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Home My WebLink AboutNC0000272_ColorRemovalStrategiesBlueRidgePaperProducts_20070814Blue Ridge Paper Comments 8/24/2007 MEMORANDUM DATE: August 14, 2007 SUBJECT: Color Removal Strategies For Blue Ridge Paper Products, Inc FROM: EPA Technology Team' TO: Technology Review Workgroup Purpose of this Review Blue Ridge Paper Products Inc. (BRPP) has requested renewal of their National Pollution Discharge Elimination (NPDES) discharge permit NC0000272. This permit allows discharge to the Pigeon River of industrial and other wastewaters from the pulp and paper mill BRPP operates in Canton, NC. In their May 2006 Color Compliance Report (Blue Ridge, 2006a), BRPP requested that North Carolina reissue the NPDES permit for the Canton Mill with an annual average effluent color limit of 39,000 lbs per day. This is a reduction from the current 42,000 lb per day annual average limit which became effective January 2004. BRPP's requested limit was based on the mill's 2005 annual average effluent color, 39,000 Ibs per day. EPA Region 4 requested that the EPA Technology Team ("Tech Team") support EPA's review of the color limits included in the draft permit renewal developed by North Carolina Department of Environment and Natural Resources. The Tech Team last evaluated color discharges at the mill in 2001 (EPA Tech Team 2001). Members of the Tech Team visited the Canton mill on February 8, 2007 with members of the Technology Review Workgroup (TRW) to observe and collect information and data on the status of technologies implemented and color discharges at the mill. This memorandum incorporates analysis of data provided by BRPP prior to and from that visit, and other data subsequently provided by BRPP at the request of the Tech Team. This memorandum reviews the process improvements previously analyzed by the Tech Team, the status of their implementation at BRPP, and identifies additional color reduction activities that BRPP could implement during its next permit term. This memorandum also reviews the variability of the mill effluent color discharges and suggests final effluent color limits for incorporation in the revised permit. Background and History BRPP operates a bleached papergrade kraft pulp and paper mill in Canton, NC, which it purchased from Champion International Corporation in May 1999. BRPP is owned 55 percent by KPS Special Situations Fund, L.P. and 45 percent by the employees through an employee stock ownership plan.2 BRPP announced on June 14, 2007 that it is being acquired by The Rank Group. The New Zealand -based Rank Group.has considerable holdings in the paper industry. Rank Group 'EPA Tech Team members are Ahmar Siddiqui, EPA/EAD; Karrie-Jo Shell, EPA Region 4; Donald Anderson, EPA/EAD; Betsy Bicknell, ERG, contractor; Neil McCubbin, subcontractor to ERG; Dan Bodien, subcontractor to ERG. 2 BRPP announced on June 14, 2007 that it is being acquired by The Rank Group. The New Zealand -based Rank Group has considerable holdings in the paper industry. Rank Group recently bought Evergreen Packaging, the former North American beverage packaging division of International Paper. Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 2 recently bought Evergreen Packaging, the former North American beverage packaging division of International Paper. Operations at the mill began in 1908, but the mill has been extensively modernized, with the most recent major project completed in 1993. The mill currently operates an 810 tpd hardwood pulping line and a 600 tpd softwood (pine) pulping line. After cooking, pulp from each line is further delignified in single -stage oxygen delignification (OD) systems, both installed in 1993. Hardwood pulp is subsequently bleached with a DED sequence (BRPP stopped adding oxygen to the hardwood E stage after 2001). Pine pulp is bleached with a DEoD sequence (BRPP stopped adding peroxide to the pine E stage after 2001). Target brightness is 86 ISO, an increase by one point from the target brightness in 2001. Up to 80 percent of the filtrate flow from the pine bleach line is returned to the recovery cycle using the unique Bleach Filtrate Recycle (BFRTm) process, developed by Champion. This 80 percent closure rate is an improvement from 2001, when the pine line closure averaged 73.7 percent. Up to 25 percent of the hardwood line bleach plant E-stage filtrate flow is also recovered. BRPP produces 300,000 tons per year of uncoated paper including offset, tablet, and envelope grades. The mill also produces 275,000 tons per year of bleached paperboard used for liquid packaging and paper cups, including FDA - approved grades for milk and juice cartons. Basic tenets of this review, which are consistent with the Tech Team's approach beginning with the original Settlement Agreement (with Champion International) and the 2001 TRW review with BRPP, are: • The first and highest priority again is focused on available in plant process changes and best management practices (BMPs) as the most cost-effective approach to color reduction in order to maximize the likelihood of success < Process changes deemed to be of highest and reasonable certainty, thereafter lowest certainty technologies < BMPs that hold promise'to further reduce generation and discharge of color • After it is clear that in plant process changes and BMPs alone may are not be sufficient, in plant segregated stream pretreatment and end -of -pipe treatment options will be are carefully considered The Tech Team recognizes that very difficult and unusual circumstances occurred in 2004, with back-to-back historical flooding of the Pigeon River and associated significant costs ($39 million) for repairing damage and replacing equipment at the BRPP mill after 21 days of being out of operation. The Tech Team also recognizes that significant additional expenditures have been made over the last permit term for environmental projects ($25.9 million), the largest portion for air pollution controls (e.g., MACT I and MACT II compliance) and including color reduction projects ($5.9 million), all building on previous projects and expenditures. All of this has occurred during a continuing period of industry -wide transformation, capacity shrinkage, and mill closings. Nonetheless, the BRPP mill management has committed to surviving these challenges. The Tech Team notes that these efforts and expenditures have resulted in substantial and commendable progress made to date by BRPP through expenditures for additional and improved best management practices, process and related technologies, and treatment technologies which have reduced the long term average color discharges. It is also noteworthy that some of these technologies and practices have been in addition to those identified in the previous Tech Team / TRW reviews. Process Improvements Previously Analyzed by Tech Team As a result of its 2001 analysis of the BRPP mill discharges and operations, the Tech Team identified five mill improvements that it judged capable of reducing the discharge of color in the mill effluent. BRPP and its consultant also identified several process optimization projects that Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 3 would reduce color discharges. The status of BRPP's implementation or evaluation of each of these improvements is summarized in Table 1, discussed below. Table 1. Review of Process Improvements Identified in 2001 _ Predicted Color: Reduction (Final _ Color - Effluent, lbs/day Reduction ,. Improvement arm. avg) Implementation Status Achieved :Comments Process 1,400 Predicted reduction in Consultant recommends reduced CIO, optimization CIO, use (27% on HW, use and evaluate adding oxygen and projects 17010 on SW) not made. peroxide to E'stages to reduce color CIO; use increased on generation SW, decreased 5% on IW Total reduction BFR reliability 1,000 — 1,200 Pine line filtrate recycle Further improvements to BFR improvement increased from 74 to from 2001: reliability may not be feasible 80%. 