ❑ Yes (list all such pollutants below) 0 No (go to Section IX) VIII. Biological Toxicity Testing Data Do you have any knowledge or reason to believe that any biological test to acute or chronic toxicity has been made on any of your discharges or on a receiving water relation to your discharge within the last 3 years? in ❑ Yes (list all such pollutants below) Q✓ No (go to Section IX) IX. Contract Analysis Information Were any of the analyses reported in Item VII performed by a contract laboratory or consulting firth? © Yes (list the name, address, and telephone number of, and pollutants No (go to Secfion X) analyzed by, each such laboratory or firm below) A. Name B. Address C. Area Code & Phone No D. Pollutant Analyzed Pace Analytical Services, Inc. 9800 Kincey Avenue, Suite 100 (704) 875-9092 _ Huntersville, NC 28078 X. Certification I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance wth a : ystem designed to assure that qualified personnel properly gather and evaluate the information submitted Based inquiry on my of the person or persons who manage the system or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. A. Name & Official Title (Type OrPnnt) B. Area Code and Phone No. Eric Matthews - General Manager II (704) 829-2400 C. Signature 0-44 D. Date Signed %/!-5N EPA Form 3510-2F (1-92) Page 3 of 3 EPA ID Number (copy from Item 1 of Form 1) Form Approved. OMB No. 2040-0086 VII. Discharge information (Continued from page 3 of Form 2F) Mppruval expires Part A — You must provide the results of at least one analysis for every pollutant in this table Complete one table for each outfall. See instructions for add tional details. Pollutant and CAS Number (ifavailab/e) Maximum Values (include units) Average Values (include units) Number of Storm Events Sampled Sources of Pollutants Grab Sample Taken During First 20 Minutes Flow -Weighted Composite Grab Sample Taken During First 20 Minutes Flow -Weighted Composite Oil and Grease N/A See attached supplemen Biological Oxygen Demand (BODS) information Chemical Oxygen Demand (COD) Total Suspended Solids (TSS) Total Nitrogen Total Phosphorus pH Minimum Maximum Minimum Maximum Part B — List each pollutant that is limited in an effluent guideline which the facility is subject to or any pollutant listed in the facility's NPDES permit for its process wastewater (if the facility is operating under an existing NPDES permit). Complete one table for each outfall. See the instructions for additional details and requirements. Max mum Values Average Values (include units) (include units) Pollutant Grab Sample Grab Sample and Taken During Taken During CAS Number First 20 Flow -Weighted First 20 Flow -Weighted (if available) Minutes Composite Minutes Composite Number of Storm Events Sampled Sources of Pollutants See attached supplemental information �.... i jai u-cr t -yc/ Page VII -1 Continue on Reverse Continued from the Front Part C - List each pollutant shown in Table 2F-2, 2F-3, and 2F4 that you know or have reason to believe is present See the instructions for additional details and requirements Complete one table for each outfall. Maximum Values Average Values (include units) (include units) Number Pollutant Grab Sample Grab Sample of and Taken During Taken During Storrs CAS Number First 20 low, Weighted First 20 Flow -Weighted Events (if available) Minutes Composite Mmute; Compo%ite Sampled Sources of Pollutants See attached supplemental information Part D Provide data for the storm event(s) which resulted in the max_mum values for the flow weighted composite sample. 1 Date of Storm Event 2. Duration of Storm Event (in minutes) 3 Total rainfall during storm event (in niche:) 4 Number of hours between beginning of storm measured and end of previous measurable rain event 5. Maximum flow rate during rain event (gallons/minute or specify units) 6 Total flow from rain event (gallons or specify unit:) See attached supplemental information 7. Provide a description of the method of flow measurement or estimate. See accacnea suppiementai information EPA Form 3510-2F (1-92) Page VII -2 ALLEN STEAM STATION Stormwater Discharge Permit Application Form 2F Supplemental Information NPDES Permit #NC0004979 GENERAL SITE INFORMATION Allen Steam Station is a fossil -fueled, electric generating plant located approximately four miles southeast of Belmont, North Carolina, in Gaston County. The facility has five active coal-fired generating units with a net generating capacity of 1,155 megawatts. Power production originally began at the site in 1957. In addition to the generation units, the station includes a Flue Gas Desulfurization (FGD) facility, a dry ash handling facility, an active ash settling basin, an ash landfill, ash structural fills, a limestone unloading and stockpile operation, a gypsum stacker and storage operation, a wastewater treatment plant, a 115 kV electrical switchyard, a 230 kV electrical switchyard, a station transformer yard, a coal handling operation and storage yard, and various storage and maintenance buildings. The Allen Steam Station property encompasses approximately 953 contiguous acres along the Catawba River in the headwaters of Lake Wylie. The station powerhouse and surrounding plant yard, the coal pile, the switchyards, and associated material and equipment storage areas encompass approximately 65 acres. The FGD facility, including the dry ash handling facility, limestone unloading and stockpile operation, gypsum stacker and storage operation, wastewater treatment plant, and all associated FGD construction laydown areas, and parking areas encompass approximately 56 acres. The remaining property is comprised of active and retired ash settling basins, an ash landfill, ash structural fills, and undeveloped areas. The site contains approximately 5 miles of rail lines and approximately 2 miles of paved roadways. Coal and limestone are shipped to the site via these rail lines. The active ash settling basin has a surface area of approximately 176 acres and a total watershed of approximately 300 acres. Ash is sluiced to the northern section of the basin and discharged into one of three rotating cells. Approximately 64 acres that were previously occupied by a retired ash settling basin are currently the site of an active ash landfill operation. In developed areas of the property, runoff generally flows overland to ditches and catch basins which are connected to a buried network of corrugated metal pipes (CMP). Concrete, cast iron pipes (CIP), and high-density polyethylene (HDPE) pipes also serve as discharge structures. In most areas, this collected runoff discharges into a system of sumps that pump to the ash settling basin. Areas of the site where stormwater is collected by sumps include areas surrounding the Powerhouse, the coal pile and coal handling areas, the FGD facility, the dry ash handling facility, the limestone unloading area, the gypsum storage area, the wastewater treatment system (WWTS), and the ash landfill. Stormwater runoff from the station transformer yard and the 115 kV switchyard is routed through oil trap tanks prior to being discharged. Stormwater runoff from all remaining areas of the site is discharged directly to the Catawba River via overland flow or subsurface drain piping. Allen Steam Station maintains an up-to-date Spill Prevention Control and Countermeasure (SPCC) Plan in place in accordance with the U.S. Environmental Protection Agency (USEPA) Oil Pollution Prevention Regulation 40 CFR Part 112. NPDES PERMITTED DISCHARGES SUMMARY Allen Steam Station has seven NPDES process water outfalls. The NPDES discharges are summarized as follows: NPDES Outfall 001 — Once -Through Cooling Water This discharge is a once -through non -contact cooling water system that condenses steam from the plant condensers. This discharge occurs at the station discharge canal. NPDES Outfall 002 — Ash Settling Basin Discharge This is the outflow from the ash settling basin. While most of the ash is conveyed to the dry ash handling facility, some residual ash is sluiced to the ash settling basins. All of the station stormwater collection sumps discharge to the ash settling basin. This includes runoff from the coal pile and the plant yard, from the FGD facility, from the limestone and gypsum operations, and from the ash landfill. The ash settling basin also receives discharges of industrial wastewater from powerhouse equipment, effluent from the septic system, and process wastewater from the wastewater treatment system. NPDES Outfall 002a — Coal Yard Sump Overflow Should the pumps in the Coal Yard Sump lose power, experience a mechanical failure, or become inundated during a large storm event, the sump would overflow through a corrugated metal pipe to the Catawba River. Overflow from this sump is not a