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HomeMy WebLinkAboutNC0000272_Performance Summary_20180216optimizing resources i water, air, earth 215 Jamestown Park, Suite 100 - Brentwood, TN 37027 o (615) 373-8532 February 16, 2018 Mr. Gregory Denton Tennessee Department of Environment and Conservation By E-mail: gregory.denton@tn.gov RE: Comments on the 2018 303(d) list for the Pigeon River in Cocke County Dear Mr. Denton: On behalf Evergreen Packaging LLC of Memphis, Tennessee, AquAeTer, Inc. of Brentwood, Tennessee submits the attached specific comments on the TDEC listing of the Pigeon River from the NC/TN stateline to Hartford, Tennessee as impaired for color. Sincerely, AquAeTer, Inc. John Michael Corn, P.E. (TN) Michael R. Corn, P.E. (TN, NC), BCEE Technical Director President COMMENTS ON THE Draft 2018 303(d) LIST Little River coming out of Elkmont in GSMNP on March 18, 2017 Evergreen Packaging LLC., a Tennessee corporation headquartered at 5350 Poplar Ave., Suite 600, Memphis, TN 38119 offers the following comments concerning the continued listing of the Pigeon River as impaired for color from the North Carolina / Tennessee (NC/TN) Stateline at Pigeon River mile (PRM) 25.85 to Hartford, TN at PRM 20.87. The listing in the 2018 303(d) proposed list is as follows: Table 1. DRAFT 2018 303(D) LISTING FOR THE PIGEON RIVER SEGMENT NUMBER SEGMENT COUNTY CAUSE OF LISTED SOURCE OF LENGTH IMPAIRMENT IMPAIRMENT Cocke i Low Flow Upstream Impoundments (Pl- TN06010106001 3000 - 5.1 County Alterations 566 NRCS) Cocke Low Flow Upstream Impoundments (Pl- TN06010106001 4000 - 5.03 County Alterations 566 NRCS) Cocke Upstream Impoundments (Pl- TN06010106001 4000 5.03 Temperature, Water 566 NRCS TN06010106001 4000 5.03 Cocke Color Sources Outside State — County Jurisdiction or Borders TN06010106001 4000 5.03 Cocke Color Industrial Point Source — County Discharge The following comments are submitted for the continuing listing of the Pigeon River as impaired for color. 1. The Tennessee Department of Environment and Conservation ("TDEC") has indicated that 5.03 miles of the Pigeon River in Cocke County are impaired due to color. "Sources Outside State Jurisdiction or Borders" and "Industrial Point Source Discharge" are identified as the "Listed Source of Impairment." The specific reach of the Pigeon River TDEC has listed is from the NC/TN stateline at Pigeon River mile (PRM) 25.85 to Hartford at PRM 20.82. More than 200,000 rafters utilize this stretch of the River every year, providing a vital economic resource for Cocke County.' TDEC also lists this reach of the River as impaired due to the Waterville Dam and power plant for low -flow alterations. The hydroelectric generation releases from the Waterville powerhouse, mandated by the FERC license, provide the necessary flow conditions for rafting and the resulting economic benefit to Cocke County. 2. The industrial source, the Evergreen Packaging Plant in Canton, North Carolina (39 miles upstream from the state line) has collected color concentration data on the Pigeon River and its tributaries since 2000. AquAeTer has completed an updated analysis of the color concentration data from 2010 — 2017. 3. There is no evidence that color discharged from the Canton Mill is contributing to any color issues in the Pigeon River in Tennessee. Since 1988, color discharged from the Canton Mill has been reduced by more than ninety percent (90%). The Long term daily average color concentration at Park Street, upstream from the Canton Mill Discharge, since July 2010, is 14 true color units.` The long term daily average color concentration at the NC/TN stateline, since July 2010. is 17 true color units.' ' In addition to the businesses and jobs the rafting industry creates, rafters pay a $2 per person user fee to Cocke County. 2 See Table 2 on page 3 3 See Table 3 on page 4 2 Table 2. Long -Term Daily Average Color Concentration at Park Street Upstream from the Industrial Source for July 1, 2010 through December 31, 2017 MONTH DISTRI- TOTAL BUTION NUMBER OF VALUES LONG-TERM DAILY AVG. WHEN FLOWS >=A30Q2 (mg/L) LONG-TERM DAILY AVG. WHEN FLOWS >=M30Q2 (mg/L) LONG-TERM 90'h PER - CENTILE WHEN FLOWS >=M30Q2 (mg/L) Jan. LN 61 11 12 22 Feb. LN 57 10 12 21 Mar. LN 64 10 11 19 Apr. LN 60 12 15 28 May LN 62 12 12 18 Jun. LN 61 16 15 27 Jul. LN 70 15 14 21 Aug. LN 72 15 15 25 Sep. LN 69 17 19 29 Oct. LN 70 18 21 31 Nov. LN 70 16 17 25 Dec. LN 71 15 18 33 Annual LN 787 14 15 26 Note: LN = Loa Normal A30Q2 = Annual 30Q2 Condition which is roughly equivalent to the average flow M30Q2 = Monthly 