6,000 lb/day, annual Improved black >5,000 Spill collection Additional improvement to black liquor leak and improvements made; average liquor control possible: further spill collection untreated color (influent eliminate overflows and pretreat control (BMPs) to treatment) variability diverted high -color wastewater. Also unchanged improve control of losses of white and green liquors to reduce or eliminate sulfide -based color Ozone/CIO, 3;000 — 6,400 Incomplete inadequate BRPP concerns for this technology are stage for evaluation (lab studies); noted. Notwithstanding inadequacies hardwood line not installed None of lab studies, this technology considered low certainty in this case and further detailed study not warranted at this time. 2nd Stage OD for I,100— 1,400 Incomplete evaluation PRailed ...._:..eeFiRg @Vale^"^^ B@Od@' pine line (lab studies); not installed REJUGti8fi, followed by None additional study aFe nated, but still Laboratory studies and engineering analysis for cost and color reduction benefits are required. Color treatment <— 2,750 Evaluated (lab studies); CRP purge stream now averages 8,745 of CRP purge not installed lb/day. Detailed testing needed for stream extended period to determine what fraction of this color is removed in the None W WTP and strategies for reducing color released in the purge. Any color that is not removed in W WTP could be reduced with segregated stream pretreatment or other options. Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 4 z Process Optimization Projects In 2001, Liebergott & Associates and GL&V Pulp Group, prepared an extensive analysis of the mill fiberlines that included identification of options for effluent color reduction. Dr. Liebergott was retained for this work by a coalition of environmental groups. This report, Bleach Environmental Process Evaluation and Report (BEPER) (GL&V 2001) presented 16 recommendations for incremental improvement to fiberline operations. These included suggestions for improving process control, OD performance, reducing the amount of C102 used on both bleach lines, and enhancing the extraction stages on both bleach lines with oxygen and/or hydrogen peroxide. The BEPER recommendations were evaluated, and BRPP implemented those deemed to be technically, economically, and operationally feasible. Process control and OD performance have been improved. However, on the hardwood line, the Dl stage kappa factor has. not been decreased as previously recommended and use of oxygen in the extraction stage was discontinued. As a result, the total C102 charge on the hardwood line as of May 2006 was only 5 percent less (not the predicted 27 percent less) than the C102 charge in 2000. Similarly, on the softwood line, the Dl stage kappa factor was not decreased as previously recommended and the use of peroxide in the extraction stage was discontinued. As a result, the total C102 charge on the softwood line as of May 2006 was 1 I percent more (not the predicted 17 percent less) than the charge in 2000. While BRPP has noted the increased portion of higher brightness pulps since 2001 as a reason for these changes, among other trade-offs cited, the Tech Team continues to believe these changes may are still be viable and should remain as high eef4aiflty options that should be pursued for further color reduction. In preparation for renewal of their NPDES permit, BRPP retained Liebergott & Associates and GL&V Pulp Group to analyze their fiber lines, review the implementation of the 2001 recommendations, and identify further options for color reduction. In the 2006 update to the BEPER (GL&V 2006), the consultants repeated their recommendations for BRPP to reduce the kappa factor in the Dl stage of each bleach line and evaluate the replacement of the C102 bleaching power with oxygen and/or peroxide in the extraction stages. Increasing the operating temperature of the hydrogen peroxide extraction stage to reduce effluent color also has been identified as a viable option to evaluate during this process. In addition to reducing the color of the bleach plant effluents,, use of a lower kappa factor means BRPP would use less C102 to bleach, which will reduce the total chloride content of bleach plant filtrates. Lower chloride content can also be expected to make it possible for the mill to reduce the CRP purge flow and the color it contributes to the mill effluent. The Tech Team also.believes that lower chloride content could will make it possible for the mill to recycle more filtrates within the hardwood fiber line, notwithstanding BRPP concerns (e.g., adverse effects to washing, carryover to D stage, possible increased chemical usage and color). Further, it also may be possible to introduce a portion of these hardwood filtrates to the BFRTM process, which to this point has been dedicated solely to recovering softwood fiber line filtrates, and reduce the total colored filtrates discharged to the sewer. BFR'Reliability Improvement As reported during the Tech Team's February 2007 site visit, BRPP spent $1.5 million over the last five years to improve the reliability of the BFRTm system. These expenditures included replacing tank liners for the three existing sand filters (now high grade stainless steel), replacing and/or upgrading existing process piping with piping with improved metallurgy, installing a fourth (new) multimedia filter, and installing a third ion exchange softener. With these improvements in more Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 5 reliable metallurgy and unit process redundancy, BRPP has increased the BFRTm closure rate from 73.7 percent in 2001 to 79.2 percent in 2006. Mill representatives stated that the present closure rate of approximately 80 percent of the pine line bleach plant effluent represents the maximum amount attainable without incurring unmanageable corrosion and scaling problems. Further increases in closure and increased recycle rates above 80 percent may be possible but are likely to be a difficult challenge because of the corrosion and scaling problems associated with current mill bleaching filtrate chemistry. Scaling from hardness minerals accelerates above closure rates of 80 percent (Bodien, 2007). Improved Black Liquor Leak and Spill Control (BMWs) BRPP continued efforts intended to improve its management of leaks, spills, and intentional diversions of black liquor over the last six years. These efforts include: • Interconnecting the pine line and hardwood line spill collection sumps so that tankage in either line can be used interchangeably for spills; • Repositioning sewer conductivity probes from sumps to in -line to more accurately and reliably identify high conductivity wastewaters; • Diverting up to one hour of total mill flow to off-line 1-million-gallon clarifier, during high color releases, thus providing some equalizing of color discharge to wastewater treatment plant; • Prior to process line outages, improved prior planning for and capture of high -color process liquors and black liquors and better managing their timed release to treatment system; • Continued operator training; and • Implementing two hour testing for color at the W WTP with one hour testing during outages or semi-annual shutdowns. BRPP has stated that these improvements in,BMPs have resulted in reduced color variability in influent to the primary treatment unit, which BRPP asserts is the best measure of color reduction through in plant changes and BMPs. Data provided by BRPP are presented in Table 2 and depict Primary (total) Influent Statistics by year. Table 2. Primary (Total) Influent Statistics, by year _- Mean True