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Home My WebLink AboutNC0004987_316 (b) Alternate Schedule Request 2014_20141015316 (b)Alternate Schedule Request Alternate Schedule Request §316(b) of the Clean Water Act Marshall Steam Station Final regulations to establish requirements for cooling water intake structures at existing facilities were published in the Federal Register on August 15, 2014 (i.e. regulations implementing §316(b) of the Clean Water Act) with an effective date of October 14, 2014. Marshall Steam Station will be subject to the regulations. The design intake flow of the station is greater than 2 million gallons per day (MGD) and the historical actual intake flows are greater than 125 MGD; therefore, the following submittals are expected to be required: — §122.21(r)(2) Source Water Physical Data — §122.21(r)(3) Cooling Water Intake Structure Data — §122.21(r)(4) Source Water Baseline Biological Characterization Data — §122.21(r)(5) Cooling Water System Data — §222.21(r)(6) Chosen Method(s) of Compliance with Impingement Mortality Standard — §122.21(r)(7) Entrainment Performance Studies — §122.21(r)(8) Operational Status — §122.21(r)(9) Entrainment Characterization Study — §122.21(r)(10) Comprehensive Technical Feasibility and Cost Evaluation Study — §122.21(r)(11) Benefits Valuation Study — §122.21(r)(12) Non -water Quality and Other Environmental Impacts Study As allowed under §125.95(a)(2), Duke Energy would like to request an alternate schedule for the submittals listed above. Information requested in §122.21(r)(2), (3), and (5) were completed under the remanded rule; however, this information must be updated to reflect current operations and information requested in §122.21(r)(4) is substantially different from the remanded rule. Information requested in §122.21(r)(6) – r(12) are new provisions and these submittals must be developed. Duke Energy will need at least 60 months to prepare the necessary submittals. This timeframe includes complying with the peer review requirement for submittals §122.21(r)(10), §122.21(r)(11), and §222.21(r)(12). The rule requires the necessary submittals to be included with the permit renewal application for permits with an effective date after July 14, 2018. Duke Energy, therefore, would like to request the 316(b) submittals, with the exception of §122.21(r)(6) Chosen Method(s) of Compliance with Impingement Mortality Standard, for Marshall Steam Station to be required with the subsequent permit renewal application due after July 14, 2018. Since Marshall Steam Station is subject to the entrainment best technology available (BTA) determination, a compliance schedule to complete §122.21(r)(6) Chosen Method(s) of Compliance with Impingement Mortality Standard will be requested to be included in the permit upon issuance of the entrainment BTA determination. Fish Tissue Monitoring Marshall Steam Station NPDES Permit No. NC0004987 Monitoring of Arsenic, Selenium, and Mercury in Fish Muscle Tissue from Lake Norman, NC. Duke Energy 2014 Table of Contents Page 1.0 Introduction....................................................................................................................... 1 2.0 Study Site Description and Sampling Locations............................................................... 1 3.0 Target Species................................................................................................................... 1 4.0 Field Sampling Methods................................................................................................... 1 5.0 Laboratory Processing and Arsenic, Selenium, and Mercury Analysis ............................ 2 6.0 Data Analysis and Reporting............................................................................................ 