Loading...
HomeMy WebLinkAbout7 EPA Demo Project Vale OR Ion Exchange_20170726EPA/600/R-1 1/040 April 2011 Arsenic and Nitrate Removal from Drinking Water by Ion Exchange U.S. EPA Demonstration Project at Vale, OR Final Performance Evaluation Report by Lili Wang§ Abraham S.C. Chen§ Anbo Wangi Wendy E. Condit* +Battelle, Columbus, OH 43201-2693 §ALSA Tech, LLC, Columbus, OH 43219-6093 Contract No. 68-C-00-185 Task Order No. 0029 for Thomas J. Sorg Task Order Manager Water Supply and Water Resources Division National Risk Management Research Laboratory Cincinnati, Ohio 45268 National Risk Management Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Cincinnati, Ohio 45268 DISCLAIMER The work reported in this document is funded by the United States Environmental Protection Agency (EPA) under Task Order 0029 of Contract 68-C-00-185 to Battelle. It has been subjected to the Agency's peer and administrative reviews and has been approved for publication as an EPA document. Any opinions expressed in this paper are those of the author(s) and do not, necessarily, reflect the official positions and policies of the EPA. Any mention of products or trade names does not constitute recommendation for use by the EPA. ii Ia[/] 7 WViY1 '7 F The United States Environmental Protection Agency (EPA) is charged by Congress with protecting the nation's land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural systems to support and nurture life. To meet this mandate, EPA's research program is providing data and technical support for solving environmental problems today and building a science knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental risks in the future. The National Risk Management Research Laboratory (NRMRL) is the Agency's center for investigation of technological and management approaches for preventing and reducing risks from pollution that threaten human health and the environment. The focus of the Laboratory's research program is on methods and their cost-effectiveness for prevention and control of pollution to air, land, water, and subsurface resources; protection of water quality in public water systems; remediation of contaminated sites, sediments and groundwater; prevention and control of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public and private sector partners to foster technologies that reduce the cost of compliance and anticipate emerging problems. NRMRL's research provides solutions to environmental problems by developing and promoting technologies that protect and improve the environment; advancing scientific and engineering information to support regulatory and policy decisions; and providing the technical support and information transfer to ensure implementation of environmental regulations and strategies at the national, state, and community levels. This publication has been produced as part of the Laboratory's strategic long-term research plan. It is published and made available by EPA's Office of Research and Development to assist the user community and to link researchers with their clients. Sally Gutierrez, Director National Risk Management Research Laboratory iii ABSTRACT As part of the EPA Arsenic Removal Technology Demonstration Program, a 540-gal/min (gpm) ion exchange (IX) system proposed by Kinetico was selected for demonstration at Vale, OR to remove arsenic and nitrate from a groundwater supply to meet their respective maximum contaminant level (MCL) of 10-µg/L and 10-mg/L (as N). This report documents the activities performed and results obtained from a 3.5-year long demonstration study that evaluated the performance of IX technology for arsenic and nitrate removal, determined the required system operation and maintenance (O&M) and operator skills, characterized the residuals produced by the technology, and determined the capital and O&M cost of the technology. This demonstration study was divided into three periods: Study Periods I and II and an interim period between the two. Study Period I (extending from September 19, 2006, through January 14, 2008) evaluated the originally proposed Purolite Arsenex II anion exchange (AIX) resin. Because of its deteriorating performance due to organic fouling and difficulties in restoring its exchange capacity after resin cleaning, a dual resin approach was identified and implemented in the interim period to address the relevant issues. In February 2009, Arsenex II resin was replaced with Purolite PFA300E resin, which was overlain with an organic scavenger, Purolite A850END. The performance of PFA300E/A850END was evaluated in Study Period II from February 10, 2009, through March 22, 2010. Summary of System Design The IX treatment system consisted of two banks of sediment filters, two 63-in X 86-in pressure vessels configured in parallel, two 11-ton salt saturators, two 1,050-gal day tanks, two brine transfer pumps, one automatic system control panel, and associated valves, pressure gauges, flow totalizers, and sample ports. By design, each vessel was to be loaded with 110 ft3 of AIX resin, treating 270 gpm of flow at a hydraulic loading rate of 12.5 gpm/ft2 and an empty bed contact time (EBCT) of 3 min. The amount of Arsenex II resin in each vessel was found to be less than the design value of 110 ft3. During resin replacement in February 2009, it was discovered that the maximum amount of dual resin that could be loaded into each vessel was 98.5 ft3, which was 90% of the design value. The volume of Arsenex II resin in each vessel, based on the freeboard measurement, was estimated to be 93 ft3, which was 85% of the design value. The smaller resin bed resulted in a shorter EBCT, i.e., 2.6 min for Arsenex II and 2.8 min for dual resin (on average). Summary of System Operation Routine operational data and sample collections were conducted in Study Periods I and II. The IX system operated for a total of 4,440 and 3,215 hr, treating approximately 128 and 93.6 million gal of water in Study Periods I and 11, respectively. The average daily operating time was 9.5 hr in both periods. Average flowrates were 534 and 536 gpm in Study Periods I and II, respectively, very close to the design value of 540 gpm. Pressure losses across each IX vessel averaged 11 pounds per square inch (psi), as expected for a 5-ft deep resin bed. However, two 270-gpm flow restrictors installed at vessel outlets to prevent overrun during regeneration created additional headlosses (up to 30 psi) across the IX system. The IX system was regenerated in a downflow, co -current mode using brine. Triggered automatically by a volume throughput setpoint in a programmable logic controller (PLC), the two IX vessels were regenerated sequentially, each cycling through the steps of spent brine draw, fresh brine draw, slow rinse, and fast rinse before returning to service. The spent brine draw step was designed to minimize wastewater production, but was discontinued in December 2007 due to concerns over possible resin iv fouling caused by dissolved organic matter (DOM) accumulating in the spent brine solution. The regeneration waste stream was discharged to an evaporation pond outside of the treatment plant. A total of 278 and 144 regeneration cycles took place in Study Periods I and II, respectively. Regeneration parameters, such as brine draw rate, brine volume, and specific gravity of diluted brine were monitored and adjusted, if needed. During the first six months of Study Period 1, salt usage per regeneration cycle was much higher than the target level of 12 lb/ft3 (up to 25.1 lb/ft). After a brine injection pump had been installed to replace the Venturi eductor, the control of salt usage was greatly improved. In Study Period I1, the average salt usage was 8.4 lb/ft3, 16% lower than the target value of 10 lb/ft3. Summary of System Performance Based on analytical data from a total of 63 sampling events in both study periods, raw water contained 16.0 to 31.8 µg/L of total arsenic (averaged 21.1 µg/L, primarily as soluble As[V]) and 1.4 to 7.6 mg/L (as N) of nitrate (averaged 5.5 mg/L [as N]). Although arsenic and nitrate concentrations showed some variations (presumably due to fluctuations in individual wells), the water quality, in general, remained rather constant in both study periods. On average, raw water had a pH of 7.4, 319 mg/L of total alkalinity (as CaCO3), 78 mg/L of sulfate, 277 µg/L of total phosphorus, 58 mg/L of silica (as SiO2), 506 mg/L of total dissolved solids (TDS), 1.9 mg/L of total organic carbon (TOC), 53 µg/L of total vanadium, and 165 mg/L of total hardness (as CaCO3). Total iron was below its reporting limit of 25 µg/L and total manganese was less than 1 µg/L. Weekly samples were collected from the treatment process during both study periods. Five run length studies also were conducted on Arsenex II and PFA300E/A850END to obtain breakthrough curves of arsenic, nitrate, and other competing anions. At system startup in September 2006, Arsenex II achieved a run length of 562,000 gal (or 404 bed volume [BV]) to 10-µg/L arsenic breakthrough, which was 59% of the vendor -projected run length of 680 BV. Since then, the system performance continued to deteriorate, as evidenced by more frequent exceedance of the arsenic MCL in system effluent and increasingly shortened useful run lengths (e.g., to 450,000 gal and then to 376,900 gal after four and seven months of operation, respectively). Analysis of a resin core sample revealed that the resin was severely fouled by organic matter. A cleaning procedure using a mixture of caustic/brine was developed in the laboratory by Purolite and implemented in the field in October 2007. Although the cleaning was able to restore the resin's capacities, such as volumetric capacity and strong base capacity, to 93% and 79% of the virgin resin level, respectively, the total organic content of the resin was reduced only by 24% and the useful run length improved only by 20% to 445,700 gal (320 BV). While organic matter continued to build up on the resin, the useful run length was shortened again to 323,500 gal (233 BV) about 10 months after the cleaning. Shorter run lengths (i.e., only 34 to 47% of the vendor projection) would require more frequent resin regeneration and produce more wastewater, which potentially could overflow the evaporation pond. In seeking an alternative approach to address DOM in source water, the City of Vale expressed its desire to continue with the IX technology in case nitrate became an issue in the future, and to achieve a volume throughput of 600,000 gal to prevent the pond from overflowing. Thus, the option of replacing Arsenex 11 resin with other resin types was explored. Purolite proposed a dual resin approach, i.e., PFA300 top - dressed with A800END, which had been successfully implemented at the McCook Water Treatment Plant in McCook, NE for the removal of arsenic, nitrate, and uranium from water containing >3 mg/L of TOC. Following a site visit to McCook and a run length and elution study, it was confirmed that the dual resin approach could be an effective remedy to treat waters containing high levels of TOC. After the IX system was rebedded with PFA300E/A850END in February 2009, weekly sampling data and run length study results revealed that the system could achieve a useful run length of approximately 454,400 gal (or 372 BV). This run length was calculated based on the actual PFA300E resin volume of 163.3 ft3. For a system containing 220 ft3 of resin, it would treat 612,174 gal of water. Therefore, the smaller resin bed was the key reason for not meeting the treatment target of 600,000 gal desired by the City. TOC concentrations in treated water were consistently removed below the reporting limit of 1 mg/L, confirming the usefulness of the dual resin approach to address DOM issues throughout the desired service cycle. Because the IX system was set to regenerate at 600,000 gal during most of the study, it was not surprising to detect high arsenic concentrations in system effluent when samples were collected past the resin's useful run lengths. Periodically, effluent concentrations exceeded raw water concentrations, a phenomenon referred to as chromatographic peaking or arsenic dumping. Arsenic dumping is caused by displacement of arsenic by more preferred anions such as sulfate, which often has a concentration three orders of magnitude higher than that of arsenic. Arsenic dumping is a major drawback of the IX technology and can be mitigated by properly controlling system run lengths and regeneration frequencies. Nitrate chromatographic peaking also was observed in system effluent, but effluent nitrate concentrations never exceeded its MCL. Total phosphorus concentrations in system effluent were reduced to <10 µg/L most of the time but rose rapidly to exceed influent levels after reaching a throughput of approximately 415,000 gal in Study Period I and 488,000 gal in Study Period 11. Sulfate was removed to less than 1 mg/L most of the time in both study periods and began to break after reaching a throughput of 376,940 gal in Study Period I and 487,940 gal in Study Period 11. It reached 1/3 to 1/2 of its influent concentration at the end of the 600,000-gal service cycle. Because of its higher selectivity than arsenate and nitrate, sulfate continued to be removed even when arsenate and nitrate had reached their respective MCL in the effluent. Vanadium was removed to <5 µg/L in system effluent most of the time. Chromatographic peaking was not observed for vanadium in either period, suggesting that vanadium might have an equivalent or even higher selectivity than sulfate. Slight reductions in treated water pH values were observed for a short period immediately after the system had just been regenerated. Although pH changes were small, i.e., no more than 0.3 pH unit, corresponding reductions in total alkalinity across the system were significant (up to 50%). The reduction in pH and alkalinity was attributed to removal of bicarbonate ions by the AIX resin. pH values of treated water returned to raw water levels afterwards due to complete breakthrough of bicarbonate ions, which had a lowest selectivity by the strong base AIX resin. Distribution system water samples were collected only in Study Period 1. Because treated water from the IX system was stored in a 200,000-gal reservoir before supplying the distribution system, the water quality of the distribution system water samples reflected the general quality of the plant effluent after being blended in the reservoir. After system startup, arsenic concentrations at all three sampling locations ranged from 7.1 to 24.0 µg/L and averaged 12.6 µg/L, which were significantly lower than the baseline levels, but not to the low level (i.e., <5 µg/L) that would be expected from an IX treatment plant because the IX system had been operated beyond 10 µg/L. Although occasionally, some low pH and low alkalinity were measured in treated water samples collected from the freshly regenerated vessels, the blending effect in the reservoir had mitigated any pH or alkalinity swing. Therefore, low pH and low alkalinity were never measured in the distribution samples. Residual Characterization Residuals produced by the IX system, including spent brine and rinse water, were discharged to the evaporation pond adjacent to the treatment building. Ferric chloride was added to the spent brine stream vi in an attempt to precipitate arsenic and allow the iron sludge to settle in the evaporation pond. The design and construction of the evaporation pond and the ferric chloride treatment system were performed by the City's contractors. The volume of wastewater produced was determined by regeneration frequency and the volume of wastewater produced per regeneration cycle. On average, each regeneration cycle produced 8,681 gal of wastewater per vessel in Study Period I and 7,244 gal per vessel in Study Period 11, which is 17% less than that in Study Period 1. To characterize the quality of residuals, samples were collected from the waste stream from each regeneration step as well as the pond water. Total arsenic concentrations in spent brine, fresh brine, slow rinse, and fast rinse samples averaged 2,678, 2,221, 527, and 11.3 µg/L, respectively, for Arsenex II, and averaged 2,203, 150, and 3.4 µg/L, respectively for PFA300E/A850END (note that spent brine draw was not used). Similarly, nitrate concentrations averaged 122, 517, 194, and 3.6 mg/L (as N) for Arsenex II and 450, 68, and 2.6 mg/L (as N) for dual resins. With a pH of 9.3 to 9.8 and a total alkalinity of 4,560 mg/L, the evaporation pond water contained 16 to 25.6 g/L of chloride, 13 to 30.2 g/L of sodium, and 38.2 to 60.1 g/L of TDS, indicating a highly alkaline and saline water. The pond water also contained up to 1.3 mg/L of total arsenic, 7.3 g/L of sulfate, 9.2 mg/L (as N) of nitrate, 13.3 mg/L of total phosphorus (as P), and 4.1 mg/L of vanadium. High arsenic concentrations in the pond water suggested ineffective ferric chloride treatment, presumably due to high TDS content and the presence of competing ions in the pond water. A regeneration elution study performed on dual resins indicated that the percent recoveries were 112% for arsenic, 131% for nitrate, 113% for vanadium, and 98.5% for TOC. Cost of Technology The capital cost of the IX system was $395,434, which included $260,194 for equipment, $49,840 for site engineering, and $85,400 for installation, accounting for 66%, 12%, and 22% of the total capital investment, respectively. This capital cost was normalized to the system's rated capacity of 540 gpm (or 777,600 gal/day [gpd]), which resulted in $732 per gpm (or $0.51 per gpd). The cost associated with design and construction of a new building, an evaporation pond, and a ferric chloride addition system (to treat the brine waste) was funded separately by the City of Vale, and not included in the cost of the system. The O&M cost for the IX system included the incremental cost associated with the salt supply, electricity consumption, and labor, which was estimated to be $0.35/1,000 gal of water treated. The cost of salt and caustic soda was the most significant add -on, approximately $32,826 per year, or $0.29/1,000 gal. Because the current salt saturators can only hold half truckload of salt, if more salt storage capacity is added to allow delivery of a full truckload, then the overall salt cost could be further reduced. vii DISCLAIMER.............................................................................................................................................. ii FOREWORD............................................................................................................................................... iii ABSTRACT................................................................................................................................................. iv APPENDICES............................................................................................................................................. ix FIGURES..................................................................................................................................................... ix TABLES....................................................................................................................................................... x ABBREVIATIONS AND ACRONYMS...................................................................................................xii ACKNOWLEDGMENTS......................................................................................................................... xiv 1.0: INTRODUCTION................................................................................................................................ I 1.1 Background.................................................................................................................................1 1.2 Treatment Technologies for Arsenic Removal........................................................................... 2 1.3 Project Objectives....................................................................................................................... 2 2.0 SUMMARY AND CONCLUSIONS ....... 5 3.0: MATERIALS AND METHODS.......................................................................................................... 7 3.1 General Project Approach........................................................................................................... 7 3.2 System O&M and Cost Data Collection..................................................................................... 8 3.3 Sample Collection Procedures and Schedules............................................................................ 9 3.3.1 Source Water.................................................................................................................. 9 3.3.2 Treatment Plant Water................................................................................................... 9 3.3.3 Regeneration Wastewater............................................................................................12 3.3.4 Distribution System Water...........................................................................................12 3.4 Real -Time Arsenic Monitoring with ArsenicGuardTM..............................................................12 3.5 Run Length and Regeneration Elution Studies.........................................................................13 3.5.1 Run Length Studies......................................................................................................13 3.5.2 Regeneration Elution Study.........................................................................................15 3.6 IX Resin Cleaning.....................................................................................................................16 3.7 Sampling Logistics....................................................................................................................16 3.7.1 Preparation of Arsenic Speciation Kits........................................................................16 3.7.2 Preparation of Sampling Coolers.................................................................................17 3.7.3 Sample Shipping and Handling...................................................................................17 3.8 Analytical Procedures...............................................................................................................17 4.0: RESULTS AND DISCUSSION.........................................................................................................18 4.1 Facility Description...................................................................................................................18 4.1.1 Source Water Quality...................................................................................................18 4.1.2 Distribution System Water Quality..............................................................................23 4.2 Treatment Process Description................................................................................................. 23 4.2.1 Ion Exchange Process.................................................................................................. 23 4.2.2 Treatment Process........................................................................................................27 4.3 System Installation.................................................................................................................... 36 4.3.1 Permitting.....................................................................................................................36 4.3.2 Construction of Treatment Building and Evaporation Pond ........................................ 36 4.3.3 System Installation, Shakedown, and Startup.............................................................. 38 4.4 System Operation......................................................................................................................40 4.4.1 Operational Parameters................................................................................................ 41 4.4.2 Regeneration................................................................................................................ 42 viii 4.4.2.1 Regeneration Set Points.................................................................................. 42 4.4.2.2 Regeneration Monitoring................................................................................44 4.4.2.3 Salt Usage....................................................................................................... 46 4.4.3 IX Resin Fouling..........................................................................................................48 4.4.4 Dual IX Resin Approach.............................................................................................. 49 4.4.4.1 Dual Resin Options......................................................................................... 50 4.4.4.2 Concerns over Solids in IX Resin Beds.......................................................... 50 4.4.4.3 Special Study at McCook, NE........................................................................ 51 4.4.4.4 Dual Resin Installation.................................................................................... 54 4.4.5 Residual Management.................................................................................................. 54 4.4.6 System Operation Requirement................................................................................... 55 4.4.6.1 Required System Operation and Operator Skills ............................................ 55 4.4.6.2 Preventive Maintenance Activities................................................................. 56 4.4.6.3 Chemical/Media Handling and Inventory Requirements ................................ 56 4.5 System Performance................................................................................................................. 56 4.5.1 Treatment Plant Sampling............................................................................................ 56 4.5.1.1 Arsenic Speciation.......................................................................................... 60 4.5.1.2 Arsenic Removal............................................................................................. 62 4.5.1.3 Nitrate Removal.............................................................................................. 65 4.5.1.4 TOC, Sulfate, Phosphate, and Vanadium Removal ........................................ 67 4.5.1.5 Other Water Quality Parameters..................................................................... 67 4.5.2 Real -Time Arsenic Monitoring by ArsenicGuardTM.................................................... 73 4.5.3 Run Length Studies...................................................................................................... 74 4.5.4 Regeneration Elution Study......................................................................................... 79 4.5.5 Regeneration Residual Sampling................................................................................. 82 4.5.6 Analysis of Evaporation Pond Water........................................................................... 85 4.5.7 Distribution System Water Sampling.......................................................................... 86 4.6 System Cost.............................................................................................................................. 88 4.6.1 Capital Cost.................................................................................................................. 89 4.6.2 Operation and Maintenance Cost................................................................................. 90 5.0 REFERENCES................................................................ APPENDICES APPENDIX A: Vale Arsenic System IX Resin Cleaning Procedure APPENDIX B: Vale, OR Project Chronology APPENDIX C: Operational Data APPENDIX D: Analytical Data FIGURES 92 Figure 3-1. Process Flow Diagram and Sampling Locations/Analyses for Vale IX System .................. 11 Figure 3-2. Real -Time Arsenic Analyzer — ArsenicGuardTM................................................................. 13 Figure 3-3. Regeneration Monitoring Setup........................................................................................... 15 Figure 4-1. Existing Well House in Vale, OR........................................................................................ 19 Figure 4-2. Existing Chlorination System in Vale, OR.......................................................................... 19 Figure 4-3. Historic Nitrate Data from Wells No. 1 Through No. 7....................................................... 22 Figure 4-4. Simulation of Arsenex II Resin Run Length........................................................................ 26 ix Figure 4-5. Simulation of A850END/PFA300E Resin Run Length (June 2008)................................... 26 Figure 4-6 Schematic of Kinetico's IX-263 As/N Removal System for Vale, OR ............................... 27 Figure 4-7. System Inlet Piping and Booster Pump................................................................................ 29 Figure 4-8. Photograph of Two Banks of Cartridge Filters.................................................................... 30 Figure 4-9. Photographs of Arsenic/Nitrate Removal IX System at Vale, OR ....................................... 31 Figure 4-10. Skid -Mounted Piping/Valving Rack.................................................................................... 31 Figure 4-11. Photographs of IX Regeneration System at Vale, OR ......................................................... 33 Figure 4-12. Salt Delivery to Fill Salt Saturators..................................................................................... 34 Figure 4-13. Wastewater Evaporation Pond............................................................................................. 35 Figure 4-17. Vale Treatment System Delivering and Offloading............................................................. 38 Figure 4-18. PLC Regeneration Setpoints Shown on OIP........................................................................ 43 Figure 4-19. The McCook, NE Water Treatment Plant............................................................................ 51 Figure 4-20. Sample Collection and pH/TDS Monitoring during Regeneration of AIX Vessel 5 atMcCook, NE.................................................................................................................... 52 Figure 4-21. Results of McCook AIX Vessel 5........................................................................................ 53 Figure 4-22. Concentrations of Arsenic Species across Treatment System .............................................. 61 Figure 4-23. Total Arsenic Concentrations Measured During Study Period I .......................................... 63 Figure 4-24. Total Arsenic Concentrations Measured During Study Period 11........................................ 64 Figure 4-25. Reconstructed Breakthrough Curves for Nitrate.................................................................. 66 Figure 4-26. Reconstructed Breakthrough Curves for Sulfate.................................................................. 68 Figure 4-27. Reconstructed Breakthrough Curves for Total Phosphorus ................................................. 69 Figure 4-28. Reconstructed Breakthrough Curves for Total Vanadium ................................................... 70 Figure 4-29. pH Measured During Study Period I.................................................................................... 71 Figure 4-30. Reconstructed Breakthrough Curves for Total Alkalinity ................................................... 72 Figure 4-31. Examples of Real -Time Arsenic Monitoring by ArsenicGuardTM....................................... 73 Figure 4-32. Vessel A Breakthrough Curves from Run Length Study 1.................................................. 75 Figure 4-33. Vessel A Breakthrough Curves from Run Length Study 2.................................................. 75 Figure 4-34. Vessel A Breakthrough Curves from Run Length Study 3.................................................. 76 Figure 4-35. Combined Effluent Breakthrough Curves from Run Length Study 4.................................. 77 Figure 4-36. Breakthrough Curves from Run Length Study 5................................................................. 78 Figure 4-37. pH and Alkalinity Breakthrough Curves from Run Length Study 5.................................... 79 Figure 4-38. Vessels A and B Elution Curves.......................................................................................... 80 Figure 4-39. Vessels A and B Elution Curves for TDS and pH............................................................... 81 Figure 4-40. Results of Vale Pond Water Jar Tests.................................................................................. 86 TABLES Table 1-1. Summary of Round land Round 2 Arsenic Removal Demonstration Locations, Technologies, and Source Water Quality................................................................................ 3 Table 3-1. Pre -Demonstration Study Activities and Completion Dates ................................................... 7 Table 3-2. Evaluation Objectives and Supporting Data Collection Activities .......................................... 8 Table 3-3. Sampling and Analysis Schedule at Vale, OR....................................................................... 10 Table 3-4. Sampling and Analysis Schedules for Run Length Studies ................................................... 14 Table 3-5. Sampling and Analysis Schedules for Resin Elution Study .................................................. 16 Table 4-1. Construction Details of Wells No. I to No. 7........................................................................ 18 Table 4-2. Vale, OR Source Water Data for Combined Wells No. 1 to No. 7........................................ 20 Table 4-3. Wells No. 1 to No. 7 Water Quality Data from June 2000 to August 2000 .......................... 21 Table 4-4. Wells No. 1 to No. 7 Water Quality Data from EPA (December 2004)................................ 21 Table 4-5. Wells No. 1 to No. 7 Nitrate Concentrations (mg/L [as N]) from Source (February 2001 to October 2004)........................................................................................................... 21 x Table 4-6. Physical and Chemical Properties of IX Resins.................................................................... 25 Table 4-7. Design Specifications of IX System...................................................................................... 28 Table 4-8. System Punch List during Startup......................................................................................... 39 Table 4-9. Key Demonstration Study Activities/Events......................................................................... 40 Table 4-10. Summary of System Operational Data.................................................................................. 41 Table 4-11. IX System Regeneration Setpoints at Vale, OR.................................................................... 44 Table 4-12. IX System Regeneration Monitoring at Vale, OR................................................................. 45 Table 4-13. Vale, IX System Salt Loading Calculations.......................................................................... 47 Table 4-14. Resin Analyses After Laboratory or Field Cleaning.............................................................. 48 Table 4-15. Freeboard Measurements During Rebedding at Vale, OR .................................................... 54 Table 4-16. Summary of Arsenic and Nitrate Analyses in Study Periods I and 11.................................... 57 Table 4-17. Summary of Other Water Quality Parameters in Study Period I ........................................... 58 Table 4-18. Summary of Other Water Quality Parameters in Study Period 11.......................................... 60 Table 4-19. Mass Balance Calculations for Total Arsenic, Nitrate, Vanadium, and TOC ....................... 83 Table 4-20. Regeneration Residual Sampling Results.............................................................................. 84 Table 4-21. Analytical Data for Pond Water at Vale, OR......................................................................... 85 Table 4-22. Distribution System Sampling Results in Study Period I at Vale, OR .................................. 87 Table 4-23. Cost Breakdowns of Capital Investment for Vale IX System ............................................... 89 Table 4-24. O&M Cost for Vale, OR Treatment System.......................................................................... 90 Xl ABBREVIATIONS AND ACRONYMS AAL American Analytical Laboratories AIX anion exchange Al aluminum AM adsorptive media As arsenic ASV anodic stripping voltammetry ATS Aquatic Treatment Systems bgs below ground surface BV bed volume C/F coagulation/filtration Ca calcium Cl chlorine Cu copper DHS DWP (Oregon) Department of Human Service, Drinking Water Program DO dissolved oxygen DOM dissolved organic matter DVB divinylbenzene EBCT empty bed contact time EPA U.S. Environmental Protection Agency F fluoride Fe iron FRP fiberglass reinforced plastic gpd gallons per day gph gallons per hour gpm gallons per minute HAA5 haloacetic acids HDPE high -density polyethylene HIX hybrid ion exchanger hp horsepower ICP-MS inductively coupled plasma -mass spectrometry ID identification IX ion exchange LCR Lead and Copper Rule MCL maximum contaminant level MDL method detection limit MEI Magnesium Elektron, Inc. Mg magnesium MGD million gallon per day xii Mn manganese mV millivolts Na sodium NRMRL National Risk Management Research Laboratory NSF NSF International NTU nephelometric turbidity units O&M operation and maintenance OIP operator interface panel OIT Oregon Institute of Technology ORD Office of Research and Development ORP oxidation-reduction potential P&ID piping and instrumentation diagram PLC programmable logic controller POU point of use ppb parts per billion psi pounds per square inch PVC polyvinyl chloride QA quality assurance QAPP quality assurance project plan QA/QC quality assurance/quality control RPD relative percent difference RO reverse osmosis SBA strong -base anion SDWA Safe Drinking Water Act STS Severn Trent Services TCLP Toxicity Characteristic Leaching Procedure TDH total dynamic head TDS total dissolved solids TOC total organic carbon TTHMs trihalomethanes V vanadium VFD variable frequency drive WTP Water Treatment Plant ACKNOWLEDGMENTS The authors wish to extend their sincere appreciation to the staff of the Department of Public Works at the City of Vale, OR. The primary operators, Mr. Les Bertalotto and Mr. Terry Harris, monitored the treatment system daily and collected water samples from the treatment and distribution systems on a regular schedule throughout the study period. This performance evaluation would not have been possible without their efforts. xiv 1.0 INTRODUCTION 1.1 Background The Safe Drinking Water Act (SDWA) mandates that the United States Environmental Protection Agency (EPA) identify and regulate drinking water contaminants that may have adverse human health effects and are known or anticipated to occur in public water supply systems. In 1975 under the SDWA, EPA established a maximum contaminant level (MCL) for arsenic (As) at 0.05 mg/L. Amended in 1996, the SDWA required that EPA develop an arsenic research strategy and publish a proposal to revise the arsenic MCL by January 2000. On January 18, 2001, EPA finalized the arsenic MCL at 0.01 mg/L (EPA, 2001). To clarify the implementation of the original rule, EPA revised the rule text on March 25, 2003, to express the MCL as 0.010 mg/L (or 10 µg/L) (EPA, 2003). The final rule required all community and non -transient, non -community water systems to comply with the new standard by January 23, 2006. In October 2001, EPA announced an initiative for additional research and development of cost-effective technologies to help small community water systems (<I0,000 customers) meet the new arsenic standard, and to provide technical assistance to operators of small systems in order to reduce compliance cost. As part of this Arsenic Rule Implementation Research Program, EPA's Office of Research and Development (ORD) proposed a project to conduct a series of full-scale, onsite demonstrations of arsenic removal technologies, process modifications, and engineering approaches applicable to small systems. Shortly thereafter, an announcement was published in the Federal Register requesting water utilities interested in participating in Round 1 of this EPA -sponsored demonstration program to provide information on their water systems. In June 2002, EPA selected 17 out of 115 sites to host the demonstration studies In September 2002, EPA solicited proposals from engineering firms and vendors for cost-effective arsenic removal treatment technologies for the 17 host sites. EPA received 70 technical proposals for the 17 host sites, with each site receiving from one to six proposals. In April 2003, an independent technical panel reviewed the proposals and provided its recommendations to EPA on the technologies that it determined were acceptable for the demonstration at each site. Because of funding limitations and other technical reasons, only 12 of the 17 sites were selected for the demonstration program. Using the information provided by the review panel, EPA in cooperation with the host sites and the drinking water programs of the respective states selected one technical proposal for each site. In 2003, EPA initiated Round 2 arsenic technology demonstration projects that were partially funded with Congressional add -on funding to the EPA budget. In June 2003, EPA selected 32 potential demonstration sites. The City of Vale, OR was one of those selected. In September 2003, EPA again solicited proposals from engineering firms and vendors for arsenic removal technologies. EPA received 148 technical proposals for the 32 host sites, with each site receiving from two to eight proposals. In April 2004, another technical panel was convened by EPA to review the proposals and provide recommendations to EPA with the number of proposals per site ranging from none (for two sites) to a maximum of four. The final selection of the treatment technology at the sites that received at least one proposal was made, again, through a joint effort by EPA, the state regulators, and the host site. Since then, five sites have withdrawn from the demonstration program, reducing the number of sites to 27. An ion exchange (IX) system proposed by Kinetico was selected for demonstration at the Vale, OR, site for the removal of arsenic and nitrate from drinking water supplies. As of February 2011, the performance evaluations of all 39 systems have been completed. 