Color pbs/day) . ' - _ -- Standard Deviation (SD) Relative _ '��, Standard Deviation (SD/mean %) Percent Decrease ', from Baseline. (2001) 2001 57,725 20,619 35.7% 0.00% 2002 54,780 17,195 31.4% 5.10% 2003 55,550 19,424 35.0% 3.77% 2004 1 49,466 18,786 138.0% 14.3 0 2005 45,175 22,297 49.4% 21.7% 2006 38,454 14,015 36.4% 33A% Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 6 Primary effluent, which is the total load to secondary treatment, is directly measured with a composite sampler. Data provided by BRPP and compiled by the Tech Team are presented in Table 3 (below) showing the mean, standard deviation, and relative standard deviation (standard deviation as a percent of the mean) by year, for the years 2001 to 2006. Prior to 2006, the acid sewer mixed with other mill wastewater prior to the treatment system, resulting in "sewer generated color." As of January 1, 2006, the acid sewer was separated from the other mill sewers and now enters the treatment plant after the primary clarifier ("primary effluent"). The primary effluent sampler is located downstream of the mixing point of the primary clarifier overflow and acid sewer. Thus, the statistics for 2006 presented in Table 3, represent the mixture of primary effluent and newly rerouted acid sewer, including any color generated from the mixing of the two streams. Some portion of the color generation is immediately measurable in primary effluent samples taken from the channel leading to the aeration basin. It is also likely that additional color generation from this mixing occurs, after the primary effluent sampling location within the aeration basin of the secondary treatment system, with additional time for any chemical reactions to proceed to completion. Table 3. Primary Effluent (Influent to Secondary Treatment) Statistics, by year Mean: ' True Color :(lbs/day) - Standard. _ 'D_eviation.(SD) _ - - Relative Standard Deviation (SD/mean'%) Number of days > 100,009lb/day' 2001 62,008 19,561 31.5% 13 2002 59,956 18,680 31.2% 16 2003 59,646 18,468 31.0% 10 2004 65,206 126,674 40.9% 40 200.9 63,838 24,158 37.8% 28 2006 65,512 25,427 38.8% 36 Table 3 presents the number of days for which the primary effluent color exceeded 100,000 lbs/day. Comments received from BRPP assert that primary effluent is not the most appropriate measure of progress. BRPP further stated that color loads to the primary treatment system have been reduced. h ealer leads kite the seeE).,a.. . treatment n stem b BRPP provided the Tech Team with notes describing mill events that were related to high peitnaFy influent color in 2006 (Blue Ridge 2007a). These events included, among others, planned mill outages, unplanned outages, a CRP slurry tank overflow, and a release from the evaporator related to an equipment failure. BRPP did not repeFt efie siiigle caused high celeF in the prifna^ errs„a.A. [This Tech Team statement is not correct. In the March 2007 response to addition questions, BRPP did provide information on cause of some elevated primary effluent color days.] Further, not all high primary effluent color resulted in a high final effluent discharge (e.g., BRPP reports that color associated with high turbidity is effectively removed in the secondary treatment system). However, from analysis of the data, the Tech Team concludes that the Canton mill can further reduce primary effluent loads through continuing efforts to minimize unplanned spills and leaks and planned discharges of high -color streams during fiber line disruptions. BRPP has reported some success through recent efforts in detailed, scheduling of Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 7 planned outages, contingency planning for unplanned outages, and continuing efforts to minimize process operation variability. The Tech Team wishes to acknowledge these efforts and their importance. While clearly challenging, these efforts must be further developed and consistently implemented where possible to minimizehigh color discharge risks all agree are associated with these fiber line disruptions, both planned and unplanned. The Tech team continues to believe that the information presented in Table 3, among other available performance data, holds valuable indicators and clues to the sources and solutions to reducing the overall performance and variability in effluent color discharged to the Pigeon River. On the other hand, BRPP has asserted that primary effluent information and other data collected within the Mill's biological treatment system are not indicative of the facility's true performance. BRPP believes that secondary effluent showed improvement, and data provided by BRPP are presented in Table 4 (below). Table 4 Secondary Effluent Statistics, by year - ' Mean - True Color Qbs/day)' _ Standard Deviation (SD) Relative Standard' Deviation (SD/mean %)_ Number of days " > 100;000lb/day 2001 42,676 10,925 25.6% 3 2002 41,166 9,928 24.1% 0 2003 44,627 11,043 24.7% 1 2004 * 41,463 32,568 76.6% 4 2005 39,092 10,092 25.8% 0 2006 37,058 8,959 24.2% 2 * - 2004 data were affected by historic floods in September 2004 Ozone/Chlorine Dioxide Stage for the Hardwood Bleach Line BRPP engaged the Pulp and Paper Research Institute of Canada (PAPRICAN) to investigate potential modifications to the hardwood pulp bleaching process and determine effluent color reduction that would result from these modifications. The PAPRICAN report entitled "Bleaching Evaluation for Effluent Color Reduction" (Audet et al, 2003) was provided to the Tech Team in early 2007. [BRPP note, copies of the 2003 PAPRICAN report were provided to the Technology Review Workgroup- which includes member of the Tech Team - during a color review meeting in at the Canton Mill in December 2003.] PAPRICAN stated that their objective was to evaluate whether modifications to the hardwood bleaching sequence at Canton specified by Mr. Johnnie Pearson (BRPP process engineer) could "generate effluents with a color reduction target of 25 percent." BRPP provided PAPRICAN with oxygen delignified hardwood pulp. PAPRICAN bleached this pulp in their laboratory, investigating various combinations of chlorine dioxide, ozone and hydrogen peroxide. The report concluded that ozone could replace some of the chlorine dioxide used in bleaching (known as a "ZD" stage), while producing pulp of equal or slightly better quality than the control sequence. This is consistent with the open literature on ozone/chlorine dioxide combinations. Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 8 PAPRICAN also concluded that replacing some of the chlorine dioxide in bleaching with ozone increased the color in the bleach plant effluents. This contradicts the experience reported by Domtar (formerly E. B. Eddy) at their Espanola mill, where a dramatic reduction in effluent color was observed when that mill installed an ozone pulp bleaching system (Munro and Griffiths, 2000). The Tech Team notes that the Espanola mill has no color discharge limits and it installed ozone to reduce its bleaching costs. The Tech Team found significant deficiencies in PAPRICAN's analysis of the laboratory results. The 2006 Liebergott / GLV report agrees with this finding. The concentration of color in the effluent for each stage was added to obtain the total concentration for each tested bleach sequence. This approach neglects two points: 1) Mixing effluents produces reactions that may increase or decrease the concentration of color in the combined effluent. 