2 7.0 References......................................................................................................................... 2 List of Tables Page Table 1 Arsenic, selenium, and mercury concentrations in axial muscle of fish from Lake Normanduring April 2014................................................................................................ 3 List of Figures Figure 1 Lake Norman arsenic, selenium and mercury monitoring locations 8 Page 4 1.0 Introduction Duke Energy owns and operates the Marshall Steam Station (MSS) located on Lake Norman in Catawba County, Terrell, NC. The MSS National Pollutant Discharge Elimination System (NPDES) Permit (No. NC0004987 Section A 25) requires monitoring of trace elements (arsenic, selenium and mercury) in fish tissues near the discharge once per permit cycle. Fish were collected according to the submitted study plan (dated December 4, 2013). The resulting data are submitted in this report. 2.0 Study Site Description and Sampling Locations Fish were collected from three locations on Lake Norman (Figure 1). These locations were adjacent to the MSS discharge (Dl), 6.3 kilometers upstream (UP) and 8.5 kilometers downstream of the discharge (DN). 3.0 Target Species The target species of fish were spotted bass and redear sunfish. As recommended by the US Environmental Protection Agency (EPA), an attempt was made to limit the smallest fish to 75% of the largest fish total length by species depending on availability (US EPA 2000). 4.0 Field Sampling Methods Fish were collected using electrofishing according to our Biology Program Procedures Manual (Procedure NR -00080, Rev. 1), which is approved by the NC Division of Water Resources under the Company's NC Biological Laboratory Certification (# 006), located at New Hill, NC. Only live fish that showed little or no signs of deterioration were retained for analysis. Retained fish were individually tagged (Floy tags), identified to species, measured for total length (mm), weight (g), placed on ice until frozen and transferred to a freezer within 24 hours of collection. Water quality data consisting of temperature, pH, dissolved oxygen, specific conductance and turbidity were recorded daily at the surface at each sampling location. Other noteworthy environmental conditions including river flow conditions and weather conditions were noted and are available upon request. I 5.0 Laboratory Processing and Arsenic, Selenium and Mercury Analysis All fish samples were processed in the New Hill trace element laboratory according to procedure NR -00107 (Rev. 4) Trace Element Monitoring Laboratory Procedure. The processed samples (lyophilized left axial muscle; right muscle occasionally included when needed) were analyzed for arsenic, selenium and mercury by x-ray spectrophotometry. Quality control was achieved by analytical standards, replicates and certified reference materials. The remaining fish carcasses were archived and will be kept for at least two years in the event that re -analysis is needed. 6.0 Data Analysis and Reporting Arsenic, selenium and mercury concentrations (converted to µg/g fresh weight) in the fish muscle tissue collected during 2014 are shown in Table 1. In addition to the length and weight of each fish, the dry -to -fresh weight ratios are presented to convert the arsenic, selenium and mercury concentrations fresh weight values back to dry weight values as desired. All fish collected during 2014 were below the US EPA Screening Values for Recreational Fishermen of 1.2 µg/g (fresh weight) for arsenic (US EPA 2000). All fish collected during 2014 were below the NC human consumption advisory level of 10 gg/g (fresh weight) for selenium. All fish collected during 2014 had mercury concentrations below the NC Health Directors Action Advisory Level of 0.4 gg/g fresh weight (NCDHHS 2006). 