1.2 Treatment Technologies for Arsenic Removal The technologies selected for the Round 1 and Round 2 demonstration host sites include 25 adsorptive media (AM) systems (the Oregon Institute of Technology [OIT] site has three AM systems), 13 coagulation/filtration (C/F) systems, two IX systems, 17 point -of -use (POU) units (including nine under - the -sink reverse osmosis [RO] units at the Sunset Ranch Development site and eight AM units at the OIT site), and one process modification. Table 1-1 summarizes the locations, technologies, vendors, system flowrates, and key source water quality parameters (including arsenic, iron, and pH) at the 40 demon- stration sites. An overview of the technology selection and system design for the 12 Round 1 demonstration sites and the associated capital cost is provided in two EPA reports (Wang et al., 2004; Chen et al., 2004), which are posted on the EPA Web site at htip://www.epa.jzov/ORD/NRMRL/wswrd/dw/arsenic/index.html. 1.3 Project Objectives The objective of the Round 1 and Round 2 arsenic demonstration program was to conduct full-scale arsenic treatment technology demonstration studies on the removal of arsenic from drinking water supplies. The specific objectives were to: • Evaluate the performance of the arsenic removal technologies for use on small systems. • Determine the required system operation and maintenance (O&M) and operator skill levels. • Characterize process residuals produced by the technologies. • Determine the capital and O&M cost of the technologies. This report documents the performance of the Kinetico IX system at the City of Vale, OR, from September 19, 2006, through March 22, 2010. The types of data collected included system operation, water quality (both across the treatment train and in the distribution system), residuals, and capital and preliminary O&M cost. Short-term special studies also were conducted to troubleshoot operational and performance issues and improve the overall effectiveness and efficiency of the treatment system. Pa M Table 1-1. Summary of Round 1 and Round 2 Arsenic Removal Demonstration Locations, Technologies, and Source Water Quality Demonstration Location Site Name Technology Media Vendor Design Flowrate m Source Water Quality As /L Fe /L pH S.U. NortheastlOhio Wales, ME S ringbrook Mobile Home Park AM (A/I Complex) ATS 14 38(a) <25 8.6 Bow, NH White Rock Water Company AM (G2) ADI 70(5F 39 <25 7.7 Goffstown, NH Orchard Highlands Subdivision AM E33) AdEdge 10 33 <25 6.9 Rollinsford, NH Rollinsford Water and Sewer District AM (E33) AdEdge 100 36 a 46 8.2 Dummerston, VT Charette Mobile Home Park AM (A/I Complex) ATS 22 30 <25 7.9 Felton, DE Town of Felton C/F (Macrolite) Kinetico 375 30(a) 48 8.2 Stevensville, MD Queen Anne's County AM (E33) STS 1 300 19(a) 270(°) 7.3 Houghton, NY Town of Caneadea C/F Macrolite Kinetico 550 27 a 1,806 ° 7.6 Buckeye Lake, OH Buckeye Lake Head Start Building AM (ARM 200) Kinetico 10 15 a 1,312 ° 7.6 Springfield, OH Chateau Estates Mobile Home Park AM (E33) AdEdge 250(°) 25 a 1,615 ° 7.3 Great Lakesllnterior Plains Brown City, MI City of Brown City AM E33) STS 640 14(a) 127(°) 7.3 Pentwater, MI Village of Pentwater C/F (Macrolite) Kinetico 400 ITT 466 ° 6.9 Sandusky, MI City of Sandusky C/F (Aeralater) Siemens 340(°) 16 a 1,38T7 6.9 Delavan, WI Vintage on the Ponds C/F (Macrolite) Kinetico 40 20(aT 1,499TcT 7.5 Greenville, WI Town of Greenville C/F (Macrolite) Kinetico 375 17 7827 °) 7.3 Climax, MN City of Climax C/F (Macrolite) Kinetico 140 39(a) 546(°) 7.4 Sabin, MN City of Sabin C/F (Macrolite) Kinetico 250 34 1,470 ° 7.3 Sauk Centre, MN Big Sauk Lake Mobile Home Park C/F (Macrolite) Kinetico 20 25 a 3,07F7 7.1 Stewart, MN City of Stewart C/F&AM (E33) AdEdge 250 42 (a 1,344 °) 7.7 Lidgerwood, ND City of Lidgerwood Process Modification Kinetico 250 146(a)1,325 ° 7.2 Midwest/Southwest Arnaudville, LA United Water Systems C/F (Macrolite) Kinetico 770(°) 35 a 2,068 ° 7.0 Alvin, TX Oak Manor Municipal Utility District AM (E33) STS 150 1 qTaT 95 7.8 Bruni, TX Webb Consolidated Independent School District AM (E33) AdEdge 40 5 6TaT <25 8.0 Wellman, TX City of Wellman AM E33) AdEdge 100 45 <25 7.7 Anthony, NM Desert Sands Mutual Domestic Water Consumers Association AM (E33) STS 320 23 a 39 7.7 Nambe Pueblo, NM Nambe Pueblo Tribe AM (E33) AdEdge 145 33 <25 8.5 Taos, NM Town of Taos AM (E33) STS 450 14 59 9.5 Rimrock, AZ Arizona Water Company AM (E33) AdEdge 90( 50 170 7.2 Tohono O'odham Nation, AZ Tohono O'odham Utility Authority AM (E33) AdEdge 50 32 <25 8.2 Valley Vista, AZ I Arizona Water Company AM (AAFS50/ARM 200) Kinetico 37 41 <25 7.8 Table 1-1. Summary of Round 1 and Round 2 Arsenic Removal Demonstration Locations, Technologies, and Source Water Quality (Continued) Demonstration Location Site Name Technology Media Vendor Design Flowrate m Source Water Quality As /L Fe /L pH S.U. Far West Three Forks, MT City of Three Forks C/F (Macrolite) Kinetico 250 64 <25 7.5 Fruitland, ID City of Fruitland IX (A300E Kinetico 250 44 <25 7.4 Homedale, ID Sunset Ranch Development POU RO Kinetico 75 gpd 52 134 7.5 Okanogan, WA City of Okanogan C/F (Electromedia-I) Filtronics 750 18 69 8.0 Klamath Falls, OR Oregon Institute of Technology POE AM (Adsorbsia/ARM 200/ArsenX"P) and POU AM (ARM 200)(9) Kinetico 60/60/30 33 <25 7.9 Vale, OR City of Vale IX Arsenex II Kinetico 525 17 <25 7.5 Reno, NV South Truckee Meadows General Improvement District AM (GFH/Kemiron) Siemens 350 39 <25 7.4 Susanville, CA Richmond School District AM (A/I Complex) ATS 12 3 7(aT 125 7.5 Lake Isabella, CA Upper Bodfish Well C142-A AM (HIX) VEETech 50 35 125 7.5 Tehachapi, CA Golden Hills Community Service District AM (Isolux) MEI 150 15 <25 6.9 AM = adsorptive media; C/F = coagulation/filtration; HIX = hybrid ion exchange; IX = ion exchange process; RO = reverse osmosis ATS = Aquatic Treatment Systems; MEI = Magnesium Elektron, Inc.; STS = Severn Trent Services (a) Arsenic existing mostly as As(III). (b) Design flowrate reduced by 50% due to system reconfiguration from parallel to series operation. (c) Iron existing mostly as Fe(II). (d) Withdrew from program in 2007. Selected originally to replace Village of Lyman, NE site, which withdrew from program in June 2006. (e) Facilities upgraded systems in Springfield, OH from 150 to 250 gpm, Sandusky, MI from 210 to 340 gpm, and Amaudville, LA from 385 to 770 gpm. (f) Including nine residential units. (g) Including eight under -the -sink units. 2.0 SUMMARY AND CONCLUSIONS Based on the data collected from this 3.5-year long demonstration study at Vale, OR, the following summary and conclusions were made relating to the overall objectives of the treatment technology demonstration study. Performance of the IX arsenic/nitrate removal technology for use on small systems: • Arsenex II resin can remove arsenic and nitrate from water supplies to below their respective MCLs of 10-µg/L and 10-mg/L (as N), provided that the system is regenerated timely. The Vale, OR IX plant achieved an initial run length of 562,000 gal (or 404 bed volumes [BV]) at 10-µg/L arsenic breakthrough. However, due to organic fouling, the useful run length was reduced to up to 80% of the initial level after seven months of system operations. • PFA300E top -dressed with A850END is effective at removing arsenic and nitrate and is less susceptible to organic fouling. The system can treat 454,400 gal (or 372 BV) of water before regeneration is required. Regenerating dual resins with an alkaline brine periodically (i.e., once every four months) can prevent PFA300E fouling. • The smaller resin bed was the key reason for not meeting the treatment target of 600,000 gal desired by the City of Vale. To meet this treatment target, an additional 55 to 60 ft3of PFA300E resin would be required. • Both Arsenex II and A850END/PFA300E consistently removed vanadium from an average of 52 µg/L in raw water to <5 µg/L in treated water for at least 600,000 gal (i.e., 431 BV). • Arsenic and nitrate peaking can occur if the system was operated beyond exhaustion. To avoid peaking, the IX system must be regenerated timely. • The presence of 1.4 to 2.2 mg/L of total organic carbon (TOC) in raw water can result in severe resin fouling. Cleaning the fouled IX resin with a mixture of caustic/brine can be effective in restoring resin's volumetric and strong base capacities and moisture content, but may not improve resin run length to the same extent. • Simulation of the IX resin run length by computer software was found to over -estimate the resin performance by as high as 50%. Required system O&M and operator skill levels: • Under normal operating conditions, the skill requirements to operate the system were minimal, with a typical daily demand on the operator of 40 min. Other skills needed for performing O&M activities include replacing filter bags periodically, using a hydrometer to check brine concentrations, monitoring salt inventory levels, scheduling salt delivery, and working with the vendor to troubleshoot and perform rmnor onsite repairs. • Monitoring salt usage during a regeneration cycle can ensure that the IX resin is properly regenerated. • Salt unloading can generate excessive salt dust that is corrosive to the electrical and mechanical components of the treatment system. Placing the salt saturators in a separate room can minimize the salt dust and corrosion issues. Process residuals produced by the technology: Residuals produced by the IX system included spent brine and rinse water. The volume of wastewater produced was dependent upon regeneration frequency and settings. • Design of residual (brine) disposal should consider that projections of wastewater production may be low because of lower than projected run lengths. • Ferric chloride treatment was ineffective at removing arsenic in spent brine discharged to the evaporation pond, probably caused by high total dissolved solids (TDS). Cost of the technology: • Using the system's rated capacity of 540 gal/min (gpm) (or 777,600 gal/day [gpd]), the capital cost was $732/gpm (or $0.51/gpd) of the design capacity. • Cost of salt supply was the significant add -on to the previous plant operation. The cost for salt and caustic soda was $0.29/1,000 gal of water treated. • Design of the salt saturator should consider the storage capacity required for entire truckload delivery of salt to achieve maximum cost savings. M 3.0 MATERIALS AND METHODS 3.1 General Project Approach Table 3-1 summarizes all predemonstration activities and respective completion dates. The performance evaluation study of the IX system at Vale, OR began on September 19, 2006, and ended on March 22, 2010. Table 3-2 summarizes types of data collected and/or considered as part of the technology evaluation process. The overall system performance was evaluated based on its ability to consistently remove arsenic and nitrate to below their respective MCLs of 10 µg/L and 10 mg/L (as N) through the collection of water samples across the treatment train, as described in a Performance Evaluation Study Plan (Battelle, 2006). The reliability of the system was evaluated by tracking the unscheduled system downtime and frequency and extent of equipment repairs and replacement. The plant operator recorded unscheduled downtime and repair information on a Repair and Maintenance Log Sheet. Table 3-1. Pre -Demonstration Study Activities and Completion Dates Activity Date Introductory Meeting Held December 2, 2004 Letter of Understanding Issued March 2, 2005 Request for Quotation Issued to Vendor March 10, 2005 Vendor Quotation Received by Battelle March 30, 2005 Purchase Order Completed and Signed April 5, 2005 Engineering Package Submitted to Oregon DHS DWP July 22, 2005 Treatment System Permit Issued August 11, 2005 Building Construction Begun December 5, 2005 Building Construction Completed February 28, 2006 Letter Report Issued March 30, 2006 Treatment System Shipped May 8, 2006 Treatment System Arrived May 12, 2006 System Installation Completed June 5, 2006 System Shakedown Completed July 23, 2006 Study Plan Issued September 14, 2006 Performance Evaluation Begun September 19, 2006 DHS DWP = Department of Human Service Drinking Water Program The required system O&M and operator skill levels were evaluated based on a combination of quantitative data and qualitative considerations, including the need for pre- and/or post -treatment, level of system automation, extent of preventive maintenance activities, frequency of chemical and/or media handling and inventory, and general knowledge needed for relevant chemical processes and health and safety practices. The staffing requirements for the system operation were recorded on an Operator Labor Hour Log Sheet. The quantity of residuals generated was estimated by tracking the flowrate and duration of each regenera- tion step (i.e., brine draw, slow rinse, and fast rinse) and the number of regeneration cycles during the study period. Spent regenerant samples were collected and analyzed for chemical characteristics. The system cost was evaluated based on the capital cost per gpm (or gpd) of design capacity and the O&M cost per 1,000 gal of water treated. This required tracking the capital cost for equipment, site engineering, and installation, as well as the O&M cost for salt supply, electrical power use, and labor. 7 Table 3-2. Evaluation Objectives and Supporting Data Collection Activities Evaluation Data Collection Objective Performance —Ability to consistently meet 10 µg/L of arsenic MCL and 10 mg/L of nitrate as N) MCL in treated water Reliability —Unscheduled system downtime —Frequency and extent of repairs, including a description of problems, materials and supplies needed, and associated labor and cost System O&M and —Pre- and post -treatment requirements Operator Skill —Level of automation for system operation and data collection Requirements —Staffing requirements, including number of operators and laborers —Task analysis of preventive maintenance, including number, frequency, and complexity of tasks —Chemical handling and inventory requirements —General knowledge needed for relevant chemical processes and health and safety practices Residual —Quantity and characteristics of aqueous and solid residuals generated by Management system operation System Cost —Capital cost for equipment, site engineering, and installation —O&M cost for chemical usage, electricity consumption, and labor 3.2 System O&M and Cost Data Collection The plant operator performed daily, weekly, and monthly system O&M and data collection according to instructions provided by Kinetico and Battelle. The plant operator recorded system operational data, such as pressure, flowrate, system throughput, hour meter, and regeneration counter readings on a Daily System Operation Log Sheet; checked brine day tank and salt saturator levels; and conducted visual inspections for leaks or faults. If any problems occurred, the plant operator contacted the Battelle Study Lead, who would then determine if Kinetico should be contacted for troubleshooting. The plant operator recorded all relevant information, including problem encountered, course of action taken, materials and supplies used, and associated cost and labor incurred, on the Repair and Maintenance Log Sheet. On a weekly basis, the plant operator measured water quality parameters, including pH, temperature, dissolved oxygen (DO), and oxidation-reduction potential (ORP), and recorded the data on a Weekly Water Quality Parameters Log Sheet. During the study period, the system was regenerated automatically when triggered by a pre -determined throughput setpoint. Occasionally, system regeneration was initiated by the operator for sampling purposes. The capital cost for the arsenic -removal system consisted of the cost for equipment, site engineering, and system installation. The O&M cost consisted primarily of the cost for salt usage, electricity consumption, and labor. Salt was delivered to the treatment plant in bulk quantities by Handy Wholesale Products, Inc. in Burley, ID, on a monthly or as -needed basis. Salt usage was tracked through monthly invoices. Electricity consumption was obtained from utility bills for the study period. The labor for routine system O&M, system troubleshooting and repairs, and demonstration -related work, was recorded on an Operator Labor Hour Sheet. Routine O&M included activities such as completing field logs, ordering supplies, performing system inspections, and others as recommended by the vendor. The labor for demonstration - related work, including activities such as performing field measurements, collecting and shipping samples, and communicating with the Battelle Study Lead, was recorded but not used for cost analysis. E:1 3.3 Sample Collection Procedures and Schedules System operation underwent three separate yet inter -related periods: • Study Period I (from September 19, 2006 through January 14, 2008) • Interim Period (from January 15, 2008 through February 9, 2009) • Study Period II (from February 10, 2009 through March 22, 2010) Sampling was performed only in Study Periods I and II with schedules noted in Section 3.3.2. The plant operator collected water samples from the treatment plant/distribution system and during regeneration either on a regular basis as summarized in Table 3-3, or through special run length/regeneration studies as described in Section 3.5. Table 3-3 provides sampling schedules and analytes measured during each regular sampling event. Figure 3-1 presents a process flow chart, along with applicable sampling/analysis schedules, for the IX system. Specific sampling requirements for analytical methods, sample volumes, containers, preservation, and holding times are presented in Table 4-1 of the EPA -endorsed Quality Assurance Project Plan (QAPP) (Battelle, 2004). 3.3.1 Source Water. During the initial visit to the site on December 2, 2004, one set of source water samples was collected for detailed water quality analyses (Table 3-3). The source water also was speciated onsite for total and soluble As (including soluble As[III) and soluble As[V]), iron (Fe), manganese (Mn), uranium (U), and vanadium (V). Special care was taken to avoid agitation, which might cause unwanted oxidation. 3.3.2 Treatment Plant Water. Routine treatment plant water samples were collected from September 20, 2006, through January 14, 2008 during Study Period 1; and from March 25, 2009, through February 8, 2010 during Study Period II. Study Period I: The plant operator collected water samples across the treatment train weekly on a four - week cycle. For the first week of each four -week cycle, water samples were collected and speciated at four locations (i.e., at the wellhead [IN], after Vessel A [TA], after Vessel B [TB], and at the combined effluent from Vessels A and B [TT]) and analyzed for the analytes listed under the monthly treatment plant analyte list in Table 3-3. For the other three weeks, treatment plant samples were collected at three locations (i.e., IN, TA, and TB) and analyzed for the analytes listed under the weekly treatment plant analyte list in Table 3-3. During Study Period I, several changes were made to the routine sampling schedule: • Weekly sampling was not performed during the Thankgiving and Christmas holidays in 2006. • One additional set of weekly samples was collected on February 6, 2007. • The four -week -cycle treatment plant water sampling was discontinued on April 16, 2007, due to performance issue related to short run lengths (Section 4.4.3). • From July 16, 2007 through January 14, 2008, limited weekly water sampling was conducted with samples collected at the TT location and analyzed for total As only. Study Period II: Weekly sampling resumed on March 25, 2009, after dual resins had been installed. Water samples were collected at IN, TA, TB, and TT locations and analyzed for the same set of analytes done before plus TOC and V. Onsite water quality measurements and arsenic speciation were not performed during this study period. Treatment plant water sampling ended on February 8, 2010. G9 Table 3-3. Sampling and Analysis Schedule at Vale, OR No. of Sample Sampling Sampling Sampling Tye Locations() Locations Frequency Anal tes Date Source IN 1 Once Onsite: pH, temperature, 12/02/04 Water DO, and ORP Offsite: As (total and soluble), As(III), As(V), Fe (total and soluble), Mn (total and soluble), U (total and soluble), V (total and soluble), Na, Ca, Mg, Cl, F, NO2i NO3i NH3, SO4i Si02, P, turbidity, alkalinity, TDS, and TOC Treatment IN, TA, and 3 Weekly Onsite: pH, temperature, See Appendix D Plant Water TB DO, and ORP (09/20/06— (Study Offsite: As (total), 01/14/08) Period I) Fe (total), Mn(total), NO3, SO4, Si02, P, turbidity, alkalinity, and TDS IN, TA, TB, 4 Monthly Same as those for See Appendix D and TT weekly samples plus (09/20/06— following: 01 /14/08) Offsite: As (soluble) As(III), As(V), Fe (soluble), Mn (soluble), V (total and soluble), F, Ca, and Mg Treatment IN, TA, TB, 4 Weekly Offsite: As (total), See Appendix D Plant Water and TT Fe (total), Mn (total), (03/25/09— (Study V (total), NO3, SO4, 02/08/10) Period II) Si02, P, turbidity, alkalinity, TDS, and TOC Distribution Two LCR 3 Monthly pH, alkalinity, Baseline: System and one As (total), Fe (total), (06/15/05— Water Non- Mn (total), Pb (total), 09/21/05) (Study Residence and Cu (total) Monthly: Period I) Locations (10/10/06- 04/ 10/07) Residuals Drain pipe 1 4 times As (total), NO3, SO4, 12/20/06, off TA and TDS, and pH 01/31/07, TB 03/20/07, and 06/29/09 (a) Abbreviations in parentheses corresponding to sample locations in Figure 3-1: IN = at wellhead, TA = after Vessel A, TB = after Vessel B, and TT = conbined effluent. (b) One composite sample from each regeneration step (i.e., reused brine draw, fresh brine draw, slow rinse, and fast rinse). DO = dissolved oxygen; ORP = oxidation-reduction potential; TDS = total dissolved solids; TOC = total organic carbon INFLUENT (COMBINED WELLS NO. 1-7) BOOSTER PUMP WITH VFD Vale, OR Ion Exchange Design Flow: 540 gpm Month (a) pH(b), temperature(b), DOroI, ORPteI, Wee a) As (total and soluble), As(III), As(V), pH(b), temperature(b), DOlbl, ORP@l, Fe (total and soluble), Mn (total and soluble), -0--------- IN ---------------- 0- As (total), Fe (total), Mn (total), NO3, SO4, V (total and soluble), Ca, Mg, F, NO3, SO4, SiO2, P, turbidity, alkalinity, and TDS Si02, P, turbidity, alkalinity, and TDS BRINE WASTE LAGOON CARTRIDGE FILTRATION SS--►TCLP Metals pH, TDS, As (total), f RG NO3, SO4 RESIN VESSEL A ...... T.......................................... RESIN VESSEL B Y--�pH@),tempera ture(e),DOIe1,ORP(6), As (total), Fe (total), Mn (total), NO3, SO4, --------------------- --- T ► SI02, P, turbidity, alkalinity, and TDS pHro>, temperature(b), DOro>, ORP(e) As (total and soluble), As(III), As(V), Fe (totalandsoluble), Mn (total and soluble), f-------- TT V (totalandsoluble), Ca,Mg, F, NO3, SO4, Si02, P, turbidity, alkalinity, and TDS Footnotes (a) Applicable only to Study Period I (b) Onsite analyses DA: C12 ATMOSPHERIC RESERVOIR (200,000 gal) BOOSTER PUMPS DISTRIBUTION SYSTEM T Fr_UN" S IN At Wellhead 0 '•� TA AfterVesselA 5 TB AfterVesselB After Vessek A and B � TT Combined RG Regeneration Sampling Location SS Sludge Sampling Location CARTRIDGE Unit Process FILTRATION DA: C12 I Chlorine Disinfection No- Process Flow ...........► Backwash Flow Figure 3-1. Process Flow Diagram and Sampling Locations/Analyses for Vale IX System 3.3.3 Regeneration Wastewater. Regeneration wastewater samples were collected three times in Study Period I and once in Study Period 11. For each sampling event, one composite sample was collected from each of the four regeneration steps, i.e., spent brine draw, fresh brine draw, slow rinse, and fast rinse, during regeneration of one IX vessel. A portion of regeneration effluent was diverted to a 32- gal plastic container via a garden hose over the duration of each regeneration step. After the content in the container was thoroughly mixed, a portion of the liquid was transferred to a sample bottle and analyzed for the analytes listed under "Residuals" in Table 3-3. A total of four samples were collected during each sampling event. Arsenic speciation was not performed on these residual samples. 3.3.4 Distribution System Water. Water in the distribution system was sampled to assess the impact of the IX system on the water chemistry in the distribution system, specifically, the arsenic, nitrate, lead, and copper levels. Prior to the installation/operation of the treatment system, four sets of baseline distribution system water samples were collected on a monthly basis starting in June 2005. Three sampling locations were selected, including two residences within the city's sampling network under the Lead and Copper Rule (LCR) and one non-residential location. Following system startup, distribution system sampling continued on a monthly basis for seven months at the same three locations. For the two LCR sampling locations, the plant operator delivered sample bottles to the residences and picked up sample bottles after sampling was complete. For the non-residential location, the plant operator collected samples directly from a spigot. Sampling followed an instruction sheet developed according to the Lead and Copper Rule Monitoring and Reporting Guidance for Public Water Systems (EPA, 2002). First -draw samples were collected from a cold -water faucet that had not been used for at least 6 hr to ensure that stagnant water was sampled. The samplers recorded the date and time of last water use before sampling and the date and time of sample collection for calculation of stagnation time. Arsenic speciation was not performed on these samples. Analytes for the baseline and monthly distribution system water samples are listed in Table 3-3. Distribution system sampling discontinued after April 10, 2007. 3.4 Real -Time Arsenic Monitoring with ArsenicGuardTM On November 19, 2008, an automated online arsenic analyzer, ArsenicGuardTM (Figure 3-2), was installed at the site to monitor total arsenic concentrations in the IX system influent (IN) and effluent (TT). ArsenicGuardTM was developed by TraceDetect (Seattle, WA) to measure total inorganic arsenic in drinking and groundwater using anodic stripping voltammetry (ASV), a voltammetric method for quantitative determination of a specific ionic species. According to the vendor, the normal measurement range is 1 to 25 µg/L. Because the analyzer also supports dilution up to 50:1, the measurement range can be extended upwards to 50 to 1,250 µg/L. The accuracy in the normal range is 1 µg/L or ±20% (whichever is larger), and 50 µg/L or ±20% for the extended range. Because the sensor is only sensitive to arsenite, sample treatment is required prior to measurements. Each measurement begins with acidification of a sample to pH —0.7 with 2M HCI, followed by reduction of arsenate to arsenite with 0.05N sodium thiosulfate. The analyzer then makes calibrated measurements by first scanning for arsenic in the treated sample, followed by adding a metered quantity of arsenite (the spike) and re -scanning. Upon completion of the measurements, the differences between the original peak and the spikes are used to calculate the concentration of the original sample. This method of standard additions is a way of calibrating the sensor for each sample matrix. ArsenicGuardTM utilizes an electrochemical plating and stripping technique to measure part -per -billion (ppb) quantities of arsenic. The treated sample as mentioned above is drawn into a measurement cell, which houses a sensor along with a reference and an auxiliary electrode. The voltage of this electrochemical cell is manipulated so that arsenic is first plated onto the tip of the sensor during an 12 Figure 3-2. Real -Time Arsenic Analyzer — ArsenicGuardTM accumulation phase, and then stripped off the sensor during a stripping phase. The duration of the accumulation phase is adjusted to ensure a good stripping signal, i.e., high concentrations are measured using a short accumulation time and low concentrations using a longer accumulation time. The sensing action occurs during the stripping phase of the measurement, during which the voltage of the electrochemical cell is ramped from the accumulation potential, due to the release of the stripping potential of arsenic. When arsenic is stripped off the sensor, it dissolves back into the test solution. This stripping process releases three electrons per arsenic atom and, therefore, the amount of arsenic accumulated on the tip of the sensor is proportional to the current measured during the stripping operation. This current is recorded for the treated sample as well as for the spiked sample in order to calculate the arsenic concentration in the original sample stream. 3.5 Run Length and Regeneration Elution Studies 3.5.1 Run Length Studies. Because routine weekly samples collected from the treatment plant represented only discrete data points on breakthrough of arsenic and nitrate from multiple service cycles, it was desirable to collect samples from complete service cycles to delineate breakthrough of arsenic, nitrate, and other competing anions and determine the appropriate run length of the IX system. The results of the studies were used to assess the system performance and to adjust the regeneration setpoint. Table 3-4 summarizes sampling and analytical schedules of five run length studies (three in Study Period I and two in Study Period II), during which effluent samples were collected from either one or both IX vessels throughout five complete service cycles. The totalizer on the combined effluent ("TT") was used to track the volume of water treated since last regeneration. The totalizer was automatically reset to "zero" when Vessel A regeneration was completed, which signaled the beginning of a service cycle even 13 Table 3-4. Sampling and Analysis Schedule for Run Length Studies Regene- ration Sampling Study Sampling Setpoint No. of No. Date Period Location (al) Samples Anal tes 1 09/19/06— I TA 905,300 10 As (total), NO3, SO4, V (total), P 09/22/06 (total), and alkalinity 2 10/24/07— TA 600,000 7 As (total), NO3, SO4, and alkalinity 10/26/07 12/08/08— INa /TA 600,000 13 As (total), V (total), and silica 3 12/10/08 4 04/21/09— II TT 600,000 6 As (total), NO3, V (total), P (total), and 04/22/09 TOC 06/29/09— INa /TA/ 600,000 26 As (total), NO3i SO4,V (total), P (total), 5 07/01/09 TB/TT(a) silica, alkalinity, pH, and TOC (a) Sample collected once during run length study. though Vessel B regeneration was just started. The service cycle ended when the totalizer reached a set throughput value, which triggered the next regeneration cycle beginning with the Vessel A regeneration. Additional information for each of the studies is provided below. Run Length Study 1: At system startup, a run length study was conducted by Battelle staff during September 19 through 22, 2006, to establish baseline performance of the IX system. Ten samples were collected from Vessel A effluent ("TA") during a service cycle. Sampling began shortly after the service cycle had started, and continued periodically, except during the night. Flow rates and throughput values were recorded at the time of sampling for run length calculations. Samples were analyzed for total As, V, and P, nitrate, sulfate, and total alkalinity. Run Length Study 2: Following a caustic/brine cleaning on October 22, 2007, the operator performed a run length study from October 24 through 26, 2007, to determine the effectiveness of the cleaning. Seven samples were collected from Vessel A effluent ("TA") during a service cycle. Flow rates and throughput were recorded at the time of sampling. Samples were analyzed for total arsenic, nitrate, sulfate, and total alkalinity. Run Length Study 3: Towards the end of Study Period I, the operator performed another run length study from December 8 through 10, 2008, to determine the extent of resin fouling. One raw water sample and 12 effluent samples from Vessel A ("TA") were collected during a service cycle. Flow rates and throughput values were recorded at the time of sampling. Samples were analyzed for total As, total V, and silica. Run Length Study 4: At the startup of Study Period II, a run length study was conducted by the operator on April 21 through 22, 2009, to assess the performance of the dual resin IX system. Six samples were collected from the combined effluent from both vessels ("TT") during a service cycle. Flow rates and throughput values were recorded at the time of sampling. Samples were analyzed for total As, V, and P, nitrate, and TOC. Run Length Study 5: To further confirm the performance of the dual resin system, Battelle staff conducted a run length study onsite from June 29 through July 1, 2009. Twelve effluent samples were collected from each vessel effluent during a service cycle. One influent (IN) and one combined effluent (TT) sample also were collected. Flow rates and throughput values were recorded at the time of 14 sampling. pH was monitored periodically onsite using a handheld pH probe. Samples were analyzed for total As, V, and P, nitrate, sulfate, total alkalinity, and TOC. 3.5.2 Regeneration Elution Study. In Study Period II, an elution study was conducted by Battelle staff members to evaluate the effectiveness of the regeneration process in removing arsenic, nitrate, and, especially, TOC from the dual IX resin beds and to explore the possibility of optimizing the regeneration process. Both the elution and follow-on run length studies were originally scheduled for March 2 through 4, 2009. However, all study activities had to be suspended due to an incident involving salt spills in the treatment plant building during a salt delivery/loading. The studies were rescheduled for June 29, 2009. The IX resin vessels were set to regenerate for a volume throughput of 600,000 gal in a service cycle. Regeneration consisted of brine draw, slow rinse, and fast rinse with one vessel being taken offline for regeneration while the other remained in service. An 8% brine solution (specific gravity of 1.06) was used for brine draw. Raw water was used for slow and fast rinse. Figure 3-3 shows the experimental setup, including the use of a flow -through cell, for the elution study. A side stream of spent brine/rinse water was directed from the regeneration waste discharge line via a piece of %-in Tygon tubing to an 800- mL plastic beaker, or a flow -through cell, in which a Hanna HI 9635 conductivity/TDS probe (Hanna Instruments, Inc., Woonsockett, RI) and a VWR pH probe were placed (after calibration) for continuous measurements of TDS and pH. Because the flow -through cell was secured using a 3-in spring clamp just inside the rim of a 32-gal plastic container, the solution that overflowed the flow -through cell was collected into the plastic container. Upon completion of one regeneration step, the flow -through cell was immediately transferred to another 32-gal plastic container for continuing measurements. This process continued until all three regeneration steps were complete. A stopwatch was used to measure elapsed time. Table 3-5 lists the number of samples collected and analyzed during each regeneration step. Figure 3-3. Regeneration Monitoring Setup 15 Table 3-5. Sampling and Analysis Schedule for Resin Elution Study Sampling Number of Number of Regeneration Time Grab Composite Steps (min) Samples Samples Anal tes Brine Draw 0-21 Vessel A: 6 Vessel A: 1 Total As, V, and Vessel B: 6 Vessel B: 1 P, NO3, SO4, TDS, pH, Slow Rinse 22-66 Vessel A: 7 Vessel A: 1 Vessel B: 7 Vessel B: 1 temperature, silica, TOC, and Fast Rinse 67-81 Vessel A: 3 Vessel A: 1 Vessel B: 3 1 Vessel B: 1 I alkalinity Note that a caustic/brine cleaning was performed one week prior to the elution study. The cleaning was conducted to remove accumulated TOC, if any, from the dual IX resin beds. The caustic/brine cleaning followed the procedures presented in Appendix A. 3.6 IX Resin Cleaning Due to deteriorating resin performance, resin core samples were collected from both IX vessels by Kinetico in March 2007 and shipped to Purolite for analyses. The resin samples were cleaned in Purolite's laboratory with either 10% brine or a mixture of 2% caustic and 10% brine and analyzed for moisture content, volumetric capacity, strong base capacity, and total organic fouling. The results are discussed in Section 4.4.3. In light of positive laboratory results with the use of 2% caustic/10% brine in Purolite's laboratory and positive field results with 5% caustic/10% brine at another EPA arsenic removal demonstration site in Fruitland, ID (where similar fouling issues were experienced with its Purolite A300E resin and the Vale operators were invited to observe field cleaning in June 2007), a decision was made to perform resin cleaning at Vale, OR using similar procedures presented in Appendix A. Field cleaning was performed by Kinetico in late October 2007. The caustic/brine mixture was prepared by dispensing two 55-gal drums of 50% NaOH into the brine day tank using a drum pump, followed by filling the day tank with saturated brine up to 1,050 gal. The specific gravity of the mixture was about 1.042, corresponding to a 6% brine. The caustic/brine mixture was drawn from the day tank downward through Vessel A or B for about 20 min. By the end of brine draw, a hand valve was closed manually to allow the resin to soak into the causticibrine mixture for 30 min. Slow and then fast rinse were then followed for about 45 and 15 min, respectively. Upon completion of the field cleaning in October 2007, a resin core sample was taken from Vessel A using a piece of 2-in diameter and 4 ft long polyvinyl chloride (PVC) pipe and sent to Purolite for analyses. The top, middle, and bottom sections of the core sample were analyzed individually for the same set of analytes mentioned above. 3.7 Sampling Logistics All sampling logistics including arsenic speciation kit preparation, sample cooler preparation, and sample shipping and handling are discussed as follows. 3.7.1 Preparation of Arsenic Speciation Kits. The arsenic field speciation method used an anion exchange resin column to separate the soluble arsenic species, As(V) and As(III) (Edwards et al., 1998). Arsenic speciation kits were prepared in batches at Battelle laboratories according to the procedures detailed in Appendix A of the EPA -endorsed QAPP (Battelle, 2004). 