30Q2 Condition which is the true hydrologic and meterorologic statistic for comparison with True Color over the seasons 4. TDEC collects samples on the Pigeon River near the stateline, as well as, on the French Broad River at the Highway 70 Bridge (near Del Rio, TN) and at the Highway 321 Bridge (near Newport, TN). Although there are not enough data points to calculate long-term daily averages for each month, and although there are not enough data points to determine the proper distribution of the datasets, the overall averages of the three datasets are presented, along with the number of samples in each calculation. Color data from the Pigeon River at the NC/TN Stateline and data for the French Broad River at Del Rio are ideal for comparison because both stations are Order 5 streams and drain the exact same ecosystem, while the French Broad River station has no known large industrial source, e.g. a pulp and paper mill. 5. The French Broad River in Newport is also an Order 5 stream, but is classified as being in a different Ecoregion. Given that the data are very similar at the two French Broad River stations, it does not appear that the Ecoregion distinction is relevant to the assessment for color in this case. This is likely because more than 92% of the drainage area contributing to the French Broad River at Newport is in Ecoregion 66, indicating that this station can be reasonably compared to the Pigeon River at the NC/TN stateline since the drainage area for the French Broad River at Newport is primarily in Ecoregion 66. TDEC's own guidance document cites that streams with more than 80% of their drainage area within an ecoregion can be compared. This analysis is presented in Table 3. Table 3. Comparison of Color Concentrations for In -Stream Measurements on Pigeon and French Broad Rivers PARAMETER PIGEON RIVER AT PARK STREET IN CANTON PIGEON RIVER NEAR NC/TN STATE LINE FRENCH FRENCH BROAD BROAD RIVER RIVER NEAR DEL NEAR RIO, TN NEWPORT, TN Drainage Area, square miles 130 538 1,713 1,858 Stream Order (Strahler) 4 5 5 5 Ecoregion 66 66 66 67 Number of Samples 787 232 30 24 Samples Collected by: EPI TDEC TDEC TDEC Average Color, mg/L 14 17 22 25 Minimum Color, mg/L .1 5 8 7 Maximum Color, mg/L 94 43 63 110 6. For comparison purposes, the color measurements collected on the French Broad River upstream from Newport, Tennessee are included in Table 3. It is noted that the difference between the upstream and downstream locations on the French Broad River and on the Pigeon River are both 3 color units. This is consistent with the general expectation that color increases in the downstream direction as stream order increases. For the French Broad River, this indicates that True Color is being added solely by Tennessee sources and not sources from another state. 7. In the past, TDEC has provided unconvincing justification for its listing of the Pigeon River as impaired for color. These included the following: M a. Whisker plots of Order 2 through 4 mountain streams collected during limited low - flow no -rain periods were compared with a whisker plot of Pigeon River data representing the full range of hydrologic and meteorologic conditions on the Pigeon River. TDEC concluded that the Pigeon River was and is impaired for color because the Pigeon River data were not within the range of data collected from the mountain streams. This comparison is scientifically flawed due to the lack of similarity in sampling regime, hydrologic conditions monitored, stream order, and time span of the dataset. This original analysis is presented in Figure 1. Figure 1. Whisker Plot Presented by Greg Denton at AWRA's 23rd Tennessee Water Resources Symposium so 70 so so s` U 40 H 30 20 10 0 Pigeon Mile 24.7 €coregion 66 Reference b. A review of the individual reference streams is presented in Figure 2. In reviewing the dataset used to make-up the original "Reference" dataset, it is apparent that the datasets for the individual streams do not follow the same patterns. The "Reference" streams represent streams from various locations and stream orders in Ecoregion 66 within Tennessee ranging from Beaverdam Creek near the Tennessee / Virginia border to the north all the way to Sheeds Creek in the South near the Tennessee / Georgia border. Within this grouping of streams, 5 are Order 2, 6 are Order 3, and 2 are order 4. c. A review of the sampling completed on the individual streams indicated no obvious systematic sampling is apparent based on sampling frequencies, hydrologic variability, or meteorologic variability. The streams appear to have