Industry update on nitrogen removal programs across the United States: What does it mean for New England?

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An industry update on nitrogen removal programs across the United States. Presented by Rick Cisterna, Senior Associate with Hazen and Sawyer during the Buzzards Bay Coalition's 2011 Decision Makers …

An industry update on nitrogen removal programs across the United States. Presented by Rick Cisterna, Senior Associate with Hazen and Sawyer during the Buzzards Bay Coalition's 2011 Decision Makers Workshop series. Learn more at www.savebuzzardsbay.org/DecisionMakers

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  • 1. Industry Update on Nitrogen Removal Programs Across the United States: What Does it Mean for New England? March 3rd, 2011 Richard H. Cisterna, P.E. Cisterna, P.E. 1
  • 2. Outline 1 Water Industry Sustainability 2 National Perspective - Nitrogen and Hypoxia 3 Massachusetts Estuaries Nitrogen Treatment Technology Overview 4 5 Conventional and Advanced Case Studies 6 2 Summary and Conclusions
  • 3. Water Industry Sustainability 3
  • 4. Sustainability is in Vogue 4
  • 5. Focus of Sustainability has been on Energy ● Energy Audits ● Energy Optimization ● Renewable Energy Sources 5
  • 6. Sustainability Balancing Act Nitrogen Water Supply / Wastewater Effluent Green Energy Carbon Footprint 6
  • 7. National Perspective on Nitrogen and Hypoxia 7
  • 8. Nitrogen is an Emerging National Concern 8
  • 9. Nitrogen’s Impact on the Ecosystem Source: evworld.com 9
  • 10. Chesapeake Bay Oxygen Depletion Source: evworld.com 10
  • 11. Long Island Sound Nitrogen Control Program ● In 1998, CT, NY, and EPA agreed to reduce human sources of N by 58.5% by 2014. A TMDL was developed and approved by EPA in 2001. 11
  • 12. Long Island Sound 12 Source: CTDEP and Long Island Sound Study
  • 13. The Mississippi River Carries A lot of Nitrogen 13
  • 14. And the Gulf of Mexico Pays the Price… Source: evworld.com 14
  • 15. Historical Development of Nitrogen Limits 10 9 Chesapeake Bay Long Island Sound, NYC 8 mg/l 8 7 TMDL (mg/l) 6 Long Island Sound, CT North Carolina 5 mg/l 5 4 3 mg/l 3 2 1.5 mg/l 1 Florida 0 1990 15 2000 2010 2020
  • 16. Massachusetts Estuaries 16
  • 17. Mass Estuaries also have nitrogen concerns 17
  • 18. Mass Nitrogen Reduction Program Goals » Reduce ‘N’ to estuaries » Consider centralized and decentralized approaches » Highly treat wastewater to new Massachusetts DEP Standards » Strategically recharge reclaimed water 18
  • 19. Western Cape Recharge Basins Source: USGS 19
  • 20. Mass. DEP: Groundwater Discharge Program (314 CMR 5.00) Requirements  Meet secondary treatment effluent limits: » Nitrate as Nitrogen < 10 mg/L » Total Nitrogen < 10 mg/L » Fecal Coliform < 200 colonies per 100 mL All Discharges  Discharges within Zone II or IWPA Effluent shall be filtered to meet: » TSS » Turbidity » TOC  Discharges within Zone II or IWPA and 2 year Travel Time < 10 mg/L < 5 NTU < 3 mg/L Effluent shall be oxidized, filtered, disinfected and coagulated to meet: » TSS » Turbidity » BOD < 5 mg/L < 2 NTU < 10 mg/L » TOC < 1 mg/L » Fecal Coliform = avg. of zero colonies per 100 mL over a continuous 7 day sampling period; no single sample shall exceed 14 colonies per 100 mL = 5 Log Inactivation and/or Removal or 20 Direct Injection (into saturated zone) » Virus  Disinfection shall not be waived.  Coagulation may be waived if meet turbidity requirement with filtration alone.