101 3.7.2 Preparation of Sampling Coolers. For each sampling event, a sample cooler was prepared with the appropriate number and type of sample bottles, disc filters, and/or speciation kits. All sample bottles were new and contained appropriate preservatives. Each sample bottle was taped with a pre- printed, colored -coded, and waterproof label. The sample label consisted of sample identification (ID), date and time of sample collection, collector's name, site location, sample destination, analysis required, and preservative. The sample ID consisted of a two -letter code for a specific water facility, sampling date, a two -letter code for a specific sampling location, and a one -letter code for the specific analysis to be performed. The sampling locations were color -coded for easy identification. For example, red, yellow, green, and blue were used for IN, TA, TB, and TT sampling locations. Pre -labeled bottles for each sampling location were placed in separate zip -lock bags (each corresponding to a specific sampling location), which were then packed in a sample cooler. When arsenic speciation samples were to be collected, arsenic speciation kits also were included in the cooler. When appropriate, the sample cooler was packed with bottles for the three distribution system sampling locations. In addition, a packet containing all sampling and shipping -related supplies such as latex gloves, sampling instructions, chain -of -custody forms, prepaid FedEx air bills, and bubble wrap also was placed in the cooler. Except for the operator's signature, the chain -of -custody forms and prepaid FedEx air bills had already been completed with the required information. The sample coolers were shipped via FedEx to the facility approximately 1 week prior to the scheduled sampling date. 3.7.3 Sample Shipping and Handling. After sample collection, samples for offsite analyses were packed carefully in the original coolers with wet ice and shipped to Battelle. Upon receipt, sample custodians verified that all samples indicated on the chain -of -custody forms were included and intact. Sample IDs were checked against the chain -of -custody forms and the samples were logged into the laboratory sample receipt log. Any discrepancies were addressed with the field sample custodian, and the Battelle Study Lead was notified. Samples for metal analyses were stored at Battelle's inductively coupled plasma -mass spectrometry (ICP- MS) laboratory. Samples for other water quality analyses were packed in coolers and picked up by couriers from American Analytical Laboratories (AAL) in Columbus, OH, or TCCI Laboratories in New Lexington, OH, both of which were under contract with Battelle for this demonstration study. The chain - of -custody forms remained with the samples from the time of preparation through analysis and final disposal. All samples were archived by the appropriate laboratories for the respective duration of the required hold time and disposed of properly thereafter. 3.8 Analytical Procedures The analytical procedures described in detail in Section 4.0 of the EPA -endorsed QAPP (Battelle, 2004) were followed by Battelle ICP-MS, AAL, and TCCI Laboratories. Laboratory quality assurance/quality control (QA/QC) of all methods followed the prescribed guidelines. Data quality in terms of precision, accuracy, method detection limit (MDL), and completeness met the criteria established in the QAPP, i.e., relative percent difference (RPD) of 20%, percent recovery of 80% to 120%, and completeness of 80%. The QA data associated with each analyte will be presented and evaluated in a QA/QC summary report to be prepared under separate cover. Field measurements of pH, temperature, DO, and ORP were conducted by the plant operator using a WTW Multi 340i handheld meter, which was calibrated for pH and DO prior to use following the procedures provided in the user's manual. The ORP probe also was checked for accuracy by measuring the ORP of a standard solution and comparing it to the expected value. The plant operator collected a water sample in a clean, plastic beaker and placed the Multi 340i probe in the beaker until a stable value was obtained. 17 4.0 RESULTS AND DISCUSSION 4.1 Facility Description The City of Vale, located in eastern Oregon, has a population of 1,976. In 2004, the average daily demand for water was 263,000 gpd, with the peak daily demand of 388,000 gpd occurring in July 2004. As shown in Table 4-1, the water demand was met by seven groundwater wells (Wells No. 1 through No. 7), operating on a rotating basis to achieve a combined flowrate of 525 gpm. This flowrate represents a hydraulic utilization of 35% based on the average daily demand and a corresponding run time of 8.3 hr/day. Water from the individual wells was blended and then chlorinated in a centralized treatment building. In 2004, Wells No. 1 through No. 5 each operated for approximately 3 to 8.5 hr/day, while Wells No. 6 and No. 7 were used only as backup wells. The City blended raw water from the various wells in order to minimize nitrate concentrations in water entering the distribution system. In addition to the seven wells, a 500-gpm groundwater well on Washington Street in downtown also serves as a backup well. Table 4-1. Construction Details of Wells No. 1 to No. 7 Well No.l 1 No.2 1 No.3 1 No.4 No.5 No.6 No.7 Diameter (in) 8 8 8 8 8 8 8 Depth of Well (ft) 33 33 33 33 28.5 33 28.5 Screened Interval (ft bgs) 18-28 18-28 18-28 18-28 13.5-23.5 18-28 13.5-23.5 Static Water Level (ft bgs) 8 to 9 8 to 9 8 to 9 8 to 9 NA NA NA Pump Capacity (gpm) 200 100 180 100 NA NA NA bgs = below ground surface; NA = not available Wells No. 1 though No. 7 and the treatment building are located in the airfield of the county airport. The treatment building was 10 ft tall and built to the Federal Aviation Administration height limit (Figure 4- 1). The Kinetico system was designed to incorporate lower -profile tanks so that the new building could be constructed near the airfield runway. Due to lack of sewer tie-ins at the airfield, a 1.8-acre evaporation basin along with a 0.2-acre drying bed both lined with a high -density polyethylene (HDPE) liner was constructed onsite to hold the regeneration waste. A MIOX sytem was used to generate sodium hypochlorite onsite. As shown in Figure 4-2, the MIOX system consisted of a 78-gal salt drum, an electrolytic cell, an 8-gal/hr (gph) metering pump, and a 500-gal storage tank for the sodium hypochlorite solution. The target chlorine dosage was 0.2 mg/L (as C12) and the target residual level in treated water was 0.025 mg/L (as C12). Once chlorinated, the water flowed under pressure to a 200,000-gal atmospheric reservoir installed at the airport in 2001 and then was boosted by two booster pumps before entering the city's distribution system and two older reservoirs located on the hillside east of town. These reservoirs were built in 1917 and 1977 and had a capacity of 105,000 and 750,000 gal, respectively. Due to the additional pressure loss across the new arsenic and nitrate treatment system, a booster pump with a capacity of 600 gpm at 130 ft H2O (56 psi) total dynamic head (TDH) was installed to raise the influent pressure and to supply water during system regeneration. 4.1.1 Source Water Quality. Analytical results from the raw source water sampling event held on December 2, 2004, are presented in Table 4-2 and compared to the data collected by the vendor and the city for the site selection of this demonstration study. When onsite, a Battelle staff member measured pH, temperature, DO, and ORP using a WTW 340i handheld meter. In addition, source water was filtered for f.: Figure 4-1. Existing Well House in Vale, OR Figure 4-2. Existing Chlorination System in Vale, OR 19 Table 4-2. Vale, OR Source Water Data for Combined Wells No. 1 to No. 7 Parameter Units Facility Data Kinetico Data Battelle Data Date Various Not Specified 12/02/04 07/23/08 pH S.U. 7.5 7.4 7.5 NA Temperature °C NA NA 13.1 NA DO mg/L NA NA 4.8 NA ORP mV NA NA 236 NA Conductivity umhos NA 775 NA NA Total Alkalinity (as CaCO3) mg/L NA 284 158 278 Hardness (as CaCO3) mg/L NA 173 181 120 Turbidity NTU NA NA <0.1 0.2 TDS mg/L NA NA 446 458 TOC (as C) mg/L NA NA 2.1 NA Nitrate (as N) mg/L 8 to 12 NA 4.1 3.5 Nitrite (as N) mg/L NA NA <0.01 NA Ammonia (as N) mg/L NA NA <0.05 NA Chloride mg/L NA 25.3 15.0 NA Fluoride mg/L NA 0.6 0.5 NA Sulfate mg/L 83 84 75.0 63.9 Silica as Si02) m /L NA 53.5 56.7 57.7 Phosphorus (as P) m /L NA <0.5 0.3 0.3 As(total) µg/L 20 18 16.7 20.5 As (total soluble) µg/L NA NA 16.5 NA As (particulate) µg/L NA NA 0.2 NA As(Ill) µg/L NA NA 1.9 NA As(V) /L NA NA 14.6 NA Fe (total) /L NA <30 <25 <25 Fe (soluble) µ /L NA NA <25 NA Mn (total) µg/L NA <10 1.1 0.3 Mn (soluble) µg/L NA NA 0.8 NA U (total) µg/L NA NA 6.1 NA U (soluble) µg/L NA NA 6.3 NA V (total) /L NA NA 46.8 51.2 V (soluble) /L NA NA 50.4 NA Na (total) mg/L 164 114 110 NA Ca (total) mg/L NA 46.5 51.1 30.0 Mg (total) mg/L NA 14 13.0 10.8 DO = dissolved oxygen; NA = not available; ORP = oxidation-reduction potential; TDS = total dissolved solids; TOC = total organic carbon soluble arsenic, iron, manganese, uranium, and vanadium, and speciated for As(III) and As(V). Historical data from individual wells collected by EPA and the city are given in Tables 4-3, 4-4, and 4-5. Overall, Battelle's data are comparable to those provided by the other parties with the exception of the nitrate results that depend on the combination of wells as discussed previously. The analytical results of the source water sampling and implications for water treatment are briefly discussed below. Oki] Table 4-3. Wells No. 1 to No. 7 Water Quality Data from June 2000 to August 2000(a) Parameter Unit Well1 Well2 Well Well Well Well6 Well? pH S.U. 8.2 8.2 8.4 - - - - Conductivity umhos 626 492 722 - - - - Alkalinity mg/L 241 207 275 - - - - Hardness mg/L 142 144 136 - - - - TDS mg/L 343 390 833 - - - - Nitrate (as N) mg/L 4.7 2.4 6.9 - 12.7 16.7 14.4 Nitrite (as N) mg/L <0.01 <0.01 0.01 - <0.01 <0.01 <0.01 Fluoride mg/L 0.6 0.6 0.5 - - - - Sulfate m /L 77 51 91 - - - - As (total) µg/L 23 22 16 - 10 20 25 Fe (total) µg/L 820(') 480(') 5,760(') - - - - Mn (total) µg/L 50 70 280 - - - - Na (total) mg/L 160 76 200 - - - - (a) Samples analyzed by Analytical Laboratories, Inc. in Boise, ID. (b) Iron levels elevated in these wells compared to other historical source water data. Table 4-4. Wells No. 1 to No. 7 Water Quality Data from EPA (December 2004) Parameter I unit I Well 1 Well 1 Well 1 Well 1 Wells 1 Well 1 Well? As (total) µg/L 16.0 12.0 10.0 14.0 13.0 28.0 28.0 Fe (total) µg/L 43.8 5.2 10.5 11.8 14.5 23.7 66.5 Mn (total) /L ND ND 0.9 0.7 ND ND 1.8 P (total) mg/L 0.27 0.29 0.28 0.21 0.28 0.36 0.40 ND = not detected Table 4-5. Wells No. 1 to No. 7 Nitrate Concentrations (mg/L [as NJ) from Source (February 2001 to October 2004)(a) Sampling Date Well Well2 Well Well Well Well Well7 02/28/01 5.46 5.06 7.10 11.50 14.70 12.50 13.30 07/03/01 5.78 2.14 6.03 11.70 13.70 12.20 10.60 08/14/01 5.38 4.15 6.08 12.00 13.60 11.70 5.52 08/21 /01 5.54 4.84 6.02 - - 11.00 5.42 02/12/02 6.24 5.39 6.26 13.70 - - - 02/19/02 - - - - 13.60 11.30 16.90 05/08/02 7.12 5.60 10.70 14.30 13.80 14.50 18.00 08/14/02 6.40 5.36 10.70 13.50 12.10 12.20 9.14 11/13/02 4.99 4.09 7.83 8.86 8.36 9.21 10.70 05/13/03 5.54 4.24 8.47 10.50 9.85 14.50 18.90 09/09/03 3.21 2.14 3.00 9.57 7.48 10.50 10.80 11/04/03 2.86 2.81 3.12 6.82 6.63 10.30 10.50 02/10/04 4.10 3.03 5.34 5.17 7.43 12.70 13.70 05/11/04 2.70 1.88 3.12 5.24 4.80 12.60 14.30 10/12/04 2.37 1.75 3.42 5.82 4.81 7.38 8.14 (a) Samples analyzed by Magic Valley Labs in Twin Falls, ID. 21 Arsenic. Total arsenic concentrations in the blended source water ranged from 16.7 to 20 µg/L (Table 4-2). Total arsenic concentrations in raw water from the individual wells ranged from 10 to 28 µg/L (Tables 4-3 and 4-4). Based on the source water sampling results obtained by Battelle, out of 16.7 µg/L of total arsenic, 14.6 µg/L existed as soluble As(V). Therefore, As(V) was the predominating arsenic species. At raw water pH values of 7.4 to 7.5, As(V) is present primarily as HAs042 , which can be removed electrostatically by anion exchange resin. Nitrate. The City blended source water from various wells to minimize nitrate concentrations in the blended water to below the 10 mg/L MCL. As shown in Table 4-5 and Figure 4-3, nitrate concentrations in Wells No. 1 and No. 2 were less than 7.1 mg/L (as N) and exhibited a decreasing trend starting from 2002. Nitrate concentrations in Well No. 3 peaked at 10.7 mg/L (as N) and then decreased to just over 3.0 mg/L (as N) by 2004. Wells No. 4 to No. 7 had historical nitrate levels mostly over 10 mg/L and as high as 18.9 mg/L (as N). Concentrations in wells No. 4 and No. 5 also showed a significant decreasing trend with concentrations measured at 4.8 to 5.8 mg/L (as N) by October 2004. Concentrations in Wells No. 6 and No. 7 remained elevated from 2000 through 2004; the measurements made in October 2004 were less than 10 mg/L (as N) for both wells. Combined source water values were 8 to 12 mg/L (as N) from the facility and 4.1 mg/L (as N) from Battelle (Table 4-2). Similar to arsenic, the water treatment process relied upon the exchange of nitrate in source water with chloride on the resin. 20 18 16 4 2 0 Well 1 ---Well 2 ..... Well Well Well 5 — —We116 'We 117 .000, ,1 \ ---_-- _ Iw \ -- 10/1/2000 4/19/2001 11/5/2001 5/24/2002 12/10/2002 6/28/2003 1/14/2004 8/1/2004 2/17/2005 Date Figure 4-3. Historic Nitrate Data from Wells No. 1 Through No. 7 Sulfate. Sulfate concentrations ranged from 51 to 91 mg/L in Wells No. 1 through No. 3 (Table 4-3) and from 75 to 84 mg/L in combined wells (Table 4-2). Because sulfate is preferred over arsenate and nitrate and because of its higher concentrations, sulfate competes strongly with arsenic and nitrate for exchange sites. ON Iron, Manganese, Silica, and TOC. Iron and manganese concentrations in source water were less than 30 and 10 µg/L, respectively, and, therefore, should not cause iron or manganese fouling to the IX resin. Silica concentrations averaged 56 mg/L (as SiO2); polymerization of silica on the resin surface could adversely impact the IX process. TOC measured at 2.1 mg/L; it is well known that AIX resins are susceptible to fouling by dissolved organic matter (DOM) (Boodoo, 2004). Other Water Quality Parameters. Total dissolved solids (TDS) measured at 446 mg/L, a level which may impact the performance of the IX resin. Total phosphorus concentrations in the individual wells ranged from 0.2 to 0.4 mg/L (as P) (Table 4-4), which could affect the exchange of arsenic and nitrate anions. Concentrations of uranium and vanadium were measured at 6.1 and 46.8 µg/L, respectively, which could compete with arsenic and nitrate for exchange sites. Total alkalinity in source water ranged from 158 to 284 mg/L (as CaCO3); bicarbonate anions also compete for exchange sites, especially immediately after resin regeneration. Removal of bicarbonate causes the treated water pH to decrease, making the treated water corrosive as it enters the distribution system. The pH value of raw water was 7.4 or 7.5. Unlike adsorptive media, IX resins are not sensitive to water pH. 4.1.2 Distribution System Water Quality. The distribution system sampling for the EPA demonstration study included three residences (i.e., 629 15th Street North, 780 15th Street North, and 252 B Street West) supplied by the combination of Wells No. I through No. 7. These locations are a good representation of the distribution system and the first two also are part of the City's sampling network for the LCR. The distribution system consisted of PVC mains with HDPE or copper service lines to individual homes. Water in the distribution system was sampled once a year for haloacetic acids (HAA5) and trihalomethanes (TTHMs) under EPA's Disinfection Byproducts Rule. In 2004, the HAA5 level was 0.009 mg/L, compared to the MCL of 0.06 mg/L. The TTHMs level was 0.03 mg/L, compared to the MCL of 0.08 mg/L. The treated water also was sampled once every three years at 10 residences under EPA's LCR. During the latest sampling round in 2002, the lead concentration was 0.004 mg/L, compared to the action level of 0.015 mg/L, and the copper concentration was 0.865 mg/L, compared to the action level of 1.3 mg/L. 4.2 Treatment Process Description 4.2.1 Ion Exchange Process. Ion exchange is a proven technology for removing arsenic and nitrate from drinking water supplies (Clifford, 1999; Ghurye et al., 1999; and Wang et al., 2002). It is a physical/chemical process that removes dissolved arsenate and nitrate ions from water by exchanging them with chloride ions on an AIX resin. Once its capacity is exhausted, the resin is regenerated with a brine solution containing high concentrations of chloride to displace the arsenate and nitrate on the resin. Strong -base anionic (SBA) IX resins are commonly used for arsenate and nitrate removal. Resin capacity typically is not sensitive to water pH (in the range of 6.5 to 9.0). An SBA IX resin tends to have a higher affinity for more highly charged anions, resulting in a general hierarchy of selectivity as follows: 2- 2- - - - - - SO4 > HASO4 > NO3 > NO2 > CI > H2ASO4 , HCO3 >> Sl(OH)4; H3ASO4 Because sulfate is preferred over arsenate and nitrate and because its concentration is at least three orders of magnitude higher than those of arsenic, it is a major competing anion to arsenate and nitrate removal by the IX process. High TDS levels also can significantly reduce arsenic and nitrate removal efficiencies. In general, the IX process is not economically attractive if source water contains >500 mg/L of TDS and 23 >150 mg/L of sulfate. Also, particulates in feed water can potentially foul the SBA IX resin, and, therefore, must be removed prior to IX process. Most nitrate removal plants use either a nitrate selective resin or an SBA Type II or Type I resin. Nitrate selective resins typically have triethylamine functional groups, which show higher selectivity for hydrophobic anions (such as nitrate and perchlorate) over hydrophilic divalent anions (such as sulfate and arsenate). Therefore, sulfate and arsenate will break before nitrate. Since arsenate is less selective than sulfate, it will break before sulfate. Operating to arsenic breakthrough using a nitrate selective resin has two major issues: (1) the operating cost is higher because of a shorter run length to arsenic breakthrough than to nitrate breakthrough and (2) it is more expensive to monitor arsenic breakthrough than nitrate breakthrough in real time. Therefore, a nitrate selective resin would not be a good choice for removing both arsenic and nitrate (Boodoo, 2004). When sulfate is relatively low, Type II and Type I SBA resins are preferred due to their lower prices. For drinking water applications, Type II is preferred over Type I because of a fishy odor associated with Type I resins. Two types of SBA IX resins were evaluated during the demonstration study at Vale. Purolite Arsenex II was used in Study Period I. However, due to organic fouling, the resin had to be replaced with PFA300E top -dressed with A850END, in Study Period II. These resins are NSF International (NSF) Standard 61 approved for use in drinking water treatment. Their physical and chemical properties are presented in Table 4-6 and highlighted as follows: Arsenex II was claimed by the vendor as a proprietary, arsenic selective IX resin, specifically designed for arsenic removal in the presence of high sulfate. However, it was not clear whether the term "arsenic selective" actually meant higher affinity for arsenic than sulfate (like the term "nitrate selective" for higher affinity for nitrate than sulfate). No literature was available for this resin, which was posted on Purolite's Web site. PFA300 is a gel -Type II SBA resin, which has a high operating capacity at a low regeneration level because of its uniform particle size distribution (i.e., uniformity coefficient is 1.2). It is less susceptible to organic fouling than standard gel -type SBA resins. Except for its narrower size distribution, PFA300 is very similar to A300E, which was evaluated for arsenic and nitrate removal at another EPA demonstration site in Fruitland, ID (Wang et al., 2010). The physical and chemical properties of A300E also are listed in Table 4-6 for reference. A850END is specially produced from A850 with a narrower size grading of 300- to 600-µm diameter. A850 is a gel -Type I SBA resin with an acrylic matrix. This gel or highly macroporous acrylic -based SBA Type I resin can remove most naturally occurring DOM, such as humic and fulvic acids, to at least 50 to 80%. A850END can be regenerated with lower levels of sodium hydroxide than those required for a polystyrene -based Type I resin. Resin run lengths for arsenic and nitrate removal at Vale were estimated by Purolite using its computerized simulator. Figure 4-4 shows the simulation for ArseneX II based on a modeling run with 20 µg/L of arsenic, 53 mg/L of nitrate (as N), and 83 mg/L of sulfate in water. The results indicate that bicarbonate breaks first, followed by nitrate, arsenic, and sulfate. Nonetheless, breakthrough of arsenic at 10 µg/L would occur first at 680 BV followed by nitrate breakthrough at 9 mg/L (as N) at 740 BV (1 BV = 220 ft3). These run lengths, however, were significantly over -predicted than the actual run lengths (generally less than 431 BV or 600,000 gal) as discussed in Section 4.4.3. Table 4-6. Physical and Chemical Properties of IX Resins Parameters Stud Period I Study Period II Reference Arsenex II A850 a PFA300 A300E Polymer Structure Gel polystyrene crosslinked with DVB Gel polyacrylic crosslinked with DVB Gel polystyrene crosslinked with DVB Gel polystyrene crosslinked with DVB Functional Group Dimethyl ethanol amine Trimethylamine Dimethyl ethanol amine Dimethyl ethanol amine Physical Form/Appearance Opaque spherical beads Clear spherical beads Amber spherical beads Clear spherical beads Whole Bead Count 95% minimum - 95% minimum - Resin Type SBA Type II SBA Type I SBA Type II SBA Type II Ionic Form, as Shipped Cl- Cl- Cl- Cl- Shipping Weight (lbs/ft or g/L) 43 42.5-45.6 or 680-730 43 or 690 43-45 or 690-720 Specific Gravity (g/mL) - 1.09 1.10 1.09 Mesh Size (U.S. Standard) (Wet) 16 X 50 - 25 X 40 16 X 50 Bead Size Range (mm) 0.3-1.2 0.60-0.85 +0.710 mm <1%; -0.425 mm <1% 0.3-1.2 Uniformity Coefficient - 1.70 1.20 1.70 Moisture Retention (%) 42-54 57-62 40-45 40-45 Reversible Swelling Cl- to SO42-/NO3- Negligible Cl- to OH- 15% (max) Cl- to OH- 10% (max) Cl- to OH - 10% (max) Total Exchange Capacity, Cl- Form (eq/L) (wet, volumetric) 1.0 1.25 1.4 1.4 pH Range 0-14 1-10 No limit No limit Maximum Temperature Limit (°C/°F) 100/212 85/185 85/185 85/185 Source: Purolite DVB = divinylbenzene; SBA = strong base anion (a) A850END specially produced from A850 with a narrower size grading of 300- to 600-µm diameter. Some properties, such as bead size range and uniformity coefficient expect to vary from those of A850. Figure 4-5 presents results of a simulation for PFA300E done in June 2008. Similar to the simulation for Arsenex II, nitrate breaks first, followed by arsenic and sulfate. But unlike Arsenex II, nitrate breakthrough at 10 mg/L (as N) would occur first at approximately 650 BV followed by arsenic breakthrough to 10 µg/L at approximately 700 BV. The vendor recommended regenerating at 523 BV with 10 lb/ft3 of salt. In January 2009, Purolite updated the run length simulation after receiving additional source water quality data for Vale. The updated run length to 10-mg/L nitrate (as N) breakthrough was 604 BV, corresponding to 993,940 gal of throughput (1 BV = 220 ft3). 041 IX-SIM - Arsenex II Removal of As and N at Vale OR (Kinetico) 450 70 M 400 �60 O 350 Z 2 300 50 E ' tZ — — SO4 0 250 0 40 L -- HCO3 IqO 200 30 to -- N N 150 f Q As E 20 Q 100 IZ CL 10 50 Ln O Ln O Ln O Ln O Ln O Ln O Ln O Ln Bvs N peaks at 9 ppm as N at 740 BVs As breaks at 10 ppb at 680 Bvs Figure 4-4. Simulation of Arsenex II Resin Run Length Vale OR, Simulating As & NO3 removal with PFA300E -virgin resin -capacity for regenerable resin will be lower Cycle time dependent on NO3 break - expect 523 Bvs to NO3-N break at 10ppm - regenerated w/ 10 lbs NaCl/ft3 resin-Coflow or 485 Bvs Counternow 90 n 80 70 60 0 50 40 30 N 20 c. 10 a 0 L0 0 LC) O in O 0 O 0 O L0 O LO O 0 0 l0 O L0 Cfl f� N C0 (I) CY) IT O L0 (fl N r• (1) CC) V C) r r N N cam") IT ITLn LC) (fl C0 rl- r- 00 CO 0) 0) IXSIM Purolite BVs SO4 NO3-N +As V Figure 4-5. Simulation of A850END/PFA300E Resin Run Length (June 2008) 26 4.2.2 Treatment Process. The Vale IX system utilized the packed -bed anionic IX technology to remove arsenic and nitrate from source water. Figure 4-6 is a process schematic of the treatment system. The process equipment included two banks of five skid -mounted bag filters, two skid -mounted resin vessels, two salt saturators, two brine day tanks, three pre -wired brine transfer/injection pumps, one air compressor, one post -chlorination system, as well as associated valves, sample ports, pressure gauges, and flow elements/controls. The IX system was fully automated and controlled by a central control panel consisting of a programmable logic control (PLC), a touch screen operator interface panel (01P), and a data communication modem. The OIP allowed the operator to monitor system flowrate and volume throughput since last regeneration, change system setpoints, and check the status of alarms. The modem allowed the vendor to remotely dial in for monitoring and troubleshooting. All pneumatic valves were constructed of PVC and all plumbing was Schedule 80 PVC solvent bonded. Table 4-7 summarizes the design specifications of the IX system. Regeneration Waste to Pond or Reused Brine Day Tank Resin Resin TankA Tank B Booster 83" x 86" 63" x 86" Pumps (2) 31 Sediment Filters (2) Treated Water to Storage/Distribution Brine Drawn by Raw Water from Well Eductor on Ion Exchange Skid 11-Ton 11-Ton JDay Salt Salt Saturator Saturator Brine Transfer Clz Pump Existing L— Reused Brine to 2" Inlet Reused on Ion Exchange Skid Brine Day Tank NOT TO SCALE Reused Battelle Brine Pump VALE PROCESS0I.CM Figure 4-6. Schematic of Kinetico's IX-263 As/N Removal System for Vale, OR 27 Table 4-7. Design Specifications of IX System System Component/Parameter Study Period I Study Period II Pre-treatment Bag Filter Assembly Two banks of five 20-µm 5-µm filter bags bag filters in parallel IX Vessels and Media Beds Vessel Size (in) 63 D x 86 H Same Cross -Sectional Area (ft /vessel) 21.6 Same Number of Resin Vessels 2 Same Configuration Parallel Same Resin Type(s) Purolite Arsenex II Purolite A850END/PFA300E IX Resin Quantity (ft /vessel) a 110 15 and 95 ft , respectively Flint Gravel Support Media (ft /vessel) 4 Same Service Design Flowrate (gpm) 540 Same Hydraulic Loading Rate (gpm/ft) 12.5 Same Specific Flowrate (gpm/ft) 2.45 Same EBCT (min) 3.0 Same Estimated Working Capacity (BV) 550-680 523-604 Volume Throuehput (gal) 905,300-1,119,280 860.650-993.940 Regeneration Mode Co -current downflow Same Regeneration Level (lb salt/ft resin) 12 10 Brine Concentration (%) 10 8 Reused Brine Draw Duration, Flowrate, and Volume(b) 15 min, 50 gpm, 750 gal Discontinued Fresh Brine Draw Duration, Flowrate, and Volume(b) 17 min, 50 gpm, 850 gal 21 min, 64 gpm, 1,344 gal Slow Rinse Duration, Flowrate, and Volume(b) 40 min, 50 gpm, 2,000 gal 45 min, 44 gpm, 1,980 gal Fast Rinse Duration, Flowrate, and Volume(b) 20 min, 220 gpm, 4,400 gal 15 min, 260 gpm, 3,900 gal Wastewater Volume per Regeneration Event (gal)(b) 7,250 (per vessel), 14,500 (total) 7,224 (per vessel), 14,448 (total) Salt Consumption per Regeneration Event (lb) 760 (per vessel), 1,520 (total) 760 (per vessel), 1,520 (total) Brine System Brine Day Tank Size (in) 61 D x 97 H (two) Use one tank only Brine Day Tank Material HDPE Same Fresh Brine Transfer Pump 1.5 hp, max. 90 gpm @ 25 ft H2O TDH Same Fresh Brine Venturi Eductor 2 in (draw factor 0.75 to 1.0) Discontinued Reused Brine Injection Pump 5 hp, max. 200 gpm @ 45 ft H2O TDH Discontinued Salt Saturator Size (ton) 11 (two) Same Salt Saturator Material Fiberglass Same Post -treatment Target Chlorine Residual (mg/L [as C12]) 0.025 Same (a) Actual amounts were 93 ft' for Arsenex 11 and 167 and R1.7 ft' for A950F.ND and ofPFA300F. respectively. (b) Source: Kinetico "Brine Waste Minimization Memo for Vale, OR" dated April 4, 2006. pk*.: Major process steps and system components are presented as follows: Intake. Raw water from Wells No. 1 through 7 was pumped to the treatment building and then combined at a common header. To overcome the anticipated headloss from the treatment system, the incoming water was boosted by a 25-horsepower (hp) booster pump to meet the minimum influent pressure requirement of the IX system. Two booster pumps (one on standby), each rated for 600 gpm at 130 ft H2O head (or 56 psi), and a three-phase Danfoss VLT8000 series variable frequency drive (VFD) were installed at the common header. System inlet piping and a booster pump is shown in Figure 4-7. Figure 4-7. System Inlet Piping and Booster Pump Sediment Filtration. Prior to entering the IX resin vessels, raw water was filtered through two parallel, skid -mounted bag filter assemblies to remove sediment. Each assembly consisted of five parallel FSI X100 polypropylene housing units, each lined with a 20-µm (in Study Period 1) or 5-µm filter bag (in Study Period II). Each filter was rated at 65 gpm, giving a total capacity of 325 gpm per assembly or 650 gpm for both. Filter bags in the two assemblies were cleaned or replaced when headlosses across each assembly had reached 10- to 15-lb/in2 (psi) levels. Figure 4-8 presents a photograph of the bag filter assemblies. This filtration step was used to prevent the resin beds from being clogged and/or fouled by particulates. 01.9 Figure 4-8. Photograph of Two Banks of Cartridge Filters Ion Exchange. After passing through the bag filters, water flowed downward through two 63 in X 86 in pressure vessels configured in parallel (Figures 4-9 and 4-10). Mounted on a polyurethane -coated, welded steel frame, the pressure vessels were of fiber reinforced plastic (FRP) construction and rated for 150 psi working pressure. Each vessel had a 6-in top and bottom flanges, and was equipped with a diffuser -style upper distributor and a hub and laterals -style underdrain. All pneumatic valves were PVC, and all plumbing was Schedule 80 PVC solvent bond. By design, each vessel was to be loaded with 4 ft3 of flint gravel support on the bottom, 110 ft3 of resin in the middle (about 61 in deep), and 4 ft3 of polyethylene filler beads on the top. The filler material was intended to prevent resin from being washed away in an upflow, counter -current regeneration. Filler beads were not added because they were not needed for co -current regeneration. The IX system was designed for 540 gpm, yielding a hydraulic loading rate of 12.5 gpm/ft2 and an empty bed contact time (EBCT) of 3 min. Each vessel was equipped with a 270-gpm flow restrictor on the effluent piping to help balance the flow between the two vessels and prevent overrun during regeneration. An insertion -type paddle wheel flow element was installed on the combined effluent line to register flowrate and throughput of the product water since last regeneration. When a pre -determined throughput setpoint was reached, Vessel A was automatically taken out of service for regeneration, whereas Vessel B remained online for treatment. Once Vessel A regeneration was complete, the totalizer was automatically reset to zero and began to register the water treated by Vessel A. Meanwhile, Vessel B was taken out of service for regeneration. After Vessel B regeneration was complete, the totalizer registered the amount of water treated by both vessels. kill i IX Resin Vessels Salt SatUrator � — y For the study purposes, two additional insertion -type paddle wheel flow elements were installed on the individual vessel outlet to accurately track the throughput from each vessel. These flow elements were not wired to the PLC and did not reset to zero after each regeneration. Resin Regeneration. The purpose of resin regeneration is to restore exhausted resin back to its chloride form for service. The regeneration process can either be co -current (i.e., in the same direction of the process flow) or counter -current (i.e., in the opposite direction of the process flow). A counter -current regeneration maximizes the chemical's ability to regenerate the resin and minimize the volume of waste. The vendor decided to use downflow, co - current regeneration, which was thought to be superior to upflow, counter -current regeneration for arsenic and nitrate because the counter -current regeneration would force the contaminants concentrated at the bottom of the resin bed back through the entire bed, thus leaving more contaminants in the bed (Clifford et al., 1987, 2003). In addition, co -current regeneration was easier to implement. One drawback of co -current regeneration is arsenic/nitrate leakage, which may occur in the early stage of a service cycle, as observed at Fruitland (Wang et al., 2010). The Vale system was retrofitted in July 2006 by Kinetico to be capable of counter -current regeneration, if desired. However, due to a series of mechanical problems that occurred to the Fruitland system after similar retrofitting (from co -current to counter -current to curb arsenic/nitrate leakage), the Vale system remained co -current throughout the entire study period. Regeneration could be initiated either automatically based on a throughput setpoint or manually by pressing a push-button on the PLC. Once regeneration was initiated, it followed a sequence of four pre-set steps, including spent brine draw, fresh brine draw, slow rinse, and fast rinse. There was no backwash step in the original design and it could not be added later due to lack of freeboard in the vessels. During the demonstration study, the regeneration scheme was adjusted several times to optimize the regeneration efficiency and reduce waste production (Section 4.4.2.1). In doing so, the duration of each regeneration step was reset on the PLC and the brine concentration was adjusted by changing the brine draw rate using a hand valve located upstream of an eductor or a brine injection pump. The brine concentration was confirmed by measuring the specific gravity of the adjusted solution using a hydrometer. Unlike most of the IX systems, including the Fruitland system where treated water is used for preparing the brine solution and rinsing the beds, raw water was used at Vale due to insufficient head in the 200,000-gal atmospheric reservoir at the airfield. Figure 4-11 shows photographs of major regeneration system components. Table 4-7 presents relevant regeneration settings. The four regeneration steps are discussed below. Step 1. Spent Brine Draw — The treatment system was originally designed with a brine reclaim feature to minimize salt usage and brine waste. During the first half of brine draw, a spent brine solution with a concentration of 9 to 10% was pumped from a 1,050-gal day tank at approximately 50 gpm for 15 min using a 5-hp centrifugal pump. The entire volume of waste produced during spent brine draw was discharged to an evaporation pond. The volume of spent brine was tracked by a 2-in mechanical totalizer installed on a brine feed line. The use of spent brine could reduce the brine waste volume by 137 gal/vessel and the corresponding salt consumption by 885 to 758 lb/vessel, or 14%. The brine reclaim, however, was discontinued on December 10, 2007, due to concerns that DOM might accumulate in spent brine and would increase the resin fouling (Section 4.4.3). Kea l w � / � ✓ii�� J a Sat Sat or Figure 4-11. Photographs of IX Regeneration System at Vale, OR Step 2. Fresh Brine Draw — Fresh brine was used for the second half of brine draw. Saturated brine was drawn from a second 1,050-gal day tank and mixed with make-up water (i.e., raw water) via a Venturi educator (later changed to a chemical injection pump) before entering a resin vessel. The day tank was equipped with a high- and a low-level sensor interlocked with a 1.5-hp brine transfer pump to fill the tank with saturated brine (about 23 to 26%) from two salt saturators. Each salt saturator was 8-ft in diameter, 10-ft tall with an 11- ton salt storage capacity. This was modified from the initial design of one 22-ton saturator due to the height restriction on the building near the airport runway. The salt saturators were sized to hold 30 days of salt supply for daily regeneration and were re -filled by a salt delivery truck (Figure 4-12) on a monthly or as -needed basis. A 2-in mechanical totalizer was installed on the brine line to track the volume of saturated brine used. By design, 336 gal of saturated brine would be drawn from the fresh brine day tank and mixed with approximately 530 gal of make-up water to produce 866 gal of a 10% brine solution. As the fresh brine was drawn into a resin vessel, approximately 750 gal of spent brine was first directed to the spent brine day tank until reaching a high-level setpoint. The remainder of spent brine (-100 gal) was discharged directly to the evaporation pond. Step 3. Slow Rinse — At the end of brine draw, a valve on the saturated brine feed line was shut, and only the make-up water (i.e., raw water) was introduced to the resin vessel at 50 gpm for 40 min to rinse off the brine from the resin bed. This step produced approximately 2,000 gal of wastewater to be discharged directly to the evaporation pond. The resin manufacturer recommended 2.5 BV (1 BV = 110 ft3 = 823 gal), or 2,057 gal, of water for slow rinse. 33 Figure 4-12. Salt Delivery to Fill Salt Saturators Step 4. Fast Rinse — Fast rinse was performed at the service flowrate of approximately 220 gpm to further remove/flush out residual brine from resin beads and blind spots in the IX vessels. This step was set to last for 20 min and would produce 4,400 gal of wastewater to be discharged directly to the evaporation pond. The resin manufacturer recommended 5 BV (or 4,114 gal) for fast rinse. Post Chlorination. The target chlorine dosage was 0.2 mg/L (as C12) and the target residual level for disinfection of treated water was 0.025 mg/L (as C12). Once chlorinated, the water flowed to the 200,000-gal atmospheric reservoir near the airport, from which it was sent by two booster pumps to the city's distribution system and two older reservoirs located on the other side of the town. Residual Disposal. Due to lack of connection to the City sewer, an evaporation pond was constructed adjacent to the treatment building for disposal of spent brine and rinse water from the regeneration process (Figure 4-13). The evaporation pond consisted of a 368 ft (length) x 214 ft (width) x 13 ft (depth) evaporation basin and a 200 ft (length) x 55 ft (width) x 16 ft (depth) drying bed. The evaporation basin had a surface area of 1.8 acre and a storage capacity of 7,657,844 gal (or 23.5 acre-ft). As part of the pond design, ferric chloride (FeC13) was added to spent brine prior to being discharged to the pond (see Figure 4-14). Specifically, 0.25 gal of a commercial grade FeC13 solution (40% with specific gravity of 1.4) was fed to the waste brine stream at a rate of 1.0 gph for 15 min. Based on the design brine draw rate of 50 gpm, the iron dosage would be approximately 63 mg/L (as Fe). Because FeC13 was fed in a batch mode into a total waste volume of 7,250 gal (per vessel), the average iron dosage was only 6.65 ilf�■AMi o � Figure 4-13. Wastewater Evaporation Pond Figure 4-14. Ferric Chloride Addition to Treat Spent Brine 35 mg/L. The wastewater traveled via a 4-in underground PVC pipe to a wet well, then was pumped to the evaporation basin via a 6-in PVC pipe. By design, the FeC13-treated water was expected to precipitate and settle to the bottom of the evaporation basin. Over a period of time, the sludge would accumulate in a 1-ft wide, 16-ft deep depressed area (with an 8:1 sloped bottom) at one end of the basin, and then be pumped to the adjacent drying basin periodically. However, due to the presence of high TDS in the wastewater, the FeC13 treatment was not effective at removing arsenic from the brine waste (see Section 4.5.6). 