been primarily sampled during periods of low -flow or low -precipitation. This is very different from the Pigeon River database. Since 2008, TDEC has sampled the Pigeon River at least twice a month, with 5 the majority of samples being collected on a Wednesday. This indicates a systematic sampling regime, without regard to meteorologic or hydrologic conditions. Figure 2. Whisker Plot of Individual TDEC "Reference" Streams 50 45 .O - 35 U 30 25 020 O U 15 10 5 I d. A comparison of TDEC's "reference" database to other streams is shown in Figure 3. The Pigeon River at the NC/TN stateline, the Ocoee River, and the two French Broad River stations are all Stream Order 5 and primarily, or wholly in Ecoregion 66. It is apparent in reviewing the data between the streams of similar stream order that the Pigeon River is similar to other streams. 0 Figure 3. Whisker Plot Comparing TDEC Grouped "Reference" Dataset with Pigeon River and other Similar Streams 140 IM 100 a 80 60 O U 40 20 0 .w O ♦ cn y z .^. r v _' ♦ o Z , 5'1AHOIN e. The Pigeon River at the Stateline and the French Broad River at Del Rio are both in the same Ecoregion and are both Order 5 streams, which means that they can be technically and scientifically compared. Based on TDEC's original reasoning using the flawed "reference" stream database approach for keeping the Pigeon River on the 303(d) list as impaired for color, both the Ocoee and the French Broad Rivers should have also been listed as impaired for color. These other streams are not listed as impaired. In fact, the Pigeon River is the only stream in Tennessee that is listed as impaired due to color. TDEC's original Guidance Document specified that comparisons between different streams and basins must be made between streams of the same order. TDEC did not follow its own guidance and eventually changed this document to perhaps justify the analysis presented in Figures 1 and 2. f. TDEC later commented that the reason for the impairment was due to complaints from TDEC staff and others of visible color in the River. Based on our analysis of the sources of True Color in all of the Rivers and streams in this area including the Pisgah National Forest, the Great Smoky Mountains National Park, the Blue Ridge Parkway and the Cherokee National Forest, the majority of color coming to the stateline is not from an industrial source. The difference of 3 color units at the stateline cannot be related to a specific source since first, a difference of 3 color units is not distinguishable to the human eye, and second, the upstream lake acts to mix all color together so that no one color unit can be identified as to its source. 7 g. TDEC does not have credible scientific data to prove that a color impairment exists from the NC/TN stateline to Hartford. h. The number of complaints made and the people making the complaints has not been provided by TDEC. Based on the number of recreational users of the River, a small number of complaints should not be justification for listing the color for impairment. There are no data to verify or justify the complaints. The listing based on an unspecified number of complaints from anonymous sources is not rational when compared to the volume of people using the river for recreation. 8. In a previous Response to comments, TDEC stated that the color in the Pigeon River was different than the color in the French Broad River. No evidence was given to validate the statement of the source of the color in either River. Evergreen has studied the Pigeon River basin and has identified the various sources of color upstream from Waterville Lake. a. Waterville Lake upstream from the NC/TN stateline acts as an equalization basin. Discharges through the hydroelectric facility at Waterville reflect days and perhaps months of River flow coming into the lake. It is not possible to identify a specific source of color in the Pigeon River at the NC/TN stateline by visual means. CONCLUSIONS 9. The Pigeon River has similar average and range of color concentrations as other streams of comparable stream order. 10. For the Pigeon River at the Stateline, the average True Color concentration is 17 mg/L or a difference in 3 mg/L from the average at Park Street. This is not discernible by the human eye nor is it outside the range of the natural background True Color concentration for any given month at Park Street. 