normal occurrence. NPDES Outfall 002b — Powerhouse Yard Sump Overflow Should the pumps in the Powerhouse Yard Sump lose power, experience a mechanical failure, or become inundated during a large storm event, the sump would overflow overland to the Catawba River. Overflow from this sump is not a normal occurrence. NPDES Outfall 003 — Miscellaneous Non -Contact Cooling Water This is non -contact cooling water from miscellaneous plant equipment. This cooling water flows through the north oil trap tank prior to being discharged through stormwater outfall SW012 into the plant discharge canal. During a rainfall event, this discharge will co -mingle with SW012 stormwater discharge. NPDES Outfall 004 — Miscellaneous Cooling and Wash Water This discharge contains miscellaneous non -contact cooling water from plant equipment, vehicle wash water, and intake screen backwash water. Raw river water is used to backwash the condenser cooling water intake screens to remove debris. The debris typically consists of twigs, leaves, and other materials indigenous to the river. This discharge occurs through stormwater outfall SW011 and co -mingles with stormwater during a rainfall event. NPDES Internal Outfall 005 — Internal Outfall from Wastewater Treatment System This is an internal outfall from the wastewater treatment system (WWTS) to the ash settling basin and is composed of treated FGD scrubber wastewater. 2 STORMWATER OUTFALLS AND DRAINAGE AREA DESCRIPTIONS This section details drainage basin characteristics of 20 identified stormwater outfalls at Allen Steam Station (two of these are identified as outfall groups) that discharge to surface waters. The outfall locations and contributing drainage area delineations are shown on the accompanying site plan. All identified stormwater outfalls discharge into the Catawba River in the headwaters of Lake Wylie. Fourteen outfalls (including one outfall group) discharge in the region of the plant intake structure. Six outfalls (including one outfall group) discharge into the plant discharge canal. A description of the contributing drainage area for each outfall is provided below. Included with the description is the approximate location coordinates of the outfall, the amount of impervious surface area within the drainage area, any significant materials and activities within the drainage area, the type of discharge conveyance, and a description of any discharge control measures. The yards' sump systems have also been characterized to provide a complete description of the stormwater drainage system. Additional outfalls have been excluded because either they have been abandoned or because they are not located within the vicinity of the station or any industrial activity. In addition to any significant materials particular to each drainage basin, herbicides are applied to selected areas at Allen Steam Station to eliminate undesirable vegetation. Herbicides are generally used along railways, ash pipelines, and the perimeter fence. Herbicides are also applied, as needed, in the gravel parking lots, switchyard, and laydown areas. Herbicides are sprayed around the fuel oil bulk storage tanks, yard sumps, transformers, trailers, and the intake structure. All herbicides used at Allen Steam Station are approved by the company and considered safe to the environment when used according to directions. Records are retained at the facility documenting the areas treated, and the type and amount of herbicides used. Certain stormwater outfall drainage areas share similarities regarding significant materials and/or activities. Based on these similarities, stormwater discharges from certain groups of outfalls can be represented by the discharge of a designated representative outfall within the group. Outfall SW001 and SW001A (Drainage Area 1) Discharge Structures: 10 -inch -diameter CMP — SW001 12 -inch -diameter CIP — SW001A Location: North of Station Intake Coordinates: 350 11' 47.45" N 81 ° 00' 33.15" W Drainage Area: 6 acres Impervious Area: 0% Area Description The drainage area for SW001 and SW001A includes approximately 2,000 linear feet of rail lines and undeveloped wooded areas upland of the railroad tracks. This drainage area also includes approximately 345 feet of gravel road. There are no impervious surfaces in Drainage Area 1. Stormwater runoff from a strip of wooded area east of the rail lines occurs as sheet flow to the river. Significant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 1. 3 Discharge Controls None. Outfall SW002 (Drainage Area 2) Discharge Structure: 24 -inch -diameter CMP Location: North of Station Intake Coordinates: 350 11'42.66" N 81 ° 00' 31.86" W Drainage Area: 10.8 acres Impervious Area: 2% Area Description The drainage area for SW002 is comprised of primarily upland wooded areas west of the rail lines. The drainage area also includes a 2.5 -acre graveled FGD facility construction laydown yard and approximately 1,000 feet of paved road. A stormwater detention basin is present immediately down -gradient of the gravel laydown yard. Significant Materials Inert Materials: Various quantities of structural steel, cable, truck trailers, and other inert materials may be stored on the gravel yard area at various times. Discharge Controls None. Outfall SW003 (Drainage Area 3) Discharge Structure: 18 -inch -diameter HDPE Pipe Location: North of Station Intake Coordinates: 350 11' 42.60" N 81 ° 00' 31.64" W Drainage Area: 0.8 acre Impervious Area: 0% Area Description The drainage area for SW003 is comprised entirely of a small flat area that includes approximately 1,500 linear feet of rail lines. Significant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 3. Discharge Controls None. Outfall SW004 (Drainage Area 4) Discharge Structure: 10 -inch -diameter CIP Location: North of Station Intake Coordinates: 350 11' 39.01" N 81° 00' 28.11" W Drainage Area: 1.3 acres Impervious Area: 0% Area Description 4 The drainage area for SW004 is located east of the rail lines and north of the limestone unloading area, and is comprised of a small, flat, graveled area with a vegetated berm forming the northeastern boundary. Significant Materials/ Controls None. Discharge Controls None. Outfall SW006 (Drainage Area 6) Discharge Structure: 10 -inch -diameter CIP Location: North of Station Intake Coordinates: 350 11' 37.32" N 81 ° 00' 27.58" W Drainage Area: 0.9 acre Impervious Area: 0% Area Description The drainage area for SW006 is comprised entirely of a small flat graveled area east of the limestone unloading area. Significant Materials/ Controls None. Discharge Controls None. Outfall SW007 (Drainage Area 7) Discharge Structure: 18 -inch -diameter CMP Location: North of Station Intake Coordinates: 350 11' 33.50" N 81 ° 00' 26.36" W Drainage Area: 5 acres Impervious Area: 2% Area Description The drainage area for SW007 is comprised of the vegetated embankment slope east of the FGD facility, rail lines, and graveled yard areas adjacent to and extending south from the limestone unloading building. The drainage area includes approximately 1,500 linear feet of rail lines, 400 linear feet of gravel roadway, and 400 linear feet of limestone conveyor. Significant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 7. Limestone is transferred via conveyor through the area from the limestone unloading building to the limestone stockpile area. Discharge Controls None. Outfall SW008 (Drainage Area 8) Discharge Structure: 24 -inch -diameter CMP Location: North of Station Intake 5 Coordinates: Drainage Area: Impervious Area 350 11' 30.03" N 81 ° 00' 26.85" W 4.1 acres 6% Area Description The drainage area for SW008 is comprised primarily of rail lines and a gravel storage yard located south of the limestone stockpile area and south of the North Warehouse. The area contains approximately 2,400 linear feet of rail lines and approximately 1,000 linear feet of paved roadway. Drainage Area 8 also includes a small portion of the vegetated embankment slope east of the FGD facility. nificant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 8. Inert Materials: Various quantities of structural steel, cable, spare equipment, and other inert materials may be stored on the gravel storage yard area at various times. Discharge Controls None. Outfall SW009 (Drainage Area 9) Discharge Structure: 3 -foot -wide Concrete Ditch Location: North of Station Intake Coordinates: 35° 11' 26.67" N 81' 00'28.90" W Drainage Area: 0.6 acre Impervious Area: 0% Area Description The drainage area for SW009 is comprised of rail lines immediately east of the Powerhouse and a grassed embankment located between the rail lines and the intake structure. The area contains approximately 940 linear feet of rail lines. The station debris and clam filter is located within this drainage