4.3 System Installation 4.3.1 Permitting. Engineering plans for the system permit application were prepared by Holladay Engineering (Payette, ID), a subcontractor to Kinetico (the firm also provided engineering services to the City). The plans included general arrangement diagrams, specifications of the IX system, and drawings detailing connections between the treatment system and the building. After incorporating comments from the vendor and Battelle, the City submitted the plans on July 22, 2005, to the Oregon DHS DWP for review. On August 11, 2005, the permit packages were approved by Oregon DHS DWP. 4.3.2 Construction of Treatment Building and Evaporation Pond. The City issued an Advertisement for Bid on August 10, 2005, for the earthwork necessary to construct and complete a 1.8- acre evaporation basin and a 0.2-acre drying bed, a HDPE liner, fencing, a wet well lift station, a new building, a walkway, a ferric chloride shed, and chemical equipment, etc. Only one bidder submitted a bid for a total amount of $498,844.00 on September 1, 2005, which was significantly higher than the city's budget of $325,000.00. The high bid might have been affected by rebuilding efforts following the aftermath of hurricane Katrina in the Gulf of Mexico region, which created a high demand for materials, equipment, and contractors in that area. Therefore, the city council voted to re -advertise for bid on October 13 through November 13, 2005, with a new construction schedule and a final completion date of May 16, 2006. Four bids ranging from $388,960.00 to $436,070.00 were received and opened on November 14, 2005, with all exceeding the city's budget again. The city negotiated a contract with the low bidder — Holcomb Construction, and signed the Notice of Award and Notice to Proceed in early December 2005. The building construction began on December 5, 2005, and was completed ahead of schedule on February 28, 2006. The 20 ft-tall addition covered 1,025 ftz of floor space (41-ft long and 25-ft wide) and had a wood frame, steel siding and roofing, and a 12-ft wide roll -up door. Figure 4-15 shows photographs of the new structure, adjacent to the existing pump house. Construction of the evaporation pond didn't begin until the ground dried out for earthwork, was interrupted by the weather in April, and was completed in late May 2005, just before system startup. The pond consisted of an evaporation basin and a drying bed. A 40-mil textured HDPE liner was installed in the evaporation basin and drying bed to prevent any leakage to groundwater. An 8-ft tall exterior fence consisting of steel posts, wire mesh, and an access gate was installed surrounding the pond. Figure 4-16 is a photograph of the evaporation pond under construction; photographs of the completed pond are presented in Figure 4-13. Based on the cost breakdowns from the construction contractor, the cost for mobilization/demobilization and clearing/grubbing the entire construction site was $36,140.00. The cost for earthwork, HDPE liner, and fencing was $81,809.00. The cost for the new building, walkway, and ferric chloride shed was $111,018.00. The cost for the chemical equipment for ferric chloride addition was $11,353.00, including a hand truck for hauling chemical barrels, a wall -mounted chemical metering pump, and a wall -mounted first aid kit, and a combination shower/eyewash station. U11 Figure 4-15. Vale Treatment Plant Building Construction Figure 4-16. Installation of HDPE Liner in Evaporation Pond 37 4.3.3 System Installation, Shakedown, and Startup. The IX system was delivered to Vale, OR on two flatbeds on May 12, 2006. Upon arrival, system components were offloaded (Figure 4-17) and installation activities began immediately thereafter. A Kinetico technician was onsite from May 22 through May 26, 2006, to perform resin loading and system startup and then returned on June 1, 2006, to complete system startup and shakedown. The technician provided operator's training on June 6, 2006. The system was placed online in a fully automatic mode on June 21, 2006, after relevant control issues had been addressed by the city to synchronize the operation of the wells and booster pumps with the PLC of the treatment system. However, automatic regeneration of the system was found to cut short and did not complete the full cycle as designed. This problem was resolved by programming changes made by Kinetico on June 30, 2006. Figure 4-17. Vale Treatment System Delivering and Offloading U*.: During the first week of July 2006, when the system was first brought online, an unusually low system flowrate (i.e., 300 gpm at 60 psi inlet pressure) and an unusually high pressure drop across the 1X beds (i.e., 35 to 40 psi) were experienced, which prompted a recommendation by the vendor to backwash the IX beds. Because the system was not designed/equipped for resin backwashing, the vendor proposed to retrofit the piping in the field to allow for backwashing as well as counter -current regeneration, if desired. Revised piping drawings were provided to Battelle on July 17, 2006. A Kinetico technician returned to the site on July 20, 2006, to complete the retrofit and system shakedown. Four, 4-in PVC butterfly valves were added to the system piping to re -direct the flow for IX vessel backwashing, which, however, could be performed only manually by physically operating the valves. After backwashing, the system flowrate and headloss across each IX vessel became normal at 577 gpm and 13 psi, respectively. Although the vender attributed the low system flowrate and excessive pressure drop to sediment buildup in bag filters, it was apparent that the IX resin beds had to be backwashed to remove fines upon loading. Factory settings in the PLC also were adjusted in the field as needed. One of the changes made was to shorten the spent brine draw time from 15 to 10 min to avoid draining of the spent brine tank. The system was placed online in a co -current mode on July 23, 2006. Battelle performed system inspections and operator training from September 19 through 21, 2006. Training included calibration and use of the water quality meter, collection and recording of operational data, proper sample collection techniques, arsenic speciation, and sample handling and shipping procedures. The first set of samples was collected from the IX system on September 20, 2006, signifying the official start of the performance evaluation study at Vale, OR. Table 4-8 summarizes punch list items identified during the system start-up and inspection as well as corrective actions taken. Table 4-8. System Punch List during Startup Resolution Punch List/Operational Issues Corrective Action(s) Taken Date 1 Fresh brine draw rate about twice Actions taken from October 2006 03/05/07 the design value through March 2007 to reduce salt usage to target level of 12 lb/ft3 2 Flow totalizers after Vessels A Kinetico verified meters; flow through 10/19/06 and B appeared to be out of Vessel B continued to be higher than calibration; meter for Vessel B that through Vessel A in Study Period appeared to be off by 36%, I yielding higher readings than those for Vessel A over same time period 3 Flow element displayed only Cumulative volume of water 10/25/06 throughput since last regeneration processed added to PLC display 4 Pressure gauge PI-5 had a wide Old gauge replaced; new gauge 10/20/06 span, causing inaccurate readings worked well 5 Excessive salt dust generated Kinetico installed a water line to 10/20/06 from salt delivery alleviate salt dust 6 Reused brine pump failed Pump functional after being taken 10/19/06 apart and cleaned 39 4.4 System Operation Table 4-9 presents key demonstration study activities and events taking place during the three study periods. Study Period I, extending from September 19, 2006, through January 14, 2008, focused on evaluation of Purolite Arsenex II resin that was originally selected for the demonstration. At the end of this period, the system was taken offline for 4.5 months for well rehabilitation. Due to deteriorating performance of Arsenex II resin and unsuccessful attempts to clean the resin, the focus of the Interim Period was to identify an alternative approach to address the resin fouling issue. Study Period Il, extending from February 10, 2009, through March 22, 2010, focused on evaluation of dual resins - Purolite° A850END/PFA300E. Table 4-9 highlights key demonstration activities under each study period, which will be discussed in this section. A more complete site chronology is presented in Appendix B for reference. Table 4-9. Key Demonstration Study Activities/Events Demonstration Study Activities/Events Date Stud Period L Evaluating Arsenex II Resin 09119106-01114108 • Run Length Study 1 performed 09/19/06-09/22/06 • Site visit by Kinetico to addresspunch-list items 10/20/06-10/23/06 • Meeting with Kinetico and EPA at Battelle to discuss performance issues 02/21/07 • Site visit by Kinetico to install brine injection pump in place of educator and to collect resin samples 02/28/07-03/07/07 • Regular weekly sampling discontinued 04/16/07 • Limited weekly sampling at TT location 07/16/07-01/14/08 • Site visit by Kinetico to conduct resin cleaning; reused brine draw discontinued; resin samples collected 10/22/07 • Run Length Study 2 performed 10/24/07-10/26/07 Interim Period. Identifying Alternative Approaches 01114108-02109109 • IX system shutdown due to well rehabilitation 01/14/08-05/01/08 • System operation resumed 05/02/08 • Meeting with Vale, EPA, and consultants at Battelle to discuss available options 07/15/08 • Site visit by Battelle to inspect resin and vessels 08/15/08 • Special study on dual resin system at McCook, NE 08/25/08 • ArsenicGuard installed to provide online arsenic monitoring 11/19/08 • Run Length Study 3 performed 12/08/08-12/10/08 • New resins procured and arrived at site 12/26/08 Stud Period II. Evaluating A850ENDIPFA300E Dual Resins 02110109 to 03122110 • Dual resins installed 02/10/09-02/13/09 • Arsenic in system effluent monitored with ArsenicGuard 02/13/09-03/02/09 • Special study aborted due to salt loading incident 03/02/09-03/04/09 • Weekly sampling resumed 03/25/09-12/16/09 • Run Length Study 4 performed 04/21/09-04/22/09 • Resin cleaning performed 06/24/09 • Run Length Study 5 performed 06/29/09-07/01/09 • Elution study performed 06/29/09-07/01/09 • Resin cleaning performed 10/16/09 • System bypassed due to faulty flow sensor 12/22/09-01/15/10 • Weekly sampling resumed 02/02/10-02/08/10 t'9] 4.4.1 Operational Parameters. Operational data were collected for a total of 70 weeks in Study Period I and 52 weeks in Study Period 11. Table 4-10 summarizes key operational parameters collected from each study period. The complete set of operational data is presented in Appendix C after tabulation. In Study Period I, the IX system operated for a total of 4,440 hr based on readings of an hour meter installed at the wellhead. Excluding October 19, 2006, and a week in November 2007, the system operated for 466 days, resulting in an average daily run time of 9.5 hr. The system processed approximately 128,000,000 gal of water based on readings of a wellhead Mag meter (excluding the amount of water used for regeneration). Due to the lack of Mag meter readings between September 27 through October 25, 2006, the throughput for that period was estimated based on the average daily demand of 274,473 gpd. The peak daily demand was 497,751 gpd, which occurred on May 31.2007. In Study Period II, the IX system operated for a total of 3,215 hr in 337 days (excluding 24 days from December 22, 2009, through January 15, 2010, when the system was not in operation). The average daily run time also was 9.5 hr. The system processed approximately 93,600,000 gal of water with an average daily demand of 277,653 gpd. The 524,463-gpd peak daily demand occurred on July 31, 2009. Table 4-10. Summary of System Operational Data Parameter Study Period I Study Period II Data Collection Period 09/27/06-01/14/08 02/16/09-02/12/10 Total Operating Time (hr) 4,440 3,215 Total Operating Days (day) 466 337 Average Daily Run Time (hr/day) 9.5 9.5 Throughput to Distributionla, (gal) 127,904,500() 93,569,200 Average Daily Use (gpd) 274,473 277,653 Peak Daily Use (gpd) 497,751 524,463 Number of Regeneration Cycles 278 144 Regeneration Frequency (day/regeneration) 1.7 2.3 System Service Flowrate ` (gpm) 490-576 (534) 542-557 (536) Empty Bed Contact Time (min) 2.4-2.8 (2.6) 2.6-3.3 (2.8) e Hydraulic Loading (gpm/ft) 11.3-13.3 (12.3) 10.4-12.9 (12.4) Pressure Loss Across IX Vessel (psi) Vessel A 6-15 (11) Vessel B 6-17 (11) Vessel A 7-13 (10) Vessel B 7-24 (11) Pressure Loss Across System (psi) 30-47 (40) 33-42 (40) (a) Based on wellhead totalizer readings, excluding water used for regeneration. (b) Throughput from 09/27/06 to 10/25/06 estimated due to lack of totalizer readings. (c) Based on flowmeter on system effluent; excluding lower flowrate during system regeneration. (d) Based on 186 ft3 of Arsenex II in two IX vessels. (e) Based on 197 ft3 of dual resins in two IX vessels. Figures in parentheses representing average values. Key operational parameters, including product water flowrate, EBCT, hydraulic loading rate, and pressure loss across each IX vessel and across the system, are similar between the two study periods and comparable to the respective design values, as discussed below. • System service flowrates ranged from 490 to 576 gpm and averaged 534 gpm in Study Period I, and ranged from 542 to 557 gpm and averaged 536 gpm in Study Period II. These values compared well with the system design flow of 540 gpm. When one vessel was being regenerated, water continued to be treated by the other vessel at 251 to 298 gpm in Study Period I and 260 to 288 gpm in Study Period II. HI • Average EBCTs were 2.6 min and 2.8 min for Study Periods I and II, respectively; comparable to the design value of 3 min. • Average hydraulic loading rates were 12.3 and 12.4 gpm/ft2 for Study Periods I and II, respectively, close to the design value of 12.5 gp1T1/ft2. • The pressure loss across each IX vessel ranged from 6 to 17 psi and averaged 11 psi in Study Period I, and ranged from 7 to 24 psi and averaged 11 psi in Study Period II. Such headloss was expected for a 5-ft deep resin bed because 1 foot of resin normally causes 1 to 2 psi of pressure loss. • The pressure loss across the IX system averaged 40 psi in both study periods. Based on observations made for other EPA demonstration systems, including the IX system at Fruitland, ID, high pressure losses across the IX system was caused primarily by the 270-gpm flow restrictor installed on each vessel outlet. Similar flow restrictors had been found to overly restrict the flow and had to be removed for the Fruitland system. The flow restrictors were not removed at Vale because the wellhead booster pump was capable of overcoming the high pressure losses experienced, supply the water to the IX system at the design flowrate, and maintain the effluent pressure at 10 to 12 psi in the 200,000-gal atmospheric storage tank. 4.4.2 Regeneration. The system PLC initiated an automatic regeneration cycle based on a throughput setpoint. The duration of each regeneration step, e.g., brine draw, slow rinse, and fast rinse, was controlled by a timer in the PLC. In Study Period I, a total of 278 regeneration cycles took place, corresponding to a regeneration frequency of once every 1.7 days. In Study Period II, a total of 144 regeneration cycles took place, corresponding to a frequency of once every 2.3 days. The regeneration setpoints, monitoring parameters, and salt usage during the entire study period are discussed as follows. 4.4.2.1 Regeneration Setpoints. The PLC OIP contains a screen of regeneration setpoints as shown in Figure 4-18. A summary of regeneration setpoints for both study periods is presented in Table 4-11. During the initial system startup in July 2006, the system was set to regenerate every 600,000 gal of volume throughput. The regeneration cycle consisted of a 10-min spent brine draw and a 17-min fresh brine draw with an 11% brine (to achieve a salt level [a.k.a salt loading or regeneration level] of 12 lb/ft3 of resin), followed by a 30-min slow rinse and a 15-min fast rinse. Changes were made several times to the volume throughput, spent and fresh brine draw time, and brine concentration in Study Period I to ensure good effluent water quality and proper salt loading. The adjustments were made based on results of two run length studies performed during September 19 through 22, 2006, and October 24 through 26, 2007, and observations/measurements made during regeneration. • On September 13, 2006, just one week before Run Length Study 1, the volume throughput setpoint was extended to 905,300 gal to be closer to Purolite's simulation of 1,119,280 gal. Based on Run Length Study 1 results (Section 4.5.3), the volume throughput setpoint was reduced to 600,000 gal on October 5, 2006. When a Kinetico technician returned to the site on October 20, 2006, to address a high salt usage issue, spent and fresh brine draw times were reduced to 7 and 8 min, respectively, and the brine concentration was reduced to 6%. These changes, however, overly adjusted the salt usage, causing the salt loading to drop to 5.9 lb/ft3 based on the data obtained on November 21, 2006. Low salt loadings apparently had impacted the performance of the IX system. • On December 5, 2006, the brine concentration was adjusted back to 11 % and the fresh brine draw time increased to 13 min. These changes increased the salt loading back up to 25 lb/ft3 as measured on January 31, 2007. Cyl ,. FILTER 10 FIRST BRINE DRAW (REUSED) TO WASTE TIME (MIN.) 17 SECOND BRINE DRAW (NEW) TO WASTE TIME (MIN.) 30 SLOW RINSE TIME (MIN.) 15 FAST RINSE TIME (MIN.) FF-600000 TOTAL VOLUME REGEN TRIGGER (GAL.) BRINE SATURATOR A HIGH ALARM LEVEL (FT) BRINE SATURATOR A LOW ALARM LEVEL (FT) BRINE SATURATOR B HIGH ALARM LEVEL (FT) BRINE SATURATOR B LOW ALARM LEVEL (FT) 21 BRINE DRAW (NEW) TO WASTE TIME (MIN.) 45 SLOW RINSE TIME (MIN.) 5 FAST RINSE TIME (MIN.) 000000 TOTAL VOLUME - - - REGEN TRIGGER (GAL.) BRINE SATURATOR A HIGH ALARM LEVEL (FT) BRINE SATURATOR LOW ALARM LEVEL (FT) BRINE SATURATOR B HIGH ALARM LEVEL (FTJ BRINE SATURATOR B LOW ALARM LEVEL (FT) Figure 4-18. PLC Regeneration Setpoints Shown on OIP (top —Study Period I; bottom —Study Period II) To better control fresh brine injection, Kinetico installed a brine injection pump to replace the Venturi eductor during a site visit by the end of February 2007. Meanwhile, the technician inadvertently reset the system for counter -current regeneration. The mistake was corrected later during another site visit on March 5, 2007. The fresh brine draw time was increased to 15 min while the brine concentration was reduced to 6%. A salt loading close to the target of 121b/ft3 was achieved based on the data collected in March 2007. • On April 13, 2007, the volume throughput setpoint was reduced to 370,000 gal based on the arsenic breakthrough data to ensure that arsenic concentrations in system effluent were below its MCL. C193 Table 4-11. IX System Regeneration Setpoints at Vale, OR Setting ID Date of Change Regen. Trigger Run Length Spent Brine Draw Fresh Brine Draw Slow Rinse Fast Rinse Brine sp. gr. Brine Conc. % gal BV(a) Min min min min Startup 07/23/06 600,000 431 10 17 30 15 1 1.08 11 Study Period I 1 09/13/06 905,300 651 10 17 30 15 1.08 11 2 10/05/06; 10/20/06 600,000 431 7 8 30 15 1.042 6 3 12/05/06 600,000 431 7 13 30 15 1.08 11 4( 03/05/07 600,000 431 7 15 30 15 1.042 6 5 04/13/07 370,000 266 7 15 30 15 1.042 6 6 10/22/07 600,000 431 0(°) 23 30 15 1.042 6 Study Period II 7 02/13/09 600,000 491 1 Discont'd 1 21 45 1 15 1 1.06 F 8 (a) Based on 186 and 163.3 ft of IX resin(s) in Study Periods I and II, respectively. (b) After a brine injection pump installed to replace eductor. (c) Spent brine draw discontinued due to concern over resin fouling caused by DOM in spent brine. sp. gr. = specific gravity • On October 22, 2007, after resin cleaning, the volume throughput setpoint was returned to 600,000 gal, spent brine draw was discontinued, and the fresh brine draw time was increased to 23 min to compensate for the spent brine. In Study Period II, the regeneration setpoints for the dual IX resin system were established by Battelle according to resin specifications and the experience gained through system operations at Fruitland, ID. The target salt loading was 10 lb/ft3. To achieve this level, brine draw was set at 60 gpm for 21 min using an 8% brine. The brine draw rate used in Study Period I ranged from 73 to 145 gpm, which exceeded the recommended draw rate of 0.2 to 0.8 gpm/ft3 according to the resin specification sheet. Since slow rinse used the same flow as the brine makeup water, its duration was increased to 45 min to compensate for the lower flowrate. The regeneration setpoints remained unchanged throughout Study Period II. 4AZ2 Regeneration Monitoring. Regeneration of Vessels A and B were monitored and recorded on log sheets nine times in Study Period I and twice in Study Period II. Since data recorded for both vessels were rather similar, averages between the two vessels are presented in Table 4-12 for all regeneration steps. The volume of water used for each regeneration step was recorded from a totalizer located upstream of the eductor. Volumes of spent and fresh brines were recorded from individual brine totalizers on the outlet of both brine tanks. The volume of fresh brine draw (i.e., diluted brine) was calculated using Equation 1: where: Vbrine, d — (Ybrine, s X Vbrine,s + Vwater)lYbrine, d (1) Vbrine, d= volume of diluted brine (gal) Vbrine, s = volume of saturated brine (gal) Vwater= volume of brine make-up water (gal) ybrine, s = specific gravity of saturated brine, e.g. 1.176 for 23% brine Ybrine, d= specific gravity of diluted brine, e.g. 1.074 for 10% brine Table 4-12. IX System Regeneration Monitoring at Vale, OR Step 1 S ent Brine Draw Step 2 Fresh Brine Draw Step 3 Slow Rinse Step 4 Fast Rinse Total Waste Study Setting Draw Time Draw Volume Flow Rate Draw Time Makeup Water Volume Saturated Brine Volume Dilute Brine Volume Flow Rate Rinse Time Rinse Volume Flow Rate Rinse Time Rinse Volume Flow Rate Production Per Regen Cycle Period Date ID min gal gpm min gal al al gpm min gal gpm min gal gpm gal Design Value 15 750 50 17 518 336 850 50 40 2,000 50 20 4,400 220 7,250 09/21/06 1 10 760 76 17 1,239 648 1,853 109 30 2,267 76 15 3,527 235 7,646 11/21/06 2 7 579 83 8 636 123 749 94 30 2,400 80 15 3,900 260 7,048 01/31/07 3 7 515 74 13 1,027 856 1,883 145 30 2,385 80 15 3,893 260 8,160 03/05/07 4 7 525 75 15 856 301 1,161 73 30 2,637 88 15 3,296 220 7,093 I 03/07/07 4 7 530 77 15 1,111 286 1,389 93 30 2,303 77 15 3,384 226 7,075 03/20/07 4 7 528 75 15 1,230 324 1,534 102 30 2,475 83 15 3,378 225 7,387 11/27/07 6 Discontinued 23 1,932 525 2,457 107 30 2,520 84 15 3,720 248 8,697 12/13/07 6 Discontinued 23 1,730 530 2,260 113 30 2,565 86 15 3,900 260 8,725 08/15/08 6 Discontinued 23 2,000 629 2,592 113 30 2,497 83 15 3,533 236 8,622 Desi n Value Discontinued 21 924 420 1,334 64 45 1,980 44 15 3,900 260 7,214 11 02L/13/09 7 Discontinued 21 924 400 1,324 63 45 1,980 44 15 3,945 264 7,257 06/29/09 1 7 Discontinued 21 924 329 1,253 60 45 1,980 44 15 3,998 267 7,230 Note: All values refer to one Dt vessel using averages of Vessel A and B. In Study Period I, as shown in Table 4-12, spent brine draw rates ranged from 74 to 83 gpm and averaged 77 gpm, which was over 50% higher than the design value of 50 gpm. Shortening the draw duration from the design value of 15 min to 10 min, then to 7 min, helped to correct for the high draw rate issue. The fresh brine draw step was problematic during the early part of the study. Fresh brine draw rates ranged from 73 to 145 gpm, which was two to three times the design value of 50 gpm and exceeded the upper limit of the suggested regeneration rate of 0.8 gpm/ft3. A higher brine draw rate would mean more salt consumption. To maintain a lower salt level, a shorter brine draw time may be used but not desirable because it may not provide enough time for exchange reactions to occur throughout the resin bed. As such, the brine draw rate was purposely reduced to 64 gpm in Study Period II. At the beginning of the study, the saturated brine volume drawn during the fresh brine draw step was 648 gal, which almost doubled the design value of 336 gal. Follow-on adjustments performed either under- or over -corrected the problem, resulting in 123 and 856 gal of saturated brine under Settings 2 and 3, respectively. The vendor suggested that the problem might have been caused by an incorrectly sized Venturi eductor (oversized in this case) and that it would be better off to replace the eductor with a brine injection pump. Since the installation of a brine injection pump in late February 2007, the saturated brine volume was better controlled to just below or above the target value at 286 to 324 gal (under Setting 4), as monitored on March 5, 7, and 20, 2007. Under Setting 6, saturated brine volumes were higher, ranging from 525 to 629 gal due to the use of an extended draw time (i.e., 23 min) to make up the loss due to discontinuation of spent brine draw. In Study Period I, slow rinse rates ranged from 76 to 88 gpm and averaged 82 gpm, which was over 60% higher than the design value of 50 gpm. Fast rinse rates ranged 220 to 260 gpm and averaged 241 gpm, which is close to the design value of 220 gpm. Regeneration of each IX vessel produced 7,048 to 8,725 gal of wastewater during Study Period I, but averaged at 8,681 gal under Setting 6. In Study Period II, all regeneration parameters monitored were similar to the design values and appeared to be adequate based on results of the elution study (see Section 4.5.5). Regeneration of each IX vessel generated an average of 7,244 gal of wastewater, which is 20% less than that under Setting 6 in Study Period I. 4.4.2.3 Salt Usage. The amount of salt used by each regeneration cycle was calculated based on concentrations and volumes of spent and/or fresh brines according to Equation 2. The salt loading was then calculated by dividing the weight of salt by the volume of resin. The results of the calculations are presented in Table 4-13. where: Wsalt — Vbrine X Ybrine X dater X Csalt (2) Wsalt = weight of salt (lb) Vbrine = volume of brine used (gal) Ybrine= specific gravity of brine dvater = density of water, e.g., 8.34 (lb/gal) Csalt= percent of salt (%) The specific gravity of saturated brine at 23% was 1.176. Specific gravities of spent brines measured by a hydrometer ranged from 1.039 (5.4%) to 1.066 (8.9%), which were affected by concentrations of diluted fresh brines used for previous regeneration cycles. Specific gravities of diluted brine measured in Study Period I ranged from 1.042 (6%) to 1.080 (11 %), depending on regeneration settings. The specific gravity of diluted brine measured in Study Period II was 1.060 (8.1%), close to the target of 8%. I Table 4-13. Vale, IX System Salt Loading Calculations Study Period Date Setting I ID Spent Brine Fresh Brine Total Spent Brine Volume sp. gr. of Spent Brine Spent Brine Cone. Weight of Salt Saturated Brine Volume sp. gr. of Diluted Brine Diluted Brine Cone. Weight(') of Salt Total Salt Weight(b) Total Salt Loadin (0 gal % lb gal % lb lb lb/ft3 Design Value 750 1.067 9.0 600 336 1.074 10.0 760 1,346 12 09/21/06 1 760 1.047 6.5 429 648 1.080 10.8 1,462 1,891 20.3 11/21/06 2 579 1.039 5.4 272 123 1.042 5.9 276 548 5.9 01/31/07 3 515 1.066 8.9 406 856 1.080 10.8 1,931 2,337 25.1 03/05/07 4 525 1.060 8.1 377 301 1.042 5.9 678 1,055 11.3 1 03/07/07 4 360 1.045 6.2 195 286 1.042 5.9 645 840 9.0 03/20/07 4 528 1.050 6.9 318 324 1.050 6.9 731 1,049 11.3 11/27/07 6 Discontinued 525 1.051 7.0 1,184 1,184 12.7 12/13/07 6 Discontinued 530 1.042 5.9 1,196 1,196 12.9 08/15/08 6 Discontinued 629 1.057 7.8 1,419 1,419 15.3 Design Value Discontinued 420 1.059 8 945 945 10 II 02/13/09 7 Discontinued 400 1.060 8.1 902 902 9.3 06/29/09 7 Discontinued 329 1.060 8.1 741 741 7.6 (a) Based on saturated brine. (b) Sum of spent brine and fresh brine. (c) Based on actual resin volume in each vessel, i.e., 93 ft3 of Arsenex II and 97.5 ft3 of dual resin. sp. gr. = specific gravity As shown in Table 4-13, the salt loading was 20.3 lb/ft3 on September 21, 2006, approximately 70% higher than the design value of 12 lb/ft3. This higher loading was mainly caused by the higher brine volume used in regeneration. The salt loading was reduced to 5.9 lb/ft3, then increased back to 25.1 lb/ft3 following the adjustments made in October and December 2006, respectively. After the installation of the brine injection pump, salt loadings ranged from 9.0 to 11.3 lb/ft3 (under Setting 4) from 12.7 to 15.3 lb/ft3 (under Setting 6), indicating a better control of the salt use. In Study Period II, the average salt loading was 8.5 lb/ft3, about 15% lower than the design value of 10 lb/ft3. 4.4.3 IX Resin Fouling. Deteriorating resin performance was observed over the course of Study Period I, as evidenced by a decreasing trend in resin run length. For example, shortly after system startup in September 2006, the system treated approximately 600,000 gal of water before arsenic in system effluent reached 10 µg/L. The amount of water treated was reduced to 450,000 gal in early January 2007 based on weekly water sampling data (Section 4.5.1.2). After seven months into system operation, the useful run length was further reduced to 376,940 gal in April 2007 (Section 4.5.1.2), which was 63% of the initial value. To determine the causes for the shortened run lengths, resin core samples were collected from both IX vessels in March 2007 and sent to Purolite for analyses (along with resin samples collected from the Fruitland IX system). Purolite reported that some resin beads were visibly fouled by particulates and likely DOM when viewed under a microscope. These samples were cleaned in Purolite's laboratory with a 10% brine and a mixture of 2% caustic/10% brine, respectively, and analyzed after each cleaning. The results are presented in Table 4-14 and compared with the specifications of virgin Arsenex II resin. Table 4-14. Resin Analyses After Laboratory or Field Cleaning Resin Sample Moisture (%) Volumetric Capacity (e /L) Percent Volumetric Capacity (%)(a) Percent Strong Base Capacity (%) TOC (mg of C/ g of resin) Iron Content m / Silica Content (mg/g) Arsenex II -virgin 40-45 1.2 100 100 NA NA NA 10% Brine Cleaning in Purolite Laboratory (March 2007) Vessel A 35.5 0.83 69 92 12.0 26 129 Vessel B 35.0 0.94 78 81 15.4 13 204 2% Caustic/10% Brine Clea ing in Purolite Laborato (March 2007) Vessel A 38.0 1.13 94 93 9.6 NA NA Vessel B 38.9 1.16 97 87 6.0 NA NA 5% Caustic/10% Brine Clean in at Vale Treatment Plant (October 2007) Vessel A -top 43.2 1.05 88 81 10.7 157 NA Vessel A -middle 39.9 1.14 95 77 8.0 122 NA Vessel A -bottom 38.7 1.15 96 79 8.6 14 NA Average 40.6 1.11 93 79 9.1 98 NA Six Months after Field Cleaning (August 2008) Vessel A 38.7 0.96 80 NA 61.0 120 NA Vessel B 37.7 1.08 t 90 NA 46.0 100 NA (a)% = actual volumetric capacity/virgin volumetric capacity. After cleaning with 10% brine, samples collected from Vessels A and B contained 12.0 and 15.4 mg of C/g of resin, respectively, indicating organic built-up. The extent of TOC fouling was considered severe by Purolite and the primary cause for the deteriorating performance and shortened run lengths observed. IN Organic fouling resulted insignificant losses (i.e., 22 to 31%) in volumetric capacity. The reduction in resin capacity also was reflected by a lower moisture content and a lower strong base capacity. It was suspected that some SBA exchange sites were converted to a weak base type, which would not be as useful for removing arsenic or nitrate. Iron and silica levels also increased, suggesting that they also acted as foulants. The laboratory cleaning with a mixture of 2% caustic/10% brine was able to remove a significant amount of foulants, achieving a noticeable recovery of the resin's capacities. For example, the volumetric capacity was restored to 94 to 97% of the virgin resin level and the strong base capacity restored to 87 to 93%. Increases in moisture content and strong base capacities reflected the recovery of exchange sites blocked by organic matter before resin cleaning. The TOC content on the resin was reduced to 6.0 to 9.6 mg of C/g of resin (although lower than what would be expected considering the significant gain in overall capacities), suggesting reduction in TOC fouling by caustic/brine cleaning. Prompted by the promising results of the laboratory cleaning at Purolite and the field cleaning at Fruitland, ID, the IX system at Vale underwent a similar cleaning process using a mixture of 5% caustic/10% brine in October 2007 (Section 3.6). After cleaning, a core resin sample was collected from Vessel A and shipped to Purolite for analyses. Meanwhile, Run Length Study 2 was conducted from October 24 through 26, 2007, to determine cleaning effectiveness. Results of the laboratory analyses showed the highest levels of TOC and iron and the lowest volumetric capacity in the top section (see Table 4-14), suggesting that the resin was the most severely fouled by DOM and iron at the top. The resin in the middle and bottom sections contained, on average, 22% less TOC and 57% less iron, thus having 9% more volumetric capacity. The strong base capacity at the middle and the bottom was similar to that at the top. Based on the results of Run Length Study 2, the resin run length was improved by approximately 20% to 445,700 gal. In August 2008, resin samples after field cleaning were collected from both vessels and sent to Purolite for analyses. The data showed that TOC had continued to accumulate on the resin at levels up to 61 mg of C/g of resin, approximately six times the TOC level right after the field cleaning in October 2007. In December 2008, about 10 months after the October 2007 cleaning (not including the five month well rehabilitation extending from January through May 2008), the useful run length was further reduced to 323,530 gal (Section 4.5.3, Run Length Study 3), which was 27% lower than that observed right after the caustic/brine cleaning in October 2007. 4.4.4 Dual IX Resin Approach. Since the caustic/brine cleaning failed to effectively strip off all TOC from Arsenex II resin and restore its run length back to 600,000 gal, the possibilities of either converting the system into an AM or C/F system or replacing Arsenex II with other types of resin were contemplated. Because the IX system could not be easily converted to an AM or C/F system according to the equipment vendor and because the City of Vale preferred an IX system due to concerns over possible increases in nitrate concentration in the future, the investigation was focused on the search of other types of resin. In May 2008, Professor Dennis Clifford of the University of Houston recommended the use of an acrylic IX resin, such as Purolite A850, as a TOC scavenger. Meanwhile, Purolite recommended the use of dual IX resins such as PFA300E (for arsenic/nitrate removal) overlain by a layer of A850END (for TOC removal). The volume ratio between PFA300E and A850END would be 85:15. For a total of 110 ft3 of resin, one vessel would contain approximately 95 ft3 of PFA300E and 15 ft3 of A850END. Purolite's simulation software generated an estimated run length of 523 BV in June 2008 or 604 BV in January 2009 based on additional source water quality data (see Figure 4-5). The revised projection corresponded to a throughput of 993,940 gal (1 BV = 220 ft). Due to the high silica and TOC levels in source water, it was recommended that a 5% caustic/10% brine wash be performed every four months as a precautionary measure. S9 4.4.4.1 Dual Resin Options. On July 15, 2008, a meeting was held at Battelle with EPA, the City of Vale, and two technical consultants - Professor Dennis Clifford and Mr. Glen Latimer, to discuss options for implementing the dual resin approach. Because the City expressed its desire to continue with the IX technology for any future issues with nitrate, alternative treatment technologies were not further pursued. Three options regarding system configuration were explored, which are summarized as follows: • The first option was to remove the old resin and replace it with 15 ft3 (8-in depth) of A850END underlain by 95 ft3 (-52-in depth) of PFA300E in each vessel. No changes to system configuration would be needed and each vessel would retain the EBCT of 3 min. The estimated cost of the media would be approximately $50,000. This option was considered the most acceptable and most time- and cost-effective option. The second option was to add a third vessel in front of the two existing vessels. The additional vessel would be of 72-in diameter and contain 113 ft3 (48-in depth) of A850END for TOC scavenging. The existing 63-in vessels would each be rebedded with 110ft3 of PFA300E for arsenic/nitrate removal. The EBCT of the 72-in vessel would be approximately 1.5 min while the EBCT of the 63-in vessel would remain at 3 min. Significant changes to the system would have to be made to accommodate the additional vessel. The cost of media for this option was estimated to be approximately $81,765. This option could be costly and would require significant engineering support and perhaps approval by the state drinking water program. The third option was to change the configuration of the two existing 63-in vessels from parallel to series. Under this configuration, the first vessel would contain 110 ft3 of A850END for TOC removal followed by the second vessel containing 110 ft3 of A300E for arsenic/nitrate removal. The change in configuration would require cutting back the system flow to maintain an acceptable loading rate and pressure drop. The system would be regenerated by running a 10% brine solution through the PFA300E vessel followed by the A850END vessel, then discharging the wastewater to the evaporation pond. The cost of media for this option would be approximately $57,200. This option might also have required regulatory approval. The meeting concluded that the first option of replacing the old resin from the existing vessels with dual IX resins was acceptable to all parties involved and should be pursued immediately. 4.4.4.2 Concerns over Solids in IX Resin Beds. Since the beginning of the resin fouling discussion, Purolite had expressed concerns over the lack of backwashing in the Vale system operation and suspected that iron/organic complex in source water could have contributed to the resin fouling. It recommended that either a pre -filter be added ahead of the IX vessels or a backwashing step be incorporated into the regeneration cycle. Since the iron levels in raw water were consistently below the reporting limit of 25 µg/L and manganese levels were below 1 µg/L, the existing sediment filtration using 5-µm bag filters should be sufficient as long as the bag filters were changed out whenever needed. During a trip to Vale on August 15, 2008, Battelle staff performed a visual inspection of the inside of each IX vessel and saw no signs of solids accumulation on the bed surface. Therefore, the pre -filter option was deemed unnecessary. When onsite, a measurement taken on Vessel A from the top of the flange to the top of the resin bed and showed 19.75 in of freeboard in each IX vessel. This freeboard measurement indicated that there was not enough freeboard in the vessels to support IX resin backwashing. This, in conjunction with the fact that little or no iron was present in source water, led to the decision not to include a backwashing step into the IX resin regeneration cycle. The freeboard measurement was later used to estimate the actual resin volume in the vessel. KI] 4.4.4.3 Special Study at McCook, NE. A dual IX resin system was installed by the McCook Water Treatment Plant (WTP) in McCook, NE for the removal of arsenic, nitrate, and uranium from water containing high TOC (Boodoo et al., 2008). To learn more about McCook's experience with the dual IX resin approach, Battelle staff members visited the McCook WTP on August 26 and 27, 2008, and conducted an elution study on the effectiveness of the regeneration process and a run length study on the dual IX resin system. Results of the special study along with a description of the facility water quality, water treatment process, and major activities conducted onsite were documented in a technical memorandum. A brief summary is provided herein. The McCook water treatment plant, rated at a 7 million gallon per day (MGD) production capacity, began operation in February 2006. Source water quality varied depending on which groundwater wells were supplying water. Typical water quality is profiled as: pH 7.2, 382 mg/L of alkalinity, 226 mg/L of sulfate, 525 mg/L of hardness (as CaCO3), 100 µg/L of phosphorus, 850 mg/L of TDS, 12.5 µg/L of arsenic (soluble As as predominating species), 13 µg/L of nitrate, 31.1 µg/L of uranium, and 3.5 mg/L of TOC. The treatment process consists of six 10-ft X 15-ft (straight -side -height) cation vessels and six 9.5-ft X 15-ft (straight -side -height) anion vessels. Each anion vessel contained 66 in of A300E (392 ft) resin top -dressed with 12 in of A850END (69 ft3) resin for simultaneous removal of multiple contaminants (see Figure 4-19). Approximately 50% of raw water bypassed the entire treatment system and only 50% of softened water was treated by the AIX vessels. Most of the time, only two or three anion vessels were placed online; each anion vessel was set to regenerate every 579,000 gal (168 BV) of water treated for nitrate control. Co -current regeneration with a salt dosage of 10 lb/ft3 was conducted in four steps: 10-min backwash, 52-min brine draw, 45-min slow rinse, and 40-min fast rinse. Figure 4-19. McCook, NE Water Treatment Plant 51 A complete regeneration and service cycle of one anion vessel (i.e., Vessel 5) was monitored in a two-day period. Grab and composite samples were collected from each step of the regeneration cycle (see Figure 4-20). Following regeneration, time -series influent and effluent samples were collected during the Vessel 5 service cycle. In addition, a resin core sample was collected from a freshly regenerated Vessel 6 for visual inspection and analysis. Figure 4-20. Sample Collection and pH/TDS Monitoring during Regeneration of AIX Vessel 5 at McCook, NE Figure 4-21a plots elution curves of arsenic, uranium, nitrate, sulfate, TOC, TDS, and bicarbonate versus time during the regeneration cycle. The percent recovery of each contaminant (i.e., arsenic, uranium, nitrate, and TOC) from the regeneration cycle was calculated by dividing the amount of contaminant in the spent brine and rinse water by the amount removed from raw water. Figure 4-21b presents the exhaustion breakthrough curves for arsenic and nitrate. The main observations and findings from the McCook study are briefly summarized as follows: • Due to the long freeboard over the resin bed (i.e., 8 to 9 ft), it took over 40 min for brine to emerge from the vessel to the discharge line, as indicated by TDS reading. TDS readings reached the maximum level of 117 g/L approximately 10 min before the end of the slow rinse. • Resin regeneration achieved 99% recovery for TOC, 86% for arsenic, 130% for uranium, and 55% for nitrate. The spent brine had a distinctive yellowish or tea color, indicating the presence of DOM. • TOC levels in the effluent water were below detection during the run length study (576,000 gal). Arsenic and nitrate breakthrough at their respective MCLs occurred at 445,000 gal (129 BV) and 550,000 gal (161 BV), respectively. Uranium was almost completed removed. 