7.0 References NCDHHS. 2006. Health effects of methylmercury and North Carolina's advice on eating fish. North Carolina Occupational and Environmental Epidemiology Branch, Raleigh, NC. US EPA. 2000. Guidance for assessing chemical contaminant data for use in fish advisories. Vol. 1. Fish sampling and analysis. Third edition. EPA 823-B-00-007. United States Environmental Protection Agency, Office of Water, Washington, DC. N Table 1. Arsenic, selenium and mercury concentrations (fresh weight) in axial muscle of fish from Lake Norman during April 2014. * To convert to a dry weight, divide the fresh weight concentrations by the dry -to -fresh weight ratio. 3 Length Weight As Se Hg Dry -to -fresh Fish species Location Month (mm) (g) (pg/g) (pg/g) (pg/g) weigh ratio* Spotted bass UP April 350 564 0.19 0.39 <0.06 0.207 Spotted bass UP April 355 522 0.23 0.37 <0.06 0.208 Spotted bass UP April 378 590 0.10 0.40 <0.05 0.201 Spotted bass UP April 340 512 0.22 0.40 <0.06 0.224 Spotted bass UP April 380 611 0.16 0.47 <0.05 0.198 Spotted bass UP April 358 523 0.06 0.39 <0.06 0.205 Redear sunfish UP April 241 245 0.06 0.56 <0.06 0.208 Redear sunfish UP April 258 311 0.08 0.50 <0.05 0.199 Redear sunfish UP April 243 276 0.10 0.56 <0.05 0.201 Redear sunfish UP April 234 222 0.04 0.58 <0.06 0.208 Redear sunfish UP April 220 176 0.08 0.82 <0.06 0.209 Redear sunfish UP April 240 254 0.11 0.53 <0.06 0.211 Spotted bass DI April 380 668 0.15 0.62 <0.06 0.215 Spotted bass DI April 392 692 0.19 0.43 <0.06 0.215 Spotted bass DI April 424 972 0.11 0.53 0.09 0.213 Spotted bass DI April 338 458 0.13 0.44 <0.06 0.211 Spotted bass DI April 393 702 0.08 0.44 0.13 0.210 Spotted bass DI April 435 1136 0.08 0.74 0.21 0.212 Redear sunfish DI April 254 202 0.11 0.78 <0.05 0.181 Redear sunfish DI April 271 345 0.10 0.64 <0.06 0.207 Redear sunfish DI April 172 82 0.10 0.64 <0.05 0.193 Redear sunfish DI April 275 380 0.08 0.66 <0.05 0.200 Redear sunfish DI April 186 107 0.10 0.58 <0.06 0.208 Redear sunfish DI April 185 94 0.10 0.62 <0.06 0.208 Spotted bass DN April 429 890 0.08 0.68 <0.05 0.201 Spotted bass DN April 404 696 0.08 0.66 <0.05 0.199 Spotted bass DN April 367 546 0.08 0.56 <0.06 0.206 Spotted bass DN April 416 864 <0.04 0.57 <0.05 0.185 Spotted bass DN April 359 602 0.16 0.57 <0.05 0.203 Spotted bass DN April 361 562 0.10 0.56 <0.06 0.208 Redear sunfish DN April 268 340 0.06 0.77 <0.06 0.209 Redear sunfish DN April 261 288 0.10 0.83 <0.05 0.202 Redear sunfish DN April 195 109 0.04 0.37 <0.03 0.098 Redear sunfish DN April 186 100 0.06 0.82 <0.06 0.206 Redear sunfish DN April 177 89 0.04 0.80 <0.06 0.204 Redear sunfish DN April 195 118 0.04 0.71 <0.06 0.210 * To convert to a dry weight, divide the fresh weight concentrations by the dry -to -fresh weight ratio. 3 SUP rShernll5'Ford ra Marshall SS 1 Lake Norman -of Catawba 0 i 3enver r, � y .2� i Mayhh ew c Metals Sampling in the Vicinity Of Ash Basins Marshall Steam Station In -Stream Monitoring Plan I. Introduction In -Stream Monitoring Requirement A requirement to semi-annually sample water quality at locations in Lake Norman upstream and downstream of the Marshall Steam Station (MSS) ash basin discharge was implemented in 2011 under section Part I # 26 (In -stream Monitoring) of the MSS National Pollutant Discharge Elimination System permit. The following discussion describes the specific analyses, methods and analytical results of this monitoring program for the period 2011 — 2013. II. Sampling and Methodology Lake Norman Sampling Locations The water quality sampling locations associated with this monitoring plan are depicted in Figure 1. The upstream location (15.9) is approximately 2.5 miles upstream of where the MSS ash basin discharges