area. The backwash from this filter is designed to discharge through a pipe directly to the Catawba River. Occasionally the filter backwash will overflow and flow overland to a discharge point near the SW009 ditch outlet point; however, the overflow does not co -mingle with the SW009 stormwater discharge. Significant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 9. Discharge Controls None. Outfall SW010 (Drainage Area 10) Discharge Structure: 12 -inch -diameter CMP Location: South of Station Intake Coordinates: 350 11' 23.46" N 81 ° 00' 27.50" W Drainage Area: 0.7 acre Impervious Area: 0% L:1 Area Description The drainage area for SW010 is comprised of rail lines immediately east of the Powerhouse and a grassed embankment located between the rail lines and the intake structure. The area contains approximately 1,280 linear feet of rail lines. Significant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 10. Discharge Controls None. Outfall SW011 (Drainage Area 11) Discharge Structure: 72 -inch -diameter CMP Location: South of Station Intake Coordinates: 350 11' 21.1" N 81° 00' 24.0" W Drainage Area: 13.4 acres Impervious Area: 50% Area Description The drainage area for SW011 is primarily comprised of developed areas south and southwest of the station Powerhouse. The drainage area includes approximately 5.3 acres of impervious areas comprised of roof drainage from portions of the Powerhouse, the Machine Shop, the Service Building, the Lower Warehouse, the Air Compressor Building, and the Coal Unloading Hopper Building; and from paved parking areas and the station access road. The drainage area also includes approximately 3,100 linear feet of rail lines, approximately 1,600 linear feet of ash sluice piping, and some minor vegetated areas. Included within Drainage Area 11 are six large transformers located in the station transformer yard, and various types of electrical equipment located in the station 11 5k switchyard. All equipment located in these areas is within curbed gravel -surfaced containments with open drains that route stormwater into a 65,300 -gallon oil trap tank located east of the switchyard. The discharge from this oil trap tank occurs through Outfall SW011. A 500 -gallon -capacity aboveground, carbon steel gasoline tent tank is located within the Outfall SW011 drainage area. The tank is completely enclosed within a steel tent enclosure. Uncontained tanker unloading by a 1,500 -gallon tanker truck occurs adjacent to this gasoline tank. An air compressor containing 70 gallons of lube oil is located inside the Air Compressor Building. Drainage Area 11 also includes a black start diesel generator unit located adjacent to the Air Compressor Building. The generator is a self-contained unit. Uncontained tanker unloading occurs adjacent to the generator unit. The 65,300 -gallon oil trap tank processes stormwater from the contained areas of transformer yard and the 115 kV switchyard only. All other stormwater within Drainage Area 11 discharges directly through Outfall SW011. Stormwater discharged through Outfall SW011 is also co - mingled with NPDES Outfall 004 that includes miscellaneous non -contact cooling water from plant equipment, vehicle wash water, and intake screen backwash. Significant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 11. Coal is handled inside the Coal Unloading Hopper Building within Drainage Area 11. 7 Oil: Mineral oil is stored inside six large station transformers in the transformer yard and in other smaller transformers and circuit breakers in the 115 kV switchyard. This equipment is located within curbed gravel -filled containments with open drains that discharge into the 65,500 -gallon oil trap tank. The largest of these transformers contains 9,715 gallons of mineral oil, with the total quantity of mineral oil contained in all the electrical equipment being approximately 68,000 gallons. Seventy gallons of lube oil is stored in the air compressor located in the Air Compressor Building. Tanker unloading for the black start diesel generator occurs adjacent to the generator unit. Gasoline: Up to 500 gallons of gasoline is stored in the gasoline tent tank. The tank is within integral containment. Tanker unloading operations are conducted periodically at the 500 -gallon gasoline tent tank. Inert Materials: Various quantities of structural steel, cable, spare equipment, and other inert materials may be stored on a concrete laydown yard adjacent to the Warehouse at various times. Discharge Controls A 65,300 -gallon oil trap tank is available for the oil -filled electrical equipment located in the transformer yard and in the 115 kV switchyard. Outfall SW012 (Drainage Area 12) Discharge Structure: 36 -inch -diameter CMP Location: Discharge Canal Coordinates: 350 11' 23.22" N 81 ° 00' 43.53" W Drainage Area: 12.4 acres Impervious Area: 5% Area Description The drainage area for SW012 is primarily comprised of gravel -covered surfaces or vegetated yard areas west of the station Powerhouse. The drainage area includes the remaining portions of the transformer yard not included within Drainage Area 11, and the entire gravel -surfaced 230 kV switchyard. Ten large transformers are located within this portion of the transformer yard. These transformers are located in a curbed gravel -surfaced containment that discharges stormwater via subsurface drain piping into a 100,000 -gallon oil trap tank located between the Powerhouse and the switchyard. The discharge from this oil trap tank occurs through Outfall SW012. The 230 kV switchyard contains no oil -filled equipment. Stormwater runoff from the switchyard discharges into the Outfall SW012 subsurface drainage system downstream of the oil trap tank. The drainage area also includes approximately 1,400 linear feet of out -of -service rail lines, approximately 300 linear feet of paved road, approximately 800 linear feet of ash sluice piping, and the vegetated southern embankment of the FGD facility yard. Ash haul trucks use the section of the paved road that passes through the SW012 drainage area. The trucks are loaded with ash at the dry ash handling facility located up -gradient from the drainage area. Stormwater runoff from within the ash handling facility is directed into a sump that pumps to the ash settling basin. Stormwater discharged through Outfall SW012 is also co -mingled with NPDES Outfall 003 that includes miscellaneous non -contact cooling water from plant equipment. The NPDES discharge is routed through the oil trap tank prior to discharge through SW012. Stormwater runoff from non oil -containing areas with Drainage Area 12 is not processed through the oil trap tank. 0 Significant Materials Oil: Mineral oil is stored inside 10 large station transformers in the transformer yard. This equipment is located within a curbed gravel -filled containment with open drains that discharge into the 100,000 -gallon oil trap tank. The largest of these transformers contains 16,000 gallons of mineral oil, with the total quantity of mineral oil contained in all 10 transformers being approximately 77,000 gallons. Ash: Flyash is transported through ash sluice piping and in ash haul trucks that are loaded at the ash handling facility. Discharge Controls A 100,000 -gallon oil trap tank is available for the 10 transformers in the transformer yard. Outfall Group SW013 (Drainage Area 13) Discharge Structure: Thirteen 10 -inch -diameter CMPs Location: Every 200 feet along the rail lines south of the coal yard Coordinates: 350 10'55.61" N 81° 00' 21.06" W (Representative Outfall) Drainage Area: 3.9 acres Impervious Area: 0% Area Description The drainage area for Outfall Group SW013 is comprised of a narrow strip of land along the Catawba River south of the coal yard, between the ash landfill and the river. The drainage area is approximately 2,400 feet long and includes approximately 2,400 linear feet of gravel road and approximately 7,500 linear feet of rail lines. The group contains 13 outfalls spaced approximately 200 feet apart that drain the rail lines and the eastern vegetated slopes of the ash landfill. These outfalls are located every 200 feet along the railroad tracks in front of the coal composition products (CCP) landfill. The outfalls discharge onto the heavily wooded bank along the rivers edge. One outfall is identified as accessible and recommended for sampling. Significant Materials Coal and Limestone: Train cars carrying coal and limestone use the rail lines that pass through Drainage Area 13. Discharge Controls None. Outfall SW015 (Drainage Area 15) Discharge Structure: 36 -inch -diameter Reinforced Concrete Pipe (RCP) Location: Between the ash landfill and the ash settling basin Coordinates: 350 10'52.75" N 81° 00'21.01" W Drainage Area: 170 acres Impervious Area: 0% Area Description The drainage area for SW015 encompasses a large area west of the ash landfill site. The area includes a large soil borrow area; two ash structural fill areas; the eastern, western, and southern vegetated embankments of the ash landfill; and approximately 1 mile of gravel and dirt roads. Approximately 2,000 linear feet of gravel road within the drainage area is used by ash haul trucks to transport ash from the dry ash handling facility to the ash landfill. 