11. Comparison of the French Broad River near Del Rio shows the Pigeon River at the Stateline does not have color levels outside of the expected range for a stream with no large point source of color discharging to it. 12. TDEC's action of not including stream order and ecoregion as factors in comparing stream color is an unconscionable scientific error. Also, data collected on smaller streams should not be combined into one database, nor should that combination be compared to data collected on larger River systems. 13. The analyses and methodologies presented by TDEC are scientifically flawed. There has been no credible scientific rationale presented by TDEC to conclude the Pigeon River from the NC/TN Stateline to Hartford is impaired for color, and color concentrations measured 8 on the Pigeon River are comparable to or less than color concentrations measured on streams of similar stream order. In fact, a comparison of appropriate data leads to the conclusion that the Pigeon River from the NC/TN stateline to Hartford, Tennessee is not impaired for color. 14. Based on previous responses, TDEC has stated that the previously presented data methodologies presented are not used to keep the Pigeon River on the 303(d) list for impairment due to color. Instead, an unspecified number of verbal complaints from an unspecified number of people was cited as the justification for the listing. This methodology is not rational and is not supported by the more than 200,000 recreational users of the River each year. 15. Evergreen Packaging requests that this impairment be removed from the 2018 303(d) list. 0 ANALYSIS OF COLOR CONCENTRATIONS IN THE PIGEON RIVER JANUARY 31, 2018 AQUAETER, INC. SECTION 1.0 INTRODUCTION Blue Ridge Paper Products Inc. doing business as "Evergreen Packaging" (Evergreen), operates the Canton pulp and paper mill ("Canton Mill") in Canton, North Carolina. Since 1988, the Mill has reduced color loadings to the Pigeon River by more than 90%. Since 2001 the Canton Mill has sampled and analyzed True and Apparent Color in the Pigeon River upstream from the Mill's discharge and approximately 0.4-mile downstream at the Fibreville Bridge.' In 2009, Evergreen retained AquAeTer to sample and analyze True and Apparent Color in the Pigeon River and its tributaries. Based on the Mill's data, and that collected by AquAeTer, "A Comprehensive Assessment and Analysis of Color in the Pigeon River2" was developed. PURPOSE OF REPORT This report supplements the Comprehensive Assessment and Analysis of Color in the Pigeon River with an analysis of color concentrations in the Pigeon River upstream from the Canton Mill at Park Street and downstream from the Mill's discharge at the Fibreville Bridge3. The report compares the color concentrations at Fibreville and the difference in concentration between the upstream and downstream stations from July 2010 through December 2017. This is the period that the current NPDES permit and associated effluent limits have been in effect. CONCLUSIONS The long-term daily average contribution of the Canton Mill to true color in the Pigeon River since July 2010, is 23 true color units at flows greater than or equal to the annual 30Q2.4 The long term daily average color concentration at the Fibreville Bridge at flows greater than or equal to the annual 30Q2 is 34 true color units.5 The difference in the long-term daily average color concentration at Park Street in Canton (14 true color units), upstream from the Canton Mill 1 NPDES Permit NC 0000272 issued to the Canton Mill by the North Carolina Department of Environmental Quality requires the sampling. The Canton Mill also samples and analyzes color concentrations at Hepco (26 river miles downstream) and at Brown's Bridge in Tennessee, approximately %2 mile downstream from the Duke Energy Progress Hydro -electric plant. 2 AquAeTer, Inc. (2014). Comprehensive Assessment and Analysis of Color in the Pigeon River. Brentwood: AquAeTer, Inc. 3 The report will also reference color concentrations at the NC / Tennessee state line and at a similar stream from the same Ecoregion. a Table 5, page 10 5 Table 3, page 8 2 discharge, and the long term daily average color concentration at the North Carolina/Tennessee state line (17 true color units), is 3 true color units.6 METHODOLOGY AquAeTer has evaluated the color in the Pigeon River upstream from the Canton Mill discharge and at the Fibreville Bridge. The dataset used for this analysis extends from July 1, 2010 through December 31, 20177, unless otherwise noted. The color data were also evaluated in conjunction with the flows in the River. In particular, monthly flows were evaluated so that distinct hydrologic/meteorologic periods that are statistically equivalent, but occur with the varying background natural color that occurs in the River over the course of the different seasons, would be analyzed separately but equivalently. 