2) Filtrate volume affects the measured concentration (e.g., lower volume will concentrate the filtrate to a higher color). PAPRICAN's report does not present the filtrate volumes, so a comparison of concentrations may be misleading. Liebergott, et. al., reviewed the PAPRICAN report and identified the same deficiency with regard to effluent mixing. They also noted that the quantity of chlorine dioxide added to the ZD stage was too high, which would result in higher effluent color (GL&V 2006, p 18). In response to EPA's question about how the PAPRICAN results were used to estimate impacts on final effluent color; BRPP responded: The pilot study reactors were batch and not continuous and did not include filtrate recycle. The pilot studies included bleach stage filtrate color concentrations, but there was no filtrate flow rate data from which to calculate a production -normalized filtrate color mass. For these reasons, we did not attempt to calculate secondary effluent color impacts using pilot study data for individual bleach plant color streams. In the PAPRICAN study, the individual bleach stage colors were compared directly and in total. By both means, the color of the ZD stage was higher than the baseline DEoD. It is also well known that when individual bleach stage filtrates are mixed the resultant effluent color is very difficult to predict. (Blue Ridge,2007a) The Tech Team concludes that BRPP's investigation of the potential for hardwood pulp ozone bleaching to reduce the mill's effluent color was incomplete inadequate. Notwithstanding the above -noted inadequacies and upon reflection, the Tech Team believes that further laboratory trials appear not to be necessary because this application of ZD technology may not be appropriate for this mill at this time., Therefore, ZD technology is considered a technology option of lowest certainty for application at this mill at this time. Second Stage Oxygen Delignification for the Pine Bleach Line BRPP contracted with Andritz/AhIstrom ("Andritz") to study, among other things, the addition of an additional stage of oxygen delignification in the pine (softwood) bleach line at Canton. Andritz, a well established supplier of pulping and bleaching technology and equipment, maintains the Memorandum — with Blue Ridge Paper Comments 8/24107 August 14, 2007 Page 9 Pruyn's Island Technical Center, which conducted the tests. The Andritz report, entitled, "Laboratory CK and Lo-Solids Cooking with O-Do-Eop-D Bleaching Sequences on Softwood Furnish from Blue Ridge Paper, Blue Ridge, NC" (Andritz Ahlstrom Sales 2001) was provided to the Tech Team in early 2007. [BRPP note, copies of the 2001Andritz report were provided to the Technology Review Workgroup- which includes member of the Tech Team - during a color review meeting in at the Canton Mill in December 2003.1 The text of the Andritz report states that "BRPP requested the sales department of Andritz- Ahlstrom to investigate alternative methods of pulping and bleaching that would reduce their waste products and improve the quality of their hardwood and softwood paper products." As indicated by this statement of work, testing of second -stage oxygen delignification was a minor part of the work Andritz did for BRPP. Further, very few of the data in the report are useful for analysis of effluent color improvement. Specifically, Andritz compared single stage and two stage oxygen delignification of samples of pulp provided by the BRPP mill. The tests showed that a second stage of oxygen delignification could reduce the kappa number of the unbleached pine pulp by 22 percent. Andritz did not bleach the pulp after the two stage oxygen delignification, so the report provides no information on the impact of the additional oxygen delignification stage on effluent characteristics, including color. In response to EPA's question about how the Andritz results were used to estimate impacts on final effluent color, BRPP responded: The Andrtiz-Ahlstrom study of second stage 02 for pine showed delignification ranging from 42.7 percent for,the single stage, 48.6 percent for the 0-0 and 55 percent for the 00 stage. With improvements that BRPP made on the existing single stage pine 02, the deliginification increased from 40 percent to 45 percent. With BFR in place on the pine fiberline, the effluent color reduction from this improvement in 02 deliginiflcation has been very difficult to identify. The inability to quantify the effect on effluent color of improved 02 deliginification made the capital cost to install a second stage 02 on pine not economically feasible. (Blue Ridge, 2007a) BRPP's analysis of the benefits of adding a second oxygen delignification stage to the pine line is incomplete. BRPP's consultants note that even with the percent delignification currently achieved on the pine line, a second stage could achieve an additional 20 to 25 percent delignification (see GL&V 2006, p 118). By making a 20 to 25 percent reduction in the kappa number of the pine pulp before bleaching, 20 to 25 percent of the colored material currently discharged from bleaching to the BFRTM could potentially would be recovered and burned in the mill's recovery boiler. hi addition, the quantity of chlorine dioxide and caustic required in bleaching would be reduced by approximately 20 to 25 percent, reducing the load on the BFRTm system. This may ivettld allow an increased proportion of the bleach filtrates to be recycled through the BFRTm system. BRPP believes that a kappa number decrease or delignification efficiency increase would not necessarily equate to a similar decrease in color. Although with the information available it is not possible to rigorously calculate the benefit Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 10 of this change, the Tech Team would expect on the order of 1000 Ibs/day reduction in bleach plant color discharge. In 2001, the Tech Team recommended that BRPP conduct a detailed study to develop an engineering design leading to installing an additional oxygen delignification stage for the pLne (softwood) pulping/bleaching line. The Tech Team estimated that this process change would reduce effluent color by 1,100 to 1,400 Ibs/day. Liebergott, et. al., (GL&V 2006) estimated that implementing a second oxygen delignification stage on the pine fiber line would reduce color discharge by 1142 lbs/day. They estimated the capital cost of adding an additional oxygen delignification stage would be in the order of $2 to $3 million and the chemical cost savings approximately $1.2 million/year, providing a reasonable payback. Mill staff has mentioned a three year pay -back, which is consistent with this estimate. However, the mill has further asserted from their more recent estimates that the cost could be $3 to 5 million owing, presumably at least in part, to increases in the general prices of stainless steels (not as specifically fabricated and estimated for this technology). The BRPP oxygen delignification systems were installed in 1993. Since that time, the use of two -stage oxygen delignification rather than the traditional single -stage systems has become well established in the industry because it normally further reduces mill operating costs. - BRPP believes that the previous evaluation of adding a second stage oxygen delignification stage should be repeated in part because of differences cited in delignification efficiencies, and concerns for possibly lower -than -estimated color reductions. Notwithstanding these concerns, the Tech Team continues to believe this technology has progressed beyond being considered "reasonable certainty" in 2001 to "highest certainty" at this time. Therefore, the Tech Team again recommends that priority should be given to a detailed evaluation for identifying necessary adjustments to upstream pulp digestion (e.g., kappa number targets), downstream bleaching (e.g., bleaching chemical usage rates) and brightness/strength parameters, designing and costing, and refining color reduction projections. In order to satisfy BRPP's recent concerns, an update from the results of this work may need to be shared with the TRW. pFier to being implemented at the ear4iest