9 All stormwater runoff from the SW015 drainage area is collected within an elongated detention pond system located along the southern boundary of the ash landfill. Collected stormwater discharges through a riser/skimmer system to the Catawba River beneath the rail lines to the east and through the drainage area of the SWO13 Group. Significant Materials Ash: Flyash is transported in ash haul trucks that pass through the area from the dry ash handling facility. Discharge Controls None. Outfall SW016 (Drainage Area 16) Discharge Structure: 36 -inch -diameter CMP Location: Discharge Canal Coordinates: 350 11' 22.30" N 81 ° 00' 44.88" W Drainage Area: 21.8 acres Impervious Area: 2% Area Description The drainage area for SW016 encompasses primarily vegetated upland areas along the site access road south of the discharge canal. The drainage area includes approximately 1,700 feet of the site paved access road, and approximately 1,000 linear feet of the paved ash haul road. Ash haul trucks use the ash haul road to transport ash from the dry ash handling facility to the ash landfill. The drainage area also includes an additional 700 linear feet of paved road south of the access road, approximately 1,000 linear feet of dirt roads north of the access road, and a gravel -surfaced laydown and equipment parking area north of the access road. Significant Materials Ash: Flyash is transported in ash haul trucks that use the ash haul road. Inert Materials: Various quantities of structural steel, cable, truck trailers, and other inert materials may be stored on the gravel laydown yard area at various times. Discharge Controls None. Outfall SW018 (Drainage Area 18) Discharge Structure: 48 -inch -diameter CMP Location: Discharge Canal Coordinates: 350 11' 24.96" N 81 ° 00' 48.03" W Drainage Area: 91.6 acres (on-site) Impervious Area: 1% Area Description The drainage area for SW018 encompasses a large area north of the plant discharge canal and west of the FGD facility. The watershed for Drainage Area 18 also extends into a large area off- site to the north of the Allen Steam Station property. This off-site watershed area is comprised of woodlands and residential properties north of the station and east of Highway 273. A perennial stream originating off-site flows through Drainage Area 18 to Outfall SW018. 10 The drainage area includes approximately 2,000 linear feet of paved access road from Highway 273 to the FGD facility, and approximately 250 linear feet of the paved ash haul road. Ash haul trucks use the ash haul road to transport ash from the dry ash handling facility to the ash landfill. Stormwater runoff from within the ash handling facility is directed into a sump that pumps to the ash settling basin. Gypsum haul trucks use the FGD facility access road to transport gypsum off-site from the FGD facility. The area includes approximately 150 linear feet of ash sluice piping from the Powerhouse to the ash handling facility, and the gravel -surfaced CT2 Tap switchyard located east of the ash handling facility. Drainage Area 18 also includes a portion of an earth spoil area associated with construction of the FGD facility, and gravel parking areas used for parking and storage during construction of the FGD facility. Significant Materials Ash: Flyash is transported in ash haul trucks that use the short section of the ash haul road that passes through Drainage Area 18. Gypsum: Gypsum is transported in gypsum haul trucks along the FGD facility access road. Discharge Controls None. Outfall SW019 (Drainage Area 19) Discharge Structure: 48 -inch -diameter CMP Location: Discharge Canal Coordinates: 350 11' 24.64" N 81 ° 00' 52.90" W Drainage Area: 32.8 acres Impervious Area: 0% Area Description The drainage area for SW019 encompasses an undeveloped area located between the discharge canal to the north and the plant access road to the south. An active soil borrow area is located in the western end of the drainage area. All stormwater runoff from this borrow area is directed to a sediment basin located northeast of the borrow area. The remaining portions of this drainage area are grassed or wooded. Significant Materials/ Controls None. Discharge Controls None. Outfall SW020 (Drainage Area 20) Discharge Structure: 48 -inch -diameter Concrete Pipe (Inlet) Location: Discharge Canal Coordinates: 350 11' 31.14" N 81 ° 1' 20.02" W Drainage Area: 15.7 acres Impervious Area: 0% Area Description The drainage area for SW020 is comprised of upland areas west of Drainage Area 18 and located on both sides of the paved FGD facility access road. Approximately 1,300 feet of paved 11 access road passes through the center of the drainage area. Gypsum haul trucks use the road to transport gypsum off-site from the FGD facility. Drainage Area 20 also includes a portion of an earth spoil area associated with construction of the FGD facility, and a gravel parking area used for parking and storage during construction of the FGD facility. The outlet to the discharge canal was inaccessible and not located in the field. The 48 -inch - diameter concrete inlet located north of the of the haul road is recommended for sampling. Significant Materials/ Controls Gypsum: Gypsum is transported in gypsum haul trucks along the FGD facility access road. Discharge Controls None. 12 REMAINING DRAINAGE AREA DESCRIPTIONS This section describes additional non -industrial stormwater runoff areas at Allen Steam Station that discharge into station sumps that pump to the ash settling basin. Also described is a drainage area outfall that was not able to be located after an extensive field reconnaissance. Drainage Area 5 Discharge Structure Location: Coordinates: Drainage Area: Impervious Area: Sheet flow North of Station 350 11' 39.1" N 4.5 acres 2% Intake 81°00'28.1"W Area Description Drainage Area 5 is primarily comprised of a gravel laydown yard and vegetated slopes located west and upland of the limestone unloading area. The gravel laydown yard comprises approximately 3 acres. The drainage area also includes approximately 500 linear feet of paved roadway. A stormwater outfall was believed to convey runoff from Drainage Area 5, however, after an exhaustive search this outfall could not be located. Consequently Drainage Area 5 should be considered to discharge via sheet flow and should be removed from any permitting requirements. Significant Materials Inert Materials: Various quantities of structural steel, cable, truck trailers, and other inert materials may be stored on the gravel laydown yard area at various times. Discharge Controls None. Outfall SW014 (Drainage Area 14) Discharge Structure: 36 -inch -diameter CMP Location: Between the coal yard and the ash landfill Coordinates: 350 11' 21.29" N 81 ° 00' 42.63" W Drainage Area: 3.4 acres Impervious Area: 0% Area Description The drainage area for SW014 is comprised of a narrow strip of land located between the coal yard and the ash landfill. The drainage area is primarily wooded and includes approximately 1,000 linear feet of gravel road. Outfall SW014 (Drainage Area 14) should be removed from any permitting requirements. Significant Materials/ Controls None. Discharge Controls None. 13 Outfall Group SW017 (Drainage Area 17) Discharge Structure: Numerous 12 -inch -diameter CMPs Location: Every 170 feet along both sides of the discharge canal Coordinates: 350 11' 24.51" N 81° 00' 46.59" W (Representative Outfall) Drainage Area: 35.1 acres Impervious Area: 0% Area Description The Outfall Group SW017 drainage area is comprised of a narrow strip of land on both side of the plant discharge canal. The drainage area includes gravel access roads that run along both sides of the entire length of the canal. The numerous SW017 stormwater outlets are spaced approximately 170 feet apart along both sides of the discharge canal and direct runoff from vegetated embankments along the canal, beneath the gravel roads, and into the canal. Outfall Group SW017 should be removed from any permitting requirements. Significant Materials/ Controls None. Discharge Controls None Powerhouse Yard Sump The Powerhouse Yard Sump collects effluents and wastewater from the Unit 5 area inside the Powerhouse, from a portion of the Powerhouse roof, and from yard areas east of the Powerhouse. The sump is located northeast of the Powerhouse and has