6 Table 4, page 9 and Table 6, page 11. This is the period of the current NPDES Permit. SECTION 2.0 ANALYSIS OF STREAM FLOWS 15A N.C.A.C. 213.0206 (a) (5) specifies that aesthetic standards will be met at flows greater than or equal to the minimum average flow for a period of 30 consecutive days that has an average recurrence of once in two years (30Q2). The actual period for the calculation is not specified. Historically, the period used has been an annual number, so an annual 30Q2 has been calculated for the analyses in this report. However, the annual 30Q2 event is not reflective of the actual stream conditions through the year for this stream. The chance for the annual 30Q2 to occur in any given month for an equivalent 30-day period is much greater than a 2-year return interval, which is not in keeping with the NC standard. The period that is presented in this report is for a monthly basis, which more accurately reflects the hydrologic cycle over the course of the year. A comparison of the monthly 30Q2's to the annual 30Q2 is presented in Figure 1. Each of the monthly 30Q2 Table 1. 30Q2 Monthly and Yearly Flows and flows plotted in Figure 1 is Recurrence Intervals statistically equivalent to the other months meaning they have the same statistical probability of occurring. However, the annual 30Q2 is not statistically likely to occur in four months, and represents a greater than a two- year return interval in the other eight months. The actual calculated flows are provided in Table 1. This demonstrates that while the annual 30Q2 may statistically have a 50% chance of occurring in any given year, the actual chance of the annual 30Q2 MONTH 30Q2 (cfs) Chance of Annual Flow Occurring (1 in Yrs) (%) January 390 57.1 1.8 February 420 >88 <1.1 March 457 >88 <1.1 April 419 >88 <1.1 May 288 >88 <1.1 June 207 57.9 1.7 July 149 15.1 6.6 August 127 4.4 22.8 September 133 4.5 22.3 October 172 4.2 23.9 November 207 9.7 10.3 December 285 44.0 2.3 Annual 90.5 2 50 flow occurring in any given month is much less. The United States Environmental Protection Agency (USEPA) also recognizes that, in some cases, streams need to and can be evaluated on a monthly basis$ due to the variable hydrologic conditions found. This analysis is and has been applied in many southern states as well 'US EPA. (1997). Technical Guidance Manual for Performing Wasteload Allocations, Book IT Streams and Rivers - Part 1: Biochemical Oxygen DemandlDissolved Oxygen and Nutrients/Eutrophication. Washington, DC: US EPA. 4 as in some northern states and was originally proposed by the old U.S. Public Health Service, or pre-USEPA.9 Figure 1. Comparison of Annual and Monthly 30Q2 Low Flows 500 450 400 u 350 300 250 200 1.50 a �+ 100 50 0 y__...._..___.,..____..________-_____________-_______._________________________________________----_.,.._-----i • o � a MONTH *Monthly 30Q2 ■Annual 30Q2 � U'1 O o Z v A Y There are multiple NPDES Permits in the southeast which use monthly flow limits (DS Smith Riceboro on the North Newport River and Georgia Pacific's Brunswick Mill on the Turtle River (Ga.)), (Georgia Pacific mill in Naheola, Alabama on the Tombigbee River and West Rock Mill on the Tombigbee (Alabama)) and (Domtar Mill at Ashdown, Arkansas). 5 SECTION 3.0 ANALYSIS OF COLOR CONCENTRATIONS The Canton Mill has been collecting in -stream color data since 2001. AquAeTer collected samples from 2009 through 2011 in the stream and in the tributaries. There are 1,601 days with measurements collected at Fibreville since January 1, 2001. This report focuses on the period beginning July 1, 2010, the effective date of the most recent NPDES Permit.10 The analyses presented evaluate True Color in the River in various ways. The first is an analysis of the samples collected at Fibreville. This location is approximately 0.4-mile downstream from the Mill's outfall, and has been considered the compliance point or edge of mixing zone. The dataset for the period July 1, 2010 through December 31, 2017, as well as the entire period of record was evaluated. The Comprehensive Assessment and Analysis of Color detailed that concentration in the River is not related to flow, but the color loading or pounds per day can be reasonably predicted based on the flow. The predicted mass loading can then be converted back to a concentration in order to predict a concentration. However, the analysis in this report focuses on measured concentration data. EVALUATION OF DATA The first evaluation is the proper identification of an average. The arithmetic mean is a common way to calculate an average. An arithmetic mean is simply the sum of the individual values divided by the number of values, or mathematically: n 1 Xi x= - t=1 n The arithmetic mean is strongly influenced by both large and small values. When a dataset is normally distributed, the arithmetic mean is appropriate. However, when a dataset is skewed, the arithmetic mean will no longer represent the central tendency of the dataset. Another average is the median value. 