  • 21. Treatment Approaches? ● Decentralized Advanced Septic Systems ● Biological Treatment ● Centralized MF/RO, (AOP?) – Concentrate Issue ● MF, GAC, (AOP?) 21
  • 22. Regulations for Indirect Potable Reuse Florida Mass. 10 ppm* 10 ppm* 5 ppm 10 ppm 1 ppm TOC 3 ppm 3 ppm 1 ppm 0.5 ppm --- 1 ppm Emerging Contaminants No/Yes No? Yes No/Yes Yes Nitrogen California Arizona * Local requirements can be more stringent 22 Australia
  • 23. Nitrogen Treatment 23
  • 24. Nitrification / Denitrification Activated Sludge Process - MLE TKN = 30 mg/L TP = 7 mg/L Aeration Tanks 3Q Pretreated Wastewater Primary Clarifiers NH3-N < 2 mg/L NO3-N < 5 mg/L TN = 8 mg/L TP = 5 mg/L Secondary Clarifiers Anoxic Air Blowers Secondary Effluent Aerobic Return Sludge Primary Sludge Waste Activated Sludge N&P Removal ● Solids in primary sludge (5 - 10 %) ● Biosynthesis in WAS (10 - 20 %) ● Denitrification (40 - 60 %) 24 TN ~ 8 to 10 mg/L
  • 25. BNR Step Feed Configuration TWO-STEP FEED PROCESS Step Feed Secondary Clarifiers Pretreated Wastewater Anoxic Aerobic Anoxic Secondary Effluent Aerobic RAS TN ~ 6 to 9 mg/L Waste Activated Sludge FOUR - STEP FEED PROCESS Secondary Clarifiers Pretreated Wastewater Secondary Effluent Anoxic Aerobic Anoxic Aerobic Anoxic Aerobic Anoxic Aerobic RAS 25 TN ~ 4 to 6 mg/L Waste Activated Sludge
  • 26. BNR Process Configurations – 5-stage Typical 5-stage BNR Process – Lower TN limit Carbon Secondary Clarifier Wastewater Anaerobic Primary Anoxic Aerobic Secondary Anoxic BNR Aeration Tank Secondary Effluent Reaeration WAS TN ~ 3 to 4 mg/L 26
  • 27. 3+ Stage with Denitrification Filters TN < 3 mg/L Acetate Methanol Secondary Clarifier Wastewater Anaerobic Anoxic Aerobic BNR Aeration Tank WAS 27 Granular Media Filter Secondary Effluent
  • 28. Denitrification Filters ● Nitrified secondary effluent sent to filtration ● Filter media used to grow an attached biomass that will denitrify the secondary effluent ● Supplemental carbon addition ● Good solids removal + denite – 2 gpm/ft2 28
  • 29. Membrane Bioreactor (MBR) Typical MBR Process 29
  • 30. Integrated Fixed Film Activated Sludge (IFAS) ● Media held in Aeration Basins to provide attached growth for Nitrifying biomass ● Typical Floating and Fixed IFAS Media » Kaldnes (plastic) » Linpor (sponge) » Ringlace (cord) 30 30
  • 31. IFAS in Nutrient Removal ANA ANOX AEROBIC •Higher capacity in same volume •“Modular” phasing •Improved wet weather stability 31 ANOX
  • 32. TZ Osborne WRF – Pilot Layout RAS To Final Clarifier No. 7 Primary Effluent IFAS Cell 1 ~ 35% fill (AK-K3) 3 distinct zones 32 IFAS Cell 2 IFAS Cell 3 Screens for each cell Isolation / throttle air valve for each cell
  • 33. IFAS Pilot Results / Lessons Learned ● Effective nitrification in approximately half the aerobic volume ● Dynamic microbial population ● Higher air usage ● Screen headloss higher than expected ● Foam handling a must ● Influent screening must be sized correctly (i.e. opening size) 33 Biomass on Media (gTSS/m2 of media surface) 30 25 20 15 10 5 0 04/01/08 06/13/08 08/25/08 11/06/08 01/18/09 04/01/09 Date Cell D Biomass Cell E Biomass Cell F Biomass
  • 34. BioMag From CWT Website http://cambridgewatertech.com/technology/biomag 34
  • 35. Typical Process Treatment Train for Ultra-Low UltraNutrient Standards 35
  • 36. Cost vs. Nitrogen Removal Cost ($) Nitrogen Removal (mg/L) 36