a contributing total drainage area of 3.6 acres. The drainage area for the Powerhouse Yard Sump includes a 100,000 -gallon fuel oil storage tank within a secondary containment basin, an adjacent curbed tanker truck unloading station. These containments drain to the sump through valved catch basin inlets within the containments. The drainage area for the Powerhouse Yard Sump also includes numerous small transformers for the Units 1-5 precipitators. The maximum mineral oil content of any single transformer is 205 gallons. The Powerhouse Yard Sump discharges into the Yard Drainage Sump (see below). Rarely occurring emergency overflows for the Powerhouse Yard Sump will discharge onto the ground and then flow overland easterly to the Catawba River. This overflow is permitted as NPDES Outfall 002b. Yard Drainage Sump The Yard Drainage Sump receives all effluent from the Powerhouse Yard Sump (above). The Yard Drainage Sump also collects effluents from the turbine room sumps and boiler room sumps located inside the Powerhouse. These interior sumps essentially collect effluents from various areas and equipment located in the Powerhouse. The sump is located east of the coal yard and has a contributing total drainage area of 5.2 acres. The drainage area for the Yard Drainage Sump includes portions of the Powerhouse roof, portions of the coal handling operation, the Maintenance Garage roof, the Warehouse roof, approximately 1,300 linear feet of rail lines, approximately 600 linear feet of ash sluice piping, and other miscellaneous buildings and yard areas east of the coal yard. The drainage area for the Yard Drainage Sump includes the remaining small transformers for the Units 1-5 precipitators (the maximum mineral oil content of any single transformer is 205 gallons), two 270 -gallon -capacity transformers for sump operation, and two 196 -gallon -capacity transformers associated with the coal handling operation. 14 Also located within the contributing drainage area for the Yard Drain Sump are several chemical containers, petroleum containers, and fuel dispensers. A 200 -gallon -capacity kerosene tank is located along an ash sluice trench with open drains to the sump. A 4,500 -gallon -capacity used oil storage tank within a steel containment enclosure is located in the coal handling area. This valved containment also drains to the ash trench and then to the sump. A nominal amount of 55 -gallon drums are stored adjacent to the warehouse, inside the Maintenance Garage, and inside a tractor shed. Fuel oil dispensers are located adjacent to the Maintenance Garage. A 5,000 -gallon sulfuric acid tank is located adjacent to the Warehouse. The tank is maintained within a concrete containment dike with open drains to the aforementioned ash sluice trench. Miscellaneous drums of chemicals are stored inside a covered and locked shed adjacent to the Warehouse. A hazardous waste satellite accumulation area for paints, solvents, and chemicals is located in a covered area adjacent to the Maintenance Garage. The Yard Drainage Sump discharges into the ash settling basin. Rarely occurring emergency overflows for the Yard Drainage Sump will discharge into the Coal Yard Sump (see below). Coal Yard Sump The Coal Yard Sump collects effluent from the station septic system, and collects stormwater runoff from the coal pile and from portions of the coal handling operation. The sump is located east of the coal yard and has a contributing total drainage area of approximately 24 acres. Also located within the drainage area for the Coal Yard Sump are two 270 -gallon -capacity transformers for sump operation, and approximately 800 linear feet of rail lines. The Coal Yard Sump discharges into the ash settling basin. Rarely occurring emergency overflows for the Coal Yard Sump will discharge through a corrugated metal pipe to the Catawba River. This overflow is permitted as NPDES Outfall 002a. FGD Stormwater Sump The FGD Stormwater Sump is located at the FGD facility and routes stormwater to the ash settling basin from the FGD stormwater collection basin. The contributing drainage area for the sump and the stormwater collection basin is approximately 26 acres. Included within this drainage area are the FDG facility buildings, the gypsum stacker operation and storage pile, and the wastewater treatment facility. Stormwater runoff from the dry ash handling facility and the surrounding paved area is also routed to the stormwater collection basin. Effluent from the wastewater treatment facility is discharged independently to ash settling basin as internal NPDES Outfall 005. The drainage area for the FGD Stormwater Sump also includes four large FGD transformers within secondary containment basins. These containments drain through open drains to an oil/water separator that discharges into the stormwater collection basin, and then into the FGD Stormwater Sump. Limestone Unloading Area Sump The Limestone Unloading Area Sump has a contributing drainage area of approximately 6 acres and is located at the limestone unloading operation. The sump drainage area receives stormwater runoff from the roof of the limestone unloading building, from limestone hoppers and conveyors, and from the surrounding gravel -surfaced area. Stormwater runoff is collected within a trench at the eastern edge of the drainage area. This trench discharges into the Limestone Unloading Area Sump that subsequently pumps to the ash setting basin. 15 Ash Landfill Sump The Ash Landfill Sump collects all leachate from the lined ash landfill located south of the Coal Yard and subsequently pumps to the ash settling basin. The landfill encompasses approximately 64 acres. IDENTIFICATION OF NON-STORMWATER DISCHARGES A visual assessment for non-stormwater discharges was conducted on August 28, 2014. Each outfall was observed for outflow after a period of at least 72 hours of dry weather. NPDES discharges of process water were excluded. Non-stormwater discharge flows were observed at SW014 and at a 10 -inch CMP within the outfall group for Drainage Area 13. The source at both of these locations is assumed to be groundwater. Both outfalls were sampled as part of the investigation for the Allen Steam Station - Surface Water Seep Monitoring Report. MONITORING AND SAMPLING Stormwater samples were collected from Outfall SW008 and Outfall SW010 on August 12, 2014. The remaining outfalls at the station will be sampled in due course as qualifying rainfall events occur. After an exhaustive search no outfall was found conveying runoff from Drainage Area 5, consequently runoff from this area will be excluded from any future sampling efforts. Outfall SW014 and Outfall Group SW017 will also be excluded as these drainage areas include no industrial uses associated with the Allen Steam Station. 16 Allen Steam Station Stormwater Monitoring Summary August 2014 Stormwater samples were collected from two stormwater outfalls at Allen Steam Station during a storm event on August 11, 2014 as follows: Date Outfalls SampledRainfall Event Duration Rainfall Amount August 11, 2014 SW -08, SW -10 120 minutest 10.45 inchest tThis information was obtained from a nearby USGS site (#351247080592745). Samples were collected directly into properly preserved bottles and shipped on ice to Duke Energy's analytical laboratory in Huntersville, NC. Analyses were conducted by Duke Energy's Huntersville analytical laboratory (NC Wastewater Certification #248) and Pace Analytical Laboratories (NC Wastewater Certification # 12). Analytical parameters for analysis were: TSS, TDS, Oil &Grease, Cl, SO4, F, COD, Al, As, B, Ba, Ca, Cd, Cu, Cr, Fe, Mn, Mo, Mg, Ni, Pb, Sb, Se, Tl, Zn, Hardness and Hg. Laboratory analytical methods used for each parameter are provided in Appendix A. Storage and preservation techniques of the samples after collection, and prior to analyses, were followed according to Appendix B. Analytical results are summarized in Appendix C. Appendix A Laboratory Analytical Methods Method Reporting Limit Units Lab COD HACH 8000 20 mg/L Duke Energy Chloride EPA 300.0 0.1 mg/L Duke Energy Fluoride EPA 300.0 0.1 mg/L Duke Energy Sulfate EPA 300.0 1 mg/L Duke Energy Oil and Grease EPA 1664B 5 mg/ Pace Analytical Mercury (Hg) EPA 245.1 0.05 µg/L Duke Energy Aluminum (AI) EPA 200.7 0.005 mg/L Duke Energy Barium (Ba) EPA 200.7 0.005 mg/L Duke Energy Boron (B) EPA 200.7 0.05 mg/L Duke Energy Calcium (Ca) EPA 200.7 0.1 mg/L Duke Energy Hardness EPA 200.7 0.19 mg/L (CaCOj Duke Energy Iron (Fe) EPA 200.7 0.01 mg/L Duke Energy Magnesium (Mg) EPA 200.7 0.005 mg/L Duke Energy Manganese (Mn) EPA 200.7 0.005 mg/L Duke Energy Zinc (Zn) EPA 200.7 0.005 mg/L Duke Energy Antimony (Sb) EPA 200.8 1 µg/l- Duke Energy Arsenic (As) EPA 200.8 1 pg/L Duke Energy Cadmium (Cd) EPA 200.8 1 µg/l- Duke Energy Chromium (Cr) EPA 200.8 1 pg/L Duke Energy Copper (Cu) EPA 200.8 1 pg/L Duke Energy Lead (Pb) EPA 200.8 1 µg/l- Duke Energy Molybdenum (Mo) EPA 200.8 1 pg/L Duke Energy Nickel (Ni) EPA 200.8 1 I pg/L Duke Energy Selenium (Se) EPA 200.8 1 µg/l- Duke Energy Thallium (TI) Low Level EPA 200.8 0.2 pg/L Duke Energy TDS SM2540C 25 mg/L Duke Energy TSS SM2540D 7.25 mg/L Duke Energy Appendix B Sample Preservation and Hold Times Parameter name Container' Preservations 33 Maximum holding time' Table IB—Inorganic Tests: 1. Acidity P, FP, G Cool, 56 °C" 14 days. 2. Alkalinity P, FP, G Cool, :56 °C18 14 days. 4. Ammonia P, FP, G Cool, 56 °C", H2SO4 to pH <2 28 days. 9. Biochemical oxygen demand —NEELL.