10 This report presents an analysis of color concentrations for the period July 1, 2010 — December 31, 2017. The specified term of the current NPDES Permit is July 1, 201 - June 30, 2015. However, Evergreen timely submitted its renewal application on December 31 2014. As such, the current permit is administratively continued pursuant to N.C. Gen. Stats. 150B-3 pending final action by NCDEQ on the permit. 6 A skewed dataset may follow a log -normal distribution. For these datasets, the mean and median are calculated using the formulas: 2 Mean, x1n =exp n ln(xi) n i=1 z p \ �n Li r (xL - x) / \ n (xL - x)z / ex 2* ti=1 n+ L=1 n * exp �i=1 n - 1 + 2 n In(xi) 3 Median, acjn = exp n i=1 Determination of Dataset Distribution The evaluation of the full dataset that extends from January 1, 2001 to the present indicates that most months follow a log -normal distribution. The goodness of fit results using the Anderson - Darling (A-D) test for both normal and log -normal distributions for the full dataset and the most recent dataset are presented in Table 2. When the result presented in the table is greater than 0.05, relating to a 95% probability, the dataset fit the specified distribution. The best fit distribution for each case is highlighted in Table 2. The appropriate calculations will be. used for calculating the monthly averages. Table 2. Goodness of Fit for a 95% Probability for Dataset at Fibreville MONTH Normal Distribution Log -Normal Distribution Full Dataset July 1 2010 - Present Full Dataset July 1, 2010 - Present January 0.00 0.03 0.23 0.16 February 0.00 0.00 0.20 0.34 March 0.02 0.20 0.12 0.22 April 0.00 0.00 0.40 0.10 May 0.00 0.00 0.08 0.29 June 0.00 0.00 0.22 0.37 July 0.00 0.90 0.19 0.01 August 0.00 0.00 0.21 0.24 September 0.00 0.00 0.00* 0.00* October 0.00 0.00 0.25 0.60 November 0.00 0.01 * 0.00* 0.00 December 0.00 0.04* 0.04* 0.01 Note: * = Value does not pass A-D test, but this distribution was used. EVALUATION OF IN -STREAM COLOR AVERAGES Long-term Daily Average for each Month for In -Stream Color Concentrations Measured at Fibreville The long-term average of the daily concentration values for each month for the period from July 1, 2010 through December 31, 2017 is presented in Table 3. This table demonstrates that the color concentration measurements at Fibreville are less than or equal to 40 color units on a long- term average for each month when flows are greater than or equal to the monthly 30Q2. The 90cn percentile column is presented since that method is used and accepted by EPA to determine if a set of data for a pollutant parameter is meeting a numerical water quality standard. The table shows that one month is as high as 61 color units at the 90t' percentile, while the remaining months are 53 color units or less. Though there is no North Carolina numerical water quality standard for color, discussions of acceptable target values for the Pigeon River in the range of 50 to 100 have been considered in the past. All of the values in Table 3 fall within or below this range. Table 3. Long-term Daily Average Color Concentration for each Month for In -Stream Measurements at Fibreville for July 1, 2010 through December 31, 2017 MONTH DISTRI- BUTION TOTAL NUMBER OF VALUES LONG-TERM DAILY AVG. WHEN FLOWS >=A30Q2 (mg/L) LONG-TERM DAILY AVG. WHEN FLOWS >=M30Q2 (mg/L) LONG-TERM 901h PER - CENTILE WHEN FLOWS >=M30Q2 m /L Jan. LN 61 27 18 29 Feb. LN 57 27 19 30 Mar. LN 64 26 19 27 Apr. LN 60 22 20 29 May LN 62 26 23 34 Jun. LN 54 43 31 45 Jul. N 70 48 30 40 Aug. LN 72 46 40 61 Sep. LN 70 51 39 53 Oct. LN 70 45 35 51 Nov. N 71 49 31 46 Dec. N 71 1 36 25 38 Annual LN 782 1 34 127 41 Note: LN = Log Normal A30Q2 = Annual 30Q2 Condition M30Q2 = Monthly 30Q2 Condition 1.1 The values in Table 3 do not represent a separation of background color and color contributed by the Mill. The long-term daily average Park Street measurements for each month are presented in Table 4. Table 4. Long -Term Daily Average Color Concentration at Park Street Upstream