into the MSS condenser cooling water (CCW) intake cove. The downstream location (14.0) is approximately 0.5 miles downstream of the MSS CCW discharge into Lake Norman. Sampling and Analytical Methods Grab samples collected from the surface (0.3 m) at both locations in Lake Norman were analyzed for the following parameters: arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb), selenium (Se), zinc (Zn), and total dissolved solids (TDS). Storage and preservation techniques of the samples after collection and prior to analyses were followed according to Appendix A. Methods of analysis and results for each parameter are presented in Table 1. Analyses were conducted by Duke Energy's Huntersville analytical laboratory (NC Wastewater Certification #248). III. Results & Recommendations All trace metal results were low, with most values either tabulated as less than the analytical reporting limit (RL) for the method or close to the RL (Table 1). For example, all samples for arsenic, cadmium, chromium, mercury, lead and selenium were reported as less than the RL, whereas only four zinc values were greater than the RL of 1.0 Ng/L. All zinc values were below the water quality standard (50 Ng/L). Most of the copper values were above the RL, but only marginally so, and all values were also well below the water quality standard (7.0 Ng/L). Total dissolved solids (TDS) values were low, and reflective of the low ionic strength and conductivity of waters in Lake Norman and the Catawba River Basin . All values for the nine water quality parameters monitored were below NC water quality standards. Duke Energy proposes that the in -stream monitoring frequency be reduced from semi-annually to annually. IL•/ w`Ai(Naw+l.sAMPLI WCA ONswlKlrVA"olow WATER QUALITY SAMPLE LOCATION MAP OVKi INlRG7 ANO AR( A►IRORIMATI. I- +wA. sounct USGS TOPOGRA/NK "" uun NORMANMARSHALL STEAM STATION ASH BASIN NORTH pUAORANGI(, CR(ATI0 1»I, UP"VID 2031. DUKE ENERGY CAROLINAS, LLC CATAMA COUNTY, NC 1 Figure 1. Marshall Steam Station in -stream water quality monitoring locations. Table 1. MSS in -stream monitoring analytical results and methodology. Locations 15.9 and 14.0 represents the upstream and downstream, respectively, sampling sites. Method EPA 200.8 EPA 200.8 EPA 200.8 EPA 200.8 EPA 245.1 EPA 200.8 EPA 200.8 EPA 200.8 SM2540C Facility Date Location Depth m < Arsenic < Cadmium < Chromium Copper < < Mercury < Lead < Selenium < Ziac TDS < m MSS 2/7/2011 15.9 0.3 < 1.00 < 1.00 < 1.00 2.09 < 0.05 < 1.00 < 1.00 < 2.00 50 MSS 2/7/2011 14.0 0.3 < 1.00 < 1.00 < 1.00 3.59 < 0.05 < 1.00 < 1.00 < 2.16 55 MSS 8/1/2011 15.9 0.3 < 1.00 < 1.00 < 1.00 1.69 < 0.05 < 1.00 < 1.00 < 2.00 37 MSS 8/1/2011 14.0 0.3 < 1.00 < 1.00 < 1.00 5.31 < 0.05 < 1.00 < 1.00 < 2.00 47 MSS 2/6/2012 15.9 0.3 < 1.00 < 1.00 < 1.00 1.31 < 0.05 < 1.00 < 1.00 < 2.00 51 MSS 2/6/2012 14.0 0.3 < 1.00 < 1.00 < 1.00 2.31 < 0.05 < 1.00 < 1.00 < 2.00 64 MSS 8/6/2012 15.9 0.3 < 1.00 < 1.00 < 1.00 < 1.00 < 0.05 < 1.00 < 1.00 < 1.00 50 MSS 8/6/2012 14.0 0.3 < 1.00 < 1.00 < 1.00 < 1.00 < 0.05 < 1.00 < 1.00 < 1.00 56 MSS 2/4/2013 15.9 0.3 < 1.00 < 1.00 < 1.00 1.12 < 0.05 < 1.00 < 1.00 2.67 47 MSS 2/4/2013 14.0 0.3 < 1.00 < 1.00 < 1.00 2.46 < 0.05 < 1.00 < 1.00 3.56 47 MSS 8/5/2013 15.9 0.3 < 1.00 < 1.00 < 1.00 2.46 < 0.05 < 1.00 < 1.00 < 1.00 40 MSS 8/5/2013 14.0 0.3 < 1.00 < 1.00 < 1.00 5.06 < 0.05 < 1.00 < 1.00 2.23 60 MSS 8/6/2012 15.9 0.3 < 1.00 < 1.00 < 1.00 < 1.00 < 0.05 < 1.00 < 1.00 < 1.00 50 MSS 8/6/2012 14.0 0.3 < 1.00 < 1.00 < 1.00 < 1.00 < 0.05 < 1.00 < 1.00 < 1.00 56 Appendix A Sample Preservation and Hold times Parameter name Containerl Preservationz-:- Maximum holding timet Table IB --Inorganic Tests: 1. Acidity P, FP, G Cool, 56 'C" 14 days 2. Alkalinity P, FP, G Cool, 56 °C" 14 days. 4. Ammonia P, FP, G Cool, 56 'C'", H2SO4 to pH <2 28 days. 9. Biochemical oxygen demand 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, <_6 'CI" 48 hours. 