- P, FP, G = Cool, 56 °C" ' 48 hours. 10. Boron P, FP, or Quartz HNO3 to pH <2 6 months. 11. Bromide P, FP, G None required 28 days. 14. Biochemical oxygen demand, carbonaceous P, FP G Cool, 56 °C" 48 hours. 15. Chemical oxygen demand P, FP, G Cool, 56 °C18, H2SO4 to pH <2 28 days. 16. Chloride P, FP, G None required 28 days. 17. Chlorine, total residual P, G None required Analyze within 15 minutes. 21. Color P, FP, G Cool, 56 °C" 48 hours. 23-24. Cyanide, total or available (or CATC) and free P, FP, G Cool, 56 °C18, NaOH to pH >105 14 days. e, reducing agent if oxidizer present 25. Fluoride P None required 28 days. 27. Hardness P, FP, G HNO3 or H2SO4 to pH <2 6 months. 28. Hydrogen ion (pH) P, FP, G None required Analyze within 15 minutes. 31, 43. Kjeldahl and organic N P, FP, G Cool, :56 °C18, H2SO4 to pH <2 28 days. Table IB—Metals:' 18. Chromium VI P, FP, G Cool, 56 °C'8, pH = 9.3-9.7° 28 days. 35. Mercury (CVAA) P, FP, G HNO3 to pH <2 28 days. 35. Mercury (CVAFS) FP, G; and FP- 5 mL/L 12N HCI or 5 mL/L BrCI" 90 days." lined cap" 3, 5-8, 12, 13, 19, 20, 22, 26, 29, 30, 32-34, 36, 37, 45, P, FP, G HNO3 to pH <2, or at least 24 6 months. 47, 51, 52, 58-60, 62, 63, 70-72, 74, 75. Metals, except hours prior to analysis19 boron, chromium VI, and mercury 38. Nitrate P, FP, G Cool, <_6 °C18 48 hours. 39. Nitrate -nitrite P, FP, G Cool, 56 °C18, H2SO4 to pH <2 28 days. 40. Nitrite P, FP, G Cool, 56 °C1' 48 hours. 41. Oil and grease G Cool to 156 °C18, HCl or H2SO4 to 28 days. PH <2 42. Organic Carbon P, FP, G Cool to 56 °C18, HCI, H2SO4, or 28 days. H3PO4 to pH <2 44. Orthophosphate P, FP, G Cool, to 56 °C1824 Filter within 15 minutes; Analyze within 48 hours. 46. Oxygen, Dissolved Probe G, Bottle and top None required Analyze within 15 minutes. 47. Winkler G, Bottle and to Fix on site and store in dark 8 hours. 48. Phenols G Cool, 56 °C18, HISO4 to pH <2 28 days. 49. Phosphorous (elemental) G Cool, 156 °C" 48 hours. 50. Phosphorous, total P, FP, G fi Cool, :56 °C18, H2SO4 to pH <2 28 days. 53. Residue, total P, FP, G Cool, 56 °C18 7 days. 54. Residue, Filterable P, FP, G Cool, 56 °Ce 7 days. 55. Residue, Nonfilterable (TSS) P, FP, G Cool, 56 °C18 7 days. 56. Residue, Settleable P, FP, G Cool, 56 °C18 48 hours. 57. Residue, Volatile P, FP, G Cool, 56 °Ce 7 days. 61. Silica P or Quartz Cool, <_6 °Ct8 28 days. 64. Specific conductance P, FP, G Cool, :56 °C18 28 days. 65. Sulfate P, FP, G Cool, 56 °C1' ' 28 days. 66. Sulfide P, FP, G Cool, 156 °C18, add zinc acetate 7 days. plus sodium hydroxide to pH >9 67. Sulfite P, FP, G None required Analyze within 15 minutes. 68. Surfactants P, FP, G Cool, 56 °C18 48 hours. 69. Temperature P, FP, G None required Analyze. 73. Turbidity P, FP, G Cool, :56 °Ce 48 hours. 1"P" is for polyethylene; "FP" is fluoropolymer (polytetrafluoroethylene (PTFE); Teflon°), or other fluoropolymer, unless stated otherwise in this Table ll; "G" is glass; "PA" is any plastic that is made of a sterilizable material (polypropylene or other autoclavable plastic); "LDPE" is low density polyethylene. 2Except where noted in this Table II and the method for the parameter, preserve each grab sample within 15 minutes of collection. For a composite sample collected with an automated sample (e.g., using a 24-hour composite sample; see 40 CFR 122.21(g)(7)(i) or 40 CFR Part 403, Appendix E), refrigerate the sample at :56 °C during collection unless specified otherwise in this Table II or in the method(s). For a composite sample to be split into separate aliquots for preservation and/or analysis, maintain the sample at 156 °C, unless specified otherwise in this Table II or in the method(s), until collection, splitting, and preservation is completed. Add the preservative to the sample container prior to sample collection when the preservative will not compromise the integrity of a grab sample, a composite sample, or aliquot split from a composite sample within 15 minutes of collection. If a composite measurement is required but a composite sample would compromise sample integrity, individual grab samples must be collected at prescribed time intervals (e.g., 4 samples over the course of a day, at 6 -hour intervals). Grab samples must be analyzed separately and the concentrations averaged. Alternatively, grab samples may be collected in the field and composited in the laboratory if the compositing procedure produces results equivalent to results produced by arithmetic averaging of results of analysis of individual grab samples. For examples of laboratory compositing procedures, see EPA Method 1664 Rev. A (oil and grease) and the procedures at 40 CFR 141.34(f)(14)(iv) and (v) (volatile organics). 3When any sample is to be shipped by common carrier or sent via the U.S. Postal Service, it must comply with the Department of Transportation Hazardous Materials Regulations (49 CFR part 172). The person offering such material for transportation is responsible for ensuring such compliance. For the preservation requirement of Table 11, the Office of Hazardous Materials, Materials Transportation Bureau, Department of Transportation has determined that the Hazardous Materials Regulations do not apply to the following materials: Hydrochloric acid (HCI) in water solutions at concentrations of 0.04% by weight or less (pH about 1.96 or greater; Nitric acid (HNO3) in water solutions at concentrations of 0.15% by weight or less (pH about 1.62 or greater); Sulfuric acid (H2SO4) in water solutions at concentrations of 0.35% by weight or less (pH about 1.15 or greater); and Sodium hydroxide (NaOH) in water solutions at concentrations of 0.080% by weight or less (pH about 12.30 or less). 4Samples should be analyzed as soon as possible after collection. The times listed are the maximum times that samples may be held before the start of analysis and still be considered valid. Samples may be held for longer periods only if the permittee or monitoring laboratory has data on file to show that, for the specific types of samples under study, the analytes are stable for the longer time, and has received a variance from the Regional Administrator under Sec. 136.3(e). For a grab sample, the holding time begins at the time of collection. For a composite sample collected with an automated sampler (e.g., using a 24-hour composite sampler; see 40 CFR 122.21(g)(7)(i) or 40 CFR part 403, Appendix E), the holding time begins at the time of the end of collection of the composite sample. For a set of grab samples composited in the field or laboratory, the holding time begins at the time of collection of the last grab sample in the set. Some samples may not be stable for the maximum time period given in the table. A permittee or monitoring laboratory is obligated to hold the sample for a shorter time if it knows that a shorter time is necessary to maintain sample stability. See 136.3(e) for details. The date and time of collection of an individual grab sample is the date and time at which the sample is collected. For a set of grab samples to be composited, and that are all collected on the same calendar date, the date of collection is the date on which the samples are collected. For a set of grab samples to be composited, and that are collected across two calendar dates, the date of collection is the dates of the two days; e.g., November 14-15. For a composite sample collected automatically on a given date, the date of collection is the date on which the sample is collected. For a composite sample collected automatically, and that is collected across two calendar dates, the date of collection is the dates of the two days; e.g., November 14- 15. For static -renewal toxicity tests, each grab or composite sample may also be used to prepare test solutions for renewal at 24 h, 48 h, and/or 72 h after first use, if stored at 0-6 °C, with minimum head space. 5ASTM D7365 -09a specifies treatment options for samples containing oxidants (e.g., chlorine). Also, Section 9060A of Standard Methods for the Examination of Water and Wastewater (20th and 21st editions) addresses dechlorination procedures. 