possible date- Andritz also evaluated modifications to the mill cooking process. These would require complete replacement of the digester systems at Canton, which would cost (at least) several tens of millions of dollars, if they are feasible at all within the mill's space constraints. The Tech Team concluded that while theoretically possible, modifications to the mill cooking process do not merit further analysis at this time. Treatment of CRP Purge Stream for Color Removal The Chloride Removal Process (CRP) purge is a low flow, highly concentrated stream. Color is typically 41,000 platinum cobalt units (pcu) in a stream that discharges at 10 gpm (15,000 gal/day eF 3 tank tFueks/day). BRPP reported that in 2006 the CRP purge contributed approximately 8,745 lb/day (23 percent) of the total mill color loading to the treatment system but only 0.05 percent of the discharge flow. By comparison, in 2001 the CRP contributed approximately 5,000 lb/day (13 percent) to the treatment system loading (EPA Tech Team, 2001). Thus, in the last five years there has been a significant increase in color contributed by the CRP, both in lb/day and in percent of total mill load. BRPP reported on its investigations into technologies for reducing CRP purge color in its March 2005 report, "Chloride Removal Process (CRP) Color Reduction Technology Assessment" (Blue Ridge 2005). In this report, BRPP points out that the CRP purge is a very concentrated material (360,000 mg/L or 36 percent total dissolved solids) that is discharged to sewer at 165' F. Handling the material is difficult because it will crystallize as it cools. Also, it is quite corrosive due to the high chloride content. Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 11 As described in their 2005 report, BRPP assessed more than nine alternatives for disposal or treatment of the CRP purge and concluded that none was technically feasible. Although consistent performance was not demonstrated, C1O2 bleaching was a low cost, potentially effective means of reducing the CRP purge color prior to introduction to the treatment system. BRPP found that C1O2 bleaching could potentially remove up to 75 to 90 percent of the color in the CRP purge stream, with some concern about consistency. This is a n., era:a:eant reduet:nn : a now prominent sourse ne Geier. Although CRP purge is a relatively low flow stream, BRPP estimated that off -site solidification and land disposal would cost more than $3.6 million/year, which does not include the additional cost of loading facility infrastructure. During the Tech Team's 2007 mill visit, BRPP stated that there was no apparent decrease in secondary effluent color when CRP wastewater was not flowing into the treatment system. In response to a Tech Team request, BRPP presented data correlating the days on which the CRP process was shut down with secondary effluent discharge color, for August 2006 to January 2007 (Blue Ridge 2007a). During this period, there were nine widely dispersed pairs of days when the CRP process was down for part of the day. BRPP believes that CRP color is removed in the secondary treatment system, based on their analysis of variance (ANOVA) comparing "down" days with CRP operating days and "general observations." In response to a Tech Team follow-up request for clarification, BRPP later asserted that these data allowed no definitive conclusion, and that there is no relationship of presence or absence of CRP purge to secondary effluent color based upon general observations. The Tech Team does not agree with this belief or rationale for the following reasons. First, with one exception, the periods of CRP shutdown are only a day or so each, which is insufficient time for the W WTP to stabilize with the change in raw effluent characteristics. Second, the times of shutdown and startup of the CRP do not correspond with the effluent sampling times in the mill system, so that there is no direct correlation in time with the effluent sample. Further, the fact that all CRP "off' days are in pairs suggests that CRP was down for a period that spanned parts of two mill sampling days. The simple mathematical average of treated effluent color discharge during "CRP off' days for August to December 2006 is 39,995 lbs/day. The average when the CRP process was operating is 36,958 lbs/day. This suggests that the presence of the CRP purge stream in the wastewater treatment system causes a reduction in effluent color. This defies common sense. Also, the difference in effluent color between the "CRP on" and "CRP off' days is 7 percent, while day to day variations in color discharge values are frequently over 20 percent, tending to subsume and confound any analysis of the impact of changes in the CRP purge stream. BRPP asserted that color performance data from this period likely varied due only to normal day-to-day performance variation. In short, because there are so few consecutive days without a CRP purge, the data from the period August to December 2006 are not sufficient for establishing the extent to which the CRP purge contributes to final effluent color. In order to explore this further, BRPP could conduct a fall sea4e H 414 trials in which BRPP would further evaluate the impact of CRP on effluent color. the FF h GRP .. a F.. at least three weeks, ...! allow the ehlefide ntfatiOn t.. nln...ly bUil 7 Up �r Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 12 _... _..-_ :r- -1-1111 _-- - - - i NWMW r r•. tl r r . tl BRPP mill staff asserted expressed concern that a full-scale shut off of CRP purge to the treatment system for sack a an extended period of time (e.g., at least three weeks) would not be operationally feasible. but offered . speeifig farA9 OF FRMORS .. I., this would be the Gase. Nonetheless, ; Given BRPP's concerns for operational feasibility at full scale, the Tech Team is open to another reasonable approach that could be devised. Such an approach would need to gather the data necessary over a sufficient period of time to better identify and quantify the underlying color loads to the treatment system, both with and without the purge from CRP. Moreover, it would be important to identify and quantify to the extent possible any changes in the downstream color generation and removal processes that are occurring with the current acid sewer introduction point just upstream of the aeration basin in the secondary activated sludge wastewater treatment system. BRPP also could investigate approaches to prevent color from accumulating in the CRP. The source of the color in the CRP purge stream is carryover of black liquor particles in the direct contact evaporators (DCE) in the recovery boiler systems. This carryover could be eliminated if the two traditionally designed recovery boilers (which are 34 and 42 years old) were replaced by one modern boiler. This would probably represent a capital cost of over $100 million, and would very substantially reduce the energy costs at the mill, since today's recovery boilers are much more efficient than the DCE / recovery boiler systems of the vintage installed at Canton. Analysis of all the economics and long term life of the mill would be necessary to evaluate such a major investment. On a more modest level, it may be feasible to reduce black liquor carry over by adjusting operating conditions in the existing DCE's. The Tech Team is not aware of any experience with this in other mills, or research, but the situation at Canton strongly suggests that at least some investigation and trials of modifications to the operations is warranted. Any of the measures discussed previously in this document to reduce C102 use could reduce the quantity of chloride to be removed in the CRP purge stream. If this is reduced, the color discharge also would be reduced. BRPP should also further investigate