52 4,000 3,500 3,000 J rn c£ 2,500 O r J E 2,000 O Z J m 1,500 1,000 500 120 100 80 J O J 60 I: J m N 40 ~ 20 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Time (min) —�As —0—NO3-N —0—TOC —Bicarb tTDS —*—U -+SO4 (a) Regeneration Curves Run Length (BV) o in 0 Ln CD Lo N N n OD �2 50 40 J Gl C 30 R 0 10 --------- ----------------- Nitrate Breakthrough at 161 BV Nitrate MCL 10 mg/L --------------------------------------------------------------------------------------- -------- 13 -------------------------------------------------------------------------------------------- As MCL 10 Ng/L As Breakthrough at 129 1 BV = 3,449 GAL 0 0 100,000 200,000 300,000 400,000 500,000 Volume of Water Treated (gal) 0 — Inlet -As +Outlet -As --A— Inlet -Nitrate +Outlet -Nitrate (b) Exhaustion Curves Figure 4-21. Results of McCook AIX Vessel 5 30 25 0 R 20 J a1 E c O 15 — C d v c 10 U O z 5 0 600,000 W • The resin core sample did not show two distinctive layers; A850END and A300E resins appeared to be mixed. Purolite's laboratory could not find enough A850END sample for separate resin analyses. Per Purolite, resin capacities were "acceptable" after 2.5 years of service. Findings at McCook suggest that A850END can be effective at removing TOC from raw water, thus preventing the underlying resin from being fouled. Based upon these findings, a decision was made to replace Arsenex II with A850END/PFA300E at Vale. 4.4.4.4 Dual Resin Installation. Rebedding of the two IX vessels was performed during February 10 and 13, 2009, by Accurate Water Solutions, a subcontractor to Battelle. Arsenex II resin was removed from the vessels using a vacuum truck, but the gravel underbedding remained in the vessels to be reused. Freeboard measurements were then made from the top of the flange to the top of the gravel. Purolite PFA300E and A850END IX resins were then loaded sequentially into each vessel with freeboard measurements taken immediately after loading of each IX resin. It was noted that the top of the A850END layer had already reached the bottom of the top diffuser, indicating maximum loading in the two resin vessels. Calculations of resin volumes based on the freeboard measurements resulted in 197 ft' of resins in both vessels, compared to the design volume of 220 ft3. Freeboard measurements and resin volumes are presented in Table 4-15. Table 4-15. Freeboard Measurements during Dual Resin Rebedding Freeboard Measurement Vessel A Vessel B Total Resin Volume (ft) To top of Gravel (in) 70.75 71.25 - To top of PFA300E (in) 25.5 26.0 - To top of A850END (in) 16.0 17.0 - Depth of PFA300E (in) 45.25 45.25 - Depth of A850END (in) 9.5 9.0 - Volume of PFA300E (ft) 81.6 81.7 163.3 Volume of A850END (ft) 17.1 16.2 33.3 Total Resin Volume (ft) 98.7 97.9 196.6 Once the IX resins had been loaded, each vessel underwent a regeneration cycle. Based on the results from the first regeneration of each vessel, the regeneration settings were adjusted to achieve the target salt loading of 10 lb/ft3. 4.4.5 Residual Management. Residuals produced by the IX system included spent brine and rinse water, which were discharged to the evaporation pond adjacent to the treatment building. FeC13 was added to spent brine in an attempt to precipitate arsenic and allow the iron sludge to settle in the evaporation pond. The design and construction of the evaporation pond and the FeC13 treatment system were performed by the City's contractors and described in Sections 4.2.2 and 4.3.2. The volume of wastewater produced was determined by the regeneration frequency and the volume of wastewater generated per regeneration cycle. Table 4-12 presents relevant calculations of wastewater production under different regeneration settings. Reclaiming spent brine could save salt use and reduce wastewater production. Comparing amounts of wastewater produced under Regeneration Setting 6 (without brine reclaim) and Regeneration Setting 4 (with brine reclaim), 17% less wastewater was produced (reduced from an average of 8,622 to 7,185 gal) when spent brine was reused per vessel when reused brine was applied. The use of spent brine, however, was discontinued on December 10, 2007 due to concerns over resin fouling by TOC. The evaporation pond was designed based on the Purolite-projected resin run length and regeneration frequency. Shorter run lengths and higher regeneration frequencies experienced caused the pond to fill faster than originally designed. In April 2008, the City obtained one-time approval from the Oregon DHS to use the pond water as a dust suppressant in the nearby area. This helped to lower the water level in the pond. To characterize the water quality of the residuals, samples were collected from the waste stream from each regeneration step as well as the pond water. The results are provided in Sections 4.5.5 and 4.5.6. Prior to dual resin installation, a sample of the old Arsenex II resin was collected on August 15, 2008, and sent to Belmont Labs for the Toxicity Characteristic Leaching Procedure (TCLP) test. The results showed less than MDL of arsenic, cadmium, chromium, selenium, mercury and silver, 0.25 mg/L of barium, and 0.058 mg/L of lead. After passing the TCLP, the spent Arsenex II resin was disposed of as a non -hazardous waste. 4.4.6 System Operation Requirement 4.4.6.1 Required System Operation and Operator Skills. The required system operation and operator skills are further discussed below according to pre- and post -treatment requirements, levels of system automation, operator skill requirements, preventive maintenance activities, and frequency of chemical/media handling and inventory requirements Pre- and Post -Treatment Requirements. Pretreatment included filtration with two banks of bag filters (each containing five) to remove sediment from source water. Filter bags were replaced when differential pressure (Op) readings across the bag filter assembly were greater than 12 to 15 psi. Filter bags were replaced five times from September 27, 2006 to January 14, 2008 in Study Period I; and twice from February 16, 2009 to March 22, 2010 in Study Period II. It took approximately two hours each time to replace all 10 filter bags. The only post -treatment was post -chlorination for disinfection. System Automation. The IX system was fully automatic and controlled by the PLC in the central control panel. The control panel contained a touch screen OIP that allowed the operator to monitor system flowrate and throughput since last regeneration. The OIP also allowed the operator to change system setpoints, as needed, and check alarm status. Setpoint screens were password -protected so that changes could be made only by authorized personnel. Typical alarms were for no flow, storage tank high/low, and regeneration failure. The IX system was regenerated automatically based on a throughput setpoint, except during regeneration sampling events when regeneration was initiated manually to record log sheets and capture spent regenerant and rinse samples. It is a good practice to periodically check on relevant parameters during a complete regeneration cycle, including specific gravity of dilute brine and volumes of spent and/or fresh brines used, to ensure adequate salt loadings and identify operational issues, if any, at an early stage. Operator Skill Requirements. Operating and maintaining an IX system required minimal additional operator skills beyond those required for small system operators, such as solid work ethic, basic mathematical skills, abilities to understand chemical properties, familiarities with electronic and mechanical components, and abilities to follow written and verbal instructions. Understanding of and compliance with all occupational and chemical safety rules and regulations also were required. Since all major system operations were automated and controlled by the PLC, the operator was required to WI understand and learn how to use the PLC and OIP to perform tasks after receiving training from the vendor. Oregon state law requires owners of public and private drinking water and wastewater systems to have their systems under the responsible control and direction of certified operators. Oregon DHS DWP administers the certification program for drinking water system operators. DHS DWP classifies water distribution systems and treatment plants according to their complexity and size: • Water systems with 149 and fewer connections and utilizing groundwater as their only source or purchasing all their water from another public water system without adding any additional treatment require a small water system "S" certification. • Water systems with 150 or more connections require certification at Levels 1 to 4 in either treatment and/or distribution. Distribution systems are classified as Levels 1 to 4 according to the population served by the system. Treatment plants are classified as Levels 1 to 4, depending on factors such as system complexity, size, and source water. The plant operator at Vale, OR had a treatment plant Level 1 license. After receiving proper training from the vendor during system startup, the operator understood the PLC, knew how to use the OIP, and worked with the vendor and Battelle to troubleshoot and perform minor on -site repairs. 4.4.6.2 Preventive Maintenance Activities. Preventive maintenance tasks recommended by the vendor included daily to monthly visual inspection of the piping, valves, vessels, flow meters, and other system components. Routine maintenance also may be required on an as -needed basis for the air compressor motor and the replacement of o-ring seals or gaskets on automated or manual valves and the brine transfer pump. During the demonstration study, maintenance activities performed by the operator included replacing filter bags periodically, checking the brine concentration using a hydrometer, and adjusting regeneration frequency and setpoints as instructed by the vendor or Battelle. 4.4.6.3 Chemical/Media Handling and Inventory Requirements. Routine regeneration requires sodium chloride and periodically, caustic soda for resin cleaning. The IX system has fully automated controls with IX resin regeneration triggered by volume throughput. A salt truck delivered salt on a monthly or as -needed basis with the operator's presence. The salt saturators were sized to hold 22 tons of salt supply. Assuming that the system regenerated 13 times per month (based on regeneration frequency in Study Period II, Table 4-10) and used 1,633 lb of salt per event (as designed for Study Period I1), it would require 21,229 lb or 9.5 tons of salt per month. Therefore, the salt saturators held about two months of salt supply. Because the salt saturators were situated in the same room as the treatment system, excessive salt dust was generated during salt delivery. The salt is corrosive to the electrical/mechanical components of the treatment system. Placing the salt saturators in a separate room would minimize the salt dust and corrosion issues. 4.5 System Performance The performance of the IX system was evaluated based on analyses of water samples collected across the treatment train, during regeneration, and from the distribution system. In addition, special run length studies and an elution study were conducted to provide additional insight into system performance. 4.5.1 Treatment Plant Sampling. In Study Period I, Arsenex II performance was evaluated through sampling across the treatment train on 31 occasions, including two duplicate sampling events and 041 eight speciation events. Regular weekly sampling was discontinued after April 16, 2007; only TT samples were collected for total arsenic and nitrate analyses between July 16, 2007 and January 14, 2008. In Study Period II, A850END/PFA300E were evaluated through sampling across the treatment train on 32 occasions. No duplicate sampling or speciation sampling took place in Study Period 11. Table 4-16 summarizes arsenic and nitrate analytical results in both study periods. Tables 4-17 and 4-18 summarize results of other water quality parameters in Study Periods I and 11, respectively. Appendix D contains a complete set of analytical results. The results obtained are discussed in the following subsections. Table 4-16. Summary of Arsenic and Nitrate Analyses in Study Periods I and II Parameter Unit Sampling Location(., Count Minimum Maximum Average Standard Deviation Study Period I As (total) µg/L IN 31 18.3 31.8 22.6 3.1 TA 30 0.5 45.8 _(FT - TB 29 0.4 33.8 - TbT- - TT 30 0.7 48.7 - As (soluble) µg/L IN 8 19.2 22.9 21.0 1.1 TA 8 1.6 42.1 _(FT - TB 7 1.8 29.8 - -( TT 8 1.6 35.9 - As (particulate) µg/L IN 8 <0.1 3.7 1.9 1.3 TA 8 <0.1 3.6 0.7 1.2 TB 7 <0.1 3.0 1.2 1.3 TT 8 <0.1 3.4 1.0 1.2 As (11I) µg/L IN 8 0.4 2.3 1.0 0.6 TA 8 0.4 2.5 0.9 0.7 TB 7 0.3 2.8 0.9 0.9 TT 8 0.3 2.7 0.9 0.8 As (V) µg/L IN 8 17.8 22.5 20.0 1.5 TA 8 0.8 39.6 - - TB 7 1.0 27.0 - - TT 8 0.9 33.1 - - Nitrate (as N) mg/L IN 31 1.4 7.6 5.4 1.5 TA 30 <0.05 9.9 - - TB 29 <0.05 8.9 - TT 30 0.4 7.1 - - Study Period II As (total) µg/L IN 32 16.0 23.3 19.6 1.8 TA 31 0.1 34.7 - - TB 31 <0.1 31.1 - - TT 32 <0.1 31.4 - - Nitrate (as N) mg/L IN 32 4.0 7.5 5.6 0.7 TA 31 0.1 9.9 _(b) -TET- TB 31 0.6 9.9 - - TT 32 0.1 9.3 -� - (a) See Figure 3-1 for sampling locations. (b) Not meaningful for concentrations related to breakthrough, see Figures 4-23 through 4-25 and Appendix D for results. One-half of detection limit used for non -detect samples for calculations. Duplicate samples included in calculations. Table 4-17. Summary of Other Water Quality Parameters in Study Period I Parameter Unit Sampling Location(a) Count Minimum Maximum Average Standard Deviation Alkalinity mg/L IN 31 254 358 329 23.8 TA 30 171 432 -° TB 29 143 427 -` TT 8 194 400 cc - Fluoride mg/L IN 8 0.5 1.1 0.7 0.2 TA 8 0.5 1.1 0.7 0.3 TB 7 0.5 1.4 0.8 0.3 TT 8 0.5 1.3 0.7 0.3 Sulfate mg/L IN 30(') 63.9 97.0 81.8 7.7 TA 30 <1 38.0 - ° - TB 29 <1 38.0 TT 8 <1 40.0 - ` - Phosphorus (as P) µg/L IN 31 212 337 278 33.4 TA 30 <10 664 - - TB 29 <10 458 -° -° TT 8 <10 559 cc -cT Silica (as Si02) mg/L IN 31 46.1 59.2 55.6 2.1 TA 30 53.6 60.0 56.1 1.4 TB 29 10.3 59.8 54.2 8.6 TT 8 54.6 59.9 56.4 1.9 Turbidity NTU IN 31 0.2 0.9 0.5 0.2 TA 30 0.1 1.2 0.5 0.2 TB 29 0.1 1.6 0.6 0.3 TT 8 0.4 1.1 0.6 0.2 TOC mg/L IN 1 2.0 2.0 2.0 - TDS mg/L IN 31 434 766 514 61.7 TA 30 412 606 485 40.8 TB 29 432 550 486 32.1 TT 8 430 554 483 42.5 pH S.U. IN 22 7.2 8.0 7.4 0.2 TA 22 7.1 8.3 7.5 0.3 TB 22 7.0 8.2 7.5 0.3 TT 22 7.0 8.2 7.4 0.3 Temperature °C IN 22 14.6 17.5 15.5 0.8 TA 22 14.4 17.9 15.4 0.8 TB 22 14.3 18.2 15.4 0.9 TT 22 14.0 16.8 15.3 0.7 DO mg/L IN 22 1.6 6.3 3.7 1.4 TA 22 2.0 6.5 4.0 1.5 TB 22 1.8 6.9 3.9 1.6 TT 22 2.0 6.5 4.1 1.5 OPP my IN 22 127 295 253 33.1 TA 22 126 262 222 32.1 TB 22 120 252 214 33.2 TT 22 118 252 216 36.3 Total Hardness mg/L IN 9 120 251 165 36.0 TA 8 140 240 171 30.4 TB 7 142 241 173 33.2 TT 8 137 229 171 28.7 W.i Table 4-17. Summary of Other Water Quality Parameters in Study Period I (Continued) Parameter Unit Sampling Location(a) Count Minimum Maximum Average Standard Deviation Ca Hardness mg/L IN 9 75.0 187 115 30.5 TA 8 96.2 178 120 25.4 TB 7 98.0 179 121 28.0 TT 8 92.8 169 120 24.0 Mg Hardness mg/L IN 9 44.0 63.9 50.1 6.5 TA 8 43.9 61.8 50.9 6.2 TB 7 43.6 61.6 51.7 6.2 TT 8 43.7 59.8 51.0 5.9 Fe (total) µg/L IN 31 <25 <25 <25 0.0 TA 30 <25 <25 <25 0.0 TB 29 <25 <25 <25 0.0 TT 8 <25 <25 <25 0.0 Fe (soluble) µg/L IN 8 <25 <25 <25 0.0 TA 8 <25 <25 <25 0.0 TB 7 <25 <25 <25 0.0 TT 8 <25 <25 <25 0.0 Mn (total) µg/L IN 31 <0.01 2.1 0.4 0.4 TA 30 <0.01 2.3 0.5 0.4 TB 29 <0.01 1.4 0.4 0.3 TT 8 <0.01 0.6 0.4 0.2 Mn (soluble) µg/L IN 8 <0.01 0.5 0.4 0.1 TA 8 0.2 0.6 0.4 0.1 TB 7 <0.01 0.5 0.3 0.2 TT 8 <0.01 0.6 0.4 0.2 V (total) µg/L IN 9 46.5 60.5 54.1 5.5 TA 8 0.6 3.6 2.0 1.0 TB 7 0.7 4.5 2.2 1.3 TT 9 0.6 3.9 2.1 1.0 V (soluble) µg/L IN 8 48.5 61.2 54.2 5.1 TA 8 0.5 3.5 2.0 1.0 TB 7 0.6 4.5 2.1 1.3 TT 8 0.7 3.5 2.1 0.9 (a) See Figure 3-1 for sampling locations. (b) Excluding an outlier on 10/02/2006. (c) Not meaningful for concentrations related and Appendix D for results. One-half of detection limit used for non -detect Duplicate samples included in calculations. to breakthrough, see Figures 4-26 and 4-27; samples for calculations. M Table 4-18. Summary of Other Water Quality Parameters in Study Period II Parameter Unit Sampling Location (a) Count Minimum Maximum Average Standard Deviation Alkalinity mg/L IN 32 279 346 309 15.1 TA 31 76.0 402 - - TB 31 26.4 390 - - TT 32 52.8 400 - - Sulfate mg/L IN 32 63.6 83.2 74.0 4.4 TA 31 <0.1 61.7 - 3 - TB 31 <0.1 16.0 - - TT 32 <0.1 21.3 - - Phosphorus (as P) µg/L IN 31 249 345 275 19.7 TA 30 <10 452 - - TB 30 <10 447 - - TT 31 <10 457 - - Silica (as Si02) mg/L IN 32 54.5 66.2 59.4 2.6 TA 31 54.9 65.2 59.8 2.3 TB 31 54.4 67.2 60.1 2.8 TT 32 53.6 64.6 59.8 2.5 Turbidity NTU IN 32 <0.1 2.6 0.3 0.5 TA 31 <0.1 1.3 0.4 0.4 TB 31 <0.1 4.2 0.5 0.7 TT 32 <0.1 2.1 0.4 0.4 TOC mg/L IN 32 1.4 2.2 1.8 0.2 TA 31 <1 <1 <1 0.0 TB 31 <1 <1 <1 0.0 TT 32 <1 <1 <1 0.0 TDS mg/L IN 32 434 588 498 32.1 TA 31 416 606 476 41.6 TB 31 420 724 484 62.4 TT 32 368 650 478 51.7 Fe (total) µg/L IN 32 <25 <25 <25 0.0 TA 31 <25 <25 <25 0.0 TB 31 <25 <25 <25 0.0 TT 32 <25 <25 <25 0.0 Mn (total) µg/L IN 32 0.2 5.3 0.7 1.1 TA 31 0.1 3.2 0.5 0.6 TB 31 0.2 3.3 0.5 0.6 TT 32 0.2 3.0 0.5 0.6 V (total) µg/L IN 32 46.9 59.4 51.3 3.1 TA 31 <0.1 7.3 2.3 2.0 TB 31 <0.1 14.5 2.9 3.5 TT 32 <0.1 11.5 2.7 2.7 (a) See Figure 3-1 for sampling locations. (b) Not meaningful for concentrations related to breakthrough, see Appendix D for results. One-half of detection limit used for nondetect samples for calculations. 4.5.1.1 Arsenic Speciation. Eight speciation sampling events were conducted in Study Period I. Figure 4-22 presents arsenic speciation results at the IN, TA, TB, and TT sampling locations. Soluble As(V) was the predominant species in raw water, ranging from 17.8 to 22.5 µg/L and averaging 20.0 µg/L (Table 4-16). Trace amounts of particulate As and soluble As(III) also existed with concentrations RTC 50 40 30 oio 20 10 0 50 40 30 20 10 0 50 40 30 20 10 0 50 40 t� 30 on 20 10 0 As Species at Inlet (IN) ❑ As(particualte) ■As(V) ■As(III) 09/20/06 10/18/06 11/14/06 12/13/06 01/10/07 02/12/07 03/12/07 04/10/07 As Species after Vessel (TA) ❑As(particulate)■As(V) 43,862 l'ga ■As(III) 653,391 gal 475,337 gal 451 9996 gal it 407, 216,079 gal 114,230 gal 09/20/06 10/18/06 11/14/06 12/13/06 01/10/07 02/12/07 03/12/07 04/10/07 As Species after Vessel B (TB) 653,391 gal 407,330 gal 125,750 gal ❑As(particulate) ■As(V) 543,862 gal ■AS(III) 475,337 gal 451,996 gal 114,230 gal 09/20/06 10/18/06 11/14/06 12/13/06 01/10/07 02/12/07 03/12/07 04/10/07 As Species after Vessels A and B Combined (TT) 543,862 gal ❑As(particulate) 653,391 gal ❑As(V) 475,337 gal ❑AS(III) 451,996 gal 407,330 gal j]I,750 gal 216;079 gal 114,230 1 09/20/06 10/18/06 11/14/06 12/13/06 01/10/07 02/12/07 03/12/07 04/10/07 Figure 4-22. Concentrations of Arsenic Species across Treatment System 61 averaging 1.9 and 1.0 µg/L, respectively. After the IX treatment, a small amount of particulate As (0.9 µg/L [on average]) was removed by either the bag filters or the IX resin beds. Soluble As(III) concentrations, however, remained essentially unchanged at 0.9 µg/L. This was as expected because the IX process does not remove neutral species such as arsenite. Speciation sampling was not conducted in Study Period II. For each sampling event, the volume throughput at the time of sampling is marked on Figure 4-22 to relate treatment results with the run length. As shown on the figure, arsenic was removed to below the 10-µg/L MCL during the early stage of service cycles. Elevated arsenic concentrations (i.e., >10 µg/L) were measured in IX vessel effluent on September 20, 2006, and January 10, February 12, and March 12, 2007, when samples were collected at a throughput of 653,391, 451,996, 475,337, and 543,862 gal, respectively, indicating that the IX system needed to be regenerated before reaching 450,000 gal. 4.5.1.2 Arsenic Removal. Arsenic and nitrate were the two primary contaminants of concern in source water; thus, their removal was key to assessing the performance of the IX system. Figures 4-23 and 4-24 present total arsenic concentrations across the treatment train for Study Periods I and II, respectively. Figure 4-23 plots the concentration data against either sampling dates ("temporal plot") or volume throughputs at the time of sampling ("reconstructed breakthrough curves"). Because the temporal plot does not explain why arsenic exceeds the MCL, the reconstructed breakthrough curves provide more insight into system performance. Typically, a breakthrough curve is constructed with data collected from one complete service cycle. Because the IX system was regenerated once every two to three days, routine weekly treatment plant water samples were collected from different service cycles. Collectively, these data, after being sorted by volume throughput (from low to high), can exhibit breakthrough behaviors similar to those one would expect in a service cycle. Therefore, "reconstructed breakthrough curves" were used to discuss nitrate, sulfate, and other parameters in the following sections (Note that the September 25 and October 31, 2006 data were not plotted due to lack of throughput data). Study Period I. As shown in Table 4-16, total arsenic concentrations in source water varied from 18.3 to 31.8 µg/L and averaged 22.6 µg/L in Study Period 1. These concentrations were slightly higher than those (i.e., 16.7 and 20 µg/L [see Table 4-2]) sampled previously during the initial site visit on December 2, 2004. The temporal plot in Figure 4-23a can be divided into three sub -periods: from startup to April 13, 2007; from April 13, 2007, to October 22, 2007; and after October 22, 2007. The volume throughput setpoint was 600,000 gal for the first sub -period, shortened to 370,000 gal for the second sub -period, and returned to 600,000 gal for the sub -third period (after resin cleaning). Arsenic had been consistently removed to below the MCL in the second sub -period, but its concentrations were erratic in the first and third sub - periods. The "reconstructed breakthrough curves" in Figure 4-23b showed that, except for three TT samples collected on November 14, November 19, and December 3, 2007, all other TA, TB, and TT samples collected prior to a volume throughput 370,000 gal contained <10 µg/L of arsenic. In contrast, all but one sample collected after 370,000 gal had arsenic concentrations exceeding the MCL. In addition to sampling time, operational issues such as low salt loadings (between October 20 and December 5, 2006) and counter -current regeneration (set by mistake in late February 2007) also had contributed to the high effluent concentrations observed (such as those collected on November 6, 14, and 28, 2006, and on March 5 and 12, 2007). The IX system performance was deteriorating with time as evidenced by the weekly arsenic monitoring data and special run length study results. The run length to 10-µg/L arsenic breakthrough was reduced from 562,300 gal at startup in September 2006 to 449,702 gal in early January 2007, and then to 376,940 row 50 40 30 20 10 0 IN O o TA Ffiegenat600,000g�l Regenat370,000!gal Reggnat600,000gaI .......... TB (efore 04/13/07) (04/13/07-10 22 07) a terl 2 7 ❑ TT , ❑ b o --------------------------- -o---- -------'-------------- A 0 O ❑ i ❑ �S ----r--------------- 0 ---------------- ---- — 0 g O ❑ ° ° ❑ O I� �� Q 9 ❑� Q ° ❑°❑❑ ❑ 09/01 /06 50 40 30 20 10 11/30/06 02/28/07 05/29/07 Sampling Date 08/27/07 11/25/07 02/23/08 Study Period I: Purolite Arsenex II Resin —IN - 6-- 0 TA ' ' ' 09/20/06 TB 653,391gal - ❑ TT --'------ -------------'-Q-------- ----'---- -` ' c I ' 0 TAregenby+assedon ; 11/14/07, 1�/19/07, i 04/02/07 376,940ga{ 0:01/02%07 12/03/p7_ ,,'449,7Q2 gal �i 10 µg/L MCL -------------------- ° ❑ g 0 ❑ Q n ElQ0 ❑ �C]0 0 n° o 0 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated (gal) Figure 4-23. Total Arsenic Concentrations Measured During Study Period I (a) Temporal Plot; (b) Reconstructed Breakthrough Curves roil 50 Study Period II: Purolite Dual Resin A850END/PFA300E TIN 40 o TA ----------- 1----------- ;----------- ----------- ---------------------- JJ I �`p I 1 .1 I `- ❑ TT O I I 0 I I I I CC i i i � p -10p w I I I h.l I I p I V I I I I I 020 V I I ❑ I I I � I I I I I I � I I y.� I I I ❑ I I F 10 µg/L MCL " O I I I I 10 ----------- 1-----------------------;------------------------ ----------- L----------- I I 1 I I I I I I ❑ I p O V ❑ ❑ o 0 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated (gal) Figure 4-24. Total Arsenic Concentrations Measured During Study Period II gal in early April 2007. As discussed in Section 4.4.3, shortened run lengths most likely were caused by organic matter buildup, which could block exchange sites and reduce resin capacities. Immediately after resin cleaning on October 22, 2007, A TT sample collected at a volume throughput of 377,889 gal contained 2.1 µg/L, which was significantly lower than the 11.1 µg/L measured in another TT sample collected at 376,940 gal on April 2, 2007 (see data in Appendix D). However, all of the six subsequent TT samples collected between October 29 and December 10, 2007 exceeded the arsenic MCL. Three of the samples were collected at high volume throughputs of 595,337, 533,870, and 530,622 gal, with arsenic concentrations of 33.5, 33.8, and 48.7 µg/L, respectively. The other three were collected at low volume throughputs of 131,979, 50,196, and 51,996 gal, with lower arsenic concentrations of 11.8, 10.2, and 11.9 µg/L, respectively, all of which were over the MCL. According to Run Length Study 2 conducted on October 24 to 26, 2007, throughput to 10-µg/L arsenic breakthrough was approximately 445,700 gal, which explained why the high -throughput samples contained high arsenic concentrations. Puzzled by the low -throughput sample results, the operator observed a regeneration cycle on November 27, 2007, and noticed that while in the automatic mode, Vessel A skipped regeneration and only Vessel B was regenerated. During troubleshooting, Kinetico discovered that because the spent brine draw time was set to zero after the caustic wash on October 22, 2007, the PLC did not work properly as the software could not accept zero as a setpoint. Once the draw time was temporarily set to 1 min on December 10, 2007, the PLC worked correctly to regenerate both vessels. (Note that the spent brine draw step was removed from the PLC in February 2009 after installation of dual resins.) The subsequent two TT samples collected at 200,373 gal on December 17, 2007, and at 195,150 gal on January 7, 2008, contained CZI 1.3 and 2.2 µg/L of arsenic, respectively. However, the TT sample collected at 418,136 gal on January 14, 2008 contained 20.6 µg/L of arsenic, indicating that the run length to 10 µg/L was shortened again, compared with the 445,700 gal established right after resin cleaning in October 2007. Because the IX system was shut down for well rehabilitation during January 14 and May 1, 2008, another resin cleaning was not performed. As the IX system was allowed to operate beyond the 10-µg/L breakthrough, effluent arsenic concentrations became significantly higher than influent arsenic concentrations, a phenomenon commonly known as chromatographic peaking or dumping. This arsenic dumping was caused by more preferred anions such as sulfate, which displaced previously exchanged arsenic from the resin. In addition, because sulfate concentrations were more than three orders of magnitude higher than those of arsenic, these concentration effects further accelerated displacement. Arsenic dumping is a major drawback of the IX technology, but can be mitigated by controlling the timing of regeneration to prevent overrun. Study Period IT Total arsenic concentrations in raw water ranged from 16.0 to 23.3 µg/L and averaged 19.6 µg/L in Study Period II. Run Length Study 4 performed in April 2009 indicated a useful run length of approximately 436,350 gal. Based on the "reconstructed breakthrough curves" in Figure 4-24, arsenic breakthrough at 10 µg/L occurred at TT between 444,200 gal (3.2 µg/L on July 20, 2009) and 487,900 gal (13.7 µg/L on September 2, 2009) and was estimated to be 472,500 gal. The average of the two values (i.e., 436,350 and 472,500 gal) was 454,400 gal, which was 51% of the projected run length by the Purolite simulation. The run length for Vessel B was slightly longer than that of Vessel A, i.e., by approximately 20,000 to 40,000 gal. Arsenic dumping also was observed in Study Period II as samples were collected at a throughput higher than 487,900 gal. Unlike the Fruitland IX system where elevated arsenic concentrations were measured in effluent up to 50,000 to 60,000 gal (67 to 80 BV) after the system had just been regenerated, arsenic leakage was not noticeable at Vale, OR. Because co -current regeneration was employed at both Fruitland and Vale, it was not clear what had caused the difference between the two sites. 4.5.1.3 Nitrate Removal. As shown in Table 4-16, nitrate concentrations in source water ranged from 1.4 to 7.6 mg/L (as N) and averaged 5.4 mg/L (as N) in Study Period I; and ranged from 4.0 to 7.5 mg/L (as N) and averaged 5.6 mg/L (as N) in Study Period II. Figures 4-25a and 4-25b present "reconstructed breakthrough curves" of nitrate for Study Periods I and II, respectively. While consistently below the nitrate MCL of 10 mg/L (as N) in both study periods, effluent nitrate concentrations exhibited an increasing trend and approached or even exceeded influent nitrate concentrations towards the end of a service cycle. For example, effluent nitrate concentrations reached or exceeded coresponding influent concentrations at a volume throughput of approximately 380,000 gal in Study Period I and 480,000 gal in Study Period II. Because these volume throughput values were longer than those to the 10-µg/L arsenic breakthrough, useful run lengths for both the ArseneX II and dual resin systems were controlled by arsenic breakthrough, not nitrate breakthrough. The original intent of system design was to control system operations based on nitrate breakthrough because it was easier and cheaper to monitor nitrate using a Hach test kit and because the regular resin is cheaper than the nitrate selective resin. The facility reported a higher nitrate concentration of 8 to 12 mg/L (as N) for technology selection and computer simulation. The facility also indicated that it preferred the IX system over other technologies because of its ability to remove both arsenic and nitrate. CI.i r� i/ 12 10 t4 'i d In 12 10 0 4 0 IN (a) TA Study Period I: Purolite Arsenex 11 Resin TB ❑ TT --- ---- o• - ------------ -- 0 --------------i--- ------- --r r ---------- --�0 0---�❑------�-------------- �- QJ ; O 0 O --------•---------- - --- - • - - ------ - --- --- -- --- n- P, ❑ s ❑ 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated �IN (b) , ° TA Study Period U: Purolite Dual Resins A850END & A300E TB Ei TT ❑ s -- ----- ;-------- ------ a 0 0 0 0 O ❑I ------------- -------------- ------------- -------------- -----cr------------------------------ 0 $- -------------`---------------------------`- o--- -------------------------------- ° ❑ ;a 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated (gal) Figure 4-25. Reconstructed Breakthrough Curves for Nitrate (a) Study Period I; (b) Study Period II 041 4.5.1.4 TOC, Sulfate, Phosphate, and Vanadium Removal. TOG. In Study Period 1, TOC was measured only once on April 16, 2007, at a concentration of 2.0 mg/L in raw water. After it was identified as a foulant, TOC concentrations were monitored across the dual resin system in 32 sampling events throughout Study Period 1I. Raw water TOC concentrations ranged from 1.4 to 2.2 and averaged 1.8 mg/L, which were consistent with the 2.1 mg/L measured on December 2, 2004 during the initial source water sampling. At the TA, TB, and TT locations, TOC concentrations were consistently reduced to below the MDL of 1 mg/L, suggesting effective removal by the dual resin system throughout the entire service cycle of 600,000 gal. Sulfate. Figure 4-26 presents "reconstructed breakthrough curves" for sulfate in Study Periods I and II. Sulfate concentrations in raw water averaged 82 mg/L in Study Period I and 74 mg/L in Study Period Il. Sulfate was removed to less than 1 mg/L most of the time in both periods until reaching a volume throughput of 376,940 gal in Study Period I and 487,940 gal in Study Period 1I. Afterwards, sulfate concentrations began to rise as more water was treated and reached 1/3 to 1/2 of its influent concentration by the end of the 600,000-gal service cycle. Because of its higher selectivity than arsenate and nitrate, sulfate continued to be removed even when arsenate and nitrate had reached their respective MCL in the effluent. Displacement of arsenate and nitrate by sulfate would result in higher effluent arsenate and nitrate concentrations than the respective influent concentrations, as discussed in Sections 4.5.1.2 and 4.5.1.3. Deteriorating resin performance also was reflected by sulfate concentrations in system effluent. For example, in Study Period I at system startup on September 20, 2006, the sulfate concentration at TT was 9 mg/L at a volume throughput of 653,391 gal. After six months into system operation on March 19, 2007, the average of sulfate concentrations at TA and TB was 9 mg/L at a volume throughput of only 415,021 gal, indicating a 36% reduction in run length for sulfate. Phosphate. Figures 4-27 presents "reconstructed breakthrough curves" for total phosphorus. Raw water contained 212 to 345 µg/L of total phosphorus, which averaged 278 µg/L in Study Period I and 275 µg/L in Study Period II. Total phosphorus concentrations in effluents were reduced to less than 10 µg/L most of the time, but rose rapidly and exceeded influent levels after reaching a volume throughput of approximately 415,000 gal in Study Period I and 488,000 gal in Study Period II. The pre -adsorbed phosphate was displaced by more preferred sulfate. Vanadium. Total vanadium concentrations in raw water measured in both study periods were similar, ranging from 46.5 to 60.5 µg/L. Figure 4-28 presents "reconstructed breakthrough curves" of total vanadium in Study Period I and 11. Arsenex II reduced vanadium concentrations to <5 µg/L throughout Study Period 1. PFA300E/A850END also reduced vanadium concentrations to <5 µg/L on all but four occasions on March 25, April 2, September 30, and December 10, 2009, when TT samples collected at 59,084, 551,090, 56,986, and 27,963 gal of volume throughput contained total vanadium concentrations of 11.5, 6.0, 7.4, and 9.8 µg/L, respectively. Chromatographic peaking was not observed for vanadium in either period, suggesting that vanadium ions, such as V043 , HV042 and/or H2VO4 , may have an equivalent or even higher selectivity than sulfate and/or uranium ions. 4.5.1.5 Other Water Quality Parameters. Figures 4-29 and 4-30 present a "reconstructed pH plot" and "reconstructed breakthrough curves" for pH and total alkalinity, respectively. Raw water pH values ranged from 7.2 to 8.0 and averaged 7.4 in Study Period I. pH was not measured in Study Period II. Total alkalinity concentration in raw water ranged from 254 to 358 and averaged 329 mg/L (as CaCO3) in Study Period 1; and ranged from 279 to 346 and averaged 309 mg/L (as CaCO3) in Study Period 11. 120 100 �1 80 60 /l 120 100 80 40 20 I I (a) Study Period I: Purolite Arsenex II Resin I I I I I I 1 I 1 I I I I I 1 I I 1 1 I I I I I 1 I I I I I I I ____ 1__ -------- L--- _____J __ __ __L_____ ____---------- ---------- I 1 I I I I 1 I I I 1 I I I I 1 I 1 I 1 1 1 I I I I 1 1 I I I I I I 1 I I 1 I I 1 1 1 I I I 1 I 1 I I I 1 I 1 I I 1 1 1 1 I I 1 1 1 1 I I I 1 1 1 I I I 1 I 1 I I I SIN ------------------------------------------ --- ------------- I 1 I I I $-- I I I 1 I I g I o TA I 1 1 I I I 1 1 I 1 I I 0 I TB I 1 I 1 ❑ TT i 376,943gal i 1 1 ❑ I ' ''` 11i 0 Q i 09/20/06 i 1 10l I\ -(,7, i 653,391gal% ' I.,! Ig ;t 1 �Qi 100,000 200,000 300,000 400,000 500,000 600,000 Water Treated (gal) 700,000 I I 1 I I I IN (b) o TA Study Period II: Purolite Dual Resins A850END/PFA300E - -'-----------'----------------------'-----------'-----------'-- TB 1 I I I 1 I I I 1 I 1 I I I I I I I ❑ TT I I I I I I I I 1 I 1 I I I I 1 I 1 I I I 1 I I I I I 1 I I I I I 1 1 1 I 1 O I I 1 I I I 1 I I I 1 I I I 1 1 1 I i I 1 I 1 I 1 I 1 I I I I I 1 I I I I I I I I I 1 I 1 I I 1 I I 1 I I I I I I I I I I 1 I I I 1 I 1 I I I 1 Q 1 I 1 I I ---------- 1----------- I----------- 1---------- J- 1__________L q(�['J� � Si!__________ 09/02/09 ❑ 487,940ga1 0 C' �\21 1 1 1 I 0 1 p I I I 1 I I I I I I � ❑ 100,000 200,000 300,000 400,000 500,000 600,000 Water treated (gal) Figure 4-26. Reconstructed Breakthrough Curves for Sulfate (a) Study Period I; (b) Study Period II 700,000 rOM 700 ill 500 400 a 300 9 200 100 ITI 500 .a 400 0. 0. 300 200 100 (a) 00 _ _ _ _ _ _ _ _ _Study Period 1• Purolite Arsenex II Resin L_____________J -------------- I-------------- 1_ T______________I__________-__-T-_-_ ----------------------------- -------------- J I I I I I I ° ❑ O 0 O I I I I -----------------------------------------= - - - - -=---- - - = - --- SIN O TA --------- ------- - - -----r - --; --- - ----; TB a O ° ❑ TT 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated (b) n Study Period II: Purolite Dual Resins A850END & A300E i L_____________J______________1___________-- IN I I I I O TA TI3 4 ❑ TT ------------ O I I I I I I � I I I °I ❑ O ❑ , c° O o- ----- -----,- I ----- o------------------=I- I---❑ - - =-- I I I I I I I I 0 O ❑ ❑ ; 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated Figure 4-27. Reconstructed Breakthrough Curves for Total Phosphorus (a) Study Period I; (b) Study Period 11 CSC 70 60 50 a =L 40 a 0 30 a a� u U 20 Fo 10 70 60 50 an 40 0 30 V U 20 9 10 IN (a) o TA Study Period I; Purolite Arsenex II Resin --- - -- I- ---------- ----- _ -- - - ,---------- ---I ---- -- - TB ❑ TT 1------------- I -------------- -------------- L ------------- I ------------- i --------------- -------------- I I 100,000 200,000 300,000 400,000 500,000 Water Treated (gal) 600,000 700,000 0 IN (b) o TA Study Period H: Purolite Dual Resins A850END & A300E ---------------------------- TB ❑ TT I I I 1 1 __ __---_ ___ i__ __________f____ T_ I I I 1 go 100,000 200,000 300,000 400,000 500,000 600,000 Water Treated (gal) Figure 4-28. Reconstructed Breakthrough Curves for Total Vanadium (a) Study Period I; (b) Study Period II 700,000 8.5 = 7.5 7.0 6.5 Studv Period I: Purolite Arsenex II Resin ; IN 1 1 I 1 I I 1 I 1 1 1 I I I I 1 I 1 1 I I 1 1 1 1 I I 1 I I 1 I 1 I 1 I I 1 1 1 I I 1 1 o TA I 1 O , TB I 1 I I i IL13 TT I 1 I I 1 1 I I 1 I 1 I I 1 I I 1 1 I I 1 I I I 1 I I 1 I I I 1 I I I 1 I I 1 I I I 1 ----------- ----------- ;--------- --;------ --;------ --- '---- o --;- ---------II 1 I I ® I I I I I A I p 1 I I I I I I I i I 1 I �, •, a l 1 I I I 13 I 1 1 I 1 I 1 I l 110/18/06 i 4 1 I I I 1 I I 1 04 f 1b/07 1 1 1 1 1 I 1 1 I 1 I I I I I I I I I I 1 I I I I I I 1 I I I I I I 1 I 1 I I 1 1 1 1 1 I I I I 1 I 1 I 1 I I I I I 1 I I I I I 1 I 1 I 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated (gal) Figure 4-29. pH Measured During Study Period I Slight reductions in pH values were observed for a short period immediately after the IX system had been freshly regenerated. For example, pH values at the IN, TA, TB, and TT locations were 7.3, 7.2, 7.1, and 7.2, respectively, on October 18, 2006, after 125,800 gal of water had been treated; and 7.3, 7.1, 7.0, and 7.1, respectively, on April 10, 2007 after 114,200 gal of water had been treated. Although pH changes were small, i.e., no more than 0.3 pH unit, corresponding reductions in total alkalinity across the IX system were quite significant, i.e., 306, 209, 190, and 194 mg/L (as CaCOA respectively, on October 18, 2006; and 357, 286, 251, and 282 mg/L (as CaCOA respectively, on April 10, 2007. The most significant decrease in total alkalinity was observed on December 4, 2006 after 69,595 gal of water had been treated: i.e., 326, 171, and 145 mg/L at the IN, TA, and TB locations, respectively. This 50% reduction in total alkalinity could not be verified by corresponding pH values because they were measured the next day. Reductions in total alkalinity also were observed in Study Period II in samples collected immediately after regeneration up to 173,000 gal of volume throughput. For example, over 90% of reduction in total alkalinity was observed on March 25 and September 30, 2009, after 59,084 and 56,986 gal of water had been treated, respectively. The reduction in pH and alkalinity immediately after regeneration was attributed to the removal of bicarbonate ions by the AIX resin. As reported in the literature, one disadvantage of the IX process is the production of low pH and corrosive water during the initial 50 to 100 BV of a service cycle (Clifford, 1999). Afterwards, the pH value of treated water returned to the raw water level due to the complete breakthrough of bicarbonate ions, which had a lowest selectivity by the SBA AIX resin. 