15. Chemical oxygen demand P, FP, G Cool, <_6'C'", 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, <_6 'C'" 48 hours. 23-24. Cyanide, total or available (or CATC) and P, FP, G Cool, 56 °C", NaOH to pH 14 days. free >1056, 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 'C'', H2SO4 to pH <2 28 days. Table IB—Metals:' 18. Chromium VI P, FP, G Cool, 56 'C", pH = 9.3-9.720 28 days. 35. Mercury(CVAA) P, FP, G HNO3 to pH <2 28 days. 35. Mercury (CVAFS) FP, G; and FP- 5 mUL 12N HCI or 5 mUL 90 days." lined cap" Bra" 3, 5-8, 12, 13, 19, 20, 22, 26, 29, 30, 32-34, 36, 37, P, FP, G HNO3 to pH <2, or at least 24 6 months. 45, 47, 51, 52, 58-60, 62, 63, 70-72, 74, 75. Metals, hours prior to analysis1fl except boron, chromium VI, and mercury 38. Nitrate P, FP, G Cool, 56'C" 48 hours. 39. Nitrate -nitrite P, FP, G Cool, 56'C", H2SO4 to pH <2 28 days. 40. Nitrite P, FP, G Cool, 56'C"" 48 hours. 41. Oil and grease G Cool to <_6 'C", HCI or H2SO4 28 days. to pH <2 42. Organic Carbon P, FP, G Cool to 56 'C", HCI, H2SO4, or 28 days. 113PO4 to pH <2 44. Orthophosphate P, FP, G Cool, to <_6 'C1NJ4 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 top Fix on site and store in dark 8 hours 48. Phenols G Cool, 56'C'", H2SO4 to pH <2 28 days. 49. Phosphorous (elemental) G Cool, :56 'C" 48 hours. 50. Phosphorous, total P, FP, G Cool, 56'C'", H2SO4 to pH <2 28 days. 53. Residue, total P, FP, G Cool, 56 °C'" 7 days. 54. Residue, Filterable P, FP, G Cool, <6'C" 7 days. 55. Residue, Nonfilterable (TSS) P, FP, G Cool, <_6'C" 7 days 56. Residue, Settleable P, FP, G Cool, 56'C"" 48 hours. 57. Residue, Volatile P, FP, G Cool, 56'C" 7 days - 61. Silica P or Quartz Cool, 56 'C'" 28 days. 64. Specific conductance P, FP, G Cool, 56'C" 28 days. 65. Sulfate P, FP, G Cool, 56'C" 28 days. 66. Sulfide P. FP, G Cool, 56 'C", 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, <_6'C'" 48 hours. 69. Temperature P, FP, G None required Analyze. 73. Turbidity P, FP, G Cool, 56 'C" 48 hours. "'P" is for polyethylene, "FP" is fluoropolymer (polytetrafluoroethylene (PTFE); Teflon), or other fluoropolymer, unless stated otherwise in this Table Il; "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 11 or in the method(s). For a composite sample to be split into separate aliquots for preservation and/or analysis, maintain the sample at 56 °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(fX14xiv) and (v) (volatile organics). 31Nhen 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 0.040/9 by weight or less (pH about 1.96 or greater; Nitric acid (HNO3) in water solutions at concentrations of 0.15°k 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 0.0800/6 by weight or less (pH about 12.30 or less). `Samples 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(gx7xi) 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. °Sampling, 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. 'For 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(gx7xi) or 40 CFR Part 403, Appendix E), fitter 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. °Guidance applies to samples to be analyzed by GC, LC, or GC/MS for specific compounds. °If 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 3 days 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 freprding the analysis of benzidine). 21f 1,2-diphenylhydrazine is likely to be present, adjust the pH of the sample to 4.0 t0.2 to prevent rearrangement to benzidine. 13Extracts may be stored up to 30 days at <0 °C. 14For the analysis of diphenylnitrosamine, add 0.008% Na2S203 and adjust pH to 7-10 with NaOH within 24 hours of sampling. 