  • 37. Nitrogen Removal Option Summary* 2-Stage BNR 4/54/5-Stage BNR + Carbon Feed 4/54/5-Stage BNR + Denite Filters 4/5-Stage 4/5BNR + MBR w/ Carbon Feed 4/5-Stage 4/5BNR + UF + NF or RO TN effluent Achievable 8 - 12 mg/L 3 - 6 mg/L 3 - 4 mg/L 2 - 3 mg/L < 1.5 mg/L Capital Cost per GPD $0.25 - $1.25 $0.50 - $2.00 $1.25 - $2.50 $2.50 - $3.00 $3.00 - $4.00 40 kW 50 kW 55 kW 100 kW 125 kW $21k - $28k $30k - $40k $35k - $47k Criteria Energy Usage per MGD Annual O&M Cost per MGD $121k - $161k $261k - $348k *Relative cost for additional treatment only. Total cost will depend on the available plant infrastructure. 37
  • 38. Supplemental Carbon 38
  • 39. Available Supplemental Carbon Sources ● Methanol ● Ethanol ● Acetic acid ● Corn syrup/sugar ● Glycerin ● MicroC™ ● Primary fermentate 39
  • 40. Methanol Considerations ● Benefits » Low cost (relative to alternatives) » Low yield (low solids production) » Proven technology ● Drawbacks » Requires specialist population ■ Slow growing » Volatile price » Slower kinetics » Flammable 40 Recent Methanol Accident Site at Bethune Point WWTP
  • 41. 41 www.methanex.com Mar-09 Sep-08 Mar-08 Sep-07 Mar-07 Sep-06 Mar-06 Sep-05 Mar-05 Sep-04 Apr-04 Oct-03 Apr-03 Oct-02 Apr-02 Oct-01 Apr-01 Methanol Price ($/Gallon) Methanol Costs – 2001 to 2009 (Expect Price Fluctuations) $3.00 $2.50 $2.00 $1.50 $1.00 $0.50 $0.00
  • 42. Glycerin ● Typically byproduct of biodiesel production ● Benefits » Faster kinetics ● Drawbacks » Potential for product inconsistencies with waste products » Viscous in cold weather » Specialist population not required ● Products » Brenntag » Unicarb-DN » BioCarb DN (Denite-1) » MicroC-Glycerin » Waste products 42
  • 43. Alternative Carbon Testing Parameter NRWWTP HCWRF Size (mgd) Feed point Basins fed carbon Control (if applicable) 75 75 One All Substrate 43 PWWTP SDWRF NDWRF 7.5 Second anoxic zone All 20 20 One 4 out of 5 One parallel Full-scale Full-scale One parallel One parallel basin that evaluation, evaluation, basin that basin that was fed therefore no therefore no was not fed was not fed methanol control control carbon carbon Glycerin Sugar water Glycerin Glycerin Glycerin and glycerin
  • 44. Parkway WWTP CHLORINE CONTACT BASINS INFLUENT PUMP STATION RAS PUMP STATION SECONDARY CLARIFIERS BNR BASIN #2 (RB2) GRIT REMOVAL PRIMARY CLARIFIERS BNR BASIN #1 (RB1) SOLIDS HANDLING 44 MLR PUMP STATION
  • 45. Parkway Full-Scale Pilot Data Full■ No Acclimation Period Required Full Scale Pilot Data 1/26/2008 1/19/2008 1/12/2008 45 Effluent NOx Effluent TN Brenntag Glycerin 7 per. Mov. Avg. (Effluent NOx) 7 per. Mov. Avg. (Effluent TN) Carbon dose, gal/day 0 1/5/2008 0 12/29/2007 20 12/22/2007 1 12/15/2007 40 12/8/2007 2 12/1/2007 60 11/24/2007 3 11/17/2007 80 11/10/2007 4 11/3/2007 100 10/27/2007 120 5 Concentration (mg/L) 6
  • 46. Cell 1 Cell 2 Cell 3 3848-047 Primary Anoxic/ Aerobic Zone Cell 4 Cell 5 Secondary Anoxic/ Aerobic Zone Aerobic Zone Cell 6 Cell 7 Cell 8 R eAeration Zone Prim ary A noxic/ Anaerobic Zone Anaerobic Zone RA S Ferm entation Henrico VA Cell 9 Cell 10 Cell 11 Cell 12 Cell 13 NRCY RAS M istributionC LD hannel PED istributionChannel RA SPipeline BNR Tank 8 NRCY RAS BNR Tank 7 NRCY RAS BNR Tank 6 NRCY RAS To Secondary Clarifier No. 8 BNR Tank 5 ML Distribution Channel RAS/WAS Pump Station RAS 46 To Secondary Clarifier No. 7