6Sampling, preservation and mitigating interferences in water samples for analysis of cyanide are described in ASTM D7365 -09a. There may be interferences that are not mitigated by the analytical test methods or D7365 -09a. Any technique for removal or suppression of interference may be employed, provided the laboratory demonstrates that it more accurately measures cyanide through quality control measures described in the analytical test method. Any removal or suppression technique not described in D7365 -09a or the analytical test method must be documented along with supporting data. 7For dissolved metals, filter grab samples within 15 minutes of collection and before adding preservatives. For a composite sample collected with an automated sampler (e.g., using a 24-hour composite sampler; see 40 CFR 122.21(g)(7)(i) or 40 CFR Part 403, Appendix E), filter the sample within 15 minutes after completion of collection and before adding preservatives. If it is known or suspected that dissolved sample integrity will be compromised during collection of a composite sample collected automatically over time (e.g., by interchange of a metal between dissolved and suspended forms), collect and filter grab samples to be composited (footnote 2) in place of a composite sample collected automatically. 8Guidance applies to samples to be analyzed by GC, LC, or GC/MS for specific compounds. 91f the sample is not adjusted to pH 2, then the sample must be analyzed within seven days of sampling. 10The pH adjustment is not required if acrolein will not be measured. Samples for acrolein receiving no pH adjustment must be analyzed within 3days of sampling. "When the extractable analytes of concern fall within a single chemical category, the specified preservative and maximum holding times should be observed for optimum safeguard of sample integrity (i.e., use all necessary preservatives and hold for the shortest time listed). When the analytes of concern fall within two or more chemical categories, the sample may be preserved by cooling to 56 °C, reducing residual chlorine with 0.008% sodium thiosulfate, storing in the dark, and adjusting the pH to 6-9; samples preserved in this manner may be held for seven days before extraction and for forty days after extraction. Exceptions to this optional preservation and holding time procedure are noted in footnote 5 (regarding the requirement for thiosulfate reduction), and footnotes 12, 13 (regarding the analysis of benzidine). 121f 1,2-diphenylhydrazine is likely to be present, adjust the pH of the sample to 4.0 ±0.2 to prevent rearrangement to benzidine. 13Extracts may be stored up to 30 days at <0 °C. 14 For the analysis of diphenylnitrosamine, add 0.008% Na2S2O3 and adjust pH to 7-10 with NaOH within 24 hours of sampling. 15The pH adjustment may be performed upon receipt at the laboratory and may be omitted if the samples are extracted within 72 hours of collection. For the analysis of aldrin, add 0.008% Na2S2O3. 16 Place sufficient ice with the samples in the shipping container to ensure that ice is still present when the samples arrive at the laboratory. However, even if ice is present when the samples arrive, immediately measure the temperature of the samples and confirm that the preservation temperature maximum has not been exceeded. In the isolated cases where it can be documented that this holding temperature cannot be met, the permittee can be given the option of on-site testing or can request a variance. The request for a variance should include supportive data which show that the toxicity of the effluent samples is not reduced because of the increased holding temperature. Aqueous samples must not be frozen. Hand -delivered samples used on the day of collection do not need to be cooled to 0 to 6 °C prior to test initiation. 17 Samples collected for the determination of trace level mercury (<100 ng/L) using EPA Method 1631 must be collected in tightly - capped fluoropolymer or glass bottles and preserved with BrCI or HCI solution within 48 hours of sample collection. The time to preservation may be extended to 28 days if a sample is oxidized in the sample bottle. A sample collected for dissolved trace level mercury should be filtered in the laboratory within 24 hours of the time of collection. However, if circumstances preclude overnight shipment, the sample should be filtered in a designated clean area in the field in accordance with procedures given in Method 1669. If sample integrity will not be maintained by shipment to and filtration in the laboratory, the sample must be filtered in a designated clean area in the field within the time period necessary to maintain sample integrity. A sample that has been collected for determination of total or dissolved trace level mercury must be analyzed within 90 days of sample collection. 18Aqueous samples must be preserved at 56 °C, and should not be frozen unless data demonstrating that sample freezing does not adversely impact sample integrity is maintained on file and accepted as valid by the regulatory authority. Also, for purposes of NPDES monitoring, the specification of "<_°C" is used in place of the "4 °C" and "<4 °C" sample temperature requirements listed in some methods. It is not necessary to measure the sample temperature to three significant figures (1/100th of 1 degree); rather, three significant figures are specified so that rounding down to 6 °C may not be used to meet the :56 °C requirement. The preservation temperature does not apply to samples that are analyzed immediately (less than 15 minutes). 19An aqueous sample may be collected and shipped without acid preservation. However, acid must be added at least 24 hours before analysis to dissolve any metals that adsorb to the container walls. If the sample must be analyzed within 24 hours of collection, add the acid immediately (see footnote 2). Soil and sediment samples do not need to be preserved with acid. The allowances in this footnote supersede the preservation and holding time requirements in the approved metals methods. 20To achieve the 28 -day holding time, use the ammonium sulfate buffer solution specified in EPA Method 218.6. The allowance in this footnote supersedes preservation and holding time requirements in the approved hexavalent chromium methods, unless this supersession would compromise the measurement, in which case requirements in the method must be followed. 21Holding time is calculated from time of sample collection to elution for samples shipped to the laboratory in bulk and calculated from the time of sample filtration to elution for samples filtered in the field. 22 Sample analysis should begin as soon as possible after receipt; sample incubation must be started no later than 8 hours from time of collection. 23 For fecal coliform samples for sewage sludge (biosolids) only, the holding time is extended to 24 hours for the following sample types using either EPA Method 1680 (LTB -EC) or 1681 (A-1): Class A composted, Class B aerobically digested, and Class B anaerobically digested. 24 The immediate filtration requirement in orthophosphate measurement is to assess the dissolved or bio -available form of orthophosphorus (i.e., that which passes through a 0.45 -micron filter), hence the requirement to filter the sample immediately upon collection (i.e., within 15 minutes of collection). [38 FR 28758, Oct. 16, 1973 Appendix C Analytical Data Summary Parameter Units Sample Location SW -08 SW -10 COD mg/L < 20 < 20 Cl - Chloride (00940) mg/L 0.28 0.86 Fluoride mg/L < 0.1 0.13 SO4 - Sulfate (00945) mg/L 55 50 Oil & Grease mg/L < 5 < 5 Hg - Mercury (71900) µg/L < 0.05 < 0.05 Al - Aluminum (01105) mg/L 2.34 0.688 Ba - Barium (01007) mg/L 0.038 0.026 B - Boron (01022) mg/L < 0.05 < 0.05 Ca -Calcium mg/L 33.4 28 Hardness mg/L (CaCO3) 92.7 76.4 Fe - Iron (01045) mg/L 3.61 1.16 Mg -Magnesium mg/L 2.29 1.57 Mn - Manganese (01055) mg/L 0.076 0.02 Zn - Zinc (01092) mg/L 0.048 0.067 Sb - Antimony (01097) µg/l- < 1 < 1 As - Arsenic (01002) pg/L 1.12 1.79 Cd - Cadmium (01027) µg/L < 1 < 1 Cr - Chromium (01034) pg/L 2.5 1.43 Cu - Copper (01042) pg/L 6.87 5.41 Pb - Lead (01051) pg/L 2.32 1.13 Molybdenum (Mo) pg/L 3.44 5.37 Ni - Nickel (01067) pg/L 2.93 < 1 Se - Selenium (01147) pg/L 2.24 7.32 TI - Thallium (01059) pg/L < 0.2 < 0.2 pH SI Units 6.95 6.24 Specific conductance µS/cm 163 174 TDS - Total Diss. Solids (70300) mg/L 130 120 Temperature °C 23.9 23.2 TSS -Total Suspended Solids mg/L 46 12 PropertyST Legend qb YU, -�♦F F -7 ,. 3 aoel Rd'~ Duke Energy Revel °ve Ad µe l'l`Ylip p ¢� 7, Dillard Rd Gaston w p.4d I qb, ��q z onSs I� �• \ \et Fd / Oho \ `b iD i nJ�� •\ F: LLy Valky Rdof Vj •� S as oY`' ice^ pRa v �__ • T, .