C1O2 treatment and other treatment of color in the segregated CRP purge stream and other approaches for excluding the CRP purge stream from the mill discharge. Additional Color Reduction Strategies The Tech Team has identified the following color reduction activities that should be for improving the color removed by the Canton Mill wastewater treatment plant: • Investigate in further depth color formation when acid wastewater is mixed with mill wastewater in the current configuration, with and without the CRP purge, and identify techniques to reduce this effect; Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 13 Maintain addition of polymer and/or other treatment chemicals to the high -color wastewater diverted to the extra primary clarifier, and investigate improving equalization and pretreatment performance; and Further investigate adding polymer and/or other treatment chemicals to aeration basin mixed liquor prior to introduction to the secondary clarifiers. These strategies are discussed below. Color Formation When Acid Wastewater Is Mixed With Mill Wastewater BRPP provided the Tech Team with daily color data for the "Low Lift" (mill sewer), acid sewer, and primary effluent sampled after the acid sewer is added in the discharge channel of the.primary clarifier leading, to the aeration basin of the secondary activated sludge biological treatment system. Figure I (below) presents the total mill color calculated by adding the mill sewer lb/day to the acid sewer lb/day (the lower (blue line) on the figure). For comparison, the primary effluent sampled after the acid sewer is introduced is also shown on the figure (the upper red line on the figure). Thus, the figure depicts the impact of mixing the acid sewer with the rest of the mill effluent3. 150,000 Total untreated color, before and after mixing, 2006 125,000 100,000 75,000 50,000 25,000 Wan 31-Jan 1-Mar 31-Mat 30-Apr 30-May 29-Jun 29+tut 28-Aug 27-Sep 27-Oct 26-Nov 26-Oec Figure 1: Impact of Mixing Acid Sewer and Mill The Tech Team observed: The quantity of color formed on mixing the acid sewer and mill sewer is striking. On average, the quantity of color formed is 78 percent of the total color in the two streams. In other words, the simple mixing of these streams forms nearly half the total color discharge from the mill. The variation in quantity of color formed by mixing the effluent streams from day- to-day is dramatic, as is evident in the graphs. When expressed as a percentage of primary input color, the value ranges from essentially zero on some days to a maximum of 480 percent. There is no obvious correlation between the values on any one day, or series of days close to one another; however, statistical analysis has not been attempted. 3 The color of the mill sewer wastewater may be reduced somewhat by treatment in the primary clarifier. This color reduction is neglected in the calculated untreated color, so Figure I is probably a slight underestimate of the impact of mixing the acid sewer with the rest of the mill effluent. Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 14 Notwithstanding these observations, the Tech Team understands and appreciates BRPP's efforts during the last permit term to reduce color formation through the acid sewer relocation project. The Tech Team suggests that BRPP build on this project and the above color reduction strategies to better understand the mechanisms of and the follow-up strategies for reducing color formation in, the current sewer configuration. BRPP could investigate, among other things', how sulfides introduced by leaks, spills, and unplanned discharges from white and green liquor systems into the mill wastewater contribute to effluent color. In particular, BRPP could investigate whether sulfides in the mill wastewater contribute to color formation when acid sewer is added to mill effluent prior to biological treatment. Approaches to this investigation should include: Laboratory experiments on effluent with varying degrees of sodium sulfide addition; and Daily measurement of the, sulfide content of the effluent from the primary clarifier influent at the low lift pump sampling station for a period of at last three months to determine correlation of sulfide concentration with color formation. In most mills, losses of sulfides can be reduced. Well known sources include imbalance in the weak wash system, as well as spills of white, black, and green liquor. BRPP should further investigate losses from the green and white liquor systems and technologies that can reduce these losses. Improving WWTP Performance Using Chemicals Several bleached kraft mills around the world have successfully reduced color to well below 5 lb/ton pulp by installing tertiary treatment systems. These systems use polymers and other chemicals to precipitate color bodies, then remove the precipitate in tertiary clarifiers. One of the newest of these mills is Celco in Valdivia, Chile. This mill has excellent in -plant effluent control, a conventional secondary wastewater treatment plant, followed by a small tertiary system. l €€luent ffafn ♦6:s mill is depieted in Figure 2 (below) beside the effluent Henn ODUD BRPP Comment — the effluent comparison pictures are not appropriate and do not add anything to the technical discussion Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 15 The Tech Team notes that treatment systems like the one operated at Valdivia have a capital cost in the tens of millionsof dollars, and can create issues with solid waste disposal. lRPP-alse However, some more modest control measures using variations of this technology also exist. For example, since March 2004, Glatfelter hic., Spring Grove, PA has supplemented its in -plant color control strategies by using a commercially available polyaluminum chloride polymer to enhance color removal in the wastewater treatment plant. The polymer is added in the discharge flume from the aeration basin, just upstream of the mixing box feeding the four secondary clarifiers. The polymer reduces pH and complexes with organic compounds that produce color. Colored material settles out with the secondary sludge which is held in the former stabilization basin before dewatering. Glatfelter has not reported sludge dewatering problems. Polymer used for additional color removal reportedly costs on the order of $2,000 to $3,000/day. Moreover, neither the Valdivia mill nor the Glatfelter mill employs the BFRTm system as applied at BRPP. As further in -plant process changes and improved BMPs are implemented and color loads are reduced in magnitude (long term average and variability) and change chemical composition, BRPP could conduct further laboratory trials of commercially available polymers and other wastewater treatment chemicals. In some cases this may entail repeats of previous tests, for example for polyamine, but under potentially different circumstances and wastewater chemistry than previously tested. In addition to those previously evaluated, it could be helpful to assess adding one or more of these chemicals upstream of the secondary clarifiers. During these trials BRPP would determine the potential for reducing color discharge and estimate the costs. Such analysis would consider seasonal use of the additive chemicals (i.e., adding the chemicals during periods when river flow is low and the mill discharge has the greatest impact on the river color). The Tech Team acknowledges BRPP concerns regarding significant issues that may occur, such as possible effluent toxicity, difficulty in sludge dewatering, and cost. If the laboratory trials are successful, BRPP could institute a full-scale trial for one month, and report results to the TRW. Pretreatment of Diverted High -Color Wastewater BRPP currently diverts up to one hour of total mill flow at current flow rates to