71 A A 500 400 300 200 100 fe 400 300 200 100 (a) Stud Period I: Purolite Arsenex H Resin g y , ---------------------------------- - - �- --- ; - -8 -;-------------;- 0 ,' g _____------ T'r`-------- ____O----------- T------------- T T 1__ oa/io/o? g 0 -------- ---- -r o rofi$/os;----------------------------------------------------------------- IN o TA TB I TT 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated (gal) (b) Study Period H: Purolite Dual Resins A850END & A300E 1 �_ _tea 0 S- o go a----- �o C3� SIN 0 TA o , TB El TT 100,000 200,000 300,000 400,000 500,000 600,000 700,000 Water Treated (gal) Figure 4-30. Reconstructed Breakthrough Curves for Total Alkalinity (a) Study Period I; (b) Study Period II %Zd 4.5.2 Real -Time Arsenic Monitoring by ArsenicGuardTM. The ArsenicGuardrm analyzer was installed on November 19, 2008, to provide real-time monitoring of arsenic in raw and treated water. ArsenicGuardTM took one measurement every 45 min (even when the well pump was off and the system was not in operation) with data displayed as strip charts, which can be downloaded from the computer for further processing. Figure 4-31 shows two examples of real-time total arsenic plots using data downloaded from ArsenicGuardTM. The top graph plotted data from January 16 through February 9, 2009, right before Arsenex I1 replacement in February 2009. The bottom graph plotted data from August 6 through 30, 2009, after dual resins installation. The plots clearly showed reoccuring service/ regeneration cycles as arsenic concentrations in system effluent cycled between a few µg/L and higher than corresponding influent concentrations. As shown in Table 4-11, system regeneration was set at a volume throughput of 600,000 gal during applicable operating periods shown in Figure 4-31 (under Setting 6 in Study Period I and Setting 7 in Study Period 7). Arsenic breakthrough to 10 µg/L occurred before reaching 600,000 gal for both Arsenex Il and PFA300E/A850END and continuning operations resulted in arsenic dumping in every regeneration cyle. Because ArsenicGuardTM continued analyzing "samples" even when the system was not in operation, the plots shown in Figure 4-31 do not represent actual arsenic breakthrough curves or reflect actual run lengths. 40 30 0 40 30 Q 1 0 ArsenicGuard rTT-ArsenieGuardStudy Period I IN- ArsenicGuard Arsenex II Beds ________L _ _ _ _ _ __,O_ _ __ __ __._.�. Ob _ _ _ ___ __ _ _ _ _ _ _ _____�,,,,_ _____ O �o __. __ _____ _ O :' 91 ® Qg o 40 e© b 1 ® o Q 0 O O o q o --1 10 µg/L MCL O \�^ADO \����0 \��QO \�O��O \���0 \����0 \���0 \���0 \�h�DO \����0 \�^��O \alb \�C� \�O�O \�1�0�\ON�O�\Ory�O�\O���O \ON�O�\O1-) (��O�\O^�O�\O��O�\0���� ��O��O��O^��gro�0�����0°� X� ' XN\����1`�����ti�����~�����5���~10� '\���ti%����°����� 1 41�ti\���ti�\���ti�\���ti��ti��ti�����ti��ti���\�q O O O O O O O O O O O O O O O O O O O O O O O O O O Figure 4-31. Examples of Real -Time Arsenic Monitoring by ArsenicGuardTM 73 For comparsion purposes, Figure 4-31 also plotted three sets of influent/effluent weekly arsenic data measured by ICP-MS during the period from August 6 through August 30, 2009. The ArsenicGuardTM and ICP-MS data appeared to be consistent with each other both at low ppb and around 20 µg/L levels. In addition to arsenic monitoring, the ArsenicGuardrm was equipped with a nitrate sensor for real-time nitrate monitoring. However, the nitrate sensor failed about one week after installation. Inspections of the unit revealed coating and/or clogging of the sample chamber, all Teflon lines, and other assoicated parts with a white powdery film/deposit. After cleaning and/or replacing of all affected parts, the nitrate sensor resumed functioning normally, but this normalcy could not be sustained. The salty, corrosive environment was thought to have affected the nitrate measurements. The nitrate monitoring was abandoned afterwards. 4.5.3 Run Length Studies. Three run length studies (1 to 3) were conducted on Arsenex II in Study Period I and two (4 and 5) on A850END/PFA300E in Study Period II. Results of these studies are discussed below. Note that all throughput readings were taken from the totalizer on the combined effluent even though samples were collected from individual vessel effluent or combined effluent. Run Length Study I (September 19 to 22, 2006). Run Length Study 1 was conducted on Vessel A shortly after system startup in September 2006 to establish baseline system performance. Raw water samples collected on September 20, 2006 contained 24.8 µg/L of total arsenic, 3.5 mg/L of nitrate (as N), 73 mg/L of sulfate, 325 µg/L of total phosphorus, 60 µg/L of total vanadium, and 301 mg/L (as CaCO3) of alkalinity (See Appendix D). Figure 4-32 presents total arsenic, nitrate, sulfate, total vanadium, total phosphorus, and total alkalinity breakthrough curves from Vessel A. The first sample collected at 10,700 gal contained slightly elevated total arsenic, total phosphorus, and total vanadium at 11, 117, and 6.9 µg/L, respectively, indicating leakage from the freshly regenerated resin bed. Total arsenic concentrations decreased to <1 µg/L, stayed at this low level through 500,000 gal, and then peaked at 10 µg/L between 550,000 and 600,000 gal (approximately 562,300 gal based on linear interpolation). Afterwards, the effluent arsenic concentration reached the influent level at approximately 650,000 gal, then continued to increase to 60.8 µg/L in the last sample collected at 904,350 gal. Arsenic dumping resulted in an effluent concentration almost 2.5 times the influent level, the highest level ever detected at this plant throughout the entire study. Therefore, the regeneration setpoint was reduced to 600,000 gal on October 5, 2006 as soon as the sample results became available. Nitrate was below detection before reaching 550,000 gal and gradually increased to 5.2 mg/L (as N) at 904,350 gal by the end of this special study period. This effluent nitrate level exceeded the influent level but was lower than the 10-mg/L (as N) MCL. Sulfate stayed below 1 mg/L until 550,000 gal, and then increased sharply to 42.8 mg/L (or 60% of the influent level) at 904,350 gal. Total phosphorus also rose sharply after 550,000 gal and reached 766 µg/L (or 2.4 times the influent level) at 904,350 gal. Total vanadium was below 3 µg/L throughout the entire cycle (except for the initial spike mentioned above), suggesting that it might have a higher selectivity than sulfate. Total alkalinity concentrations started off low at 10 mg/L (as CaCO3) at 10,700 gal, rose steadily to its influent level at 323,700 gal, and then leveled off between 312 and 368 mg/L (as CaCO3) through the end of this special study period. Run Length Study 2 (October 24 to 26, 2007). Run Length Study 2 was conducted on Vessel A two days after resin cleaning using a mixture of 5% caustic/10% brine in October 2007 to assess the effectiveness of the cleaning. Figure 4-33 presents total arsenic, nitrate, sulfate, and total alkalinity breakthrough curves, which are similar to those shown in Figure 4-32, except that the first breakthrough point for total As, nitrate, and sulfate occurred at approximately 400,000 gal, shorter than the 550,000 gal observed in Run Length Study 1. The run length to 10-µg/L of arsenic breakthrough was approximately 445,720 gal, which was 20% more than the pre -cleaning level, but only 80% of the baseline level. The highest arsenic W,I au avv —As Run Length Study 1 j Vessel i 70 ----- Nitrate ----------------------- September 19 to 22, 2006 ________ ______________ 700 a b 60 a 50 E 4 10 0 40 35 30 ra 8 25 O o20 8 m �15 z� 510 d 5 600 ; 4 cam, a 500 W 400 F' K 300 8 200 .p 100 0 0 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 900,000 1,000,000 Throughput (gal) Figure 4-32. Vessel A Breakthrough Curves from Run Length Study 1 Run Length Study 2 Vessel A ---------------- October 24 to 26, 2007--------------------j---- -------------------------------- ------------ ------ (After Caustic Wash) —As —Nitrate —SO4 —Alkalinity ;----- ; ---_r--------------------- ------- Runlength=445,722ga\1 As MCL =l0µg/L \ . ------ 0 -H 0 400 350 300 250 100 50 - L 0 100,000 200,000 300,000 400,000 500,000 600,000 Throughput, (gal) Figure 4-33. Vessel A Breakthrough Curves from Run Length Study 2 VA7 concentration was 35.7 µg/L in the last sample collected at 565,000 gal. Nitrate concentrations were below 10 mg/L (as N) throughout this run length study. Sulfate concentrations stayed below 1 mg/L until 400,000 gal, and then increased sharply to 23 mg/L at the end of this special study. Total vanadium concentrations were <3 µg/L throughout this run length study (data not shown in the graph). Total alkalinity concentrations started off at 24 mg/L (as CaCO3) at 5,000 gal, increased rapidly to 345 mg/L (as CaCO3) at 300,000 gal, and then leveled off between 335 and 364 mg/L (as CaCO3) thereafter. Run Length Study 3 (December 8 to 10, 2008). Run Length Study 3 was conducted on Vessel A to assess the condition of the resin following nine months of system operation after the October 2007 caustic/brine cleaning. Raw water samples collected at the beginning of the study contained 24.0 µg/L of total arsenic, 53.3 µg/L of total vanadium, and 57.7 mg/L (as SiO2) of silica. As shown in Figure 4-34, the run length to 10-µg/L of arsenic breakthrough was shortened significantly from the previous 445,720 gal to approximately 323,530 gal. The deteriorating performance also was reflected by the total vanadium breakthrough curve, which showed a concentration of 11.3 µg/L at 600,000 gal, compared to <1 µg/L in both Run Length Studies 1 and 2. Silica concentrations stayed constant throughout this special study, ranging from 58.0 to 59.3 mg/L (as SiO2). 80 70 60 50 C N C 40 a� 30 o� 20 tAs (total) Run Length Study 3 VesselA -B-V (total) ----- December 8 to 10, 2008 ------------------------F----------------- --X- Silica - ----------- Run Length = 323,530 gal AsMCL=10 g$- ------------------ 200,000 300,000 400,000 5009000 600,000 Throughput (gal) Figure 4-34. Vessel A Breakthrough Curves from Run Length Study 3 Run Length Study 4 (April 21 to 22, 2009). To establish baseline performance of the dual resins at the beginning of Study Period II, combined effluent samples were collected mostly between 400,000- and 600,000-gal volume throughput. Raw water samples collected on April 22, 2009 at 162,061 gal of water Wei treated contained 23.3 µg/L of total arsenic, 308 µg/L of total phosphorus, 59.4 µg/L of total vanadium, 6.8 mg/L of nitrate (as N), and 2.0 mg/L of TOC (See Appendix D). As shown in Figure 4-35, arsenic breakthrough at 10 µg/L occurred between 403,000 and 450,000 gal and estimated to be 436,350 gal using linear interpolation, which was consistent with the results of weekly sampling discussed in Section 4.5.1.2 (Figure 4-24). Arsenic peaking occurred after 500,000 gal with the highest concentration measured at 30 µg/L. Similarly, total phosphorus began to exceed its influent level around 500,000 gal with the highest concentration measured at 438 µg/L. Total vanadium was removed to <5 µg/L in all but the first sample. Nitrate was below its MCL for the entire study period, reaching its influent concentration by the end of the study. TOC was removed to below the reporting limit of 1 mg/L consistently throughout, suggesting that A850END had worked well as a TOC scavenger. 40 35 P D 30 b a 25 U 20 15 z 10 5 +As (total) Run Length Study 4 Vessel s A and B ---- ---�-NO3-NApril and 22, 2009-i--- --- -6-TOC --E+-V (total) t ------------------- -- - +Total P ---------------------------------------------------- r---------------------------------r------------- ----------------'-------------------------------- Run Length = 436,350-gar\--- - -------------------- As MCL=10µg/t \ w ---------------------------------- 800 700 600 on a 500 a 400 F 300 200 100 100,000 200,000 300,000 400,000 500,000 600,000 Throughput (gal) Figure 4-35. Combined Effluent Breakthrough Curves from Run Length Study 4 Run Length Study 5 (June 29 to July 1, 2009). Resin cleaning was performed one week prior to this run length study. Figures 4-36a and 4-36b show breakthrough curves of arsenic, nitrate, sulfate, total phosphorus, and total vanadium for Vessels A and B, respectively. pH and alkalinity data were plotted for both vessels on Figure 4-37. TOC and silica data were not plotted. As shown in Figure 4-36, effluent from Vessels A and B reached 10-µg/L arsenic breakthrough at approximately 443,000 and 493,000 gal, respectively, or 468,000 gal (on average). Nitrate did not reach the 10 mg/L MCL in either vessel. TOC stayed below the MDL of 1 mg/L throughout the study, indicating good removal by the TOC scavenger. Total phosphorus rose sharply around 400,000 gal for both vessels. Sulfate and total vanadium remained low throughout the study period while silica concentrations in the treated water were similar to the raw water level (i.e., 58.7 mg/L [as Si02D- MA 40 35 PO 30 9 25 O 20 15 z 10 C (a) Run Length Study 5 -*-As (total) �-Nitrate ' VesselA ---- ------ ---------------------------------- June 29 to July 1, 2009 - -SO4 $V (total) ------------------ ;-----------------;----------------- +----- ----------- -40- Total P Run Length = 443,000 gal As MCL =10 µg/L 400 350 300 250 200 A, F° 150 100 50 0 100,000 200,000 300,000 400,000 500,000 600,000 Throughput (gal) 40 400 35 9 30 bD 25 O Z 20 15 z 10 3 5 0 As (total) (b) �Run LegthStudyS '-----------------'--- ------'-------------------------- Nitrate _ Vessel B --G--SO4 June 29 to July 1, 2009 -----------------*---------------------------------- *----------------- ----- --&- V (total) tTotalP Run Length = 493,000 gal AsMCL=10 µg/L 100,000 200,000 300,000 400,000 500,000 Throughput (gal) Figure 4-36. Breakthrough Curves from Run Length Study 5 350 300 250 _ on 200 a 0 H 150 100 50 600,000 VO 9.0 8.5 8.0 x 7.5 a 7.0 6.5 6.0 Run Length Study 5 June 29 to July 1, 2009 ------------ ------------------ -- *----------------- f Vessel A: pH —6—Vessel B: pH --A— Vessel A: Alkalinity Wessel B: Alkalinity 400 350 300 250 200 150 100 50 100,000 200,000 300,000 400,000 500,000 600,000 Throughput (gal) Figure 4-37. pH and Alkalinity Breakthrough Curves from Run Length Study 5 Similar to the re -constructed plot (Figure 4-29) based on weekly samples, decreases in pH values were observed at the beginning of the run length study after the IX system had been freshly regenerated. pH values were at 6.2 at throughput up to 70,000 gal, and increased to 7.1 and 7.0 at 178,360 and 175,240 gal for Vessels A and B, respectively. The decreases in pH corresponded to the decreases in total alkalinity, i.e., from 26.7 mg/L initially to 283 mg/L at 178,360 gal for Vessel A; and from 29 mg/L initially to 216 mg/L at 175,240 gal for Vessel B. Alkalinity for both vessels remained steady at 370 mg/L after 300,000 gal of water treated. 4.5.4 Regeneration Elution Study. The results of the elution study conducted on June 29, 2009 are discussed as follows. Elution Curves. Figure 4-38 presents elution curves of arsenic, nitrate, total phosphorus, alkalinity, sulfate, vanadium, silica, and TOC for Vessels A and B. Figure 4-39 shows similar curves for TDS and pH. All figures have a primary and a secondary y-axis to accommodate all intended analytes on the same graphs. TDS concentration reflects salt concentration in the eluent. As the brine solution entered an IX vessel, arsenic, nitrate, sulfate, TOC, and other analytes of concern on the exhausted resin were displaced into the eluent by highly concentrated chloride ions. The highest concentrations of arsenic, sulfate, and TOC from Vessel A were measured at 6,963 µg/L, 33,560 mg/L, and 327 mg/L, respectively, approximately 11 min into the brine draw step. Nitrate did not peak until 18 min into brine draw at 942 mg/L (as N). Peak concentrations of arsenic, nitrate, sulfate, and TOC from Vessel B occurred between 5 min and 15 min into the brine draw step and were measured at 6,882 µg/L, 900 mg/L (as N), 40,000 mg/L, and 308 mg/L, respectively. Maximum TDS concentrations for each vessel occurred approximately 6 min into the slow rinse step. After 41 min into the 45 min slow rinse step, arsenic and nitrate concentrations decreased to below their respective MCLs while TOC was below its detection limit. Sulfate concentrations fell below its secondary MCL (250 mg/L) at 36 and 28 min into the slow rinse step for Vessels A and B, respectively. TDS concentrations for both vessels exceeded its secondary MCL (500 mg/L) during the entire regeneration cycle. VU Vale, OR Anion Tank A Regeneration 12,000 120,000 Brine Slow i Fast 11,000 Draw Rinse Rinse 1 Q,000 (21 min) , (45 min) i (15 min) 100,009, 9,000 ' I J t..: 8,000 80,000 E 7,000 1 N J Y 6,000 1 60,000 5,000 1 ' I to Z 1 I � J m O z 4,000 ' ' - 40,000Z J , 1 , I Z V 3,000 1 I - \ J rn C 2,000 ~\ 20,000a 1,0 10 I I I 0 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 Time (min) --�As NO3-N o Alkalinity -TOC -e-P --*-V --*--SO4-rSilica -TDS 14,000 , 1 Vale, OR Anion Tank B Regeneration , 120,000 13,000 IE Brine Slow I Fast Draw Rinse ' Rinse 12,000 (21 min) (45 min) (15 min) 100,000 11,000 i rn E ' E U 10,000 m O 80,000 � 9,000 I I � E 8,000 m z I N 0 7,000 60,000 N z ; 6,000 ' J ' E 5,000 ; 40,000 O J , N � 4,000 J N 3,000 v 20,000 2,000 I 1,000 , 0 I 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 Time (min) --A'-AS tV --XNO3-N o Alk -TOC --*-P--W-SO4 +Silica -TDS Figure 4-38. Vessels A and B Elution Curves R Vale, OR Tank A Regeneration 120,000 9.0 Brine Dmw (21 min) Slow Rinse (45 min) FastRinse (15 min) TDS 8.0 100,000 t pH 7.0 80,000 6.0 E 60,000 4.0 n 40,000 3.0 2.0 20,000 1.0 0 0.0 0 10 20 30 40 50 60 70 80 Time (min) Vale, OR Tank B Regeneration 120,000 9.0 Brine Draw 21 min i Slow Rinse (45 min) i Fast Rinse 15 mi 1 i TDS 8.0 100,000 i i i —pH 7.0 80,000 1 i 1 6.0 5.0 _ 60,000 i i 1 x 4.0 a 40,000 i i 3.0 2.0 20,000 i 1.0 I i i 1 0 0.0 0 10 20 30 40 50 60 70 80 Time (min) Figure 4-39. Vessels A and B Elution Curves for TDS and pH 01 As shown on Figure 4-39, starting pH values were approximately neutral, i.e., 7.1 for TA and 7.0 for TB. During brine draw, pH values continued to rise until peaking at 8.4 after 16 min into the slow rinse step for Vessel A and 8.6 after 13 min into the slow rinse step for Vessel B. By the end of the fast rinse, pH values in each vessel had decreased to approximately 6.2. Regeneration Flowrate and Wastewater Volume. As part of the June 29, 2009 elution study, regeneration flowrates were monitored during the regeneration of each vessel. Flowrates for Vessel A were 44 gpm for brine draw, 42 to 44 gpm for slow rinse, and 260 to 261 for fast rinse, compared to the target values of 64, 44, and 260 gpm. Flowrates for Vessel B varied from 40 to 43 for brine draw, 43 to 44 gpm for slow rinse, and 263 to 277 gpm for fast rinse. The average flowrate for brine draw was 43 gpm, which was about 33% lower than the target value of 64 gpm. The lower brine draw flowrate resulted in lower salt usage and lower salt loading as discussed below under "Saturated Brine Usage." The volume of wastewater produced was 6,363 gal by Vessel A and 6,491 gal by Vessel B and 12,900 gal by both vessels. The wastewater produce was discharged to the evaporation pond. Saturated Brine Usage. The amount of 23% saturated brine used was tracked by the brine totalizer. Regeneration Vessels A and B used 338 and 319 gal of saturated brine, respectively, equivalent to 760 and 718 lb of salt, respectively. Salt loadings for Vessels A and B were 7.7 and 7.33 lb/ft3, which were 23% and 27% lower than the target loading of 10 lb/ft3. Mass Recovered During Regeneration. Concentrations of arsenic, nitrate, vanadium, and TOC were measured in composite samples collected at the conclusion of each of the three regeneration steps and the respective volumes of the waste stream were used to calculate the mass of each contaminate recovered from regeneration. The amount of each contaminant removed from influent water was calculated based on concentrations of influent and effluent samples collected prior to the regeneration and a volume throughput of 403,000 gal. Because only one set of influent and effluent samples were collected prior to regeneration, the amounts of contaminants removed from influent water could be erroneous. The percent recovery of arsenic, nitrate, vanadium, and TOC from regeneration was calculated using Equation 3: where: YO` — Mrecovered /Mremoved X 100% (3) %R = percent recovery Mreeoverea = mass of contaminate in regenerant waste (mg or g) Mremoved= mass of contaminate removed from influent water (mg or g) As shown in Table 4-19, the regeneration waste stream contained 17.3 g of arsenic, 4.2 kg of nitrate, 50.1 g of vanadium, and 1.1 kg of TOC per regeneration cycle. The percent recoveries were 112% for arsenic, 131 % for nitrate, 113% for vanadium, and 98.5% for TOC. The majority of arsenic, nitrate, vanadium, and TOC were removed during the brine draw step and the early stage of the slow rinse step. A rather small amount was removed during the fast rinse step. 4.5.5 Regeneration Residual Sampling. During regeneration of Vessels A and B in Study Period I, the operator collected composite samples from the waste stream from each regeneration step on December 20, 2006; January 31, 2007; and March 20, 2007. Composite samples also were collected on June 29, 2009, as part of the elution study on the dual resin system. Table 4-20 summarizes analytical results of the four residual sampling events. As expected, the majority of arsenic and nitrate was eluted during the brine draw step (both reused and fresh brine) for both Arsenex II and PFA300E/A850END. For Arsenex Il, total arsenic concentrations in the reused brine, fresh brine, slow rinse, and fast rinse samples averaged 2,678, 2,221, 527, and 11.3 µg/L, respectively; the corresponding concentrations for ON Table 4-19. Mass Balance Calculations for Total Arsenic, Nitrate, Vanadium, and TOC Parameter Unit Values Volume of Water Treated gal 403,000 Arsenic Mass Balance Vanadium Mass Balance Vessel A B Total A B Total Concentration in Composite Brine Draw Waste µg/L 1,471 2,935 2,203 (a)5,981 4,705 5,343 a Concentration in Composite Slow Rinse Waste µg/L 152 148 150 a 918 829 873 a Concentration in Composite Fast Rinse Waste µg/L 3.0 3.8 3.4 a 12.8 14.6 13.7 a Brine Draw Volume gal 924 882 1,806 924 882 1,806 Slow Rinse Volume gal 1,980 1,980 3,960 1,980 1,980 3,960 Fast Rinse Volume gal 3,900 4,080 7,980 3,900 4,080 7,980 Mass Recovered from Brine Draw Step mg 5,144 9,798 14,941 20,917 15,706 36,623 Mass Recovered from Slow Rinse Step mg 1,140 1,106 2,246 6,876 6,216 13,092 Mass Recovered from Fast Rinse Step mg 43.8 59.0 103 188 225 413 Total Mass Recovered mg 6,328 10,963 17,291 27,981 22,147 50,128 Mass Removed from Influent Water mg 15,482 44,388 Percent Recover % 112% 113% Nitrate Mass Balance TOC Mass Balance Concentration in Composite Brine Draw Waste mg/L 498 401 450 a 83.8 158 121 a Concentration in Composite Slow Rinse Waste mg/L 84.7 51.9 68 a 20.8 18.0 19.4 a Concentration in Composite Fast Rinse Waste mg/L 2.6 2.6 2.6 a <1.0 <1.0 <1.0(a) Brine Draw Volume gal 1,980 1,980 3,960 1,980 1,980 3,960 Slow Rinse Volume gal 3,900 4,080 7,980 3,900 4,080 7,980 Fast Rinse Volume gal 8,279 10,387 18,665 8,279 10,387 18,665 Mass Recovered from Brine Draw Step g 1,742 1,339 3,080 293 527 821 Mass Recovered from Slow Rinse Step g 635 389 1,024 156 135 291 Mass Recovered from Fast Rinse Step g 38.1 39.5 78 7.4 7.7 15 Total Mass Recovered g 2,415 1,767 4,182 456 670 1,126 Mass Removed from Influent Water g 3,203 1,144 Percent Recover % 131% 98.5% (a) Average concentrations from both vessels used for calculations. (b) Calculated using concentrations in raw and treated water. Note: One-half the detection limit used in calculations. PFA300E/A850END were 2,203, 150, and 3.4 pig/L. Similarly, nitrate concentrations averaged 122, 517, 194, and 3.6 mg/L (as N) for Arsenex II and 450, 68, and 2.6 mg/L (as N) for PFA300E/A850END. Comparing the data of spent and fresh brine samples, the TDS of spent brine was 36% of that of fresh brine, indicating dilution of spent brine during the previous regeneration cycle. Therefore, spent brine had a lower strength than fresh brine. Because it was difficult to estimate carryovers of arsenic and nitrate from the previous regeneration cycle, percent recoveries of arsenic and nitrate were not calculated for Arsenex II to assess the regeneration efficiency. Fast rinse samples contained low levels of arsenic, nitrate, sulfate, and TDS, indicating that resin beds had been rinsed thoroughly and were ready to be put online for a service cycle. This also explained why there was little or no arsenic/nitrate leakage at the beginning of a service cycle following regeneration. The lower pH value of the fast rinse water, i.e., ranging from 6.4 to 6.9, was caused by bicarbonate removal by the freshly regenerated resin, which continued through the beginning of the service cycle. 091 Table 4-20. Regeneration Residual Sampling Results Reused Brine Draw Fresh Brine Draw Slow Rinse Fast Rinse Sampling Event h n ° Date Vessel /L mg/L as N m /L m S.U. mg/L (as N) m /L m S.U. mg/L as N mg/L m S.U. L mg/L as N mg/L mg/L S.U. Study Period I 12/20/06 A 43.8(" 26.2(a) 3,800(" 22,800(a) 8.7(a) 3,208 631 13,000 89,900 8.2 942 122 974 20,800 8.4 10.7 3.5 <1 738 6.6 B 32.5(a) 134 19,000 29,800 8.7 2,934 333 6,200 96,400 8.2 688 264 1,900 42,700 8.4 4.9 2.9 2.0 678 6.4 01/31/07 A 2,962 109 14,000 26,800 8.6 1,532 808 9,700 95,500 8.3 447 201 1,600 41,900 8.4 13.7 2.1 43 744 6.5 B 2,393 124 30,000 29,100 8.6 1,775 838 13,000 91,900 8.3 115 47.3 346 10,200 8.4 10.6 3.4 1.0 728 6.5 03/20/07 A (b) (b) m> (b) (b) 1,372 248 23,000 54,100 8.4 404 5.2 3,900 74,100 8.3 15.8 5.4 295 1,000 6.8 B (b) (b) (b) (b) (b) 2,507 245 26,000 55,200 8.4 568 523 2,800 73,300 8.3 12.4 4.1 4.0 1,050 6.9 Average 2,678 122 21,000 28,600 8.6 2,221 517 15,15 1 80,500 1 8.3 527 194 1,920 43,833 8.3 11.3 3.6 69.0 823 6.6 Stud Period II 06/29/09 A Not Applicable 1,471 498 7,080 59,165 7.6 152 84.7 710 34,800 7.8 3.0 2.6 1.2 753 6.4 B Not Applicable 2,935 401 14,000 70,500 7.7 148 51.9 671 25,900 8.0 3.8 2.6 8.9 760 6.3 Average Not Applicable 2,203 450 10,540 64,833 7.7 150 68 691 30,350 7.9 3.4 2.6 5.1 757 6.4 (a) Data not included in calculating averages. (b) Data not presented due to abnormal results. 4.5.6 Analysis of Evaporation Pond Water. Table 4-21 presents analytical results of the pond water samples. With a pH of 9.3 to 9.8, the pond water contained 4,560 mg/L of total alkalinity, 16 to 25.6 g/L of chloride, 13 to 30.2 g/L of sodium, and 38.2 to 60.1 g/L of TDS, indicating a highly alkaline and saline water. The pond water also contained as high as 1.3 mg/L of total arsenic, 7.3 g/L of sulfate, 9.2 mg/L (as N) of nitrate, 13.3 mg/L of total phosphorus (as P), and 4.1 mg/L of vanadium. Table 4-21. Analytical Data for Pond Water at Vale, OR Sample Pond Water Parameter Unit 07/16/07 09/17/07 03/15/08'al 02/09/09 04/09/091" pH S.U. NA NA NA 9.8 9.3-9.7 Total Alkalinity mg/L NA NA NA 4,560 NA Sulfate (as SO4) mg/L 7,380 NA NA 7,300 NA Nitrate (as N) mg/L NA NA 4.1 9.2 NA Total P (as P) mg/L NA NA NA NA 13.3 Phosphate (as PO4) mg/L 37.3 58.4 NA 44.1 NA Silica (Si02) µg/L 34.6 18.8 NA 60.7 NA Chloride mg/L 16,000 NA 25,600 22,300 NA Turbidity NTU NA NA NA 65.0 NA TDS mg/L 38,200 NA NA 60,100 NA TSS mg/L NA NA NA 122 NA As (total) µg/L 1,070 1,330 788 1,234 1,315 As (soluble) µg/L NA 1,320 NA 1,226 NA Fe (total) µg/L 574 <1,500 NA 523 271 Fe (soluble) µg/L NA NA NA 567 NA Mn (total) µg/L NA NA NA NA 14.1 Mn (soluble) µg/L NA NA NA NA NA V (total) µg/L 3,730 4,100 NA 1,477 1,405 V (soluble) µg/L NA 4,070 NA 1,309 NA Na (total) mg/L 16,550 15,410 13,000 16,032 30,167 Na (soluble) mg/L NA 15,712 NA 15,575 NA (a) Data provided by City of Vale. (b) Samples collected on 02/09/09 re -analyzed on 04/09/09. NA = not available Based on results of the regeneration residual sampling in Table 4-20 and the volume of the waste stream produced by each regeneration step, the average arsenic concentration in the waste stream was estimated to be 834 µg/L. Although evaporation of the pond water could concentrate the contaminants in the pond, the high arsenic concentrations measured in the pond water suggested that the FeC13 treatment was not effective in treating arsenic, due presumably to the presence of high TDS in the pond water. As described in Section 4.2.2, 0.25 gal of a 40% ferric chloride solution was fed to the waste stream in a batch mode for 15 min during each vessel regeneration. The iron dosage was calculated to be 6.6 mg/L (as Fe) assuming 7,250 gal of wastewater would be produced during regeneration of each vessel. Based on the average arsenic concentration of 834 µg/L in the waste stream, the mass ratio of Fe to As was approximately 8:1, which was significantly lower than the generally recommended 20:1 ratio for effective arsenic removal in drinking water treatment. A series of jar tests were performed in Battelle's Treatability Laboratory on the pond water containing 1,315 µg/L of total arsenic. Iron dosages were 20, 60, 80, 120, 320, 800, and 1,600 mg/L (as Fe), rM corresponding to Fe to As mass ratios of 15:1 to 1,216:1 at a pH value of 6.9 to 7.2. Analytical results showed that final arsenic concentrations in the supernatant ranged from 106 to 904 µg/L and generally decreased with increasing iron dosages, as shown in Figure 4-40. However, the concentration reduction leveled off after the first 320 mg/L of iron addition. Even with the 320 mg/L of iron addition, arsenic in supernatant remained high at 200 µg/L, indicating ineffective treatment by FeC13. In contrast, the spent regenerant from an AM system containing up to 200 mg/L of arsenic (but no salt) was effectively treated to below 10 µg/L with FeC13 at a mere 30:1 Fe/As mass ratio under a neutral pH condition. As shown in Figure 4-40, total phosphorus and total vanadium also were removed, suggesting that these anions might compete with arsenic and exert a negative effect on arsenic removal. It was believed that the high salt contents along with the presence of competing anions rendered the FeC13 treatment of the pond water ineffective. Figure 4-40. Results of Vale Pond Water Jar Tests 4.5.7 Distribution System Water Sampling. Table 4-22 summarizes results of the distribution system sampling. Prior to system startup, four monthly baseline distribution water samples were collected from June through September 2005 at three locations within the distribution system. These three locations included two LCR residences and one non -residence. Following system startup, distribution system sampling continued on a monthly basis at the same locations until April 2007. No distribution water samples were collected during Study Period II. All stagnation time for the first draw samples met the minimum 6 hr requirement, except for one occasion at DS2 on August 23, 2005 (4.8 hr). M Table 4-22. Distribution System Sampling Results in Study Period I at Vale, OR Location DSl DS2 DS3 Address 629 15th St North 780 15th Street North 252 B Street West Sample Type LCR LCR Non -Residence Flushed/Is t Draw 1st Draw lst Draw 1st Draw d E d d E m = s m E Sampling a a No. Date g y Q w i a U v c d a U a d w a U BLl 06/15/05 8.5 7.4 484 21.4 <25 0.2 1.1 337 9.3 7.3 484 20.7 <25 1.4 1.4 154 7.2 7.3 431 22.4 <25 0.7 1.7 381 BL2 07/13/05 6.6 7.5 308 17.5 <25 0.9 1.2 194 7.4 7.4 308 16.2 <25 0.1 1.9 390 9.8 7.5 308 16.1 <25 0.8 0.7 96.1 BL3 08/23/05 7.5 7.4 308 25.6 <25 0.6 0.2 83.7 4.8 7.4 308 26.2 <25 0.1 0.3 341 14.5 7.3 308 24.9 <25 0.6 0.5 85.8 BL4 09/21/05 7.0 7.6 299 14.7 <25 0.6 1.0 210 6.2 7.5 308 14.0 <25 0.2 2.2 492 15.3 7.6 308 14.7 <25 0.7 1.8 106 1 10/10/06 6.5 7.6 280 9.7 <25 <0.1 0.5 156 7.6 7.6 288 11.1 <25 0.4 1.6 501 11.1 7.5 291 9.8 193 12.8 2.5 75.3 2 11/14/06 14.8 7.5 325 10.3 <25 <0.1 12.9 248 7.9 7.4 347 9.7 <25 0.2 2.8 891 14.9 7.4 296 7.1 34 13.7 5.1 66.9 3 12/05/06 15.0 7.5 321 11.8 <25 <0.1 21.9 277 7.3 7.5 1 323 10.6 <25 <0.1 0.9 223 12.0 7.4 323 12.4 <25 0.4 0.2 84.4 4 01/10/07 15.3 7.7 334 10.6 <25 <0.1 2.6 53.9 7.3 7.7 338 10.4 <25 0.1 0.5 134 1 14.0 7.6 326 9.7 <25 1.0 0.3 141 5 02/08/07 14.8 7.7 327 11.7 <25 0.1 7.6 157 7.3 7.7 335 14.2 <25 1.0 0.6 234 1 NA 7.6 318 10.9 <25 1.3 0.4 100 6 03/07/07'"" 14.8 7.8 329 18.0) 1 <25 <0.1 4.7 149 6.7 1 7.6 342 24.0"' <25 <0.1 1.0 381 15.0 7.7 327 16.9"' <25 1.1 0.4 141 7 1 04/10/07 15.0 1 7.7 344 17.0 1 <25 <0.1 8.3 100 7.5 1 7.6 334 16.5 <25 0.3 0.8 479 14.5 7.6 365 12.8 <25 1.6 0.3 108 BL = baseline sampling.; Lead action level = 15 µg/L; copper action level = 1.3 mg/L µg/L as unit for all analytes except for pH and alkalinity (mg/L [as CaC031). (a) System not functioning properly due to inadvertent switching to counter -current regeneration. Because treated water from the IX plant was stored in the 200,000-gal reservoir before supplying the distribution system, the water quality of the distribution samples would reflect the general quality of the plant effluent after being blended in the reservoir. Arsenic concentrations of the four baseline sampling events were comparable among all three locations, ranging from 14.0 to 26.2 µg/L and averaged 19.5 µg/L. After system startup, arsenic concentrations at all three locations ranged from 7.1 to 24.0 µg/L and averaging 12.6 µg/L. Arsenic concentrations were reduced significantly, but not to the low level (i.e., < 5 µg/L) that would be expected from an IX treatment plant because the IX system was allowed to operate beyond 10 µg/L. In five of seven sampling events, arsenic concentrations in distribution water were close to or slightly higher than the MCL of 10 µg/L. For the sampling event on March 7, 2007, the arsenic concentration in distribution water increased to as high as 24.0 µg/L, corresponding to the high levels in the plant effluent on March 5, 12, and 19, 2007, caused by the inadvertent switching to counter -current regeneration. For the sampling event on April 10, 2007, arsenic concentrations were 17.0, 16.5, and 12.8 µg/L at the DSI, DS2, and DS3 locations, respectively, significantly higher than the 1.6 µg/L in the plant effluent. Examination of the sampling logs revealed that plant effluent samples were collected in the middle of the day after the system had just been regenerated while distribution "first draw" samples were collected early in the morning when the reservoir was filled with water containing high levels of arsenic before regeneration. There was no obvious change to the pH value before and after system startup: the values ranged from 7.3 to 7.6 and averaged 7.5 before startup and ranged from 7.4 to 7.8 and averaged 7.6 after system startup. Alkalinity also stayed essentially the same, with concentrations ranging from 299 to 484 mg/L (as CaCO3) before startup and from 280 to 365 mg/L (as CaCO3) after startup. Although occasionally, some low pH and low alkalinity were measured in treated water samples collected from freshly regenerated vessels (see Section 4.5.2), the blending effect in the reservoir had mitigated any potential pH or alkalinity swing. Therefore, low pH and low alkalinity were never measured in distribution system water samples. Lead levels at DS2 and DS3 were similar to those in baseline samples. The average concentrations were 1.4 µg/L at DS2 and 1.2 µg/L at DS3 before system startup; and were 1.2 µg/L at DS2 and 1.3 µg/L at DS3 after system startup. Lead level at DS1, however, increased after system startup to an average of 8.3 µg/L, compared to 1.2 µg/L in baseline samples. On December 5, 2006, lead concentrations at DSI reached 21.9 µg/L, exceeding the action level of 15 µg/L. The reason for the elevated lead concentrations at DSI is unknown since the pH and alkalinity appeared normal. Baseline copper concentrations varied from 83.7 to 492 µg/L and averaged 239 µg/L. After system startup, copper concentrations decreased slightly to an average of 224 µg/L, with no samples exceeding the 1,300 µg/L action level. Total iron concentrations in all samples were <25 µg/L and total manganese <2 µg/L, as expected, except for two occasions at DS3 on October 10 and November 14, 2006 when total iron concentrations were measured at 193 and 34 µg/L, respectively, and total manganese concentrations measured at 12.8 and 13.7 µg/L, respectively. 4.6 System Cost The cost of the IX system was evaluated based on the capital cost per gpm (or gpd) of design capacity and the O&M cost per 1,000 gal of water treated. This required tracking of the capital cost for the treatment equipment, site engineering, and installation and the O&M cost for salt supply, electricity consumption, and labor. The cost associated with the design and construction of the evaporation pond, the new building, and FeC13 addition system was not included in the capital cost because it was out of the scope of the demonstration project, and was funded separately by the City of Vale. Information on the construction cost is included in Section 4.3.2 at the courtesy of the City of Vale. RK 4.6.1 Capital Cost. The capital investment for the Vale IX system was $395,434, which included $260,194 for equipment, $49,840 for site engineering, and $85,400 for installation. Table 4-23 presents breakdowns of the capital cost provided by Kinetico. The equipment cost included the cost for the IX resin, filter skid, vessels, brine system, pre -filters, air compressor, instrumentation and controls, shipping, and labor. The equipment cost was 66% of the total capital investment. Table 4-23. Cost Breakdowns of Capital Investment for Vale IX System Description Quantity Cost % of Capital Investment Cost E ui went Cost Welded Stainless Steel Frame 1 $8,030 — Fiberglass IX Vessels 2 $16,134 — Distributors 2 $2,718 — Arsenex II Resin 220 ft $64,400 — Brine System — $43,784 — Process Valves and Piping — $24,868 — Air Compressor — $1,500 — Pre-treatment Filters — $8,800 — Instrumentation & Controls — $13,090 — Initial Salt 22 Tons $5,808 — Sample Taps and Totalizer/meters — $1,728 — Shipping — $17,000 — Labor — $52,334 — Equipment Total — $260,194 66% En eering Cost Vendor Labor — $42,840 — Subcontractor Labor — $7,000 — Engineering Total — $49,840 12% Installation Cost Vendor Labor — $15,400 — Subcontractor Labor — $65,750 — Travel — $4,250 — Installation Total — $85,400 22% Total Capital Investment $395,434 100% The site engineering cost included the cost for preparing a process design report and the required engineering plans and obtaining the required permit approval from Oregon DHS DWP. The engineering plans included a general arrangement drawing, piping and instrumentation diagrams (P&IDs), inter- connecting piping layouts, vessel fill details, a schematic of the PLC panel, an electrical on-line diagram, and other associated drawings. The engineering cost of $49,840 was 12% of the total capital investment. The installation cost included the cost for travel and labor to perform system unloading and anchoring, plumbing, mechanical and electrical connections, resin loading, system shakedown and startup, and operator's training. The installation cost was 22% of the total capital investment. The total capital cost of $395,434 was normalized to the system's rated capacity of 540 gpm (777,600 gpd), which resulted in $732 per gpm ($0.51 per gpd). The capital cost also was converted to an annualized cost of $37,325/yr using a capital recovery factor of 0.09439 based on a 7% interest rate and a 20-year return. Assuming that the system operates 24 hr/day, 7 day/wk at the design flowrate of 540 gpm :' to produce 283.8 million gal of water per year, the unit capital cost would be $0.13/1,000 gal. In reality, the system operated an average of 9.5 hr/day at 534 gpm (in Study Period I, see Table 4-10), producing 111.1 million gal of water per year. At this reduced rate of operation, the unit capital cost increased to $0.34/1,000 gal. 4.6.2 Operation and Maintenance Cost. The O&M cost included primarily the cost associated with salt supply, electricity consumption, and labor, as summarized in Table 4-24. Salt supply was a major operating cost. Coarse solar salt manufactured at the North American Salt's Ogden, Utah facility, was used for the resin regeneration. This salt is NSF -certified for drinking water treatment. Over the first year of demonstration study, a total of 397,100 lb of salt was consumed. The salt delivery charge totaled $30,180 for the same period. Based on an annual water production of 111.1 million gal, the average salt use was 3.6 lb/1,000 gal, corresponding to a salt cost of $0.27/1,000 gal. This salt cost was almost 50% lower than that ($0.49/1,000 gal) at Fruitland, ID. The lower salt use rate and the cheaper salt unit price are the two factors contributing to the lower salt cost at Vale. The average salt use rate was 3.6 lb/1,000 gal at Vale vs 4.4 lb/1,000 gal at Fruitland (due to an improper flow control of brine draw at Fruitland). The unit salt price was $0.076/lb at Vale vs $0.11/lb at Fruitland because Vale purchased salt in bulk quantities (i.e., half a truck load for two 11-ton saturators), which was cheaper than smaller quantities. If more storage capacity is added to allow delivery of a full truck load, then the overall salt cost can be further reduced. In addition, the Vale IX system adopted a caustic cleaning procedure every four months to prevent resin fouling. Each cleaning consumed two 55-gal drums of caustic soda (each 700 lb), which cost $882. Based on three cleanings in a year, the cost of the caustic soda is $2,646 or $0.02/1,000 gal. Therefore, the sum of salt and caustic cost is $0.29/1,000 gal. Table 4-24. O&M Cost for Vale, OR Treatment System Cost Category Value I Assumptions Volume Processed (1000 gal/year) 111,100 Based on 9.5 hr/day and 534 gpm flowrate Salt Usage Salt Unit Price ($/lb) 0.076 — Total Salt Usage (lb/year) 397,100 Quantity delivered Salt Use (lb/1,000 gal) 3.6 — Total Salt cost ($/year) 30,180 — Unit Salt Use Cost ($/1,000 gal) 0.27 — Caustic Soda Unit Price ($/lb) 0.63 Delivery charge included Total Caustic Usage (lb/year) 4,200 Three cleanings, each using 1,400 lb of caustic Total Caustic cost ($/year) 2,646 — Unit Caustic Cost ($/1,000 gal) 0.02 — Sum of Salt and Caustic Cost ($/1,000 gal) 0.29 — Electricity Consumption Power Use ($/1,000 gal) 0.028 Monthly electric bill increased by $250 Labor Average Weekly Labor (hr/wk) 3.33 40 min/day; 5 day/wk Total Labor Hours (hr/year) 173.33 52 week a year Total Labor Cost ($/year) 3,640 Labor rate = $21/hr Labor Cost ($/1,000 gal) 0.034 — Total O&M Cost/1,000 gal 0.35 — Incremental electricity consumption associated with the IX system was estimated based on the monthly electricity bill before and after the system startup. For example, the electricity bill at the treatment plant 90 was approximately $850 a month in 2006 and increased by 29% to $1,100 a month in 2007. Thus, the annual increase was $3,000, or $0.028/1,000 gal. The routine, non -demonstration related labor activities consumed about 40 min/day, five days a week. Based on this time commitment and a labor rate of $21/hr, the annual labor cost was $3,640, or $0.034/1,000 gal. In sum, the total O&M cost was approximately $0.35/1,000 gal. 91 5.0 REFERENCES Battelle. 