- (n I - • !.. nn ♦ • � Y rp 't J 13 t •- yVa b 3 vp WesY,Blvd n o 7P S Moorm9 ® SitoraO � � ' � " .r a •�Y\, o QJ � V OR i `. , :;; tE : ♦ ..,, t;ALLEN STEAM STATION ke; y alk : _ - y� � fl ' South Fork Catawba /�"Tz er pw Dor s 1 T� i r',♦ 't� �+ River .rir -.,. Di eaF T. f •+ .� 1 '�',j.. ..s ��_ ,- '�a� k. e1L. . , ��,I,: r I •. � � `.- -.� €♦�� r Mdwood l.n s1 •NEAND ON 7 , F -"� . t •� ^ St R ♦_ ,.,:I�,... .,, Asa i N 6 C;UEEN r .. / 1_.r. - E TATES♦pd_. •. 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' ` y =-tea ' f r,�r I • DETENTION r AREA 81., • / _ --_= r • BASIN S4 I, 1,4° 0 o , OUTFALL SW018_ \\` ♦• a / Z ! c%/' .CS�1Q��NG ^- --_-_ DI SCHARG qN`-�$: ' ` \'i \ `\Ii\` 12 j♦♦♦♦: N OUTFALL • • PC ` \ ` `\`\ SW01 S/ •• O7 vP R - ,, ■ R DRAINAGE AREA 17 pEZG�\JO�/�� �y \ 1 , \ ` , ` NPDE ��✓- ` • DF ♦♦ /G� �,fc.,/moo \ \`: - - �OUTFA� LL `\ rxa OUTFALL 003 y i•,.,' 1( ♦♦ t ' ' STORMWATER/SEDIMENT_; f -.�I`�a ■ \ Ol ♦10 NO ♦ `� I i 1\_`— --_- ` DETENTION BASIN \, `.`I,�,���eu ow C1101 PNp\ _ \\`\\`_`�` \�'. / ,` ,� `\\\\ YARD SUMP : \; ♦ NF OUTFALL /` \ � ♦♦♦ GF I \ i ' 19 \ + SW01 E% �= `\` ' DRAINGE AREA ♦ � \\ \ , 1, \ \ \ yyyyl NPDES• \\\,:' \ 1 \, 4 ♦♦ SSG .' '�',���. r,'/ 1 I I \ ._ ' i 1 OUTFALL 001 CCW \ .• ♦ p SOIL BORROW AREA , , ( ) \\ 5 ♦ , ,' I ASH HAUL ROAD /// ♦ / .///., , . �`\ �` i• ��' ,-- GRAVEL /-- _ , \ .\ \, 11 `— ,_ ■ ri'pi1� .� a _STORAGE AREA_, 16 , _► r a - 1 lit 23' ♦/. / o , 3j1 , o _ • 00 Of/ /, ! / 1 _ \ r , \ \ ! d//'---. Ill �- -`\ .. • SUM 111,, \` , !\ ._ \ l� o \ \ ■r \\ • ;l; i n`` \`-' rl 1 r\_�-j� I�,\_ - o / �`.` e COAL YAR DRAI AGED AREAP \ • SOIL BORROW AREA . ; , ° ° v/% �=__:='.. . �\ �` ;�\ l ,` 1 of ■ % /1 I'/--- I1 p PAW \` �♦,..■ jr 00 IA; No •/' i /�' 1 1 ! / ! I, I 1// `\ \ .a, -, \� /- oa 90 0 00 1 1 -----rrrrTN`crc�� ���������r. F., ■ I / \ if / U' /III \\ 1/ \ 1 1 ) / \ I �,rp /' =/-i ' ! , I1„'_' ' ''lll `_I1��_�, ' //` �_- `_lir ; b/ / \ \ <-'\ orP' °, / ■ [if 14 QVW 1I \ 1 \`'� ` ✓,, ° 0 1 1 _' iii �.' °o °-/ I ■ It _�__-' \ / / 1 , u� '`.-� / '6 / I `_�' / Pim-•1r o ■ ■ ■ ■ / / 1 _ _ I Flo ■ ASH LANDFILL SUMP i ■ �`�� \/.``` i \,: \ _ ”! \`/ h /' �, ASH STRUCTURAL FILL¢ DRAINAGE AREA ■ ■ `-\ G , to \�\ ■ ■ .� o ` J/■ ♦ h I III ♦ . ■ 1111 ♦• � ■■■■•■■■■=■l■I ftl ASH BASIN STORMWATER/SEDIMENT op WATERSHED DETENTION BASINS Nil \t\, PLAN HDR Engineering, Inc. of the Carolinas License Number: F-0116 440 S Church Street, Suite 1000 Charlotte, NC 28202-2075 1 2 3 SCALE: 1"= 400' PE SEAL 4 DATE Via_ AREA 002B SUMP 11/ 004 -S OUTFALL 002A RIVER -IMP (TYP) ALL SWO14 RECOMMENDED SAMPLING) DRAINAGE AREA 13 DRAINAGE AREA OUTFALL DESCRIPTION FGD v••, I� \ STORM TER SUMP r \ I 1 10" CMP �` 1 FGD PROJECT \`1 \ \ ` \` DRAINAGE AREA `,,r\. i 1 \ \ 4 A SPOIL AREA o` ``, y I 4 10" CIP AREA 5 rDRAINAGE CATAWBA RIVER 6 ''_ ' ,+/: \\\\, c r •" f - 0 3 • DRY ASH HANDLING IN/ rE y 10 r ++ i■ SILO DRAINAGE AREAI 1\,`� ■ C w _ • 1N1 OL ==i!__; = c, iI' °� FGD DRAINAGE' I LIN• ,',' . ' ` y =-tea ' f r,�r I • DETENTION r AREA 81., • / _ --_= r • BASIN S4 I, 1,4° 0 o , OUTFALL SW018_ \\` ♦• a / Z ! c%/' .CS�1Q��NG ^- --_-_ DI SCHARG qN`-�$: ' ` \'i \ `\Ii\` 12 j♦♦♦♦: N OUTFALL • • PC ` \ ` `\`\ SW01 S/ •• O7 vP R - ,, ■ R DRAINAGE AREA 17 pEZG�\JO�/�� �y \ 1 , \ ` , ` NPDE ��✓- ` • DF ♦♦ /G� �,fc.,/moo \ \`: - - �OUTFA� LL `\ rxa OUTFALL 003 y i•,.,' 1( ♦♦ t ' ' STORMWATER/SEDIMENT_; f -.�I`�a ■ \ Ol ♦10 NO ♦ `� I i 1\_`— --_- ` DETENTION BASIN \, `.`I,�,���eu ow C1101 PNp\ _ \\`\\`_`�` \�'. / ,` ,� `\\\\ YARD SUMP : \; ♦ NF OUTFALL /` \ � ♦♦♦ GF I \ i ' 19 \ + SW01 E% �= `\` ' DRAINGE AREA ♦ � \\ \ , 1, \ \ \ yyyyl NPDES• \\\,:' \ 1 \, 4 ♦♦ SSG .' '�',���. r,'/ 1 I I \ ._ ' i 1 OUTFALL 001 CCW \ .• ♦ p SOIL BORROW AREA , , ( ) \\ 5 ♦ , ,' I ASH HAUL ROAD /// ♦ / .///., , . �`\ �` i• ��' ,-- GRAVEL /-- _ , \ .\ \, 11 `— ,_ ■ ri'pi1� .� a _STORAGE AREA_, 16 , _► r a - 1 lit 23' ♦/. / o , 3j1 , o _ • 00 Of/ /, ! / 1 _ \ r , \ \ ! d//'---. Ill �- -`\ .. • SUM 111,, \` , !\ ._ \ l� o \ \ ■r \\ • ;l; i n`` \`-' rl 1 r\_�-j� I�,\_ - o / �`.` e COAL YAR DRAI AGED AREAP \ • SOIL BORROW AREA . ; , ° ° v/% �=__:='.. . �\ �` ;�\ l ,` 1 of ■ % /1 I'/--- I1 p PAW \` �♦,..■ jr 00 IA; No •/' i /�' 1 1 ! / ! I, I 1// `\ \ .a, -, \� /- oa 90 0 00 1 1 -----rrrrTN`crc�� ���������r. F., ■ I / \ if / U' /III \\ 1/ \ 1 1 ) / \ I �,rp /' =/-i ' ! , I1„'_' ' ''lll `_I1��_�, ' //` �_- `_lir ; b/ / \ \ <-'\ orP' °, / ■ [if 14 QVW 1I \ 1 \`'� ` ✓,, ° 0 1 1 _' iii �.' °o °-/ I ■ It _�__-' \ / / 1 , u� '`.-� / '6 / I `_�' / Pim-•1r o ■ ■ ■ ■ / / 1 _ _ I Flo ■ ASH LANDFILL SUMP i ■ �`�� \/.``` i \,: \ _ ”! \`/ h /' �, ASH STRUCTURAL FILL¢ DRAINAGE AREA ■ ■ `-\ G , to \�\ ■ ■ .� o ` J/■ ♦ h I III ♦ . ■ 1111 ♦• � ■■■■•■■■■=■l■I ftl ASH BASIN STORMWATER/SEDIMENT op WATERSHED DETENTION BASINS Nil \t\, PLAN HDR Engineering, Inc. of the Carolinas License Number: F-0116 440 S Church Street, Suite 1000 Charlotte, NC 28202-2075 1 2 3 SCALE: 1"= 400' PE SEAL 4 DATE Via_ AREA 002B SUMP 11/ 004 -S OUTFALL 002A RIVER -IMP (TYP) ALL SWO14 RECOMMENDED SAMPLING) DRAINAGE AREA 13 DRAINAGE AREA OUTFALL DESCRIPTION FGD v••, I� \ STORM TER SUMP r \ I 1 10" CMP �` 1 FGD PROJECT \`1 \ \ ` \` DRAINAGE AREA `,,r\. i 1 \ \ 4 24" CMP SPOIL AREA o` ``, y I 4 10" CIP CATAWBA RIVER 5 DRAINAGE CATAWBA RIVER 6 ''_ ' ,+/: \\\\, c r •" s AREA 5 DRAINAGE i\\1\ '; 20 ° 18 `�•` \ � � �, AREA JI S " i' �` / !+/ PERENNIAL STREAM • I\' • ` >>�'® �'"> CATAWBA RIVER OUTFALL SW020 I 13 FOURTEEN 10" CMP CATAWBA RIVER INLET) 36" CMP GRAVEL PARKING AREAif 36" RCP CATAWBA RIVER 0 3 • DRY ASH HANDLING IN/ rE y 10 r ++ i■ SILO DRAINAGE AREAI 1\,`� ■ C w _ • 1N1 OL ==i!__; = c, iI' °� FGD DRAINAGE' I LIN• ,',' . ' ` y =-tea ' f r,�r I • DETENTION r AREA 81., • / _ --_= r • BASIN S4 I, 1,4° 0 o , OUTFALL SW018_ \\` ♦• a / Z ! c%/' .CS�1Q��NG ^- --_-_ DI SCHARG qN`-�$: ' ` \'i \ `\Ii\` 12 j♦♦♦♦: N OUTFALL • • PC ` \ ` `\`\ SW01 S/ •• O7 vP R - ,, ■ R DRAINAGE AREA 17 pEZG�\JO�/�� �y \ 1 , \ ` , ` NPDE ��✓- ` • DF ♦♦ /G� �,fc.,/moo \ \`: - - �OUTFA� LL `\ rxa OUTFALL 003 y i•,.,' 1( ♦♦ t ' ' STORMWATER/SEDIMENT_; f -.�I`�a ■ \ Ol ♦10 NO ♦ `� I i 1\_`— --_- ` DETENTION BASIN \, `.`I,�,���eu ow C1101 PNp\ _ \\`\\`_`�` \�'. / ,` ,� `\\\\ YARD SUMP : \; ♦ NF OUTFALL /` \ � ♦♦♦ GF I \ i ' 19 \ + SW01 E% �= `\` ' DRAINGE AREA ♦ � \\ \ , 1, \ \ \ yyyyl NPDES• \\\,:' \ 1 \, 4 ♦♦ SSG .' '�',���. r,'/ 1 I I \ ._ ' i 1 OUTFALL 001 CCW \ .• ♦ p SOIL BORROW AREA , , ( ) \\ 5 ♦ , ,' I ASH HAUL ROAD /// ♦ / .///., , . �`\ �` i• ��' ,-- GRAVEL /-- _ , \ .\ \, 11 `— ,_ ■ ri'pi1� .� a _STORAGE AREA_, 16 , _► r a - 1 lit 23' ♦/. / o , 3j1 , o _ • 00 Of/ /, ! / 1 _ \ r , \ \ ! d//'---. Ill �- -`\ .. • SUM 111,, \` , !\ ._ \ l� o \ \ ■r \\ • ;l; i n`` \`-' rl 1 r\_�-j� I�,\_ - o / �`.` e COAL YAR DRAI AGED AREAP \ • SOIL BORROW AREA . ; , ° ° v/% �=__:='.. . �\ �` ;�\ l ,` 1 of ■ % /1 I'/--- I1 p PAW \` �♦,..■ jr 00 IA; No •/' i /�' 1 1 ! / ! I, I 1// `\ \ .a, -, \� /- oa 90 0 00 1 1 -----rrrrTN`crc�� ���������r. F., ■ I / \ if / U' /III \\ 1/ \ 1 1 ) / \ I �,rp /' =/-i ' ! , I1„'_' ' ''lll `_I1��_�, ' //` �_- `_lir ; b/ / \ \ <-'\ orP' °, / ■ [if 14 QVW 1I \ 1 \`'� ` ✓,, ° 0 1 1 _' iii �.' °o °-/ I ■ It _�__-' \ / / 1 , u� '`.-� / '6 / I `_�' / Pim-•1r o ■ ■ ■ ■ / / 1 _ _ I Flo ■ ASH LANDFILL SUMP i ■ �`�� \/.``` i \,: \ _ ”! \`/ h /' �, ASH STRUCTURAL FILL¢ DRAINAGE AREA ■ ■ `-\ G , to \�\ ■ ■ .� o ` J/■ ♦ h I III ♦ . ■ 1111 ♦• � ■■■■•■■■■=■l■I ftl ASH BASIN STORMWATER/SEDIMENT op WATERSHED DETENTION BASINS Nil \t\, PLAN HDR Engineering, Inc. of the Carolinas License Number: F-0116 440 S Church Street, Suite 1000 Charlotte, NC 28202-2075 1 2 3 SCALE: 1"= 400' PE SEAL 4 DATE Via_ AREA 002B SUMP 11/ 004 -S OUTFALL 002A RIVER -IMP (TYP) ALL SWO14 RECOMMENDED SAMPLING) DRAINAGE AREA 13 DRAINAGE AREA OUTFALL DESCRIPTION RECEIVING WATER BODY 1 10" CMP CATAWBA RIVER 1A 12" CIP CATAWBA RIVER 2 24" CMP CATAWBA RIVER 3 18" HDPE CATAWBA RIVER 4 10" CIP CATAWBA RIVER 5 SHEET FLOW CATAWBA RIVER 6 10" CIP CATAWBA RIVER 7 18" CMP CATAWBA RIVER 8 24"CMP CATAWBA RIVER 9 CONCRETE DITCH CATAWBA RIVER 10 12" CMP CATAWBA RIVER 11 72" CMP CATAWBA RIVER 12 36" CMP DISCHARGE CANAL 13 FOURTEEN 10" CMP CATAWBA RIVER 14* 36" CMP CATAWBA RIVER 15 36" RCP CATAWBA RIVER 16 36" CMP DISCHARGE CANAL 17* NUMEROUS 12" CMP DISCHARGE CANAL 18 48" CMP DISCHARGE CANAL 19 48" CMP DISCHARGE CANAL 20 48" CMP DISCHARGE CANAL REPRESENTATIVE OUTFALL SWO13 RECOMMENDED FOR SAMPLING; OUTFALL SWO15 5 REVISION *NOT RECOMMENDED FOR SAMPLING CHECKED BY: APPROVED BY: 7 SHEET 1 KEY NOTE: O DRAINAGE AREA LEGEND: PUMP TO ASH BASIN DRAINAGE AREA BOUNDARY STRUCTURE LEGEND: 0 WATER TOWER 2O AIR COMPRESSOR 0 GENERATOR ® 115 KV SWITCHYARD 0 65,300 GAL OIL TRAP TANK © TRANSFORMER YARD 0 POWERHOUSE ® 100,000 GAL OIL TRAP TANK 0 230 KV SWITCHYARD 10 FGD FACILITY 1 "=400' 400 0 400 800 SCALE IN FEET DUKE ENERGY CAROLINAS, LLC ALLEN STEAM STATION SITE PLAN STORMWATER OUTFALLS SHEET 1 8 H Ce F E R C 0 G