their off-line 1- million-gallon clarifier, during high color releases. The purpose of this flow diversion is to equalize color contributions to the wastewater treatment plant. Diverted high color wastewater is batch pretreated by polyamine and returned to the wastewater treatment system. The Tech Team believes that BRPP should further investigate options for increasing the performance of equalization and pretreatment capacity beyond that which cuirently exists. This would probably be an important contribution to both further reducing color variability, an increasingly higher priority endeavor as long term averages are reduced, and to removing color before being introduced into the secondary activated sludge biological treatment system. Summary: Additional Identified Color Load and Variability Reducing Activities that BRPP can Pursue in the Next Five Years Since installing the BFR process and other improvements (OD, BMPs, etc.), BRPP is to be commended for the important progress in reducing their annual average color discharges, which needs to be continued. However, high color discharges continue to be experienced for short periods (e.g., daily) and these discharges become more evident as the annual average discharge is reduced. When these discharges coincide with periods of low river flow (typically in the late summer), they can contribute to an elevation in river color that could be noticeable to the citizens who use the Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 16 river. Thus, reducing the impacts of the peaks in color discharged from the mill requires not just reducing the annual average color discharged but also reducing variability measured by the daily color discharges. Mill process changes that reduce wastewater color are generally preferred to end - of -pipe treatment because they may have lower capital costs and may benefit the mill by reducing operating costs and improving process efficiencies. However, mills in environmental regulatory jurisdictions with severe restrictions on their color discharges have been required to implement end - of -pipe color removal technologies since the 1970's. Although the Tech Team continues to maintain the highest priority for in -mill improvements such as process changes and optimization, increased black liquor recovery and further improvements in BMPs, external color removal technologies should continue to be considered carefully in the mix of options for further controlling the color of BRPP's discharges. These color removal technologies include, with first priority, treatment of segregated low -volume concentrated wastestreams (e.g., the CRP purge) and thereafter end -of -pipe wastewater treatment. The Tech Team identified strategies focused primarily on in -mill process improvements but also including color treatment that BRPP can use to further reduce its effluent color discharges. These strategies are summarized below. Continue to improve the performance of BMPs to further substantially reduce and ultimately eliminate discharges of highly -colored wastewaters directly to the wastewater treatment system through further improvements in - o managing and controlling planned and unplanned releases of highly colored process liquors through regular mill staff meetings o interconnected collection sump capacity within the mill available to both fiber lines for capture and recovery of leaks, spills, and planned diversions of black liquor and other highly -colored wastewater o increasing use of short-term testing to supplement advanced real-time process monitoring, rapid communication among mill staff, identifying and immediately repairing failed equipment / parts, regular operator training, and o moving forward with the planned CRP sump and containment project to eliminate unplanned releases of this highly -colored material to the mill sewer. On the pine bleaching line, conduct full-scale trials with iniple...ent the use of peroxide fortification of the Eo stage and decrease the target kappa factor as recommended in BEPER 2001 and by Liebergott / GL&V 2006. Evaluate the use of high temperature for the peroxide -fortified extraction stage. On the hardwood bleaching line, conduct full-scale trials with implement of oxygen and peroxide fortification of the E stage and decrease the target kappa factor as recommended in BEPER 2001 and 2006. Evaluate the use of high temperature for the peroxide -fortified extraction stage. Complete an expedited and detailed evaluation of and install an additional oxygen delignification (OD) stage for the pine pulping/bleaching line. Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 17 f+en. the GRP n nif4e.nt nn.Nnn of thO tnt.d ..819F discharged f em the .nlll 1rooesses. Continue to evaluate the impact of the CRP purge on treated effluent color to determine if the CRP color, now a significant portion of the total color discharged from the mill processes, is removed by the treatment system. Such an effort may take special efforts to accomplish and for a meaningful period of time. If CRP color is not removed in the treatment system, investigate approaches to prevent color from accumulating in the CRP, such as reducing black liquor carryover by further adjusting operating conditions in the direct contact evaporators. Also, if CRP color is not removed in the treatment system, further investigate C1O2 pretreatment of the CRP purge to reduce its color prior to being introduced into the mill wastewater treatment system. If the CRP purge color is found not to be removed in secondary treatment, avoid releasing the CRP purge during periods of low stream flow (or truck it off site); Continue to investigate and implement strategies for improving color removed by the Canton Mill wastewater treatment plant: — Further analyze color formation when acid wastewater is mixed with mill wastewater in the current configuration, particularly in the activated sludge aeration basin, and identify other techniques, such as minimizing sulfide releases to the mill sewer from white and green liquor leaks, spills, and/or diversions, to reduce this effect — Maintain or further increase the performance for pretreating highly -colored wastewaters prior to introducing them to the wastewater treatment system, including further optimizing adding polymer and other pretreatment chemicals to the highly -colored wastewater diverted to the extra primary clarifier and/or any additional facilities that may be provided; — Further investigate treating total mill biological system effluent prior to discharge using polymers or other wastewater treatment chemicals upstream of the secondary clarifiers, particularly during periods of high influent color and/or low river flow; and Curtail pulp production during periods of low stream flow; this should continue to be considered an option of last resort, given that best performance has been noted by the mill to be during extended periods of steady production and greater risk of elevated color during process shutdown and startup. See Low Flow Contingency Plan, December 1, 1998. Suggested Final Effluent Color Limits for Blue Ridge Pulp and Paper Substantial and commendable progress has been made to date by BRPP through expenditures for additional and improved process and related management practices and treatment technologies which have reduced the long term average color discharges. Some of these technologies and practices have been in addition to those identified in the previous Tech Team / TRW reviews. This .. b., ..b . ..................... ........ . r.,.... ... ....... ........... T h T d 1. TDlll/ .....1 tt.e T.Tn.tl. !'...nl:..., T�.....�t..,ent nF IIn.:. ent and x cam.. .�...... _........ nn..._--___ Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 18 quality of the Pigee.. River. ....