for Julv 1.2010 through December 31.2017 MONTH DISTRI- TOTAL BUTION NUMBER OF VALUES LONG-TERM DAILY AVG. WHEN FLOWS >=A30Q2 (mg/L) LONG-TERM DAILY AVG. WHEN FLOWS >=M30Q2 (mg/L) LONG-TERM 901h PER - CENTILE WHEN FLOWS >=M30Q2 (Ma/L) Jan. LN 61 11 12 22 Feb. LN 57 10 12 21 Mar. LN 64 10 11 19 Apr. LN 60 12 15 28 May LN 62 12 12 18 Jun. LN 61 16 15 27 Jul. LN 70 15 14 21 Aug. LN 72 15 15 25 Sep. LN 69 17 19 29 Oct. LN 1 70 1 18 21 1 31 Nov. LN 70 16 17 25 Dec. LN 71 15 18 33 Annual LN 787 14 15 26 Note: LN = Log Normal A30Q2 = Annual 30Q2 Condition M30Q2 = Monthly 30Q2 Condition Table 4 shows the variable nature of color in the Pigeon River upstream from the Mill. In some months the expected long term daily average when flows are greater than or equal to the Monthly 30Q2 are as high as 21 color units. The 90'h percentile values in some months are as high as 33 color units. Background concentrations have been measured as high as 94 mg/L in the Pigeon River upstream from the Mill.'' This means that no numerical water quality value below this can be a realistic target even if the Mill were not located on the river. Determination of In -Stream Color Delta at Fibreville The Pigeon River coming to the Mill in Canton has been measured for color on a routine basis. Because of the variability in background color as shown in Table 4, an in -stream delta between the background and the downstream location is more appropriate to evaluate the Mill's contribution to color in the River. Similarly to the in -stream values, the majority of the long-term " December 24, 2015 at Park Street Bridge in Canton E daily average delta concentrations for each month do not fit a normal distribution. The long-term daily average in -stream delta concentrations for each month are provided in Table 5. This table demonstrates that for any month, the long term daily average contribution of the Canton Mill to color at Fibreville when flows are greater than or equal to monthly 30Q2 is 25 true color units or less. The 90' percentile of color contribution of the Canton Mill does not exceed 43 true color units for any month when flows are greater than or equal to the monthly 30Q2. Table 5. Long -Term Daily Average In -Stream Delta Color Concentration at Fibreville Bridge downstream for Each Month for July 1, 2010 through December 31, 2017 MONTH DISTRI- BUTION TOTAL NUMBER OF VALUES LONG-TERM DAILY AVG. WHEN FLOWS >=A30Q2 (mg/L) LONG-TERM DAILY AVG. WHEN FLOWS >=M30Q2 (mg/L) LONG-TERM 90`h PER - CENTILE WHEN FLOWS >=M30Q2 m /L Jan. LN 61 16 6 11 Feb. LN 57 17 7 14 Mar. LN 64 16 8 13 Apr. LN 60 10 5 11 May LN 62 14 11 21 Jun. LN 53 28 17 25 Jul. N 70 33 16 29 Aug. LN 72 32 25 43 Sep. N 69 34 21 41 Oct. LN 70 27 14 30 Nov. N 70 32 14 24 Dec. N 71 21 7 17 Annual LN 779 23 13 28 Note: LN = Log Normal A30Q2 = Annual 30Q2 Condition M30Q2 = Monthly 30Q2 Condition Determination of Average Color on the French Broad River and Comparison to the Pigeon River at or near the North Carolina — Tennessee state line For comparison purposes, the color measurements collected on the French Broad River upstream from Newport, Tennessee are also included in Table 6. It is noted that the difference between the upstream and downstream locations on the French Broad River and on the Pigeon River are both 3 color units. This is consistent with the general expectation that color increases in the downstream direction as stream order increases. The Tennessee Department of Environment and Conservation collects samples on the Pigeon River near the state line, as well as, on the French Broad River at the Highway 70 Bridge 10 (near Del Rio, TN) and at the Highway 321 Bridge (near Newport, TN). There are not enough data points to calculate long-term daily averages for each month, nor to determine the proper distribution of the datasets. Overall averages of the three datasets are presented, along with the number of samples in each calculation. Table 6. Comparison of Color Concentration for In -Stream Measurements on Pigeon and French Broad Rivers PARAMETER PIGEON RIVER PIGEON RIVER FRENCH FRENCH AT PARK NEAR NC/TN BROAD RIVER BROAD RIVER STREET IN STATE LINE NEAR DEL RIO, NEAR CANTON TN NEWPORT, TN Drainage Area (sq. 130 538 1,713 1,858 mi.) Number of Samples 787 232 30 24 Samples Collected EPI TDEC TDEC TDEC by Average Color, mg/L 14 17 22 25 Minimum Color, mg/L 1 5 8 7 Maximum Color, mg/L 94 43 63 110 Note: Both French Broad TDEC stations are upstream from the confluence of the Pigeon River and the French Broad River near Newport, Tennessee. The Pigeon River near the state line and