2004. Revised Quality Assurance Project Plan for Evaluation of Arsenic Removal Technology. Prepared under Contract No. 68-C-00-185, Task Order No. 0029, for U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH. Battelle. 2006. Study Plan for Evaluation of Arsenic Removal Technology at Yale, OR. Prepared under Contract No. 68-C-00-185, Task Order No. 0029, for U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH. Boodoo, F. 2004. "Multi -Contaminant Control with Ion Exchange." Water Technology Magazine, 5(27). Boodoo, F., G. Schreiber, T. Satchell, L. Benton, B. Szczesny, E. Woo, D. Mielke. 2008. "Simultaneous Ion Exchange Removal of Arsenic, Nitrate, Uranium, and TOC at City of McCook, NE." AWWA Inorganic Contaminants Workshop, Albuquerque, NM. Chen, A.S.C., L. Wang, J.L. Oxenham, and W.E. Condit. 2004. Capital Costs of Arsenic Removal Technologies: U.S. EPA Arsenic Removal Technology Demonstration Program Round 1. EPA/600/R-04/201. U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH. Clifford, D.A. 1999. "Ion Exchange and Inorganic Adsorption." Chapter 9 in R. Letterman (ed.), Water Quality and Treatment Fifth Edition. McGraw Hill, Inc., New York, NY. Clifford, D.A., C.C. Lin, L.L. Horng, and J.V. Boegel. 1987. Nitrate Removal from Drinking Water in Glendale, Arizona. EPA/600/52-86/107, U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH. Clifford, D.A, G. Ghurye, and A.R. Tripp. 2003. "Arsenic Removal from Drinking Water Using Ion - Exchange with Spent Brine Recycling." JAWWA, 95(6): 119-130. Edwards, M., S. Patel, L. McNeill, H. Chen, M. Frey, A.D. Eaton, R.C. Antweiler, and H.E. Taylor. 1998. "Considerations in As Analysis and Speciation." JAWWA, 90(3): 103-113. Ghurye, G.L., D.A. Clifford, and A.R. Tripp. 1999. "Combined Arsenic and Nitrate Removal by Ion Exchange." JAWWA, 91(10): 85-96. Kinetico, 2006. Operation and Maintenance Manual, IX-263-As/NArsenic/Nitrate Removal System, Kinetico. EPA. 2001. National Primary Drinking Water Regulations: Arsenic and Clarifications to Compliance and New Source Contaminants Monitoring. Federal Register, 40 CFR Parts 9, 141, and 142. EPA. 2002. Lead and Copper Monitoring and Reporting Guidance for Public Water Systems. EPA/816/R-02/009. U.S. Environmental Protection Agency, Office of Water, Washington, D.C. EPA. 2003. Minor Clarification of the National Primary Drinking Water Regulation for Arsenic. Federal Register, 40 CFR Part 141. 92 Wang, L., W.E. Condit, and A.S.C. Chen. 2004. Technology Selection and System Design: U.S. EPA Arsenic Removal Technology Demonstration Program Round 1. EPA/600/R-05/001. U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH. Wang, L., A.S.C. Chen, T.J. Sorg, and K.A. Fields. 2002. "Field Evaluation of As Removal by IX and AA". JAWWA, 94(4):161-173. Wang, L., and A.S.C. Chen. 2010. U.S. EPA Arsenic/Nitrate Removal Technology Demonstration at Fruitland, ID. EPA/600/R-10/152. U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH. 93 APPENDIX A Vale Arsenic System IX Resin Cleaning Procedure Original (Revision 2) provided by Kinetico on September 21, 2007 Revision 3 provided by Battelle in June 2009 Revision 4 provided by Battelle in February 2010 Step 1: Add sodium hydroxide (NaOH) to brine day tank a. Make sure that brine day tank level is between low and low -low float so that there is enough room for adding NaOH. b. Using a drum pump to add two 55-gal drums of 50% NaOH to the day tank. Be sure to add all 110 gal of NaOH to the tank. To assist in mixing, turn on brine refill valve and pump while NaOH is being added. Slow down brine refill as needed to ensure that all NaOH is used. c. After brine day tank is full, close brine refill valve and turn off brine transfer pump. Step 2: Verify flow configuration a. Verify that valves and the PLC are set to co -current regeneration (valve #HV9 is open and valve #HV 10 is closed). Step 3: Update/change slow rinse setpoint a. Change slow rinse time from 45 to 75 min using touch screen. The extra 30 min is provided for resin soak in Step 5. Go to setpoint screen, touch the box next to slow rinse time, type in 75, and press enter key. Step 4: Begin cleaning Vessel (A or B) a. Start a regeneration using pushbutton for the selected vessel Step 5: Soak resin bed a. When brine draw on the selected vessel is finished (21 min), manually close valve #HV9. b. Using slow rinse timer on the screen as the clock, allow resin to soak in caustic/brine solution for 30 min. Step 6: Rinse resin bed a. After 30 min have elapsed, 45 min will be showing on slow rinse timer, manually open valve #HV9 to allow slow rinse and fast rinse to proceed automatically. Step 7: Repeat for other vessel a. When the selected vessel regeneration is finished, repeat steps 4 to 6 for the other vessel. Step 8: Reset slow rinse setpoint a. When both vessels have been regenerated, change slow rinse time back to 45 min. Using touch screen to go to setpoint screen and touch box next to slow rinse time. Another box will appear, type in 45 and press enter key. Step 9: Check brine draw setpoint, (fresh brine only, no brine recycle) a. While in setpoint screen, make sure that second (fresh) brine draw time is set at 21 min. This will provide approximately 500 gal of fresh brine during regeneration. Step 10: Reset total volume setpoint I_VI a. Go to filter setpoint screen, press box next to total volume regen button and type in desired setpoint (e.g., 600,000 gal) and press enter key. Step 11: Perform back to back regeneration a. Repeat regeneration using pushbutton for each vessel; let both vessels regenerate automatically. Step 12: Return system to service. Step 13: Continue sampling a. Sample effluent for arsenic and nitrate from each vessel during first 30,000 to 80,000 gal and again at 400,000 to 480,000 gal. APPENDIX B Vale, OR Project Chronology VALE, OR PROJECT CHRONOLOGY • 09/19/06: Study data collection begun. • 09/19/06 — 09/22/06: Run length special study showed significantly lower than designed run length to As 10-µg/L breakthrough at 600,000 gal and higher than designed salt usage during regeneration events. • 09/27/06: Punch list items issued to Kinetico for resolution. • 02/21/07: Meeting with Kinetico and EPA at Battelle to discuss performance issues and punch list items. • 02/28/07 — 03/07/07: Kinetico was onsite to collect ion exchange resin samples for Purolite's analysis, install a fresh brine pump in place of the eductor system, and address punch list items. Ion exchange system was unexpectedly changed to counter -current mode by technician (not planned). • 03/09/07: Kinetico indicated no record of vessel fill with polymer beads, which was required for counter -current mode and agreed to change back to co -current mode. Action items resolved were fresh brine pump installation and fresh brine totalizer replacement. • 03/12/07: System was returned to co -current operation and continued to exhibit short run lengths to 10 µg/L breakthrough after this visit even though design salt loading had been achieved. • 04/16/07: Regular weekly sampling was discontinued until performance issues resolved. Battelle requested reduced regeneration frequency from 600,000 gal to 370,000 gal on April 16, 2007 to maintain ion exchange performance to below 10 µg/L MCL. • 05/18/07: Kinetico and Purolite discussed that tests on Vale and Fruitland resin indicated organic matter buildup on the IX resin, which might have affected the IX resin performance. Kinetico and Purolite tested a caustic/brine cleaning procedure in the laboratory and recommended implementing the procedure in the field at Fruitland and then at Vale. • 06/19/07: Fruitland caustic wash was conducted, Vale operators invited to attend for observation purposes, decision was made to wait on results of Fruitland wash before moving forward at Vale. • 07/10/07: Operator replaced fresh brine pump that failed. • 07/16/07: Limited weekly sampling (at TT location only) resumed at Vale per EPA request. • 10/22/07: Caustic wash was performed at Vale by Kinetico, post -caustic wash resin samples were collected, and reused brine was turned off • 10/24/07 to 10/26/07: Post -caustic wash run length special study was conducted immediately on first run after caustic wash. Run length at 445,722 gal. • 12/10/07: PLC updates were made to allow for reused brine regeneration to be turned off. • 12/14/07: Post -caustic wash resin sample results were received from Purolite. • 01/14/08: Ion exchange system was shut down for well rehabilitation and weekly limited sampling efforts were discontinued. • 02/14/08: After reviewing Purolite's resin analyses and run length study results, Kinetico recommended further caustic washing to reduce fouling of the IX resin and suggested that the reused brine system components be used for a periodic, manual cleaning cycle. I • 04/11/08: Battelle held a conference call with Kinetico and requested that it look into alternate IX resin selection (including TOC scavenging resin) and the feasibility of converting the system to adsorption and/or coagulation filtration. • 04/22/08: The City of Vale initiated pumping from lagoon after one-time approval from the State of Oregon to pump the wastewater in the lagoon to the airport grounds in order to lower the water level in the pond. • 05/01/08: The City of Vale informed Battelle that the treatment system would be restarted on May 1, 2008 at the 600,000-gal regeneration interval. • 05/07/08: Kinetico responded that they would not be able to provide services to reconfigure the treatment system to another process per EPA request and that they were willing to provide a credit in lieu of one more trip to the site for a caustic wash. • 05/09/08: Battelle contacted Purolite to provide a run length simulation for the Purolite resin A850 suggested by Dennis Clifford of University of Houston. • 05/15/08: Francis Boodoo of Purolite responded with an alternate suggestion for replacing the resin bed with new PFA300E and a top protective layer of a special grading of A850 known as A850END. • 06/04/08: Battelle received a revised run length simulation and cost quote from Purolite for its proposed new resin design configuration of $50,000 including 95 ft3 of PFA300E (for arsenic/nitrate removal) and 15 ft3 of A850End (for TOC scavenging) in one vessel. The estimated run length was equivalent to 639,000 gal (523 BV adjusted based on 163.3 fe of A300E resin). • 07/15/08: Battelle held a meeting with EPA, Kinetico, and the City in Columbus, OH to discuss next steps for the project and to troubleshoot IX treatment system performance. Dennis Clifford and Glen Latimer were in attendance to provide consultation support. • 07/23/08: The city collected additional source water samples on July 23, 2008, from the combined inlet and each of the individual seven wells for analysis of key parameters. These results were later provided to Purolite to update the IX simulation. • 08/15/08: Battelle visited Vale and worked with the operator to view the inside of the IX vessels and collect IX resin samples and spent filter samples. Battelle also observed a regeneration cycle and recorded salt usage parameters. • 08/25/08: Battelle visited McCook to collect IX resin samples from the dual resin vessels and perform an elution study on both service and regeneration cycles for arsenic, nitrate, and more. • 11/07/08: Purolite provided a quote for the new IX resin resins on November 7, 2008 and Battelle coordinated with Purolite to set up the purchase order. • 11/19/08: TraceDetect installed the ArsenicGuard system. • 11/19/08: Purolite reported that the Vale IX resin samples had moderate fouling by silica with Vessel A at 1,375 ppm SiO2 and Vessel B at 2,500 ppm SiO2. • 11/20/08: A Purolite local rep, Steve Soldatek, visited Vale on November 20, 2008, to inspect the system and investigate optimizing salt usage and wastewater regeneration. However, Steve Soldatek indicated that he did not have a chance to run any elution tests because the city was having some issues with the wellhead pumps. • 12/08/08: A special run length study was performed on the fouled IX resin from December 8 to 10, 2008. The results of this study indicated that 10-µg/L arsenic breakthrough continued to occur at a relatively low bed volume (323,531 gal), which is 27% lower than the post -caustic wash run length of 445,722 gal in October 2007. The operator continued to operate the treatment system through 600,000 gal due to wastewater generation issues. 0 02/19/08: Purolite shipped A300E and A850END IX resins to Vale, which arrived on December 26, 2008. • 01/14/09: Purolite issued an updated run length simulation for the dual IX resin beds based on the water quality samples collected in July 2008. The simulation results were comparable to the simulation results provided based on previous water quality samples in June 2008. Purolite run length estimate was 738,000 gal (604 BV adjusted based on 163.3 W of A300E resin). • 02/10/09 to 02/13/09: Tom Jadach of Accurate Water Solutions was onsite to remove original IX resin, load new resins, and restart the system. Tom Jadach reported lower -than -designed IX resin volumes. • 02/13/09 to 03/02/09: Monitored effluent arsenic levels via ArsenicGuard system. • 03/2/09 to 03/4/09: Battelle was onsite to conduct an elution study and a run length study. Due to an incident that occurred during the salt loading, the studies were compromised and had to be postponed until later. • 03/25/09: Weekly sampling resumed. • 04/21/09: The run length study was conducted by the operator starting on this date. • 04/23/09: The operator informed Battelle that the City was switching salt suppliers from Handy Wholesale to Western Step Savers. • 06/24/09: One week prior to a scheduled visit by Battelle, the operator performed a caustic wash on the dual IX resin beds. • 06/28/09 to 06/30/09: Battelle was onsite to conduct the elution and run length studies originally scheduled for March 2009. • 07/13/09: Eight drums of A300E (including two off-color drums) were picked -up by Smith's Pack & Ship to be returned to Pulrolite's warehouse in Santa Fe Springs, CA, for refund. • 07/21/09: Drums arrived at Purolite warehouse in Santa Fe Springs, CA • 08/12/09: Battelle received notification from Steve Soldatek that the refund payment for the returned resin would be issued that week. • 10/16/09: The operator performed a caustic wash on the dual IX resin beds. • 12/22/09: The operator informed Battelle that the treatment system was bypassed because of a faulty flow sensor. The operator was in contact with Tom Jadach of Accurate Water Solutions to place an order for the new sensor. 0 01115110: The operator replaced the main flow sensor and put the system back online. APPENDIX C OPERATIONAL DATA n US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period I) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Boaster Pump Pressure T4 System Inlet Pressure Tl Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Regen BV Treated Since Last Regen. Regen. Counter(Per Regen Water Totalizer Event Fresh Brine Day Tank Totalizer Reused Brine Day Tank Totalizer Unit hr hr/day k al gpd Psig Psigsi sig Psig 911m gal RV gal gal gal 09/18/06 NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR NR 09/19/06 NR NRN5662 NR NR NR NR NR NR NR NR NR NR NR NR NR 1 09/20/06 NR NRNR NR NR NR NR NR NR NR NR NR NR NR NR 09/21/06 NR NRNR NR NR NR NR NR NR NR NR NR NR NR NR 09/22/06 NR NRNR NR NR NR NR NR NR NR NR NR NR NR NR 09/25/06 NR NRNR NR NR NR NR NR NR NR NR NR NR NR NR 09/26/06 NR NRNR NR NR NR NR NR NR NR NR NR NR NR NR 09/27/06 1,467 NRNR 53 52 43 42 14.0 NR NR NR 1 14,056 54,229 86,084 09/28/06 1,476 7.3NR NR NR NR NR NR 551 72,934 52.4 2. 14,042 55,018 87,617 10/02/06 1,519 11.1NR 60 53 40 38 10.0 563 14,150 10.2 3 400,672 56,800 89,000 10/04/06 1,540 9.9NR 60 53 40 40 10.0 560 86,162 61.9 4 14,025 58,000 90,500 l 10/05/06 1,550 11.3NR 60 53 40 40 10.0 555 379,886 273.0 4 14,025 NR NR 10/06/06 1,560 9.9NR 10 10 NR NR NR NR 23,593 17.0 5 14,023 59,300 92,000 10/09/06 1,585 8.6NR 60 53 40 40 10.0 560 132,197 95.0 6 14,139 60,600 93,600 10/10/06 1,599 13.4NR 60 53 42 42 10.0 542 551,907 396.7 6 14,139 NR NR 4 10/11/06 1,607 8.5 NR NR NR NR NR NR NR NR 158,533 113.9 7 14,013 61,924 95,148 10/12/06 1,615 7.6 NR NR NR NR NR NR NR NR 371,711 267.2 7 14,013 NR NR 10/13/06 1,628 1 13.0 NR NR NR NR NR NR NR NR 135,259 97.2 8 1 14,003 63,200 96,680 10/16/06 1,655 8.9 NR NR 60 53 42 1 42 14.0 554 303,084 217.8 9 12,529 63,733 97,165 10/17/06 1,661 5.9 NR NR 60 53 42 42 14.0 561 480,521 345.4 9 12,529 63,733 97,165 5 10/18/06 1,671 10.6 NR NR 60 53 42 42 14.0 550 125,750 90.4 10 12,475 64,235 97,165 10/20/06 1,675 2.1 NR NR 60 53 42 41 11.5 550 254,901 183.2 10 12,475 64,235 97,165 10/23/06 1,704 10.0 NR NR 60 53 40 40 12.0 547 181,240 130.3 12 12,620 64,918 99,300 10/25/06 1,723 8.3 450 NR 60 53 40 40 12.0 547 110,143 79.2 13 12,605 65,238 100,310 6 10/26/06 1,731 8.7 721 292,315 60 53 40 40 12.0 561 352,840 253.6 13 NR NR NR 10/27/06 1,739 7.8 1,063 349,277 60 53 42 42 12.0 527 581,176 417.7 13 12,605 65,250 100,310 10/30/06 1,768 9.5 1,789 234,667 60 53 40 39 11.5 560 112,126 80.6 15 1 66 71,265 102,390 11/01/06 1,783 8.1 NR NR NR NR NR NR NR NR 546,698 392.9 15 66 71,265 102,390 7 11/02/06 1,792 8.6 2,520 NR 60 53 42 41 12.0 555 169,900 122.1 16 78 71,590 103,441 11/03/06 1,803 11.8 2,904 384,000 60 53 41 40 12.0 550 525,750 377.9 16 78 71,590 103,441 11/06/06 1,822 6.3 3,478 193,121 60 52 40 39 11.5 550 443,420 318.7 17 12,546 71,912 104,482 11/07/06 1,831 8.8 3,734 256,000 60 52 40 39 11.5 552 63,142 45.4 18 12,540 72,234 105,528 8 11/08/06 1,844 11.7 4,163 380,160 60 52 41 41 11.5 538 460,960 331.3 18 12,540 72,234 105,528 11/09/06 1,852 7.0 4,383 198,621 60 52 41 41 11.5 551 50,212 36.1 19 12,517 72,549 106,587 11/13/06 1,879 7.0 5,248 220,851 60 52 40 38 11.5 522 235,410 169.2 20 12,516 72,868 107,630 11/14/06 1,885 7.5 5,435 242,595 60 52 40 38 11.5 522 407,330 292.8 20 12,516 72,868 107,630 9 11/15/06 1,889 3.5 5,580 121,749 60 52 40 39 11.5 548 543,182 390.4 20 12,516 72,868 107,630 11/16/06 1,898 10.8 5,838 313,519 10 10 2 3 10.0 NR 167,266 120.2 21 12,516 73,145 108,635 11/17/06 1,908 8.7 6,166 279,479 60 52 41 1 40 11.5 550 472,401 339.5 21 1 12,519 NR NR 11/20/06 1,932 8.0 6,887 248,502 60 54 41 40 11.5 551 526,727 378.6 22 12,606 73,396 109,695 10 11/21/06 1,934 1.9 6,962 66,380 60 52 40 39 11.0 550 595,910 428.3 22 12,606 73,400 109,695 11/27/06 1,987 9.1R58276,766 60 52 40 40 1L5 542 263,888 189.7 25 12,434 74,149 112,810 II 11/28/06 1,997 9.5308,070 60 52 41 40 11.5 549 547,771 393.7 25 NR NR NR 11/29/06 2,008 10.7317,729 60 51 40 40 12.0 536 250,659 180.2 26 12,424 74,442 113,860 12/04/06 2,045 7.6230,277 60 52 38 42 12.0 525 69,595 50.0 28 12,411 74,910 115,922 12/05/06 2,053 8.0259,592. 60 52 39 40 12.0 530 315,840 227.0 28 12,411 NR NR 12 12/06/06 2,062 8.5246,857 60 51 40 40 12.0 550 120,650 86.7 29 12,328 75,338 117,901 12/07/06 2,066 4.3139,607 60 51 NR NR NR 550 251,583 180.8 29 12,328 NR NR 12/08/06 2,078 11.5339,918 60 51 41 42 11.5 540 292,407 210.2 30 13,120 75,538 11,854 12/11/06 2,102 7.9 12,119 244,913 60 51 40 40 12.0 545 376,161 270.4 31 13,080 75,540 119,110 t120,120 13 12/12/06 2,115 13.8 12,492 413,169 10 10 4 4 10.5 NR 105,469 75.8 32 13,061 NR NR 12/13/06 2,118 4.0 12,611 132,837 60 51 41 41 11.5 NR 216,079 155.3 32 13,061 75,540 n i N US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period I) (Continued) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Booster Pump Pressure T4 System Inlet Pressure Tl Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Regen BV Treated Since Last Regen. Regen. Counter Regen Water Totalizer (Per Event Fresh Brine Day Tank Totalizer Reused Brine Day Tank Totalizer Unit hr hr/da k al d si si si si psig m al BV al al al 12/14/06 2,126 7.7 12,880 249,910 60 51 41 41 11.5 544 466,119 335.0 32 13,061 75,540 120,122 12/15/06 2,134 7.1 13,084 197,154 59 54 41 41 11.5 550 40,752 29.3 33 13,310 75,540 121,130 12/18/06 2,161 9.0 13,901 273,282 59 54 41 40 11.5 550 115,597 83.1 35 13,321 75,540 123,230 12/19/06 2,170 7.9 14,212 259,617 59 54 43 44 11.5 540 402,769 289.5 35 13,321 NR NR 14 12/20/06 2,176 8.0 14,402 263,077 59 54 43 44 12.0 545 576,250 414.2 35 13,321 NR NR 12/21/06 2,185 7.6 14,673 221,727 59 54 43 44 12.0 545 217,873 156.6 36 13,308 NR 124,230 12/26/06 2,227 8.7 15,968 272,234 3 2 0 0 2.5 NR 179,036 128.7 38 13,302 75,540 126,310 15 12/27/06 2,235 6.6 16,223 215,367 3 2 0 0 2.5 NR 414,177 297.7 38 NR NR 126,310 12/29/06 2,248 7.1 16,633 215,868 59 54 43 43 12.0 551 175,878 126.4 39 13,307 75,542 127,363 01/02/07 2,279 7.6 17,599 240,249 59 54 43 43 11.5 542 449,702 323.2 40 13,407 75,540 128,384 16 01/03/07 2,290 10.3 17,930 303,592 60 54 40 40 11.5 540 141,462 101.7 41 13,300 75,540 129,415 01/05/07 2,304 7.5 18,403 245,892 59 54 43 44 11.5 541 576,326 414.2 41 13,300 NR 129,416 01/08/07 2,328 7.9 19,115 240,394 59 54 40 0 11.0 281 616,000 442.8 43 6,377 75,540 130,945 01/10/07 2,343 8.1 19,605 255,190 59 54 43 43 11.5 542 451,996 324.9 43 13,310 75,547 131,473 17 01/11/07 2,354 9.0 19,923 266,233 NR NR NR NR NR 548 128,699 92.5 44 13,297 NR 132,530 01/12/07 2,361 6.3 20,098 158,690 59 53 43 43 11.5 545 290,201 208.6 44 13,297 NR 132,530 Ol/16/07 2,395 9.0 21,140 278,279 0 0 0 0 2.5 NR 13,149 9.5 46 476 75,547 134,582 01/17/07 2,401 5.6 21,326 183,452 1 59 54 1 40 40 12.0 554 189,175 1 136.0 46 13,522 75,547 134,582 18 01/18/07 2,412 9.8 21,698 318,478 59 54 43 43 12.0 544 532,119 1 382.5 46 13,522 NR 134,582 01/19/07 2,421 8.9 21,972 259,068 59 54 43 43 12.0 545 170,210 122.3 47 13,450 NR NR 01/22/07 2,450 10.2 22,857 322,470 59 54 40 40 12.0 561 371,180 266.8 48 13,293 75,548 136,634 19 01/23/07 2,461 9.6 23,187 284,041 59 54 43 43 12.0 542 61,367 44.1 49 13,484 NR 137,629 01/24/07 2,468 9.7 23,439 312,828 59 54 43 43 12.0 547 294,135 211.4 49 13,484 NR NR 01/30/07 2,516 8.0 1 24,940 250,167 59 54 40 40 12.0 550 443,388 318.7 51 13,286 75,550 139,680 20 01/31/07 2,524 6.8 25,148 193,114 59 54 40 40 12.0 548 18,456 13.3 52 13,282 NR 140,710 02/02/07 2,544 9.3 25,799 301,719 60 57 1 46 11.0 280 910,940 654.7 53 2,698 NR 141,840 02/06/07 2,575 8.2 26,786 257,152 59 54 43 43 11.5 562 278,676 200.3 54 585 75,548 142,755 02/07/07 2,584 10.1 27,099 335,108 59 54 43 43 11.0 552 562,856 404.6 54 13,284 NR NR 21 02/08/07 2,593 6.4 27,337 182,784 10 10 12 12 10.5 NR 164,220 118.0 55 13,272 NR 143,800 02/09/07 2,601 9.5 27,622 315,692 59 54 43 43 11.5 560 424,369 305.0 55 13,272 NR NR 02/12/07 2,625 8.1 28,353 253,343 59 53 43 43 11.5 559 475,337 341.7 56 13,284 75,548 144,826 02/13/07 2,635 11.3 28,666 342,753 10 10 5 5 4.0 NR 144,490 103.9 57 13,397 NR 145,840 22 02/14/07 2,642 5.9 28,898 194,233 59 53 43 43 11.5 539 NR NR 57 13,397 NR 145,840 02/15/07 2,651 10.5 29,186 320,247 60 56 43 43 11.0 285 4,775 3.4 58 764 NR 146,372 02/16/07 2,658 6.0 29,480 249,035 59 56 42 42 11.5 546 207,772 149.3 58 6,514 NR 146,372 02/19/07 2,682 8.3 30,138 235,409 59 53 43 43 11.5 555 251,951 181.1 59 13,267 75,546 147,434 02/20/07 2,691 8.6 30,453 283,500 59 53 43 43 11.5 576 546,795 393.0 59 13,267 NR 147,434 23 02/21/07 2,702 9.4 30,768 280,867 59 53 43 43 11.0 540 218,240 156.9 60 13,267 NR 148,435 02/23/07 2,715 7.6 31,202 242,326 59 54 7 43 11.0 267 614,474 441.7 61 4,992 NR 148,963 02/26/07 2,741 8.9 31,995 273,121 59 53 43 42 11.5 529 108,319 77.9 62 13,243 75,547 150,482 02/27/07 2,747 6.0 32,191 200,170 59 53 42 43 11.5 544 287,695 206.8 62 13,243 NR NR 24 02/28/07 2,758 8.6 32,536 1 280,678 60 56 42 43 11.5 284 602,492 433.0 62 76 NR 150,482 03/Ol/07 2,766 11.6 32,795 340,292 59 53 43 43 11.5 547 225,515 162.1 63 13,200 NR 151,018 03/02/07 2,774 7.6 33,046 251,174 59 53 40 40 11.5 555 453,950 326.3 63 13,200 NR 151,018 03/06/07 2,809 8.5 34,133 263,737 9 8 1 0 9.0 NR 214,272 154.0 65 13,577 830 153,680 25 03/08/07 2,827 8.4 34,664 245,865 59 52 43 42 11.5 537 260,560 187.3 69 13,594 1,992 154,982 03/09/07 2,835 8.2 34,920 270,066 59 52 43 42 11.5 556 495,180 355.9 69 13,594 1,992 154,982 03/12/07 2,858 8.0 35,648 249,600 59 52 43 42 11.5 548 543,862 390.9 70 13,622 2,558 156,042 26 03/14/07 2,875 8.6 36,173 266,667 59 52 43 42 11.5 548 409,561 294.4 71 13,621 3,162 157,055 03/16/07 2,894 9.5 36,759 292,290 59 52 44 43 11.5 541 332,918 239.3 72 13,862 3,770 158,056 03/19/07 2,919 8.4 37,514 260,220 59 53 41 40 12.0 536 415,021 298.3 73 14,038 4,420 159,065 27 03/20/07 2,925 5.6 37,709 181,748 NR NR NR NR NR 560 595,140 427.8 73 NR 4,420 159,065 n W US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period I) (Continued) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Booster Pump Pressure T4 System Inlet Pressure PTl Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Regen BV Treated Since Last Regen. Regen. Counter(Per Regen Water Totalizer Event Fresh Brine Day Tank Totalizer Reused Brine Day Tank Totalizer Unit hr hr/day k al gpd Psig psigsi si pig Out gal RV gal gal gal 03/21/07 2,937 10.8 38,076 322,244 59 53 44 43 11.5 527 317,445 228.2 74 14,016 5,074 160,121 03/23/07 2,954 9.0 38,587 273,546 59 53 44 43 11.5 549 174,150 125.2 75 14,071 5,727 161,168 03/26/07 2,981 9.2 39,441 288,270 59 52 43 43 11.5 536 346,850 249.3 76 14,022 6,375 162,180 03/27/07 2,992 10.1 39,761 294,629 59 52 43 43 11.5 532 26,348 18.9 77 13,963 7,035 163,240 28 03/29/07 3,007 7.8 40,231 252,537 59 52 42 42 11.5 537 463,076 332.8 77 13,963 7,035 163,240 03/30/07 3,020 10.4 40,621 308,571 58 50 41 40 11.5 525 210,119 151.0 78 13,836 7,682 164,284 04/02/07 3,047 9.8 41,461 301,270 58 56 41 40 11.5 538 376,943 270.9 79 13,735 8,324 165,283 04/03/07 3,056 9.2 41,722 272,348 60 56 41 1 11.0 276 3,065 2.2 80 7,172 8,720 166,348 29 04/05/07 3,079 10.2 42,393 303,849 60 56 46 I 11.0 280 12,778 9.2 8.1 10,171 9,621 167,366 04/06/07 3,091 1 12.6 42,786 395,748 57 49 39 39 11.5 524 378,643 272.2 81 13,776 9,631 167,866 04/09/07 3,119 9.3 43,648 285,286 10 10 12 12 10.5 NR 565,850 406.7 82 13,782 10,288 168,366 04/10/07 3,126 8.5 43,824 226,488 58 50 40 38 11.5 547 114,230 82.1 83 13,785 10,950 169,410 30 04/11/07 3,135 8.2 44,096 263,758 58 50 40 39 11.5 547 367,940 264.5 83 13,785 10,950 169,412 04/12/07 3,146 9.0 44,427 260,459 10 10 12 12 10.5 NR 59,387 42.7 84 13,777 11,612 170,426 04/13/07 3,153 9.4 44,656 294,429 57 48 39 38 11.5 521 274,003 196.9 84 13,777 11,612 170,426 04/16/07 3,178 8.5 45,422 259,539 58 49 40 39 11.5 537 371,129 266.8 85 13,780 12,275 171,488 04/17/07 3,189 10.7 45,722 306,383 58 49 40 39 11.5 545 262,587 188.7 86 13,781 12,940 172,490 31 04/18/07 3,199 9.7 1 45,997 275,000 58 49 40 39 11.5 538 132,727 95.4 87 1 13,796 13,610 173,492 04/19/07 3,209 9.3 46,282 266,494 60 55 45 1 11.0 275 12,064 8.7 88 9,991 14,288 174,533 04/20/07 3,217 8.9 46,544 278,435 58 49 39 39 11.5 542 256,340 184.2 88 13,802 14,288 174,533 04/23/07 3,248 10.4 47,472 305,096 58 49 40 37 12.0 530 347,130 249.5 90 13,804 15,648 176,644 04/24/07 3,259 10.5 47,755 293,180 58 49 39 39 11.5 505 223,305 160.5 91 13,807 16,328 177,682 32 04/26/07 3,283 12.2 48,456 351,110 10 10 12 12 10.5 NR 102,190 73.5 93 13,824 17,693 179,725 04/27/07 3,291 8.1 48,715 255,452 10 10 12 12 10.5 NR 341,774 245.7 93 13,824 17,693 179,725 05/01/07 3,343 12.2 50,223 352,519 10 10 12 12 10.0 NR 197,948 142.3 97 13,812 20,424 183,793 05/02/07 3,354 13.3 50,521 376,421 1 58 48 1 38 38 11.5 513 87,897 63.2 98 1 13,819 21,111 184,788 33 05/03/07 3,363 9.3 50,806 291,064 58 48 39 38 11.5 516 352,636 253.5 98 13,819 21,111 184,788 05/04/07 3,374 9.1 51,118 256,731 10 10 12 12 10.5 NR 253,914 182.5 99 13,852 21,795 185,850 05/07/07 3,405 11.2 52,038 327,111 58 48 38 37 11.5 509 335,786 241.4 101 13,814 23,165 187,920 05/08/07 3,421 14.2 52,490 421,282 10 9 11 11 10.0 NR 369,427 265.5 102 14,112 23,851 188,910 34 05/09/07 3,430 10.9 52,744 308,658 58 53 38 37 11.5 535 220,929 158.8 103 14,193 24,538 189,960 05/10/07 3,446 14.7 53,218 437,538 56 52 42 41 11.5 512 276,815 199.0 104 14,104 25,215 191,020 05/11/07 3,459 13.5 53,627 400,653 56 1 52 42 1 41 11.5 526 271,212 194.9 104 14,187 25,957 192,000 05/14/07 3,497 12.6 54,734 369,000 57 53 40 40 12.0 545 144,125 103.6 1 108 14,256 27,990 195,145 35 05/16/07 3,526 14.9 55,575 438,783 57 53 40 40 12.0 540 155,497 111.8 110 14,157 29,390 197,220 05/18/07 3,556 15.0 56,450 439,791 57 52 42 42 12.0 529 199,287 143.2 112 14,170 30,800 199,252 05/21/07 3,600 13.4 57,761 397,022 57 52 42 42 11.5 524 261,712 188.1 115 14,170 32,914 202,297 05/22/07 3,612 14.8 58,106 432,000 57 52 42 42 11.5 529 197,650 142.1 116 13,977 33,600 205,205 36 05/24/07 3,639 14.1 58,899 413,739 58 53 42 42 11.5 547 163,510 117.5 118 14,167 35,010 205,342 05/25/07 3,653 1 14.4 59,320 1 423,944 57 52 42 42 11.5 1 540 170,056 122.2 119 14,175 35,718 206,360 05/29/07 3,710 13.3 60,985 389,854 NM NM NM NM NM NR 126,115 90.6 123 14,176 38,555 210,490 37 05/30/07 3,719 11.9 61,259 350,720 58 53 40 40 12.0 525 47,125 33.9 1 124 14,177 39,265 211,525 05/31/07 3,735 16.8 61,717 497,751 58 52 42 42 12.0 526 87,834 63.1 125 14,147 39,977 212,517 06/04/07 3,797 15.6 63,553 460,599 58 52 40 40 10.5 530 252,860 181.7 129 14,141 42,810 216,580 06/OS/07 3,812 15.1 64,015 455,671 60 58 41 47 11.0 257 373,790 268.7 131 0 43,520 217,880 38 06/06/07 3,825 12.9 64,387 365,652 58 52 40 40 10.5 545 331,505 238.3 131 14,129 44,230 218,620 06/07/07 3,836 11.8 64,700 337,618 58 52 42 41 11.5 515 237,575 170.8 132 14,087 44,933 219,674 06/O8/071 3,849 1 11.8 1 65,076 1 340,528 58 52 42 41 1 11.5 1 537 1 201,225 144.6 133 14,129 45,640 220,727 06/11/07 3,884 11.6 66,103 342,333 58 52 6 41 11.5 251 384,127 276.1 136 14,630 47,422 223,312 06/12/07 3,893 9.8 66,377 289,055 58 52 42 41 12.0 517 253,790 182.4 136 14,120 47,773 223,836 39 06/14/07 NR NR 67,197 391,642 10 10 12 12 10.5 NR 243,032 174.7 138 14,100 49,199 225,882 06/15/07 NR NR 1 67,569 326,634 10 10 11 11 10.0 NR 203,743 146.4 139 14,086 49,910 226,950 n -P US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period I) (Continued) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Booster Pump Pressure T4 System Inlet Pressure Tl Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Regen BV Treated Since Last Regen. Regen. Counter Regen Water Totalizer (Per Event Fresh Brine Day Tank Totalizer Reused Brine Day Tank Totalizer Unit hr hr/da k al d si si si psig psig m al BV al al al 06/18/07 3,974 12.9 68,722 379,502 58 51 41 40 11.5 520 11,904 8.6 142 14,025 52,050 230,015 06/19/07 3,989 15.1 69,155 437,558 58 51 41 40 11.5 515 132,038 94.9 143 14,005 52,759 231,044 40 06/20/07 4,005 16.5 69,646 491,000 58 51 40 40 11.0 512 201,487 144.8 144 14,022 53,472 232,034 06/21/07 4,019 14.6 70,036 420,674 58 51 40 40 11.5 524 176,651 127.0 145 14,015 54,122 233,061 06/22/07 4,031 14.5 70,370 412,841 58 51 40 40 11.5 520 100,460 72.2 146 14,006 54,895 234,190 06/25/07 4,067 11.8 71,458 348,160 58 50 40 39 12.0 517 337,432 242.5 148 13,985 56,380 236,165 06/27/07 4,101 15.6 72,410 440,797 58 49 39 39 12.0 512 60,061 43.2 151 13,955 58,446 239,242 41 06/28/07 4,112 12.3 72,758 373,970 60 55 1 43 11.0 270 378,895 272.3 152 2,363 58,870 239,715 06/29/07 4,125 15.1 73,136 438,968 58 49 39 38 11.5 515 343,410 246.8 152 13,959 59,159 240,239 07/02/07 4,170 13.9 74,425 403,075 49 36 14 33 11.0 260 370,762 266.5 156 0 60,680 243,380 07/03/07 4,182 13.3 74,759 377,224 58 48 38 38 11.5 512 292,509 210.2 156 13,930 60,690 244,328 42 07/05/07 4,212 16.1 NR NR 58 1 48 38 37 11.5 512 332,328 238.9 158 13,877 60,690 246,349 07/06/07 4,228 16.7 76,095 NR 58 47 38 37 11.5 509 362,331 260.4 158 13,760 60,690 247,366 07/09/07 4,269 13.4 77,267 382,694 58 46 38 32 11.5 520 277,140 199.2 162 13,661 60,690 250,425 07/10/07 4,287 15.4 77,757 416,283 3 3 0 0 1.0 NR 40,305 29.0 164 13,442 61,058 252,490 43 07/11/07 4,301 14.6 78,175 429,943 58 53 44 43 11.5 536 45,396 32.6 165 14,813 61,665 253,481 07/12/07 4,314 1 14.7 78,553 438,968 60 58 44 0 11.0 298 10,491 7.5 166 9,858 62,295 254,495 07/13/07 4,326 12.1 78,917 384,000 60 58 44 44 11.0 540 345,067 248.0 166 14,311 NR NR 07/16/07 4,365 12.7 80,035 366,307 58 52 40 40 11.0 535 242,110 174.0 169 14,342 64,298 257,534 07/18/07 4,391 12.9 80,806 381,526 58 53 40 40 11.0 535 179,240 128.8 171 14,353 65,650 259,568 44 07/19/07 4,404 13.9 81,204 406,468 58 53 40 40 11.0 537 163,285 117.4 172 14,359 66,330 260,565 07/20/07 4,418 13.4 81,597 393,000 58 53 40 40 11.0 510 143,135 102.9 173 14,360 67,010 261,555 07/23/07 4,452 11.0 82,623 326,146 10 9 11 11 10.0 NR 327,278 235.2 175 14,361 68,300 263,500 45 07/25/07 4,471 10.5 83,153 295,814 58 52 42 42 11.5 529 50,201 36.1 177 14,368 69,760 265,600 07/26/07 4,483 1 11.2 83,522 1 337,371 60 57 47 40 11.0 275 1 6,949 5.0 178 8,761 70,388 266,690 07/30/07 4,530 11.4 84,899 335,229 58 1 53 43 1 42 11.5 541 131,433 94.5 181 14,251 72,429 269,820 08/Ol/07 4,550 11.1 85,494 332,738 58 53 43 42 11.5 530 300,162 215.7 182 14,301 73,100 270,340 46 08/02/07 4,562 9.6 85,994 396,694 60 57 0 42 11.0 260 380,170 273.3 184 2,766 74,130 272,315 08/03/07 4,576 18.2 86,270 348,632 50 52 42 42 11.5 523 251,367 180.7 184 14,332 74,467 272,838 08/06/07 4,608 10.7 87,204 315,718 58 52 42 42 12.0 504 348,955 250.8 186 14,262 75,830 274,840 08/07/07 4,623 11.7 87,641 343,869 58 52 42 42 12.0 520 369,901 265.9 187 14,264 76,510 275,890 47 08/08/07 4,632 12.2 87,886 336,000 58 52 42 42 12.0 535 21,930 15.8 188 14,293 77,190 276,925 08/09/07 4,644 9.4 88,238 276,984 58 52 42 42 12.0 550 1 153,813 110.6 189 14,343 77,870 277,935 08/10/07 4,649 7.6 88,409 241,412 5 1 5 6 1 7 6.0 NR 312,975 225.0 189 14,343 77,873 277,935 08/14/07 NR NR 89,581 294,534 51 45 35 35 11.5 511 243,014 174.7 192 14,072 79,920 281,038 48 08/15/07 4,704 10.6 89,999 345,931 52 44 35 34 11.5 508 239,783 172.3 1 193 13,778 80,650 282,044 08/17/07 4,722 8.8 90,520 256,932 59 50 41 40 11.0 518 342,527 246.2 194 13,937 81,242 283,024 08/21/07 4,754 8.5 91,430 243,388 59 50 40 40 12.0 533 26,825 19.3 197 14,104 83,248 286,122 49 08/24/07 4,786 10.5 92,359 307,107 59 49 40 39 11.5 511 115,436 83.0 199 14,023 84,060 288,220 08/28/07 4,823 9.3 93,456 272,829 59 49 40 39 11.5 531 359,292 258.2 201 13,930 85,954 290,251 50 08/29/07 4,835 10.1 93,807 289,319 10 10 12 12 10.5 NR 297,923 214.1 202 13,931 86,634 291,350 08/30/07 4,845 8.8 94,067 245,831 10 1 10 0 1 0 10.0 NR 153,020 110.0 203 13,897 87,305 292,330 51 09/04/07 4,883 7.6 95,161 219,257 60 52 42 4 11.0 275 7,733 5.6 206 8,717 89,261 295,324 09/11/07 4,945 9.2 96,937 261,899 59 47 37 37 12.0 490 94,079 67.6 210 13,726 91,910 299,420 52 09/12/07 4,957 10.2 97,276 282,173 10 10 12 12 10.0 NR 286,755 206.1 211 13,723 92,575 300,432 09/14/07 4,974 8.6 97,760 245,408 59 46 37 36 11.5 521 346,283 248.9 212 13,777 93,245 301,439 53 09/17/07 4,997 8.1 98,398 226,565 59 46 36 36 11.5 501 163,149 117.3 214 13,674 94,563 303,492 09/24/07 5,048 7.3 99,858 208,882 59 45 36 35 12.0 509 346,796 249.3 217 13,618 96,580 306,500 54 09/26/07 5,065 7.5 100,324 202,731 60 45 36 0 11.0 262 14,640 10.5 219 11,373 97,910 308,580 10/01/07 5,100 7.4 101,328 209,835 60 43 34 30 12.0 505 167,558 120.4 221 13,316 99,240 130,620 55 10/04/07 5,126 8.1 102,063 229,091 10 10 2 2 10.0 NR 72,808 52.3 223 13,803 lOQ,507 312,660 56 10/08/07 5,161 9.3 103,087 270,810 10 9 2 2 10.0 NR 243,918 175.3 275 13,821 1 101,915 314,565 US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period I) (Continued) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Booster Pump Pressure T4 System Inlet Pressure Tl Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Regen BV Treated Since Last Regen. Regen. Counter Regen Water Totalizer (Per Event Fresh Brine Day Tank Totalizer Reused Brine Day Tank Totalizer Unit hr hr/da k al d si si si si si m al BV al al al 10/09/07 5,172 11.1 103,377 310,253 59 47 37 37 11.5 518 192,807 138.6 226 13,735 102,580 315,762 10/11/07 5,195 10.7 104,032 300,478 0 0 3 3 2.0 NR 22,197 16.0 228 13,687 103,924 317,818 10/17/07 5,257 10.5 105,798 300,596 58 53 42 42 11.5 549 313,849 225.6 232 13,656 106,622 321,460 57 10/18/07 5,266 9.6 106,060 273,391 58 53 42 42 12.0 513 170,643 122.7 233 14,298 107,295 322,505 10/19/07 5,277 9.4 106,390 273,103 58 53 42 42 11.5 543 9Q330 64.9 234 14,296 107,974 323,541 10/22/07 5,301 8.4 107,113 258,985 2 2 1 4 0.0 NR 377,889 271.6 236 707 108,835 325,081 58 10/26/07 5,329 6.9 107,853 181,688 58 52 42 42 12.5 529 481,370 346.0 243 15,508 111,487 325,628 10/29/07 5,353 8.4 108,624 263,402 58 52 42 42 12.5 535 595,337 427.9 244 7,802 112,505 323,605 59 10/31/07 5,371 8.7 109,183 1 273,796 57 52 42 42 12.5 540 1 514,266 369.6 245 1 7,833 113,040 325,610 11/13/07 5,427 4.2 110,543 102,803 0 0 0 1 0 0.0 NR 573,610 412.3 2 7,644 114,160 325,610 11/14/07 5,433 7.9 110,713 224,587 58 48 38 38 12.5 531 131,979 94.9 3 7,646 114,725 325,601 61 11/15/07 5,444 9.0 111,069 281,670 58 47 38 38 12.5 520 461,098 331.4 3 7,646 114,725 325,607 11/16/07 5,450 7.8 111,243 225,730 58 43 37 37 12.5 518 22,399 16.1 4 7,607 115,275 325,607 11/19/07 5,473 7.6 111,921 230,809 8 7 1 0 9.0 NR 50,196 36.1 5 7,683 115,850 323,610 62 11/20/07 5,481 8.5 112,180 262,648 58 47 38 38 12.0 520 289,615 208.2 5 NM NR NR 11/26/07 5,527 7.6 113,568 230,799 10 10 4 4 11.0 NR 368,683 265.0 7 7,663 116,995 323,610 63 11/27/07 5,533 5.9 113,747 179,000 58 47 38 32 12.0 515 1 533,870 383.7 7 7,663 NR NR 11/30/07 5,559 8.3 114,523 245,053 1 58 47 37 1 32 12.0 500 109,755 78.9 1 9 7,637 118,068 NR 12/03/07 5,579 6.9 115,114 205,565 58 44 38 38 12.5 490 51,996 37A 10 7,582 118,625 323,625 12/04/07 5,586 8.1 115,350 248,967 10 10 2 2 11.0 NR 267,669 192.4 10 7,582 NR NR 64 12/05/07 5,596 8.5 115,601 215,143 58 43 34 33 11.0 513 162,353 116.7 I� 14,721 120,265 325,608 12/06/07 5,603 6.5 115,815 192,000 NM NM NM NM NM 520 359,550 258.4 15 14,721 NR NR 12/07/07 5,608 7.0 115,966 211,107 10 10 12 12 11.0 NR 498,457 358.3 15 14,721 120,265 325,608 12/10/07 5,633 8.0 116,671 230,727 9 9 2 0 10.0 NR 530,622 381.4 16 14,748 120,800 325,610 12/11/07 5,641 8.8 116,897 233,290 59 42 35 32 12.5 510 124,577 89.5 17 14,664 121,860 NR CS 1t13/07 5,655 6.9 117,359 234,667 2 2 3 3 3.0 NR 553,516 397.8 17 14,664 121,860 325,609 12/14/07 5,663 7.6 117,596 212,636 57 52 40 39 12.5 530 202,940 145.9 18 15,543 122,915 NR 12/17/07 5,685 7.5 118,258 228,879 3 2 0 0 2.5 NR 200,373 144.0 19 15,638 123,972 325,610 12/18/07 5,696 8.8 118,605 283,909 3 2 0 0 2.5 NR 521,946 375.2 19 15,638 NR NR 66 12/19/07 5,705 8.9 118,887 259,476 57 52 40 40 12.0 525 167,120 120.1 20 15,647 125,030 325,610 12/20/07 5,711 7.5 119,068 242,456 57 52 40 40 12.0 545 334,440 240.4 20 NM NR NR 12/21/07 5,718 7.5 119,293 1 240,000 3 2 0 0 12.0 NR 1 542,942 390.2 20 1 NM NR NR 12/24/07 5,741 1 7.6 0 NR 10 9 11 11 11.0 NR 577,116 414.8 21 15,652 126,084 325,609 12/26/07 5,757 8.1 119,998 NR 59 53 42 42 11.5 560 580,390 417.2 21 15,652 126,084 325,609 67 12/27/07 5,768 10.6 120,306 289,882 3 2 0 0 4.0 NR 247,665 178.0 22 14,282 126,610 325,609 12/28/07 5,776 7.7 120,543 237,000 59 53 38 38 12.0 530 467,584 336.1 22 NM NR NR 12/31/07 5,797 7.1 121,160 211,795 3 2 4 4 4.0 NR 420,181 302.0 23 15,134 127,652 325,610 01/02/08 5,815 8.8 121,687 261,683 4 4 6 6 6.0 NR 292,510 210.2 24 15,251 128,662 325,610 68 01/03/08 5,820 5.7 121,865 178,000 3 2 4 4 4.0 NR 457,264 328.7 24 15,251 128,662 325,610 01/04/08 5,831 10.2 122,162 290,939 59 48 38 37 11.5 545 118,761 85.4 25 15,235 129,706 325,610 01/07/08 5,855 8.2 122,907 246,621 59 49 38 40 12.0 515 195,150 140.3 26 15, 164 130,750 325,610 01/08/08 5,862 5.7 123,128 191,851 6 6 7 7 6.5 NR 399,702 287.3 26 15, 160 130,750 325,610 69 01/09/08 5,870 8.8 123,351 272,136 2 1 0 4 3.0 NR 606,504 435.9 27 2078, 131,280 325,610 01/10/08 5,878 8.9 123,575 250,047 10 10 10 12 12.0 NR 197,588 142.0 27 15,346 131,790 325,610 01/11/08 5,885 7.0 123,796 219,476 10 10 12 12 11.5 NR 403,332 289.9 27 15,346 131,790 325,610 70 01/14/08 5,907 7.5 124,475 224,928 9 9 0 1 0 10.0 NR 418,136 300.5 28 15,396 132,815 325,610 NR = not recorded 1 BV = 186ft3 I, US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period II) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Booster Pump Pressure PT4 System Inlet Pressure TI Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Re