  • 47. Henrico County WRF Plant Effluent Nitrogen Profile vs. Substrate Feed Rate ● Sugar water and glycerin both effective. 47
  • 48. North Carolina “Conventional” Case Studies 48
  • 49. Neuse River WWTP, Raleigh, NC ● 60 mgd Advanced WWTP » Primary Clarifiers » 4-stage BNR w/ methanol addition » Denitrification Filters w/ methanol addition ● Largest Plant in Eastern U.S. Achieving LOT for TN Utilizing Conventional Suspended Growth BNR Process ● Upcoming Expansion to 75 mgd » TN = 2.7 mg/L, TP = 1 mg/L ● Calibrated BioWin Model Used to Evaluate/ Optimize Expansion 49
  • 50. Neuse River – 4-stage w/ denitrification filters Typical Operating Parameters 50
  • 51. Neuse River - Operation and Performance ● Most TN Removal in BNR Basins ● Filters “Trimming” ± 1 mg/L (~ 5 mg/L Methanol Dose) ● Annual Average Effluent TN = 2.4 mg/L (2004 - 2008) S E a n d F in a l E fflu e n t N itr o g e n C o n c e n tr a tio n s 6 ● 2007 Annual Average Effluent TN = 1.96 mg/L Concentration (mg/L) 5 4 3 2 1 EFF TN SE TN 3 0 p e r. M o v . A v g . (E F F T N ) 3 0 p e r. M o v . A v g . (S E T N ) Sep-07 Jul-07 May-07 Mar-07 Jan-07 Nov-06 Sep-06 Jul-06 May-06 Mar-06 Jan-06 Nov-05 Sep-05 Jul-05 May-05 Mar-05 Jan-05 Nov-04 Sep-04 Jul-04 May-04 Mar-04 51 Jan-04 0
  • 52. High Point, NC – 26 mgd, 5-stage process mgd, 5- 52
  • 53. 53 EFF TN No alum or ferric 10/29/2008 7/31/2008 5/2/2008 2/2/2008 11/4/2007 8/6/2007 5/8/2007 2/7/2007 11/9/2006 8/11/2006 5/13/2006 2/12/2006 11/14/2005 20 8/16/2005 5/18/2005 2/17/2005 11/19/2004 8/21/2004 5/23/2004 2/23/2004 11/25/2003 8/27/2003 5/29/2003 2/28/2003 11/30/2002 9/1/2002 EFF Total Nitrogen (mg/L) High Point Performance 22 Average Eff TN 1/07 to 12/08 = 3.3 mg/L 18 16 14 12 No supplemental carbon 10 8 6 4 2 0 30 per. Mov. Avg. (EFF TN) Avg TP = 0.18 mg/L Biologically
  • 54. Major Recycle Impacts ● Solids handling recycle streams » Filtrate, centrate, gravity thickener overflow ● Frequency of return Parameters Plant Recycle Loads (lbs/day) Contribution From Plant Recycles (%) BOD 43,600 2,830 6.5 TSS 39,300 6,590 17 TKN 54 Plant Influent Loads (lbs/day) 5,700 1,620 29 TP 1,280 680 53
  • 55. Florida “Advanced” Case Studies 55
  • 56. Florida vs. Mass Estuary Nitrogen Challenge ● FL - Existing Ocean Outfalls and Septic Tanks ● Cape – Mostly Septic Tanks ● Both – High Level Nitrogen Treatment / Recharge 56
  • 57. Historically, South Florida’s sole source supply (the Biscayne Aquifer), was fiercely protected Effluent Reuse Class I Deep Injection Wells 57 Two Key issues for FDEP: ● Alternate Water Supply Resource ● Environmental enhancement (Nitrogen)
  • 58. Existing Supply Limited for Utilities C.E.R.P No New Water for the Public 58
  • 59. Recent Legislation – Ocean Outfall Ban ● Outfall shut down due to nitrogen – Coral Reefs ● Achieve significant TN & TP reductions by 2018 ● “Reuse” 60% of outfall flow by 2025 ● After 2025, outfall for wet weather back-up, w/ nutrient reductions 59
  • 60. Legislated Water Reuse Requirements Lake Okeechobee 7.7 MGD 6.2 MGD 22.4 MGD 24.1 MGD 48.6 MGD 68.9 MGD Total = 178 MGD 60 South Central Regional Boca Raton Broward Co. North Hollywood Miami-Dade North Miami-Dade Central District
  • 61. Recharging Groundwater is Essentially a Surface Water Discharge – nitrogen concerns County / Local Issues 61
  • 62. Miami Dade County 62