the French Broad River near Del Rio are especially suited for comparison purposes since 1) they both drain the identical ecosystem classification; 2) they are both level 5 on the Schuler stream classification system (stream order); and 3) the French Broad near Del Rio has no known large sources of color discharging to it. The comparison shows that the Pigeon River near the state line actually has less color than the French Broad River near Del Rio when compared to an equivalent stream system (i.e., same ecosystem and same order stream). This indicates the Pigeon River at the state line does not have color levels outside of the expected range for a stream with no large point source of color discharging to it. These data also show the difference in color at the Park Street Bridge on the Pigeon River and the color at the state line on the Pigeon River is only 3 color units which is outside the range perceptible by the human eye. 11 SECTION 4.0 FINDINGS AND CONCLUSIONS FINDINGS FOR THE PERIOD DULY 1, 2010 THRU DECEMBER 31, 2017: The long-term daily average color concentration at the Fibreville Bridge when flows are greater than or equal to the annual 30Q2 is 34. The long-term daily average contribution of the Canton Mill to true color in the Pigeon River is 23 true color units when flows are greater than or equal to the annual 30Q2. Based on a methodology used by and recognized by EPA, 30Q2 values for each month of the year for the Pigeon River more accurately reflects the hydrologic cycle over the course of the year. Color concentration measurements at Fibreville are less than or equal to 40 color units on a long- term average for each month when flows are greater than or equal to the monthly 30Q2. The 90th percentile of the long-term daily color concentrations at Fibreville when flows are equal to or greater than the monthly 30Q2, ranged from 27 in March to 61 in August. (90th percentile was examined from EPA's guidance on comparing a set of data to a specific water quality standard i.e. if the 901h percentile is less than a target value, then water quality standards are being met). The long term daily average color concentration added, i.e., the delta, to the Pigeon River by the Mill, at flows greater than or equal to the monthly 30Q2, is less than 25 color units for any month except August. Also, the 90th percentile of the color concentration added by the Mill, at flows greater than or equal to the monthly 30Q2, is less than 43 color units for any month except August. The color concentrations in the Pigeon River upstream from the Mill are variable. In some months the expected long term daily average color concentration, when flows are greater than or equal to the monthly 30Q2, are as high as 21 color units; and 901h percentile values in some months are as high as 33 color units. Also, color concentrations upstream from the Mill have been measured as high as 94 color units. This means that no numerical water quality value below. this can be a realistic target even if the Mill were not located on the river. OTHER FINDINGS: Comparison of the French Broad River near Del Rio shows the Pigeon River at the Stateline does not have color levels outside of the expected range for a stream with no large point source of color discharging to it. 12 The difference in the long-term daily average color concentration at Park Street in Canton, upstream from the Canton Mill discharge, and the long-term daily average color concentration at the North Carolina -Tennessee Stateline is 3 true color units. CONCLUSIONS: The long term daily average contribution (delta) of the Canton Mill to true color in the Pigeon River is 23 color units at flows greater than or equal to the annual 30Q2. The long term daily average color concentration at the Fibreville Bridge at flows greater than or equal to the annual 30 Q2 is 34 true color units. The difference in the long term daily average color concentration at Park Street in Canton (14 true color units), upstream from the Canton Mill discharge and the long term daily average color concentration at the North Carolina -Tennessee state line (17 true color units) is 3 true color units. This difference is minimal and imperceptible to the human eye. Though there is no North Carolina numerical water quality standard for color, discussions of acceptable target values for the Pigeon River in the range of 50 to 100 have been considered in the past. The long-term average and 90'h percentile values at Fibreville and the long-term average and 90a` percentile contributed by the Mill meet this target range. 13