en BV Treated Since Last Re en. Reg-. Counter Regen Water Totalizer (Per Event Fresh Brine Day Tank Totalizer Unit hr hr/day legalgal/day si sig Psig psigsi m gal BV gal gal 02/16/09 8,739.8 NR 208,128 NR 60 58 48 1 11.5 288 11,619 8 19 8,245 251,980 1 02/17/09 8,746.7 8.5 208,342 263,385 11 10 12 12 12.0 NR 207,050 141 19 12,789 251,980 02/18/09 8,754.1 1 6.2 208,583 202,947 58 53 42 40 12.0 547 428,634 291 19 12,789 251,980 03/02/09 8,846.9 7.9 211,433 243,416 59 53 43 42 12.0 545 564,199 383 23 12,699 254,962 03/03/09 8,847.5 0.6 211,452 19,683 20 19 16 16 11.0 260 581,683 395 23 12,699 254,962 3 03/04/09 8,855.5 8.8 211,612 175,878 59 53 43 42 11.5 532 184,164 125 24 13,051 255,682 03/05/09 8,859.0 2.8 211,786 141,559 9 9 11 11 11.0 NR 284,169 193 24 13,051 255,682 03/09/09 8,887.6 7.1 212,676 220,966 59 53 43 43 12.5 547 480,300 326 25 12,725 256,439 4 03/11/09 8,901.5 7.0 213,085 205,213 58 53 43 43 12.5 544 236,500 161 26 12,668 257,170 03/12/09 8,909.6 11.3 213,347 364,522 58 53 43 1 42 12.5 542 476,392 324 26 12,668 257,170 5 03/18/09 8,953.1 1 6.7 214,675 205,958 59 53 43 42 12.5 538 457,846 311 28 12,699 258,661 03/25/09 9,005.9 7.7 216,260 231,246 59 53 42 42 12.5 542 59,084 40 31 12,682 260,844 6 03/26/09 9,017.9 9.4 216,647 302,049 9 8 10 10 10.0 NR 416,060 283 31 12,682 260,845 03/31/09 9,050.9 6.9 217,630 206,495 10 10 11 11 11.0 NR 84,260 57 33 12,655 262,293 04/01/09 9,061.9 9.1 217,987 295,448 58 53 42 41 12.0 542 414,217 281 33 12,655 262,293 7 04/02/09 9,066.6 6.4 218,136 204,343 58 53 41 41 12.0 540 551,090 375 33 12,655 262,293 04/03/09 9,073.8 7.4 218,330 200,258 10 9 11 11 11.0 NR 109,993 75 34 12,697 263,030 04/06/09 9,097.9 7.8 219,068 238,545 9 9 10 11 11.0 NR 171,948 1 117 35 12,701 263,768 8 04/07/09 9,121.7 1 26 219,794 10 9 11 11 11.0 NR 22,448 15 36 12,678 264,505 04/08/09 9,128.4 6.8 220,010 220,596 9 9 11 11 10.0 NR 424,882 289 36 12,678 264,505 04/20/09 9,229.6 8.3 223,092 252,020 58 52 43 44 12.0 544 70,972 48 41 12,767 268,095 04/21/09 9,238.9 11.7 223,453 456,000 10 9 11 11 11.0 NR 404,067 275 41 12,767 268,095 10 04/22/09 9,254.6 15.7 223,861 408,000 5 5 8 8 8.0 NR 162,061 110 42 12,679 268,792 04/23/09 9,268.8 12.4 224,318 398,836 10 10 11 11 11.5 NR 584,472 397 42 12,679 268,792 04/24/09 9,275.9 7.7 224,509 208,364 NA NA NA NA NA NR 140,650 96 43 12,701 269,500 04/28/09 9,320.1 11.2 225,856 342,095 10 10 8 2 11.0 1 NR 145,268 99 1 45 12,659 270,975 11 04/30/09 9,341.5 1 10.3 226,509 315,015 58 - 41 40 12.0 545 126,680 86 46 12,635 271,685 05/01/09 9,352.0 11.0 226,847 352696 1 10 10 NA NA 12.0 NR 440,049 299 46 NR NR 05/04/09 9,377.9 8.6 227,643 265,333 58 52 41 41 13.0 541 557,387 379 47 12,622 272,420 05/05/09 9,387.3 7.8 227,907 220,383 58 52 43 42 12.5 535 181,123 123 48 12,632 273,168 12 05/06/09 9,393.1 7.5 228,093 241,297 59 52 43 43 12.5 521 353,486 240 48 12,632 273,168 05/08/09 9,409.6 8.2 228,586 244,800 58 52 43 1 42 12.5 530 189,355 129 49 12,613 273,909 05/12/09 9,451.5 10.0 229,856 304,293 59 52 42 42 12.5 546 125,277 85 51 12,640 1 275,382 13 05/13/09 9,461.0 8.8 230,156 276,923 NA NA NA NA NA 1 530 402,920 1 274 51 NR 05/14/09 9,474.1 1 12.8 230,538 374,204 NA NA NA NA NA 535 138,366 94 52 12,623 276,110 05/19/09 9,528.1 11.4 232,153 340,997 1 9 9 11 11 11.0 NR 434,234 295 54 1,267 277,567 14 05/22/09 9,570.4 13.0 233,873 526,979 59 54 42 42 12.5 530 381,710 259 56 1,268 279,035 05/26/09 9,585.3 4.0 234,573 185,635 2 1 NA NA NA NR 806,720 548 58 37,156 279,775 05/27/09 9,599.6 14.5 234,993 424,421 59 52 43 42 12.5 557 769,698 523 58 49,741 280,452 15 2S/28/09 9,615.0 17.0 235,450 504,276 9 9 11 11 11.0 NR 172,559 117 59 12,668 281,170 05/29/09 9,633.0 14.4 235,989 431,200 59 52 42 42 11.0 530 52,930 36 60 12,677 281,890 06/03/09 9,694.9 13.0 237,900 400,559 9 8 10 10 10.0 1 NR 587,423 399 62 12,692 283,340 16 06/05/09 9,720.5 12.8 238,640 370,000 10 9 11 11 11.0 NR 34,114 23 64 12,660 284,721 06/08/09 9,748.6 9.3 239,499 284,359 11 10 11 12 11.0 NR 212,475 144 65 12,666 285,424 17 06/09/09 9,755.5 7.2 239,720 230,609 10 9 10 11 10.0 NR 417,977 284 65 NR 06/10/09 9,767.2 10.2 240,055 292,364 9 9 11 11 11.0 NR 108,900 74 66 12,630 286,104 07/01/09 9,993.7 10.7 246,822 320,964 59 52 40 1 38 12.0 540 344,380 234 5 1,842 293,400 20 07/02/09 9,996.3 3.0 246,907 99,512 NA NA NA NA NA 545 412,530 280 5 NR 07/06/09 10,053.3 14.4 248,600 427,705 NA NA NA NA NA NR 1 138,378 1 94 8 12,710 295,490 07/08/09 10,082.8 14.7 249,502 448,663 8 8 10 10 11.0 NR 357,543 243 9 12,700 296,160 21 07/09/09 10,097.0 14.7 249,915 426,323 59 51 40 40 12.5 535 122,440 83 10 12,783 296,835 07/10/09 10,116.1 15.9 250,487 477,496 NA NA NA NA NA 540 33,650 23 11 12,726 297.525 n J US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period II) (Continued) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Booster Pump Pressure PT4 System Inlet Pressure TI Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Regen BV Treated Since Last Regen. Regen. Counter Regen Water Totalizer (Per Event Fresh Brine Day Tank Totalizer Unit hr hr/day legalgal/day si sig Psig psigsi m gal BV gal gal 07/13/09 10,155.3 14.1 251,697 435,056 59 51 40 40 12.5 542 539,420 367 12 12,696 298,190 22 07/17/09 10,212.8 13.6 253,402 403,153 59 51 41 41 12.0 534 267,078 181 15 12,738 300,245 07/20/09 10,241.0 10.2 254,259 309,293 NA NA NA NA NA NR 444,177 302 16 12,725 300,920 23 07/21/09 10,258.6 16.1 254,779 475,429 NA NA NA NA NA NR 308,249 209 17 12,721 301,570 07/22/09 10,276.5 15.8 255,307 465,028 59 50 40 40 12.0 531 180,895 123 18 12,672 302,200 07/28/09 10,367.9 15.9 258,038 475,819 10 10 11 12 10.0 NR 241,137 164 NA 12,677 304,536 24 07/30/09 10,396.8 13.4 258,916 407,188 59 49 40 40 12.0 550 439,340 299 23 12,695 305,400 07/31/09 10,414.3 17.7 259,435 524,463 59 49 42 42 12.0 550 300,669 204 24 12,746 306,160 08/04/09 10,466.0 13.0 260,698 317,126 10 7 2 2 11.0 NR 236,355 161 26 12,776 307,470 08/05/09 10,476.8 9.0 261,299 503,163 59 49 38 40 12.0 525 177,010 120 27 12,685 308,110 25 08/06/09 10,487.0 12.6 261,626 402,462 NA NA NA NA NA 545 480,240 326 27 NR NR 08/07/09 10,497.4 11.6 261,916 323,721 10 9 2 2 11.0 NR 129,315 88 28 12,708 308,780 08/11/09 10,545.0 11.2 263,362 340,235 59 53 40 40 12.0 535 233,175 158 30 12,857 310,210 26 08/12/09 10,556.3 13.2 263,722 421,463 NA NA NA NA NA 520 568,210 386 30 NR NR 08/17/09 10,627.2 14.5 265,322 326,115 10 9 2 2 11.0 NR 46,305 31 34 12,879 313,140 27 08/18/09 10,641.3 12.9 266,276 872,229 59 53 40 40 12.0 542 464,470 1 316 34 NR NR 08/19/09 10,655.4 14.4 266,635 366,638 10 9 2 2 11.0 NR 229,445 156 35 12,907 313,870 08/26/09 10,740.0 12.2 269,221 372,757 10 9 2 2 11.0 NR 104,715 71 39 12,911 316,775 28 08/28/09 10,769.1 12.8 269,815 261,578 59 53 40 40 12.0 535 45,035 31 40 12,935 317,510 08/31/09 10,800.4 11.2 270,781 344,743 59 54 45 45 12.0 536 321,775 219 41 12,934 318,239 29 09/02/09 10,828.0 12.8 271,630 392,475 59 54 45 45 12.0 543 487,940 332 42 12,914 318,965 09/10/09 10,926.1 12.6 274,561 377,517 10 9 11 11 10.0 NR 112,792 77 47 12,889 322,664 30 09/11/09 10,938.7 10.9 274,961 345,946 59 53 43 43 12.0 537 486,293 330 47 12,889 322,604 09/14/09 10,973.0 11.7 275,974 346,078 59 54 45 45 12.0 540 188,347 128 49 12,916 324,100 31 09/15/09 10,984.4 10.1 276,333 319,111 - - 545 522,690 355 49 NR NR 09/16/09 10,996.2 13.8 276,670 394,537 59 54 45 45 12.0 542 216,000 147 50 12,915 324,840 09/21/09 11,053.3 11.6 278,403 350,987 59 53 45 45 12.0 530 522,700 355 52 12,872 326,316 09/22/09 11,066.2 11.9 278,773 341,538 - - - - - NR 313,059 213 53 12,874 327,063 32 09/23/09 11,074.9 9.5 279,050 302,182 NR 570,142 387 53 12,874 327,063 09/25/09 11,094.8 8.8 279,599 244,000 59 53 43 42 12.0 532 462,186 314 54 12,856 327,809 09/28/09 11,127.1 11.8 280,537 343,695 9 9 11 11 11.0 NR 94,673 64 56 1 12,821 329,270 09/29/09 11,139.3 12.0 280,924 379,102 1 10 10 11 12 12.0 NR 454,437 309 56 12,821 329,270 33 09/30/09 11,148.2 9.0 281,163 241,516 10 10 11 11 11.0 NR 56,986 39 57 12,725 330,021 10/Ol/09 11,158.1 10.0 281,472 312,253 59 53 45 45 12.0 530 344,480 234 57 12,725 330,021 10/02/09 11,165.7 7.4 281,712 235,102 9 9 10 11 11.0 NR 566,402 385 57 12,725 330,021 10/05/09 11,192.6 9.0 282,477 255,000 10 9 11 11 11.0 NR 37,083 25 59 12,614 331,550 10/06/09 11,204.0 11.2 282,835 350,694 10 10 11 12 11.5 NR 368,575 250 59 12,614 331,550 i4 10/07/09 11,210.5 6.4 283,041 201,796 9 9 11 11 11.0 NR 559,404 380 59 12,614 331,550 10/09/09 11,229.4 9.5 283,593 278,905 10 10 11 12 11.5 NR 150,513 102 60 1 12,634 332,300 10/14/09 11,271.4 8.3 284,833 243,934 NR 359,668 244 62 12,569 333,780 35 10/15/09 11,278.8 7.5 285,064 232,615 NR 572,792 389 62 12,569 NR 10/16/09 11,283.0 4.7 285,151 96,369 NR NR NR 63 NR NR 10/20/09 11,316.0 NR 286,138 NR 10 9 II 11 11.0 NR 309,229 210 1 11,109 335,250 36 10/22/09 11,330.0 NR 286,542 NR 4 4 5 6 6.0 NR 66,654 45 2 11,147 335,492 10/27/09 11,368.8 7.4 287,723 225,250 57 50 40 38 12.0 517 540,850 368 3 11,115 336,727 37 10/28/09 11,377.2 8.5 287,954 232,615 530 138,260 94 4 11,100 337,462 10/29/09 11,387.4 9.5 288,273 295,979 505 431,740 293 1 4 1 11,100 337,462 11/02/09 11,417.9 7.6 289,151 220,150 54 45 35 34 12.0 452 18,001 1 12 1 6 1 11,031 338,927 11/03/09 11,420.8 4.0 289,252 140,522 NR 103,182 70 6 11,031 338,927 38 11/04/09 11,429.0 8.7 289,508 273,067 57 49 38 38 12.0 526 339,549 231 6 11,031 338,927 11/05/09 11,435.3 6.0 289,704 188,160 8 8 10 10 10.0 NR 519,590 353 6 11,031 338,927 11/06/09 11,444.4 9.2 289,944 241,678 10 9 11 11 11.0 NR 125,456 85 7 11,037 339,655 US EPA Arsenic Demonstration Project at Vale, OR - Daily System Operation Log Sheet (Study Period II) (Continued) Parameters Pump Hour Meter Daily Hour Master Totalizer Daily Volume Booster Pump Pressure PT4 System Inlet Pressure TI Tank A Outlet Pressure Tank B Outlet Pressure Product Water Pressure Finished Water Flowrate Finished Water Volume Since Last Re en BV Treated Since Last Re en. Regen. Counter Regen Water Totalizer (Per Event Fresh Brine Day Tank Totalizer Unit hr hr/day legalgal/day si sig psig psigsi m gal BV gal gal 12/02/09 11,635.7 7.4 295,917 229,608 56 26 20 20 12.0 360 82,236 56 16 8,748 345,515 42 12/03/09 11,646.0 9.5 296,213 272,358 NR 356,930 243 16 NR NR 12/16/09 11,752.2 8.2 298,780 198,896 9 9 11 11 11.0 NR 319,637 217 20 9,984 348,208 44 12/17/09 11,762.9 10.6 299,028 245,443 10 9 11 11 11.0 NR 553,145 376 20 9,984 348,208 48 01/15/10 11,809.0 299,195 5,740 55 49 38 37 12.0 554 10,605 7 22 9,907 349,540 01/25/10 11,828.4 1.9 299,835 64,134 9 9 10 10 10.0 NR 590,149 401 22 9,907 349,540 50 01/28/10 11,849.6 7.1 300,501 222,000 9 9 10 10 10.0 NR 579,044 394 23 11,364 350,225 01/29/10 11,856.6 6.9 300,699 193,959 56 50 39 36 12.0 540 143,810 98 24 11,178 350,870 02/02/10 11,884.0 7.0 301,561 219,696 56 51 39 35 12.0 557 316,110 215 25 11,153 351,518 51 02/03/10 11,892.6 6.6 301,837 213,105 56 51 1 39 1 33 1 12.0 1 545 571,244 1 388 25 11,153 351,518 02/08/10 11,925.9 7.1 302,816 208,083 57 52 40 28 12.0 515 246,140 167 27 10,928 352,815 52 02/10/10 11,939.1 6.4 303,214 193,622 2 1 0 3 3.0 NR 12,356 8 28 7,155 353,141 02/12/10 11,954.5 7.9 303,674 236,150 10 9 II II 11.0 NR 421,067 286 28 11,380 353,665 NR = Not Recorded 1 BV = 197113 n 00 APPENDIX D ANALYTICAL DATA d Analytical Results from Long -Term Sampling at Vale, OR (Study Period I) Sampling Date 09/20/06 09/25/06 10/02/06 10/09/06(" 10/18/06 10/23/06(') Sampling Location IN I TA I TB TT IN TA TB IN I TA TB IN I TA TB IN TA TB TT IN TA TB Parameter Unit Throughput gal 653,391 NA 14,150 132,197 125,750 181,240 Alkalinity mg/L 301 365 363 358 305 227 204 254 355 339 316 182 157 306 209 190 194 308 269 260 (as CaCO3) - - - - - - - - - - - - - - - - - - - - Fluoride mg/L 1 0.6 0.6 0.7 0.8 - - - - - - - - 0.6 0.6 0.6 0.6 1 - - - Sulfate mg/L 73.0 4.0 10.0 9.0 67.0 <1 <1 259 ` <1 <1 75.0 <1 <1 79.0 <1 <1 <1 88.0 <1 <1 - - - - - - - - - - - - - - - - - - - - Nitrate (as N) mg/L 3.5 3.9 3.9 4.1 3.8 0.5 0.5 4.2 <0.05 <0.05 2.5 0.4 0.4 4.6 2.1 1.1 2.3 3.9( 2.2 2.5 - - - - - - - - - - - - - - - - - - - - Total P (as P) µg/L 325 290 388 370 240 <10 <10 300 <10 <10 322 <10 <10 293 24.7 16.9 21.4 266 <10 <10 - - - - - - - - - - - - - - - - - - - - Silica (as Si02) mg/L 57.3 57.9 57.4 55.7 57.7 57.0 56.2 46.1 56.5 57.4 56.1 58.2 10.3 57.0 58.5 59.7 58.6 57.4 56.5 56.4 - - - - - - - - - - - - - - - - - - - - Turbidity NTU 0.5 0.2 0.3 0.4 0.2 0.1 0.2 0.3 0.4 0.8 0.5 0.2 0.7 0.5 0.6 0.7 0.6 0.7 0.4 0.8 - - - - - - - - - - - - - - - - - - - - TDS mg/L 438 484 484 472 460 448 462 766 428 459 470 478 488 462 448 466 462 486 460 468 - - - - - - - - - - - - - - - - - - - - TOC mg/L pH S.U. 7.3 7.4 7.4 7.4 NA NA NA NA NA NA 7.5 7.5 7.5 7.3 7.2 7.1 7.2 7.3 7.4 7.4 Temperature °C 15.3 15.0 15.1 15.1 NA NA NA NA NA NA 15.3 15.4 15.4 14.9 14.8 14.9 14.8 15.6 15.4 15.4 DO mg/L 1.6 2.1 1 1.9 1 2.0 NA NA NA NA NA NA 2.3 2.5 2.4 2.1 2.8 2.2 2.7 2.1 2.0 1.8 ORP mV 127 126 120 118 NA NA NA NA NA NA 272 152 146 265 195 182 165 253 229 227 Total Hardness (as CaCO3) mg/L 155 154 154 146 138 140 142 137 - - - Ca Hardness mg/L 111 109 109 101 94.2 96.2 98.0 92.8 Mg Hardness mg/L 44.4 44.8 45.4 45.5 44.0 43.9 43.6 43.7 As (total) µg/L 24.8 19.4 27.7 26.1 18.7 5.7 5.9 25.2 0.5 0.5 22.5 1.8 1.8 24.1 3.2 3.0 3.1 24.9 2.7 2.0 - - - - - - - - - - - - - - - - - - - As (soluble) µg/L 22.9 18.7 24.7 24.2 21.8 3.3 2.9 2.9 As (particulate) µg/L 1.9 0.7 3.0 1.9 2.3 <0.1 <0.1 0.1 As (III) µg/L 0.4 0.4 0.4 0.4 0.8 0.7 0.7 0.6 As (V) µg/L 22.5 18.3 24.3 23.7 21.0 1 2.5 2.2 2.3 Fe (total) µg/L <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 - - - - - - - - - - - - - - - - - - - - Fe (soluble) µg/L <25 <25 <25 <25 - - - - - - - - - <25 <25 <25 <25 - - - Mn (total) µg/L 0.4 0.4 0.5 0.4 0.7 2.3 1.4 0.5 0.5 0.6 0.7 0.4 0.3 0.4 0.6 0.6 0.6 0.5 0.6 0.5 - - - - - - - - - - - - - - - - - - - - Mn (soluble) µg/L 0.4 0.4 0.4 0.4 1 0.4 0.6 0.5 0.6 V (total) µg/L 59.7 0.6 0.7 0.6 60.3 1.8 2.1 2.0 V (soluble) µg/L 59.2 0.5 0.7 1 0.7 58.8 1.7 2.0 1.9 (a) Water quality parameters taken on 10/10/06. (b) Water quality parameters taken on 10/26/06. (c) 10/02/06 sample rerun with similar results for sulfate. (d) Reanalysis conducted outside of hold time. Analytical Results from Long -Term Sampling at Vale, OR (Study Period I) Sampling Date 10/31/06(s) 11/06/061b1 11/14/06(`) 11/28/06 12/04/06td1 12/13/06te1 Sampling Location IN I TA I TB IN I TA TB IN I TA I TB TT IN TA I TB 77--[7 TB IN I TA I TT Parameter Unit Throughput gal NA 443,420 407,330 547,771 69,595 216,079 Alkalinity mg/l. 331 398 303 311 376 370 315 380 374 376 314 356 354 326 171 145 326 316 303 (as CaCO3) - - - - - - - - - - - - - 337 174 143 - - - Fluoride mg/L - - - - - - 0.6 0.5 0.6 0.6 - - - - - - 1.1 0.5 0.6 Sulfate mg/L 78.0 <1 <1 76.0 2.0 1.0 79.0 1.0 2.0 2.0 90.0 28.0 33.0 90.0 4.0 3.0 76.0 <1 <1 - - - - - - - - - - - - - 89.0 4.0 3.0 - - - Nitrate (as N) mg/L 4.8 2.1 0.1 4.8 3.8 4.5 5.3 3.3 4.4 3.8 6.0 9.8 7.5 6.4 4.6 4.7 5.4 0.9 0.9 - - - - - - - - - - - - - 6.8 4.5 5.0 - - - Total P (as P) µg/L 320 16.6 <10 253 97.4 197 272 59.7 121 93.1 251 403 308 218 <10 <10 256 <10 <10 - - - - - - - - - - - - - 212 <10 <10 - - - Silica (as Si02) mg/L 55.3 56.8 54.7 57.0 56.4 55.6 55.2 55.1 54.7 56.1 55.6 55.5 55.5 55.5 55.1 54.2 56.1 55.4 55.4 - - - - - - - - - - - - - 55.7 56.7 55.5 - - - Turbidity NTU 0.9 0.7 0.8 0.5 0.6 0.8 0.6 0.9 0.5 0.7 0.8 0.4 0.6 0.5 0.4 0.5 0.4 0.4 0.4 - - - - - - - - - - - - - 0.5 0.4 0.6 - - - TDS mg/L 486 470 468 462 438 432 494 442 442 448 490 468 464 500 486 498 434 412 498 - - - - - - - - - - - 488 478 502 - - - TOC mg/L - - - - - - - - - - pH S.U. 7.3 7.3 7.4 7.5 7.6 7.6 7.3 7.5 7.4 7.4 NA NA NA 7.3 7.5 7.4 7.7 7.7 7.6 Temperature °C 15.0 15.2 15.0 16.3 16.1 16.1 15.6 15.6 15.4 15.3 NA NA NA 14.6 14.5 14.5 15.0 15.0 15.0 DO mg/L 2.1 2.6 2.6 3.1 3.5 3.4 5.3 6.1 6.9 5.8 NA NA NA 3.4 4.2 3.4 5.4 5.2 5.8 ORP mV 260 229 231 278 235 206 268 244 241 241 NA NA NA 252 230 229 272 257 247 Total Hardness as CaCO3 mg/L - - - - - - 161 159 162 165 169 162 167 Ca Hardness mg/L 105 104 107 109 121 117 120 Mg Hardness mg/L 55.7 55.1 55.1 55.5 47.6 44.7 46.9 As (total) µg/L 23.6 1.8 0.4 24.6 9.2 17.9 24.0 5.0 9.7 7.7 22.3 32.7 26.3 19.6 4.5 4.5 20.9 1.5 1.5 - - - - - - - - - - - - - 20.2 4.2 4.3 - - - As (soluble) µg/L 21.4 4.5 9.1 6.7 21.0 1.6 1.8 As (particulate) µg/L 2.6 0.5 0.5 1.0 <0.1 <0.1 <0.1 As (III) µg/L 0.7 0.7 0.7 0.6 0.9 0.9 0.9 As (V) µg/L 20.7 3.8 8.4 6.1 20.1 0.8 1.0 Fe (total) µg/L <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 - - - - - - - - - - - - - <25 <25 <25 - - - Fe (soluble) µg/L - - - - - - <25 <25 <25 <25 - - - - - - <25 <25 <25 Mn (total) µg/L 0.4 0.6 0.6 2.1 0.6 0.4 0.5 0.5 0.4 0.4 0.3 0.3 0.3 0.3 0.3 0.2 0.4 0.4 0.4 - - - - - - - - - - - 0.3 0.2 0.3 - - - Mn (soluble) µg/L 0.4 0.4 0.4 0.4 0.4 0.4 0.5 V (total) µg/L - 60.5 1.9 2.2 2.0 57.9 2.3 2.6 V (soluble) µg/I 61.2 1.8 2.2 2.0 56.1 2.5 2.2 (a) Water quality parameters taken on 11/03/06. (b) Water quality parameters taken on 11/08/06. (c) Water quality parameters taken on 11/15/06. (d) Water quality parameters taken on 12/05/06. (e) Water quality parameters taken on 12/14/06. d W Analytical Results from Long -Term Sampling at Vale, OR (Study Period 1) Sampling Date 12/18/061a) 01/02/07") 01/10/07 01/17/07 01/24/07 01/30/07 Sampling Location IN TA TB IN TA TB IN TA I TB TT IN I TA TB IN I TA TB IN I TA TB Parameter Unit Throughput gal 115,597 449,702 451,996 189,175 294,135 443,388 Alkalinity (as CaCO3) mg/L 337 229 186 345 421 427 349 411 417 400 331 311 290 326 391 376 356 432 425 Fluoride mg/L - 0.6 0.5 1.4 0.7 - - - - - - - - - Sulfate mg/L 97.0 <I <1 77.0 5.0 1.0 86.0 3.0 2.0 7.0 82.0 <1 <1 84.0 <1 <1 81.0 2.0 7.0 - - - - - - - - - - - - - - - - - - - Nitrate (as N) mg/L 63 1.3 1.4 5.2 3.7 3.8 5.2 2.9 3.6 4.1 6.3 1.0 1.1 6.1 <0.05 <0.05 6.4 4.4 5.4 - - - - - - - - - - - - - - - - - - - TotalP (as P) µg/L 272 <10 <10 255 214 136 301 194 210 317 231 <10 <10 218 <10 <10 323 311 397 - - - - - - - - - - - - - - - - - - - Silica (as Si02) mg/L 56.9 56.6 55.8 56.1 57.0 56.8 54.9 55.5 55.9 54.6 55.6 57.0 55.9 54.4 54.1 54.9 54.3 53.8 53.3 - - - - - - - - - - - - - - - - - - - Turbidity NTU 0.3 0.7 0.5 0.2 0.3 0.6 0.4 0.3 0.6 0.5 0.4 0.5 0.6 0.4 0.5 0.6 0.2 0.7 0.3 - - - - - - - - - - - - - - - - - - - TDS mg/L 506 526 496 522 478 480 468 - 456 464 464 484 470 464 540 482 478 504 474 436 - - - - - - - - - - - - - - - - - - TOC mg/L pH S.U. 7.3 7.4 7.4 7.7 7.4 7.4 7.4 7.4 7.4 7.4 7.3 7.4 7.3 NA NA NA NA NA NA Temperature °C 15.0 14.9 14.9 15.6 15.5 15.4 15.5 15.5 15.5 15.5 14.6 14.6 14.6 NA NA NA NA NA NA DO mg/L 4.6 5.7 1 4.9 4.5 4.8 4.4 4.8 4.7 4.5 4.8 4.8 4.1 5.6 NA NA NA NA NA NA ORP mV 248 235 231 255 227 226 256 227 227 227 255 1 233 231 NA NA NA NA NA NA Total Hardness (as CaCO3) mg/L - - - - - - 164 164 157 159 - - - Ca Hardness mg/L Ill 112 105 106 Mg Hardness mg/L 52.6 52.3 52.0 52.4 As (total) µg/L 21.4 1.8 1.7 25.5 18.6 11.2 21.3 14.6 12.6 19.6 18.3 1.7 1.9 21.7 0.8 1.0 27.0 25.0 33.8 - - - - - - - - - - - - - - - - - - As (soluble) pg/L. 19.2 14.5 10.2 19.4 As (particulate) µg/L 2.1 0.1 2.3 0.1 As (III) µg/L 1.0 0.9 0.8 0.9 As (V) µg/L 18.2 13.6 9.4 18.5 Fe (total) µg/L <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 - - - - - - - - - - - - - - - - - - - Fe (soluble) µg/L - - - - - - <25 <25 <25 <25 - - - - - - - - - Mn (total) µg/L 0.4 0.5 0.6 0.4 0.4 0.4 0.3 0.3 0.3 0.3 <0.1 <0.1 <0.1 0.3 0.4 0.3 0.8 1.0 1.3 Mn (soluble) µg/L 0.3 0.3 0.3 0.3 V (total) µg/L 49.8 0.8 0.7 1.0 V (soluble) µg/L 49.7 0.9 0.6 1.0 (a) Water quality parameters taken on 12/20/06. (b) Water quality parameters taken on 01/05/07. A Analytical Results from Long -Term Sampling at Vale, OR (Study Period 1) Sampling Date 02/06/07 02/12/07 02/19/07 02/27/07 03/05/07 03/12/07t"b1 Sampling Location IN TA 1-13 IN TA I TR TT IN TA TR I IN TA TR IN TA I TR I IN I TA TI3 1'"I Parameter Unit Throughput gal 278,676 475,337 251,951 287,695 NA 543,862 Alkalinity mg/L 353 395 381 339 406 401 399 344 368 352 343 401 392 346 378 380 346 374 381 384 (as CaCO3) - - - - - - - - - - 340 404 394 - - - - - - - Fluoride mg/L - - - 0.6 1.1 0.6 0.5 1 - - - - - - - - - 1.1 1.1 1.0 1.3 Sulfate mg/L 84.0 <1 <1 81.0 9.0 18.0 13.0 93.0 <1 <1 92.0 <1 <1 79.0 36.0 35.0 86.1 38.0 38.0 40.0 - - - - - - - - - - 93.0 <1 <1 - - - - - - - Nitrate (as N) mg/L 7.2 0.9 0.9 6.4 5.6 7.2 6.0 6.4 1.2 1.2 7.4 1.0 1.0 6.5 9.9 8.9 1.4 1.4 1.4 1.6 - - - - - - - - - - 7.6 0.9 1.1 - - - - - - - Total P (as P) µg/L 272 <10 <10 285 329 402 394 337 43.1 43.0 290 <10 <10 281 664 454 305 659 458 559 - - - - - - - - - - 296 <10 <10 - - - - - - - Silica (as Si02) mg/L 53.6 53.6 53.6 59.2 60.0 59.8 59.9 55.4 56.0 55.8 55.4 55.4 54.8 55.1 55.2 55.1 55.5 55.2 54.1 55.2 - - - - - - - - - - 55.2 55.1 55.5 - - - - - - - Turbidity NTU 0.3 0.4 0.4 0.3 0.4 0.5 0.4 0.6 0.7 1.6 0.4 0.3 0.1 0.3 0.7 0.6 0.4 0.3 0.3 0.4 - - - - - - - - - - 0.4 0.3 0.1 - - - - - - - TDS mg/L 536 498 504 514 480 488 430 540 508 506 526 472 480 542 528 526 554 532 550 532 - - - - - - - - - - 520 492 470 - - - - - - - TOC mg/L - - - - - - - - - - - - - - - - pH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 7.2 7.4 7.4 7.4 Temperature °C NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 14.8 14.7 14.7 14.9 DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 3.3 2.8 2.9 2.8 ORP mV NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 226 217 212 252 Total Hardness (as CaCO3) mg/L 170 182 189 192 251 240 241 229 Ca Hardness mg/L 120 128 134 136 187 178 179 169 Mg Hardness mg/L 49.8 53.7 55.2 56.4 63.9 61.8 61.6 59.8 As (total) µg/L 19.4 0.9 1.0 19.9 22.2 27.3 26.6 31.8 - 8.4 9.1 20.4 1.4 1.3 1.1 18.4 - 39.4 - 27.6 22.9 45.8 32.3 39.3 - - - - - - 20.8 1.1 - - - - - As (soluble) µg/L - - - 20.9 21.5 27.2 25.4 20.1 42.1 29.8 35.9 As (particulate) µg/L <0.1 0.7 0.1 1.2 2.8 3.6 2.5 3.4 As (III) µg/L 0.9 0.4 0.3 0.3 2.3 2.5 2.8 2.7 As (V) µg/L 20.0 21.1 26.9 25.1 17.8 39.6 27.0 33.1 Fe (total) µg/L <25 <25 - <25 <25 <25 <25 <25 <25 - <25 - <25 - <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 <25 - - - - - - <25 <25 - - - - - - - Fe (soluble) µg/L - - - <25 <25 <25 <25 - - - - - - - - - <25 <25 <25 <25 Mn (total) µg/L 0.3 0.3 0.3 0.5 0.5 0.5 0.5 1.1 1.2 1.3 0.2 0.2 0.2 0.3 0.3 0.3 <0.1 0.3 <0.1 <0.1 - - - - - - - - - - 0.2 0.1 0.2 - - - - - - - Mn (soluble) µg/L 0.5 0.5 0.5 0.5 <0.1 0.2 <0.1 <0.1 V (total) µg/L 50.5 2.1 2.4 2.4 50.1 3.0 2.6 2.9 V (soluble) µg L 50.4 1.8 2.3 2.2 49.9 2.9 2.4 2.9 (a) Water quality parameters taken on 03/14/07. (b) Process samples taken in counter -current mode. Analytical Results from Long -Term Sampling at Vale, OR (Study Period I) Sampling Date 03/19/07 03/26/07 04/02/07 04/10/071a, 04/16/07 07/16/07 07/25/07 08/01/07 Sampling Location Parameter Unit IN TA TB IN TA TB IN TA TB I IN TA TB TT IN TA TB TT TT TT TT Throughput gal 415,021 346,850 376,943 114,230 371,129 242,110 50,201 3004162 Alkalinity (as CaCO3) mg/L 350 - 409 - 416 - 342 - 412 - 412 - 358 - 427 - 423 - 357 - 286 - 251 - 282 - - - - - - - - Fluoride mg/L - - - - - - - - - 0.5 0.5 0.5 0.5 Sulfate mg/L 81.0 - 11.0 - 7.0 -I 79.0 - <1 - <1 - 73.1 - 5.0 - 2.0 -I 83.0 - <1 - <1 -I <1 - - - - - - - - Nitrate (as N) mg/L 6.1 - 5.3 - 5.1 - 6.7 - 2.5 - 1.7 - 4.0 - 5.9 - 5.5 - 7.6 - 1.9 - 2.3 - 2.1 - - - - - 0.4 - 0.4 - - Total P (as P) µg/L 294 - 344 - 249 - 263 - 46.1 - <10 - 285 - 249 - 154 - 279 - 10.7 - <10 - <10 - - - - - - - - - Silica (as SiO2) mg/L 56.3 - 56.9 - 57.2 - 55.9 - 55.3 - 55.2 - 55.0 - 55.1 - 56.4 - 53.8 - 54.5 - 54.6 - 55.3 - - - - - - - - Turbidity NTU 0.4 - 0.6 - 0.7 - 0.5 - 0.3 - 0.8 - 0.5 - 1.2 - 0.7 - 0.9 - 0.8 - 1.5 - 1.1 - - - - - - - - TDS mg/L 570 - 606 - 544 - 564 - 496 - 478 - 586 - 560 - 540 - 572 - 542 - 550 - 554 - - - - - - - - TOC mg/L 2.0 - - - H S.U. NA NA NA 7.2 7.4 7.4 7.3 7.5 7.6 7.3 7.1 7.0 7.1 8.0 8.3 8.2 8.2 NA NA NA Temperature °C NA NA NA 14.7 14.8 14.8 14.8 14.8 14.8 14.8 14.4 14.3 14.0 16.3 16.0 16.1 16.0 NA NA NA DO mg/L NA NA NA 3.3 2.8 1 2.9 3.9 5.4 4.3 3.9 3.5 3.2 3.5 6.3 6.4 6.5 1 6.5 NA NA NA ORP mV NA NA NA 225 216 212 253 224 222 294 261 248 242 258 237 234 233 NA NA NA Total Hardness (as CaCO3) mg/L 158 165 164 169 - - - - Ca Hardness mg/L 110 115 115 122 Mg Hardness mg/L 48.3 50.4 48.9 47.4 - - s (total) µg/L 28.8 - 30.4 - 20.0 - 19.5 - 3.6 - 0.8 - 24.1 - 18.3 - 11.1 - 24.2 - 1.7 - 1.8 - 1.6 - - - - - - 3.6 - 0.9 As (soluble) µg/L 20.5 1.7 1.8 1.6 As (particulate) µg/L 3.7 <0.1 <0.1 <0.1 As (I11) µg/L 0.8 0.8 0.7 0.7 As (V) µg/L 19.7 0.9 1.0 0.9 Fe (total) µg/L <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - - - - - - - - Fe (soluble) µg/L - - - - - - - - - <25 <25 <25 1 <25 Mn (total) µg/L 0.6 - 0.6 - 0.5 - <0.1 - <0.1 - <0.1 - 0.2 - 0.2 - 0.3 - 0.2 - 0.3 - 0.3 - 0.3 - - - - - - - - Mn (soluble) µg/L 0.3 0.3 0.3 0.3 V (total) µg/L 46.5 3.6 4.5 3.9 (soluble) µg/L 48.5 3.5 1 4.5 1 3.5 (a) Weekly sampling temporarily stopped after 04/10/07. :I J Analytical Results from Long -Term Sampling at Vale, OR (Study Period I) Sampling Date 08/08/07 08/14/07 08/21/07 08/28/07 09/11/07 09/17/07 09/24/07 10/01/07 10/08/07 10/16/07 10/22/07 10/29/07 11/14/07 11/19/07 Sampling Location Parameter Unit TT TT TT TT TT TT TT TT TT TT TT TT TT TT Throughput gal 21,930 243,014 26,825 359,292 94,079 163,149 346,796 167,558 243,918 NA 377,889 595,337 131,979 50,196 Alkalinity (as CaCO3) mg/L - - - - - - - - - - - - - Fluoride mg/L Sulfate mg/L - - - - - - - - - - - - - - Nitrate (as N) mg/L 1 A - 0.8 - 1.9 - 0.7 - 1.4 - 1.1 - 0.7 - 1.1 - 0.8 - 1.0 - 0.7 - 6.1 - 3.7" - 3.5(a) - Total P (as P) µg/L - - - - - - - - - - - - - - - - - - - - - - - - - - - - Silica (as Si02) mg/L - - - - - - - - - - - - - - Turbidity NTU - - - - - - - - - - - - - - - - - - - - - - - - - - - - TDS mg/L - - - - - - - - - - - - - - - - - - - - - - - - - - - - TOC mg/L pH S.U. NA NA NA NA NA 8.2 NA NA NA NA NA NA NA NA Temperature °C NA NA NA NA NA 16.3 NA NA NA NA NA NA NA NA DO mg/L NA NA NA NA NA 6.5 NA NA NA NA NA NA NA NA ORP mV NA NA NA NA NA 233 NA NA NA NA NA NA NA NA Total Hardness (as CaCO3) mg/L Ca Hardness mg/L Mg Hardness mg/L As (total) µg/L 2.0 - 2.1 - 4.3 - 1.4 - 1.5 - 2.8 - 0.8 - 1.5 - 1.2 - 0.7 - 2.1 - 33.5 - 11.811, - 10.2�a) As (soluble) µg/L As (particulate) µg/L As (IIl) µg/L As (V) µg/L Fe (total) µg/L - - - - - - - - - - - - - - - - - - - - - - - - - - - - Fe (soluble) µg/L Mn (total) µg/L - - - - - - - - - - - - - - - - - - - - - - - - - - - - Mn (soluble) µg/L V (total) µg/L V (soluble) µg/L (a) Concentrations elevated due to glitches in PLC when reused brine time was set to zero, causing TA regen to be bypassed. Problem fixed on 12/10/07. d J Analytical Results from Long -Term Sampling at Vale, OR (Study Period 1) Sampling Date 11/27/07 12/03/07 12/10/07 12/17/07 01/07/08 01/14/08 Sampling Location Parameter Unit TT TT TT TT TT TT Throughput gal 533,870 51,996 530,622 200,373 195,150 418,136 Alkalinity (as CaCO3) mg/L - - - - - - Fluoride mg/L Sulfate mg/L Nitrate (as N) mg/L 6.5 3.3(a) 7.1 1.1 0.7 4.0 Total P (as P) µg/L Silica (as Si02) mg/L Turbidity NTU TDS mg/L TOC mg/L pH S.U. NA NA NA NA NA NA Temperature °C NA NA NA NA NA NA DO mg/L I NA NA NA NA NA NA ORP mV NA NA NA NA NA NA Total Hardness (as CaCO3) mg/L Ca Hardness mg/L Mg Hardness mg/L As (total) µg/L 33.8 11.91a1 48.7 1.3 2.2 20.6 As (soluble) µg/L As (particulate) µg/L As (II1) µg/L As M µg/L Fe (total) µg/L Fe (soluble) µg/L Mn (total) µg/L Mn (soluble) µg/L V (total) µg/L V (soluble) µg/L (a) Concentrations elevated due to glitches in PLC when reused brine time was set to zero , causing TA regen to be bypassed. Problem fixed on 12/10/07. I Analytical Results from Long -Term Sampling at Vale, OR (Study Period II) (Continued) Sampling Date 03/25/09 04/02/09 04/08/09 04/22/09 04/28/09 Sampling Location Parameter Unit IN TA TB TT IN TA TB TT IN TA TB TT IN TA TB TT IN TA TB TTT Throughput gal 59,084 551,090 424,882 162,061 145,268 Alkalinity (as CaCO3) mg/L 310 - 76.0 - 26.4 - 52.8F5. 368 - 372 - 372 321 - 326 - 296 - 310 - 313 - 241 - 236 - 246 - 311 - 228 - 180 - 204 Sulfate mg/L 74.5 - 0.2 - 0.2 - 0.2 -5.7 21.2 10.4 15.1 72.6 <0.1 <0.1 0.1 74.4 0.3 0.2 0.3 71.1 0.4 0.6 0.6 Nitrate (as N) mg/L - 2.1 - 2.7 - 2.9 - - 6.3 - 4.9 - 5.7 - 4.4 - 0.8 - 0.9 - 0.9 - 6.8 - 1.3 - 1.3 - 1.3 - 5.2 - 1.3 - 1.2 - 1.4 - Total P (as P) µg/L 266 - <10 - <10 - <10 - 262 - 332 - 296 - 303 - 345 - <10 - <10 - <10 - 308 - 14.5 - 14.3 - 13.7 - 293 - 20.2 - 17.2 - 19.4 - Silica (as Si02) mg/L 56.5 - 57.0 - 57.4 - 56.7 - 54.5 - 54.9 - 54.4 - 53.6 - 57.9 - 57.9 - 58.2 - 58.6 - 56.0 - 59.4 - 59.2 - 59.1 - 66.2 - 62.8 - 67.2 - 63.2 - Turbidity NTU 0.2 - 1.3 - 0.3 - 0.4 - 0.3 - 0.4 - 0.4 - 0.2 - <0.1 - 0.3 - <0.1 - 0.5 - 0.3 - 0.2 - 0.2 - 0.3 - 0.1 - <0.1 - 0.2 - 0.1 - TDS mg/L 496 - 596 - 622 - 596 - 496 - 474 - 456 - 452 - 502 - 478 - 476 - 480 - 520 - 480 - 488 - 488 - 508 - 468 - 488 - 502 - TOC mg/L 1.6 <1.0 <1.0 <1.0 1.8 <1.0 <1.0 <1.0 1.7 <1.0 <1.0 <1.0 2.0 <1.0 <1.0 <1.0 1.6 <1.0 <1.0 <1.0 pH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Temperature °C NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA ORP mV NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA As (total) µg/L 21.7 2.9 - 18.4 - 21.9 - 19.3 - 20.4 - 19.4 - 1.3 - 1.5 - 1.4 - 23.3 - 2.4 - 2.8 - 2.6 - 22.3 - 2.9 - 3.2 - 3.0 As (soluble) µg/L ]4.53.9 As (particulate) µg/L As (III) µg/L As (V) µg/L Fe (total) µg/L <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - Fe (soluble) µg/L - - - - - - - - - - - - - - - - - - - - Mn (total) µg/L 0.2 - 0.4 - 0.5 - 0.5 - 0.2 - 0.1 - 0.2 - 0.6 - 0.3 - 0.3 - 0.3 - 0.3 - 0.5 - 0.4 - 0.8 - 0.4 - 0.4 - 0.5 - 0.7 - 1.2 - Mn (soluble) µg/L V (total) µg/L 49.2 7.3 14.5 11.5 52.6 7.1 1.2 6.0 49.8 1.3 1.7 1.7 59.4 3.4 3.6 3.5 57.8 3.3 4.9 4.2 V (soluble) µg/L d �O Analytical Results from Long -Term Sampling at Vale, OR (Study Period II) (Continued) Sampling Date 05/06/09 05/19/09 05/28/09 06/03/09 06/09/09 Sampling Location Parameter Unit IN TA TB TT IN TA TB TT IN TA TB TT IN TA TB TT IN TA TB TT Throughput gal 353,486 434,234 172,559 587,423 417,977 Alkalinity (as CaCO3) mg/L g 316 - 360 - 374 - 356 - 323 - 381 - 384 - 396 - 310 - 281 - 229 - 246 - 322 - 354 - 377 - 360 - 305 - 372 - 376 - 368 - Sulfate mg/L 77.6 - <0.1 - 0.2 - 0.1 - 83.2 - 1.6 - 0.1 - 0.9 - 81.2 - 0.1 - 0.2 - 0.2 - 76.6 - 21.2 - 11.5 - 15.4 - 74.4 - 0.4 - 0.2 - 0.3 - Nitrate (as N) mg/L 6.1 - 1.1 - 0.7 - 0.9 - 6.3 - 4.4 - 2.3 - 3.6 - 5.8 - 1.2 - 1.2 - 1.5 - 5.9 - 9.9 - 9.9 - 9.3 - 5.2 - 3.3 - 1.1 - 1.8 - Total P (as P) µg/L 300 - <10 - <10 - <10 - 258 - 172 - <10 - 89.2 - 251 - <10 - <10 - <10 - 279 - 452 - 447 - 457 - 285 - 75.3 - <10 - 29.4 - Silica (as Si02) mg/L 63.6 - 61.4 - 63.7 - 63.9 - 62.4 - 62.6 - 62.5 - 63.0 - 58.5 - 59.4 - 59.7 - 59.7 - 61.7 - 61.4 - 62.0 - 62.0 - 60.3 - 60.5 - 61.4 - 60.6 - Turbidity NTU 0.4 - 0.2 - 0.5 - 0.3 - <0.1 - 0.3 - 0.1 - 0.1 - <0.1 - 0.1 - 0.3 - 0.3 - 0.2 - 0.2 - 0.1 - 0.3 - 0.4 - 0.9 - 0.5 - 0.3 - TDS mg/L 498 - 422 - 460 - 448 - 510 - 482 - 486 - 464 - 496 - 482 - 472 - 486 - 528 - 512 - 496 - 508 - 506 - 466 - 460 - 468 - TOC mg/L 2.1 <1.0 <1.0 <1.0 1.7 <1.0 <1.0 <1.0 2.0 <1.0 <1.0 <1.0 2.0 <1.0 <1.0 <1.0 2.0 <1.0 <1.0 <1.0 pH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Temperature °C NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA ORP mV NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA As (total) µg/L 18.1 - 0.6 - 0.6 - 0.6 - 20.3 - 11.2 - 1.1 - 6.0 - 16.0 - 0.6 - 1.0 - 1.0 - 20.7 - 30.8 - 31.1 - 31.4 - 20.2 - 4.9 - 0.5 - 2.4 As (soluble) µg/L As (particulate) µg/L As (1II) µg/L As (V) µP/L Fe (total) µg/L <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - Fe (soluble) µg/L Mn (total) µg/L 0.3 - 0.3 - 0.3 - 0.3 - 0.9 - 0.4 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - Mn (soluble) µg/L - - - - - - - - - - - - - - - - - - - - V (total) µg L 50.2 0.8 0.9 0.9 49.2 0.8 0.8 0.8 47.0 1.7 2.9 2.7 54.7 4.8 3.1 4.1 55.2 0.9 0.9 0.9 V (soluble) µg L d O Analytical Results from Long -Term Sampling at Vale, OR (Study Period II) (Continued) Sampling Date 06/17/09 06/30/09 07/08/09 07/13/09 07/20/09 08/04/09 Sampling Location Parameter Unit IN TA TB TT IN TT IN TA TB TT IN TA TB TT IN TA TB TT IN TA TB TT Throughput gal 339,974 528,358 357,543 539,420 444,177 236,355 Alkalinity (as CaCO3) mg/L 306 368 355 364 315 358 312 376 372 369 304 345 352 349 312 386 390 383 297 322 288 302 Sulfate mg/L 71.6 - 0.1 - 0.1 - 0.2 - 74.6 - 6.8 - 71.7 - 61.7 - 0.2 - 0.3 - 75.2 - 20.5 - 9.2 - 13.7 - 71.1 - 0.5 - <0.1 - 0.4 - 72.8 - 0.2 - 0.3 - 0.3 - Nitrate (as N) mg/L 5.1 - 0.7 - 0.6 - 0.7 - 5.1 - 5.3 - 5.4 - 2.8 - 0.7 - 0.8 - 5.6 - 6.6 - 5.8 - 5.7 - 5.3 - 3.9 - 1.4 - 3.0 - 5.8 - 0.8 - 1.1 - 1.0 - Total P (as P) µg/L 279 - <10 - <10 - <10 - 304 - 291 - 262 - <10 - <10 - <10 - 263 - 355 - 325 - 326 - 263 - 85.3 - <10 - 44.1 - 279 - <10 - <10 - <10 - Silica (as Si02) mg/L 59.6 - 59.9 - 60.3 - 60.2 - 57.9 - 58.7 - 58.0 - 58.5 - 58.7 - 59.1 - 57.9 - 59.1 - 58.9 - 58.8 - 62.2 - 62.4 - 62.7 - 62.5 - 60.2 - 60.3 - 60.5 - 60.6 - Turbidity NTU 0.5 - 1.2 - 0.8 - 0.6 - 0.1 - 0.1 - 0.3 - 0.2 - 0.4 - 0.4 - 0.2 - 0.3 - 0.2 - <0.1 - 1.0 - 1.0 - 0.9 - 1.5 - 0.2 - 0.1 - 0.8 - 0.2 - TDS mg/L 450 - 416 - 420 - 438 - 470 - 440 - 498 - 462 - 464 - 368 - 460 - 460 - 468 - 466 - 456 - 452 - 434 - 428 - 532 - 502 - 500 - 506 - TOC mg/L 1.9 <1.0 <1.0 <1.0 1.8 <1.0 1.8 <1.0 <1.0 <1.0 1.7 <1.0 <1.0 1.7 <1.0 <1.0 <1.0 2.2 <1.0 <1.0 <1.0 PH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Temperature °C NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA ORP mV NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA As (total) µg L 19.0 - 0.5 - 0.6 - 0.6 - 22.8 - 19.9 - 19.8 - 0.7 - 0.6 - 0.7 - 18.9 - 25.3 - 22.6 - 23.0 - 18.6 - 5.3 - 0.6 - 3.2 - 21.0 - 1.6 - 1.5 - 1.4 As (soluble) µg/L As (particulate) µg/L As (III) µg/L As (V) µg/L Fe (total) µg/L <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - Fe (soluble) µg/L - - - - - - - - - - - - - - - - - - - - - - Mn (total) µg/L 0.3 - 0.2 - 0.3 - 0.2 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 0.3 - 4.0 - 3.2 - 3.3 - 3.0 - 0.2 - 0.3 - 0.4 - 0.3 LMnu,ble) JtL 54.3 1.0 1.1 1.1 49.7 0.9 51.5 0.3 0.3 0.3 50.4 2.1 1.0 13 50.2 <0.1 <0.1 <0.1 51.3 1.4 2.0 1.8 e) Analytical Results from Long -Term Sampling at Vale, OR (Study Period II) (Continued) Sampling Date 08/12/09 08/19/09 08/26/09 09/02/09 09/10/09 Sampling Location Parameter Unit IN TA TB TT IN TA TB TT IN TA TB TT IN TA TB TT IN TA TBTTT Throughput gal 568,210 229,445 104,715 487,940 112,792 Alkalinity (as CaCO3) mg/L- 302 336 - 345 - 343 - 298 - 317 - 287 - 303 - 296 - 187 - 117 - 161 - 293 - 337 - 353 - 347 - 282 - 180 - 118 - 143 - Sulfate mg/L 63.6 - 19.5 - 10.1 - 14.8 - 71.8 - <0.1 - 0.2 - 0.1 - 70.6 - 0.1 - 0.2 - 0.1 - 79.2 - 7.5 - 0.2 - 3.6 - 72.4 - <0.1 - 0.2 - 0.1 - Nitrate (as N) mg/L 4.7 - 5.8 - 5.5 - 5.7 - 5.3 - 0.7 - 1.1 - 0.9 - 5.3 - 1.2 - 1.7 - 1.2 - 5.3 - 5.2 - 3.7 - 4.3 - 5.7 - 0.1 - 1.6 - 0.1 - Total P (as P) µg/L 275 - 376 - 362 - 375 - 269 - <10 - <10 - <10 - 265 - <10 - <10 - <10 - 272 - 386 - 70 - 239 - 281 - <10 - <10 - <10 - Silica (as SiO2) mg/L 58.7 - 58.5 - 58.3 - 58.7 - 57.9 - 58.4 - 58.7 - 58.4 - 59.5 - 59.0 - 60.0 - 60.1 - 60.0 - 61.2 - 60.4 - 59.6 - 59.8 - 60.8 - 61.0 - 60.5 - Turbidity NTU 0.2 - 0.3 - 0.4 - 0.3 - 0.2 - 0.2 - 0.5 - 0.3 - 0.2 - 0.8 - 0.6 - <0.1 - 0.4 - 0.9 - 4.2 - 0.4 - 0.1 - 0.2 - 0.3 - 0.2 - TDS mg/L 588 - 484 - 474 - 494 - 500 - 448 - 478 - 480 - 468 - 466 - 512 - 456 - 474 - 448 - 450 - 444 - 474 - 440 - 504 - 474 - TOC mg/L 2.2 <1.0 <1.0 <1.0 2.1 <1.0 <1.0 <1.0 1.9 <1.0 <1.0 <1.0 2.0 <1.0 <1.0 <1.0 1.8 <1.0 <1.0 <1.0 pH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Temperature °C NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA ORP mV NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA As (total) µg L 18.0 - 23.0 - 21.7 - 22.3 - 20.5 - 1.7 - 1.9 - 2.0 - 19.7 - 1.9 - 2.8 - 2.6 - 18.5 - 23.4 - 3.3 - 13.7 - 19.0 - 0.8 - 1.4 - 1.2 As (soluble) µg/L As (particulate) µg/L As (III) µg/L As (V) µg/L Fe (total) µg/L <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - Fe (soluble) µg/L - - - - - - - - - - - - - - - - - - - - Mn (total) µg/L 0.3 - 0.3 - 0.3 - 0.3 - 2.6 - 22 - 2.3 - 2.6 - 0.3 - 0.5 - 0.4 - 0.2 - 0.3 - 0.2 - 0.3 - 0.2 - 0.3 - 02 - 0.3 - 0.3 - Mn (soluble) µg/L V (total) µg/L 0.3 0.3 0.3 0.3 2.6 2.2 2.3 2.6 0.3 0.5 0.4 0.2 49.1 1.6 0.8 1.2 48.6 3.1 4.8 4.2 V (soluble) µg/L d N Analytical Results from Long -Term Sampling at Vale, OR (Study Period II) (Continued) Sampling Date 09/15/09 09/23/09 09/30/09 10/07/09 10/14/09 Sampling Location Parameter Unit IN TA TB TT IN TA TB TT IN TA TB TT IN TA TB TT IN TA TBTTT Throughput gal 522,690 570,142 56,986 559,404 359,668 Alkalinity (as CaCO3) mg/L- 279 343 - 345 - 337 - 293 - 322 - 337 - 333 298 - 107 - 29.0 - 63.5 300 - 336 - 356 - 358 - 312 - 370 - 370 - 375 Sulfate mg/L 66.4 - 11.0 - 3.1 - 6.8 - 69.2 - 19.0 - 11.5 - 14.8 - 74.0 - <0.1 - 0.1 - 0.1 - 67.3 - 24.8 - 16.0 - 21.3 - 72.8 - <0.1 - 0.1 - <0.1 - Nitrate (as N) mg/L 4.5 - 5.5 - 4.4 - 5.1 - 4.0 - 6.2 - 5.3 - 5.7 - 5.7 - 1.5 - 1.9 - 1.8 - 6.7 - 8.0 - 8.8 - 9.0 - 5.7 - 2.9 - 0.9 - 1.6 - Total P (as P) µg/L 290 - 348 - 253 - 291 - 253 - 346 - 283 - 313 - 272 - <10 - 14 - <10 - 276 - 449 - 340 - 397 - 272 - <10 - <10 - <10 - Silica (as SiO2) mg/L 59.7 - 59.4 - 58.4 - 59.3 - 56.0 - 56.2 - 56.1 - 55.2 - 59.9 - 60.8 - 60.6 - 60.4 - 58.2 - 58.4 - 58.3 - 58.4 - 55.3 - 55.7 - 54.8 - 54.5 - Turbidity NTU 2.6 - 0.3 - 0.5 - 2.1 - 0.1 - 0.1 - 0.1 - 0.1 - 0.4 - 0.2 - 0.3 - 0.1 - 0.4 - LO - 0.2 - 0.3 - 0.2 - 0.1 - 0.1 - 0.1 - TDS mg/L 434 - 462 - 454 - 446 - 466 - 438 - 426 - 430 - 540 - 606 - 724 - 650 - 502 - 468 - 454 - 466 - 486 - 442 - 454 - 460 - TOC mg/L 1.9 <1.0 <1.0 <1.0 1.8 <1.0 <1.0 <1.0 1.6 <1.0 <1.0 <1.0 1.5 <1.0 <1.0 <1.0 1.4 <1.0 <1.0 <1.0 pH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Temperature °C NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA ORP mV NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA As (total) µg/L 21.1 - 25.1 - 17.7 - 19.2 - 19.5 - 25.8 - 21.4 - 23.2 - 21.7 - 1.7 - 3.3 - 2.9 - 22.2 - 34.7 - 26.3 - 30.4 - 18.4 - 0.1 - <0.1 - <0.1 As (soluble) µg/L As (particulate) µg/L As (III) µg/L As (V) µg/L Fe (total) µg/L <25 - <25 - <25 - <25 - <25 - 26 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - Fe (soluble) µg/L - - - - - - - - - - - - - - - - - - - - Mn (total) µg/L 5.3 - 1.1 - 0.3 - 0.2 - 0.3 - 0.8 - 0.3 - 0.2 - 0.2 - 0.4 - 03 - 0.3 - 0.2 - 0.2 - 0.2 - 0.2 - 0.3 - 0.3 - 0.5 - 0.2 - Mn (soluble) µg/L V (total) µg/L 49.4 <0.1 <0.1 <0.1 48.7 3.5 2.2 2.4 49.1 3.9 9.7 7.4 52.5 3.2L2. 2.7 46.9 <0.1 <0.1 <0.1 V (soluble) µB/L d i W Analytical Results from Long -Term Sampling at Vale, OR (Study Period II) (Continued) Sampling Date 10/27/09 11/04/09 12/10/09 12/16/09 02/02/10 Sampling Location Parameter Unit IN TA TB TT IN F TA TB TT IN TA TB TT IN TA TB TT IN TA TB TT Throughput gal 540,850 339,549 27,963 319,637 316,110 Alkalinity (as CaCO3) mg/L 293 - 327 - 331 - 327 - 305 - 370 - 366 - 370 - 346 - 169 - 45.6 - 123 - 329 - 402 - 387 - 400 - 332 - 386 - 366 - 381 - Sulfate mg/L 72.8 - 19.9 - 14.1 - 17.0 - 75.3 - <0.1 - <0.1 - <0.1 - 80.6 - 0.5 - 0.1 - 0.3 - 81.1 - 0.2 - 0.1 - 0.4 - 76.4 - 0.2 - 0.2 - 0.2 - Nitrate (as N) mg/L 5.7 - 7.8 - 7.2 - 7.1 - 6.2 - 1.2 - 0.8 - 1.0 - 6.8 - 2.1 - 2.7 - 2.6 - 7.5 - 4.5 - 1.0 - 3.0 - 5.6 - 1.5 - 1.0 - 1.2 - Total P (as P) µg/L 267 420 343 380 257 <10 <10 <10 249 12.5 16.8 13.4 277 22.3 <10 12.8 271 <10 <10 <10 Silica (as Si02) mg/L 62.5 62.9 62.6 62.0 58.7 58.8 58.3 58.0 58.6 59.3 59.3 60.2 58.2 62.3 62.4 62.0 64.1 65.2 65.2 64.6 Turbidity NTU 0.8 - 0.8 - 0.9 - 0.6 - 0.2 - 0.3 - 0.2 - 0.4 - 0.2 - 0.2 - 0.2 - 0.3 - 0.3 - 0.5 - 0.4 - 0.6 - 0.2 - 0.3 - 0.2 - 0A - TDS mg/L 480 - 462 - 444 - 460 - 484 - 456 - 420 - 466 - 550 - 534 - 608 - 580 - 538 - 506 - 488 - 504 - 502 - 470 - 462 - 470 - TOC mg/L 1.6 <1.0 <1.0 <1.0 1.6 <1.0 <1.0 <1.0 1.8 <1.0 <1.0 <1.0 1.8 <1 <1 <1 1.9 <1 <1 <1 pH S.U. NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA Temperature °C NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA DO mg/L NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA ORP mV NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA As (total) µg/L 18.4 - 26.9 - 22.0 - 24.6 - 16.4 - 0.3 - 0.2 - 0.2 - 18.1 - 2.3 - 4.0 - 3.3 - 20.5 - 2.2 - 1.6 - 1.9 - 17.7 - 0.7 - 0.6 - 0.6 As (soluble) µg/L As (particulate) I µg/L As (HI) µg/L As (V) pg/L Fe (total) µg/L <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - <25 - Fe (soluble) µg/L - - - - - - - - - - - - - - - - - - - - Mn (total) µg/L 0.4 - 0.5 - 0.6 - 0.5 - 0.3 - 0.5 - 0.5 - 0.4 - 0.6 - 0.9 - 0.4 - 0.3 - 0.4 - 0.3 - 0.4 - 0.3 - 0.3 - 0.2 - 0.3 - 0.2 - Mn (soluble) µg/L - - - - - - - - - - - - - - - - - - - - V (total) µg/L 49.5 1.6 1.5 1.5 50.7 0.9 0.9 0.7 51.7 6.5 12.9 9.8 57.8 1.9 2.8 2.0 53.7 1.3 1.4 1.5 V (soluble) µg L ------------- Analytical Results from Long -Term Sampling at Vale, OR (Study Period II) (Continued) Sampling Date 02/08/10 Sampling Location Parameter Unit IN TA TB TT Throughput gal 246,140 Alkalinity (as CaCO3) mg/L 338 395 357 386 Sulfate mg/L 77.6 0.2 0.3 0.2 Nitrate (as N) mg/L 5.9 0.8 1.1 0.9 Total P (as P) µg/L 260 127 <10 <10 Silica (as Si02) mg/L 60.0 60.9 60.9 60.0 Turbidity NTU 0.2 0.1 0.6 0.2 TDS mg/L 526 474 476 484 TOC mg/L 1.9 <1 <1 <1 pH S.U. NA I NA NA NA Temperature °C NA NA NA NA DO mg/L NA NA NA NA ORP mV NA NA NA NA As (total) µg/L 18.3 0.8 1.1 1.0 As (soluble) µg/L As (particulate) µg/L As (III) µg/L As (V) µg/L Fe (total) µg/L <25 <25 <25 <25 Fe (soluble) µg/L - - - - Mn (total) µg/L 0.2 0.5 0.5 0.2 Mn (soluble) µg/L - - - - V (total) µg/L 53.6 1.7 2.5 2.0 V (soluble) I µg/L