  • 63. Miami South District Water Reclamation Plant ● 1st indirect potable reuse project in Florida ● Recharge drinking water aquifer with 23 mgd of highly treated wastewater ● Addressing pharmaceuticals and pathogens with regulators and public ● MF, RO, UV-AOP ● Ultra-pure drinking water quality 63
  • 64. Emerging Contaminants Pharmaceuticals Personal Care Products 64 Endocrine Disrupting Compounds
  • 65. Advanced Oxidation Processes (AOPs) High dosage UV w/ H2O2 UV ~ 500 mj/cm2 H2O2 ~ 1-3 ppm UV – TiO2 Ozone 65
  • 66. Hydroxyl Radical (OH°) is a very strong oxidant! OXIDIZING SPECIES RELATIVE OXIDATION POTENTIAL (V) Hydroxyl Radical 2.05 Ozone 1.52 Hydrogen Peroxide 1.31 Permanganate 1.24 Chlorine Dioxide 1.15 Chlorine 1.00 Data from Metcalf & Eddy, 2003 66 Increasing ability to degrade pollutants
  • 67. Miami Dade South District WRP Miami-Dade County Miami- 67
  • 68. Example of the complexities Moat Drainage Canal Regional Canal Proposed Biscayne Wells 68 Note: Locations are conceptual. Intended for discussion purposes only
  • 69. Biscayne National Park is Environmentally Sensitive 69
  • 70. Groundwater Recharge Criteria Miami Dade County Florida State Standard TOC -- 3 mg/l Total Suspended Solids (TSS) -- 5 mg/l Total Nitrogen (TN) -- 10 mg/L Ammonia 2.8 mg/l 0.5 mg/l -- Total Phosphorus (TP) .003 mg/l -- Yes No Parameter Emerging Contaminants 70
  • 71. Precedent Setting Treatment Levels 71
  • 72. Plantation, FL Pilot Study 72
  • 73. WWTP Located Near Canal That Could Recharge the Biscayne Aquifer Plantation WWTF East Holloway Canal East Wellfields Central Wellfields 73
  • 74. Pilot Goals ● Demonstrate technology can meet water quality » TN » TP ● Unregulated Parameters » Microconstituents » Toxicity » Algal growth potential » Hormonal impacts 74
  • 75. Things to consider 75
  • 76. Nutrient Control ● What is the technology necessary to meet the stringent TN & TP limits? ● Biological vs Chemical nutrient removal ● Are RO membranes necessary? 76
  • 77. Aquatic Organism Impact ● Whole effluent toxicity (WET) tests ● Is the RO permeate toxic? ● Will the effluent cause any hormonal impacts? 77
  • 78. Microconstituents ● Which microconstituents are in your wastewater? ● What technology will most effectively remove them? ● Are microconstituents really a concern at these concentrations (ng/L)? 78
  • 79. Recharge Modeling ● Does your point of discharge “offset” your withdrawal impacts? ● Can you get a 1/1 credit? ● What happens during the wet season? 79
  • 80. Sustainability ● Is this really sustainable? ● Water Supply vs Carbon Footprint? 80
  • 81. Public Outreach ● How do you change the “Sewer to Tap” mentality? ● How do you involve the public early in the project? 81
  • 82. Costs ● Capital cost ● Energy costs 82
  • 83. Plantation Pilot 83
  • 84. Broward County Canal Recharge Effluent Limits Parameter Effluent Limit TN < 1.5 mg/L TP < 0.02 mg/L Nitrate < 10 mg/L Ammonia TSS < 5.0 mg/L CBOD5 < 10.0 mg/L BOD 84 < 0.02 mg/L < 5.0 mg/L
  • 85. MBR Scheme 85
  • 86. Conventional Treatment Scheme 86
  • 87. MBR Scheme Data 87
  • 88. Plantation AWT MBR Scheme MBR Pilot 88 RO/UV Pilot Trailer
  • 89. Total nitrogen removal of MBR and RO Pilot Units 89
  • 90. Total phosphorus removal of MBR and RO Pilot Units 90
  • 91. Conventional Treatment Data 91
  • 92. Plantation AWT Conventional Treatment Scheme Denitrification Filter Pilot 92 UF/RO/UV Pilot Trailer