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 0.0080A Na2S203. 1°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. "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 obdized 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 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 "5"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. Them preservation temperature does not apply to samples that are analyzed immediately (less than 15 minutes). 1'An 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. 2OTo 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. 22Sample analysis should begin as soon as possible after receipt; sample incubation must be started no later than 8 hours from time of collection. 2317or 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. 24fhe immediate filtration requirement in orthophosphate measurement is to assess the dissolved or bio -available forth of orthophosphorus (i.e., that which passes through a 0.45 -micron fitter), hence the requirement to fitter the sample immediately upon collection (i.e., within 15 minutes of collection). [38 FR 28758, Oct. 16, 1973 Ash Basin Capacity Calculations Duke Energy Company Marshall Steam Station - Ash Basin Forecasting 2014 Wet Weather Detention Volume Calculation Determination of Wet Weather Detention Volume: Wet Weather Detention Volume is the sum of the runoff accumulated in the ash basin which results from a 10 -yr 24 -hr storm (assuming 100% runoff) plus the maximum 24 -hr dry weather waste stream which discharges to the Ash Basin (refer to NPDES Permit NC0004961) I. Estimate Runoff to the Ash Basin from a 10 -yr 24 -hr storm: 1. Natural Drainage Area of Ash Basin = 1180.0 Acres Station Yard Drainage Area Pumped to Ash Basin = 14.7 Acres Total = 1194.7 Acres 2. Precipitation from 10 -yr 24 -hr storm = S.0 Inches 3. Total Stormwater Runoff to Ash Basin 497.79 Acre -fee (Assuming 100% runoff) Ash Sent to Ii. Estimated Maximum 24 -hr Dry Weather Waste Stream Discharging to Ash Basin: 1. Maximum recorded Ash Basin Discharge = 11,200,000 Gallons/day IV. 2. Increase maximum daily disharge by 10% for conservatism and convert units to acre-feet = Wet Weather Detention Volume: Sum of Parts 1. and ll._ 7.81 Acre -fee 35.60 Acre -fee Estimated Quantity of Solids (Ash) to be discharged to Ash Basin through December 31, 2020. Note: NPDES Permit expiration date is 4/30/2015. Time Period Actual or % Ash Estimated Estimated Estimated Estimated Estimated Coal Total Ash Ash Sent to Ash Ash Consumption Production Structural Discharged Discharged (1000's tons) (1000's FN or Lined to Ash basin to Ash basin tons) Land Fills (1000's (Acre-feet) (1000's tons) tons) 2014 Jun -Dec 2744.79 10.00% 274.48 233.31 41.17 34.37 2015 3642.73 10.00% 364.27 309.63 54.64 45.61 2016 4106.74 10.00% 410.67 349.07 61.60 51.42 2017 3495.78 10.000/6 349.58 297.14 52.44 43.77 2018 2442.76 10.00% 244.28 207.63 36.64 30.59 20192371.18 10.00% 237.12 201.55 35.57 29.69 2020 F 2406.97 10.00% 240.70 204.59 36.10 30.14 Total 21210.94 10.000/6 2121.09 1802.93 318.16 265.60 * Calculation assumes an in-place ash density of 55 lbs. per cubic foot. V. Duke Energy Company Marshall Steam Station - Ash Basin Forecasting 2014 Wet Weather Detention Volume Calculation Estimated Total Storage Volume Required through 2015: Wet Weather Detention Volume = 535.6 Acre-feet Estimated Solids to Ash Basin = 265.6 Acre-feet Required Storage Volume Through 12/31/2020 = 01.2 Acre -fee Vi. Results: Ash Basin @ Pond Elevation 793'+9" = 849.9 Acre-feet Total Available Storage = 049.9 Acre -fee Note: Available Storage based on basin survey dated 8/13/2014 Available Storage > Required Storage Based on these calculations, there is sufficient capacity in the ash basin to provide the retention volume specified in the permit through the year 2020.