� Dell. .7..:um and maximum 30 day aye fage ..er..,:t lifnits wealthp, congktefley of day to day in stream water quality, and would be eansiment with limitq fer ..then ....r. meters eentrelled in the p e..t BRP-P .erMit (BOD-sTQQ A DV ete ) The Teeh Team alqe bAiPvP..q that these effiaefit limitations fOF eOIGF ShRI-114 contim-w. to bF,- applie-1 unambigueusly at the end of pipe Eliseharge ef the mill to the river. HeweveF, the euFrent peFmit is not ele..r that this is the point of applio tion of effl..em limits fer ealar. See Table A(!), which pFeseribes end of pipe monitering, but no eelar limits are ineluded. See the TRW's 2001 Memorandum, at item na- 9- —BR—PP has eemmetited that inelusion of a daily maximum end of pipe ., daily m ni I:...:t ♦h.,t ...... .. e„d thus diyei4ing limited mill staff and resawees away The Tech Team's recommended range of end -of -pipe permit limits and the derivation of these limits are presented in Table 5, and discussed, below. Table 5. Tech Team Recommended Range of End -of -Pipe Color Permit Limits Limit - -. -.. Range of Recommended Limits (lb/day), _ Annual Average 32,000 to 37,000 30-day (Monthly) Average 44,800 to 51,800 Daily Nimiffia+n 93840 to 96,940 Basis for Recommended Annual Average for Color BRPP provided daily measurements secondary effluent color (lb/day) for every day in 2006. Examination of the daily measurements for 2006 identified two days (July 7 and 8) with measured discharge greater than 100,000 lb/day. BRPP reported that this elevated color discharge resulted from "CRP slurry tank overflow for approximately 20 minutes, the first time the mill experienced this type of event." Because these discharges were so high and from a unique source, they were omitted from the calculation of the annual average. The annual average for 2006, without July 7 and July 8, is 36,695 lb/day, which rounds to 37,000 lb/day. This annual average load is less than the 39,000 lb/day suggested by BRPP. However, it is basedon the mill's 2006 performance and does not include any reductions that may be achieved by the process changes outlined in this memorandum. As a result of analysis of the BRPP mill discharges by the Tech Team and others in support of the 2001 permit, the permit's interim color goal was 32,000 lb/day with a range up to 39,000 lb/day. As described earlier in this memorandum, the Tech Team recommends that BRPP implement several key process improvements and investigate others in order to reduce the annual average color performance toward the overall permit interim goal of 32,000-37,000 lb/day, which the Teeh Teafn reee.. meads h,....,rr:ed F d Frafn h 2001 p@Fmit as the geai f this Basis for Suggested Daily Maximum and 30-Day Average Limits for Color The statistical analysis used for the development of EPA's Cluster Rules is documented in Statistical Support Document far the Pulp and Paper Industry: Subpart B (EPA, 1997). This Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 19 document describes EPA's development of, among other things; the variability factors that were used to calculate NSPS for BOD5 for the Bleached Papergrade Kraft and Soda (BPK) subcategory. These variability factors are reproduced in Table 6. Table 6. Bleached Paper grade Kraft NSPS Variability Factors V ari ability lFactors Analyte 4 Bag 30-Day (Monthly) BODS _ ..._. _ 1.4 Source: U.S. EPA 1997. Table 2-4. The BOD5 variability factors shown above were developed using daily monitoring data for the best performing (in terms of production normalized BOD5 load) BPK mills. The monitoring data represent the effluent from well -operated wastewater treatment systems. The calculated variability factors account for the autocorrelation of the daily loads and the log -normal distribution of the measurements. Applying the BOD5 variability factors to the 2006 recommended annual average daily color discharge results in the following daily maxifaum-and 30-day average limits: Daily Tax:.......,. 37,000 lb/day x 2.62 — 96,940 lbida y 30-Day (Monthly) Average: 37,000 lb/day x 1.40 = 51,800lb/day ., .. .. .. . . 4... . .. .. .. ... _.. .. .. ... .. ....., .. .... .. . .. ..MMMMWAM.. _ ATA .. .. ...I •. .. .... •. . .I Memorandum —with Blue Ridge Paper Comments 8/24/07 August 14, 2007, Page 20 .. .. BRPP Notes concerning suveested final effluent limits — Effluent color limits are specified on Condition A.(8.) of the 2001 NPDES permit. The compliance point is the secondary effluent sampling flume. A 95% confidence interval applied to the Canton Mill 2006 effluent color performance yields an annual limit of 38,000 lbs per day true color. The Tech Team comparison of Blue Ridge Paper Canton Mill to Glatflter Spring Grove omits several important differences between the two mills. Each mill's situation is unique. When all the differences between the mills are properly considered, the color control performance of the two mills are similar. This section should be removed. Memorandum — with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 21 References Andritz Ahlstrom Sales. 2001. Pruyn's Island Technical Center Report 2001-068 Part 1. Laboratory and Lo-Solids Cooking with O-Do-Eop-D Bleaching Sequences on Softwood Furnish from Blue Ridge Paper, Blue Ridge, NC. Part 1 Softwood Results. Part 2. Hardwood Results. (December 6). Audet, Andre, Michel Faubert, Zhi-Hua Jiang and Barbara van Lierop, PAPRICAN. 2003. Technical Service Contract Report TSC-7447. Bleaching Evaluation for Effluent Colour Reduction. Prepared for Blue Ridge Paper Products, Inc., Canton, NC. October. Blue Ridge Paper Products, Inc. 2005. Chloride Removal Process (CRP) Color Reduction Technology Assessment. (March). Blue Ridge Paper Products, Inc. 2006a. Color Compliance Report: Canton Mill. (May). Blue Ridge Paper Products, Inc. 2006b. Blue Ridge Paper response to questions from the Technology Review Workgroup (TRW) that were.e-mailed on 28 Nov 2006. (December 19). Blue Ridge Paper Products, Inc. 2007a. Response to additional questions for BRPP about data provided to TRW Don Anderson e-mail dated 5 March 2007 (March 15) Blue Ridge Paper Products, Inc. 2007b. March 19, 2007 Additional Data Required from BRPP (March 28). Bodien, Danforth G. 2007. Site Visit Report, Blue Ridge Paper Products, Canton, North Carolina. (April 2007) EPA Tech Team. 2001. Memorandum to Technology Review Workgroup. "Additional Color Removal Technologies and Their Economic Impacts on Blue Ridge Paper Products, Canton, NC." (July 25, 2001). Furjanic, Sean M. 2007. Water Quality Protection Report, P. H. Glatfelter Company, Spring Grove Borough and Jackson Township, York County, for the Renewal of NPDES Permit No. PA 0008869. PADEP Southcentral Regional Office (draft, February 2007). GL&V Pulp Group, Inc. and Liebergott & Associates Consulting. 2001. Bleach Environmental Process Evaluation and Report. Prepared for Blue Ridge Paper Products, Inc. and Clean Water Fund of North Carolina. (June 8) GL&V Pulp Group, Inc., Liebergott & Associates Consulting. 2006. 2006 Update: Bleach Environmental Process Evaluation and Report. Version containing manufacturer's proprietary information. Prepared for Blue Ridge Paper Products, Inic. (July 7, 2006) Munro, Fred and John Griffiths. 2000. Operating Experience with an Ozone -based ECF Bleaching Sequence, Proc. International Bleaching Conference, Halifax, Canada, 2000. TAPPI Press. Technology Review Workgroup, 2001. Memorandum to North Carolina Division of Water Quality and the NC Environmental Management Commission's NPDES Sub -Committee. Memorandum —with Blue Ridge Paper Comments 8/24/07 August 14, 2007 Page 22 "Additional Color Removal Opportunities, Blue Ridge Paper's (BRP) Canton, NC Bleached Kraft Paper Mill, 2001 NPDES Permit Renewal." (August 3, 2001). U.S. EPA, 1997. Statistical Support Document for the Pulp and Paper Industry: Subpart B. (November)