  • 93. Total nitrogen removal of Deep Bed Filter and RO Pilot Units 93
  • 94. Total phosphorus removal of Deep Bed Filter and RO Pilot Units 94
  • 95. Conclusions – Nutrient Removal ● Both pilots met stringent TN & TP limits ● RO membranes are necessary to meet TP limit ● Membranes alone (UF/RO) with no chemical addition met TN & TP limits 95
  • 96. Microconstituents 96
  • 97. What are Microconstituents? ● Pharmaceutically Active Compounds (PhAC) » Ethynyl Estradiol » Sulfamethaxazole ● Personal Care Products (PCP) Ethynyl Estradiol » Triclosan » Toiletries, cosmetics, fragrances ● Endocrine Disrupting Compounds (EDC) » Bisphenol-a » Atrazine » DEET 97 DEET Triclosan
  • 98. Concentration (ng/l) Microconstituents – RO Influent Concentrations 98
  • 99. Concentration (ng/l) Microconstituents – Most were removed by RO membranes 99
  • 100. Aquatic Organism Toxicity Testing 100
  • 101. Is the RO permeate toxic? ● RO permeate is too clean » RO re-stabilization/re-mineralization » Added salts and minerals ● How would this work full scale? » Dilution » Mixing zone 101
  • 102. Does RO Pre-treatment Preaffect toxicity? ● RO Pre-treatment » Antiscalant » Chloramines ● Pilot Results Fatheaded Minnow 102 Water Flea
  • 103. Summary ● The pilot demonstrated to meet stringent nutrient limits at different test conditions. ● RO membranes are necessary for surface water discharge due to stringent TP limits. ● Almost all microconstituents were removed by RO system. ● RO permeate could be toxic re-stabilization/remineralization is necessary. ● The observed toxicity to aquatic organisms was likely caused by chloramines. Other forms of RO pretreatment should be evaluated. 103
  • 104. University of Connecticut Advanced Reuse Project 104
  • 105. University of Connecticut Reuse Project 105
  • 106. This is a Spotlight Project 106
  • 107. Potential Uses of Reclaimed Wastewater Reuse Facility ► ▼ WWTP ◄ Power Plant 107 ◄ Irrigation Sites ►
  • 108. Process Flow Diagram 108
  • 109. UCONN Reclaimed Water Facility University of Connecticut – Reclaimed Water Facility Location Storrs, CT Capacity 1.0 mgd Technology Microfiltration + UV Disinfection + Chloramination Application • Cooling Tower Make-Up Water • Boiler Feed Water (post RO treatment) • Irrigation Unique Challenges 109 • Corrosion & Scaling Control for Cooling Towers
  • 110. MF System Design Criteria Parameter Type Pressurized System Rated Capacity 1 mgd No. of MF Units 3 No. of Membrane Modules per Unit 32 Membrane Type 0.1 micron PVDF Specific Design Flux 39 gfd Minimum Recovery Percent 110 Value 91%
  • 111. UV System Design Criteria Parameter Type LPHO System Rated Capacity 1 mgd No. of UV Systems 2+1 UV Design Dose 80 mJ/cm2 UV Transmittance ≥ 65% at 254 nm Effluent Turbidity ≤ 0.2 NTU (95% of the time) Effluent Total Coliform Max. 2.2/100 mL (7 day geometric mean) Suspended Solids Max. 111 Value 5 mg/L
  • 112. Sustainability Features ● Replaces as much as 40% of water supply at times ● Reclaimed water reservoir used as a heating source ● Stormwater capture and blending with wastewater ● Solar electricity 112
  • 113. Constructed New Facility? 113
  • 114. Summary and Conclusions 114
  • 115. Summary and Conclusions ● Nitrogen control programs are growing ● Very low nitrogen requires significant energy and $ ● Range of treatment options ● Good experiences and resources in other states to draw upon 115